Sustainable Wastewater Treatment Strategies in Effective Abatement of Emerging Pollutants

Abstract

The fundamental existence of any living organism necessitates the availability of pure and safe water. The ever-increasing population has led to extensive industrialization and urbanization, which have subsequently escalated micropollutants and water contamination. The environmental impact on various life forms poses a dire need for research in effective environmental management. Versatile technologies involving multiple approaches, including physiochemical and biological bioremediation strategies, draw insights from environmental biology. Metabolic annihilation mediated by microbes shows significant potential in the bioconversion of toxic micropollutants to tolerable limits. Environmentally friendly, cost-effective, and sustainable strategies are envisaged for efficient environmental protection. Phytoremediation technology, especially floating wetland treatments, facilitates micropollutant elimination, landscape management, ecosystem conservation, and aesthetic enhancement in diverse environments. The incorporation of nanomaterials in the bioremediation of toxic micropollutants augments novel and innovative strategies for water pollution abatement. This paper offers a novel strategy that combines nanomaterials to improve micropollutant degradation with bioremediation techniques, particularly the creative application of phytoremediation technologies like floating wetlands. Combining these techniques offers a novel viewpoint on long-term, affordable approaches to reducing water pollution. Additionally, the review proposes a forward-looking strategic framework that addresses the accumulation and refractory nature of micropollutants, which has not been thoroughly explored in previous literature.

1. Introduction

Water is a natural resource on Earth, and its accessibility in a pure state is indispensable for human beings and other living creatures, as the concept of life is unimaginable without it [1]. Increasing industrialization, urbanization, and the unchecked nature of human activities are directly correlated with the release of hazardous substances, often criticized as the foremost sources of pollution in aquatic ecosystems [2]. The controlled or uncontrolled discharge of industrially contaminated wastewater introduces toxic agents into groundwater, surface water, and subsurface soils [3]. The presence of dye pollutants, pharmaceuticals, personal care products (such as plastic bottles, children’s toys, cosmetics, toothpaste, detergents, and drugs like hormones, anti-inflammatory drugs, antiepileptics, statins, antidepressants, beta-blockers, antibiotics, and contrast agents), toxic metals, volatile organic compounds, pesticides, and petroleum hydrocarbons in industrial wastewater severely compromises the quality of drinking water and accumulates in the food chain. This poses a severe threat to human beings and aquatic creatures, attracting increasing scholarly attention [4,5,6,7] (Figure 1). A subclass of organic chemicals gradually being detected in our water bodies has been categorized as emerging pollutants (EPs), also known as “contaminants of emerging concern” or micropollutants (MPs) [8]. These hazardous substances deplete water quality and gravely affect water for drinking and domestic purposes. Recently, a United Nations report stated that purified and freshwater availability is a worldwide issue and has become a challenge in the 21st century because living organisms are not safe with contaminated water [9].

Emerging pollutants are divided into three main categories: the first includes newly synthesized compounds released into the ecosystem. The second category comprises compounds that have existed in the environment for a long time but are only recently being recognized. The third category includes compounds that have been detected for a long time, but their significant impact on the environment and human health has only recently been documented, such as hormones [10,11]. These emerging pollutants fundamentally alter human behavior, landscapes, water bodies, and demography through developing technologies, microbial adaptation, climate changes, increased travel, and more [12]. Some of these compounds cause endocrine disruption and are defined as exogenic agents that interfere with the synthesis, secretion, transport, binding, or elimination of natural hormones in the human body responsible for homeostasis, reproduction, development, and behavior [13]. Furthermore, the presence of these compounds is responsible for many internal and external diseases in living organisms, such as effects on embryo growth, sexual differentiation, metabolism, reproductive system fluctuations, the sexually dimorphic neuroendocrine system, endogenous steroid levels, diabetes, cardiovascular problems, abnormal neuronal behavior, and obesity [14,15,16,17]. These emerging contaminants extensively affect the atmosphere and pollute air quality and marine zones [18]. Due to the high accumulation and persistence of heavy metals, ecotoxicological effects on non-target organisms appear rapidly and pose severe threats to aquatic life [19]. The presence of toxic metals in fish has revealed tissue damage, pathological effects on blood cell indices, and disrupted hormone regulation and enzymatic activities [20].

The low concentration of emerging pollutants in water bodies can cause severe effects on humans, mammals, and beneficial flora and fauna, such as immune suppression, cancer, organ damage, and nervous system damage, potentially leading to death [21]. The genotoxicity of textile dyes is considered a major source of long-term health injuries in humans and other living organisms [22]. For example, Alaguprathana et al. [23] studied the genotoxic effects of textile dye contaminants in Allium cepa root cells. The findings revealed that the consumption of polluted Allium cepa caused chromosomal aberrations in humans. Consequently, approaches for their practical and rapid degradation have become the primary focus of governments worldwide, academic research groups, and environmental protection agencies. A wide range of remediation policies has been developed to efficiently remove and eradicate these organic and inorganic toxic pollutants from wastewater and other water systems. Various physical and chemical techniques, including adsorption, sedimentation, degasification, filtration, aeration, chemical precipitation, flocculation and coagulation, ion exchange, and ozonation, have been attempted to remove pollutants from wastewater [24,25,26,27,28]. Although these approaches can perform smoothly for remediation purposes, they are associated with various limitations and negative impacts, such as high costs, production of secondary pollutants, use of toxic chemicals and solvents, inefficiency, and time consumption [29,30,31,32].

However, researchers have been paying widespread and urgent attention to alternative approaches that are fundamentally smart, inexpensive, easy to handle, efficient, greener, and environmentally friendly. Biological methods are considered relatively novel and environmentally sustainable for the remediation of emerging pollutants from aquatic systems [33]. In this approach, different microbial species such as bacteria, fungi, yeast, algae, and archaea are developed for the remediation of contaminants from water systems. These microbial species use pollutants as substrates to enhance their enzymatic machinery, leading to the enzymatic breakdown of recalcitrant emerging pollutants into less toxic or non-toxic compounds [4]. Additionally, microbial cell cultures, components, biomolecules, and various plant extracts and seeds are utilized to synthesize sustainable nanoparticles [34]. These nanoparticles can serve as outstanding candidates in the biodegradation of different pollutants by immobilizing and facilitating the extracellular synthesis of microbial degrading enzymes and genes [35]. Nanoparticles are excellent adsorbents and catalysts extensively applied in extreme environmental conditions in both laboratory and pilot-scale studies due to their novel characteristics such as large specific surface area, modifiability at various temperatures, customizable pore size, reduced interparticle diffusion width, and diverse shapes [36].

In contrast to all the above conventional energy-intensive treatment technologies, phytoremediation, which utilizes plant species for the removal of even lower concentrations/dosages of pollutants in the aquatic system, is considered one of the most efficient, environment-friendly, low-cost, easy-to-perform, and effective approaches. This method offers engineering solutions including constructed wetlands and floating treatment wetlands [37]. In constructed and floating wetlands, plant materials uptake all pollutants from the water and utilize them as nutrients, which then accumulate in the plant biomass [38]. Hence, the ultimate aim of this review is to provide new insights for the remediation of emerging pollutants from different water systems and to understand the novel concepts and interactions with microbial species, plant species, different solvents and chemicals, physiochemical methods, and nanomaterials that are considered efficient facilitators for environmental clean-up. Moreover, this review also elucidates the impact and mechanisms of physical, chemical, and biological methods in the degradation of emerging pollutants from wastewater, establishing a myriad of promising approaches for potential ecosystem monitoring. This manuscript also highlights the cutting-edge methods for growing, gathering, and effectively cleaning up various pollutants using microbes. This assessment explores the current advancements as well as how they might fit with the objectives of global sustainability.

2. Biological Methods for Wastewater Treatment

The biological methods removed various emerging pollutants more efficiently. Using biological methods aims to establish a system for effectively eliminating pollutants from the contaminated environment [39]. Biological methods are widely utilized in both laboratory and field-scale environments, and they are considered to be less expensive, more efficient, reliable, and eco-friendly compared to physical and chemical treatments [40]. This method applied normal cellular processes that depend on different microbial species such as nematodes, bacteria, fungi, or other microorganisms involved in breaking emerging pollutants [41] (

Table 1. Source of microbial species and their degradation efficiency for wastewater treatment.

Name of Emerging Pollutant	Name of Microbial Species	Source of Isolation	Culture Conditions	Degradation Efficiency %	References
Dyes	Pseudomonas fluorescens, Bacillus sp., and Escherichia coli	Dye contaminated soil	Temperature 30 ± 1 °C Nutrient agar Shaken 110 rpm	43, 15, 90	[42]
Azo dyes	Enterobacter hormaechei SKB 16	Textile-effluent-polluted soil	Temperature 37 °C Nutrient agar Shaken 115 rpm	98	[43]
Methyl red	Vibrio logei and Pseudomonas nitroreducens	Wastewater	Temperature 25 °C Minimal medium Shaken 110 rpm	65–82	[44]
Monoazo and diazo dyes	Acinetobacter sp. and Klebsiella sp.	Activated sludge	Temperature 30 °C Minimal medium Shaken 120 rpm	80	[45]
Carmoisine	Saccharomyces cerevisiae ATCC 9763	Commercial	Temperature 30 °C Yeast extract peptone dextrose Shaken 180 rpm	100	[46]
Copper, nickel, manganese, cobalt, and dichromate	Bacillus sp., Shewanella sp., Lysinibacillus sp., and Acinetobacter sp.	Sludge	Temperature 30 °C Luria broth medium Shaken 120 rpm	90–100	[47]
Iron, copper, zinc, cadmium, manganese, nickel, and lead	Bacillus sp. PS-6	Industrial wastewater	Temperature 35 °C Luria broth medium Shaken 120 rpm	44.12–89.46	[48]
Nickel, chromium, and textile dyes	Lysinibacillus sp.	Wastewater	Temperature 30 °C Nutrient broth medium Shaken 150 rpm	70, 58, 82	[49]
Zinc, cobalt, nickel, lead, copper, chromium, mercury, arsenic, and silver	Rhodococcus sp. AQ5-07	Oil-polluted soil	Temperature 10 °C Tween-peptone agar Shaken 150 rpm	80–100	[50]
Chromium, lead, iron, cobalt, nickel, manganese, zinc, copper, and aluminum	Agaricus bisporus	Commercial	Temperature 25 °C	80–98	[51]
Sulfamethoxazole	Escherichia coli JM109 and Chlorella sorokiniana	Fish breeding tank	Temperature 37 °C Temperature 28 °C	54.34	[52]
Erythromycin	Geobacter sp. and Acetoanaerobium sp.	Wastewater	-	99	[53]
Sulfamethoxazole	Shewanella sp. Alcaligenes sp., Pseudomonas sp., and Achromobacter sp.	Wastewater	Temperature 30 °C	85.1	[54]
Tetracycline	Shewanella sp., Bacillus sp., and Pseudomonas sp.	Seed sludge	Temperature 30 °C Luria–Bertani medium Agitation 150 rpm	95	[55]
Ciprofloxacin	Lactobacillus gesseri, Enterobacter sp., Bacillus sp., Bacillus subtilius, and Micrococcus luteus	Hospital effluent water	Temperature 28 °C Luria–Bertani medium Agitation 100 rpm	100	[56]
Tetracycline	Bacillus velezensis strain Al-Dhabi 140	Municipal soil sludge	Temperature 37 °C Minimal medium Agitation 150 rpm	100	[57]
Triazophos, methamidophos, and carbofuran	Enterobacter sp. strain Z1	Wastewater	Temperature 37 °C, pH 7	100, 100, 98.7	[58]
Fludioxonil	Betaproteobacteria sp., Chloroflexi sp., Planctomycete sp., Firmicutes sp., Empedobacter sp., Sphingopyxis sp., and Rhodopseudomonas sp.	Fungicide wastewater	Room temperature Agitation 120 rpm	95.4	[59]
Chlorpyriphos, oxadiazon, and cypermethrin	Chlorella sp. and Scenedesmus sp.	Contaminated semiopen photobioreactor	Temperature 25 °C pH 7.5 Agitation 120 rpm	97, 88, 74	[60]
Deltamethrin, cyfluthrin, cypermethrin, permethrin, and lambda-cyhalothrin	Enterobacter ludwigii	Industrial wastewater	Temperature 30 °C Saline condition pH 7	90	[61]
Allethrin	Sphingomonas trueperi	Wastewater sludge	Temperature 30 °C pH 7.0 Inoculum concentration 100 mg/L	93	[62]
Anthracene, phenanthrene, fluorene, naphthalene, pyrene, benzo(e)pyrene, benzo(k)fluoranthene, and benzo(a)pyrene	Ochrobactrum sp., Bacillus sp., Marinobacter sp., Pseudomonas sp., Martelella sp., Stenotrophomonas sp., and Rhodococcus sp.	Wastewater	Temperature 55 °C pH 9 Agitation 150 rpm Salt concentration 100 g/L	100, 100, 100, 100, 93, 60, 55, 51	[63]
Phenanthrene and fluorene	Ochrobactrum halosaudis strain CEES1, Stenotrophomonas maltophilia CEES2, Achromobacter xylosoxidans CEES3 and Mesorhizobium halosaudis CEES4	Red Sea saline water and sediment samples	Temperature 37 °C pH 7	90	[64]
Naphthalene, phenanthrene, fluoranthene, pyrene, total petroleum hydrocarbons, and phenolic compounds	Stenotrophomonas sp. S1VKR-26	Polluted Damanganga river	Temperature 37 °C pH 7 Incubation time 7 days	93, 86, 92, 98.3, 72.33, 93.06	[65]
Petroleum hydrocarbons	Paramecium sp., Vorticella sp., Epistylis sp. and Opercularia sp.	Wastewater	Temperature 25 °C pH 7 Incubation time 16 days	70	[66]
Crude oil, crude oil alkanes, pristane, and phytane	Pseudomonas sp. and Bacillus sp.	Oil-polluted sediment	Temperature 30 °C pH 7 Incubation time 14 days	80.64, 76.30, 46.75, 78.23	[67]
Naphthalene	Bordetella avium	Petroleum refinery wastewater	Temperature 30 °C pH 7.5 Naphthalene concentration 100 to 500 mg/L Incubation time 10 days	100	[68]

). These toxic pollutants retarded the growth of microbial species.

In most cases, various mechanisms and co-metabolisms boosted the microbial species and promoted the growth of microbial species and the degradation rate of pollutants from the contaminated sites [69]. Apart from the application of microbial species, plants are also considered superior agents which play a vital role in the clean-up of the environment, more specifically known as phytoremediation [70]. Phytoremediation properties of plants are highly beneficial for soil properties and the environment. The plants degrade parent toxic compounds into less toxic products such as carbon dioxide, water, and ammonia, which are further taken up by plants, improving the quality of soil, enhancing the growth of plants, and increasing environmental sustainability [71,72]. In this paper, biological treatment in two broad categories, microbial biodegradation and phytoremediation, have been discussed.

2.1. Microbial Biodegradation of Emerging Pollutants

Chemical and physical treatments for removing emerging pollutants are extensively applied and considered efficient technologies. However, these techniques are related to severe drawbacks such as cost, efficiency, reliability, and production of secondary pollutants [73,74]. So, biological treatment processes are more effective and are considered an efficient approach for the clean-up of the environment. It is well known that the efficiency of microbial species for various treatment processes primarily relies on the activity and interaction of microbial species and pollutant removal efficiency is correlated with microbial species and their diversity [75] (Figure 2). The adoption of microbial species strongly depended on their ability to transfer electrons from substrates to the anode. For biological and environmental stability, different microbial species and their single and mixed cells were isolated from various contaminated places, such as marine sediments, wastewater, and polluted soil, and extensively applied to remove emerging pollutants from the environment [76,77].

Ferreira et al. [78] isolated a bacterial strain from contaminated marine sediment, and after physiochemical, morphological, and genetic identification, this strain showed a remarkable resemblance to Bacillus thuringiensis. The capability of the bacterial strain was tested for the degradation of various pesticides and polycyclic aromatic hydrocarbons. Results of this study indicated that after 10 days of incubation, microbial strains could degrade 97.3% of polycyclic aromatic hydrocarbons, and for pesticides, the findings revealed that approximately 78% was degraded after 11 days of culture. Recently, Li et al. [79] isolated a manganese-oxidizing bacterium to remove ofloxacin from the aquatic environment. Morphological and genetic findings showed that the bacterial strain revealed the highest similarity to Pseudomonas sp. and was named the F2 strain. Results of the degradation experiment demonstrated that bacteria could completely degrade ofloxacin with a concentration of 5 µg/L. The effective removal of the two most recalcitrant pharmaceutical compounds, carbamazepine and diatrizoate, by using microbes was investigated in laboratory batch experiments. In this study, mixed microbial culture was initially isolated from polluted soil and identified as Acinetobacter sp., Bacillus halodurans, and Pseudomonas putida and their degradation efficiency against the pollutants was examined. Results of this study revealed that after 12 days, mixed microbial culture could degrade 43.2% of diatrizoate and 60% of carbamazepine with a concentration of 100 µg/L. This study concluded that indigenous microbial species are a superior agent for removing emerging pollutants from the contaminated environment [80].

For the degradation of microplastics from the polluted environment, Lwanga et al. [81] obtained earthworms and identified them as Lumbricus terrestris. The degradation efficiency of the earthworm was tested against low-density polyethylene and isolated bacteria from the earthworm’s gut. Results showed that the bacteria isolated from the gut were Gram-positive and showed a high resemblance to the phyla Actinobacteria and Firmicutes. The isolated bacteria were used to treat gamma-sterilized soil and low-density polyethylene microplastics. The results of this study demonstrated that in the soil treated with bacteria the size of microplastics was significantly decreased compared to the control soil. Recently, the removal of the heavy metal cadmium and antibiotic sulfamethoxazole by bacteria was studied. The novel bacterial species was screened from the polluted soil and identified as Achromobacter sp. L3. The optimum conditions were set, and was it found that for the degradation of sulfamethoxazole, this strain performed efficiently at a pH range of 6–8, temperature range of 25–30 °C, and initial concentration of sulfamethoxazole of 10–40 mg/L. The maximum removal rate was 91.98%. Meanwhile, the optimum conditions for removing cadmium were pH 7–9, temperature 25–30 °C, and cadmium concentration 10–30 mg/L, and complete degradation was achieved. This study added valuable insights into removing emerging pollutants from wastewater, polluted soil, and sediments [82].

In another study, for the remediation of total petroleum hydrocarbons, alkanes, and polycyclic aromatic hydrocarbons by using mixed microbial cultures (Pseudomonas stutzeri GQ-4 strain KF453954, Pseudomonas SZ-2 strain KF453956, and Bacillus SQ2 strain KF453961) a microcosm experiment was carried out. Findings indicated a linear correlation between the total petroleum hydrocarbons and alkane degradation rates. Moreover, this study explained that the petroleum hydrocarbon-degrading microbial population measured by the most probable number was significantly correlated with metabolic activity in the biology assay [83]. The unique ability of microalgae to remove heavy metals and nutrients (carbon, phosphorus, and nitrogen) from wastewater has drawn a lot of interest in the past decade [84]. Oxygen-evolving organisms known as microalgae are able to absorb significant amounts of nutrients (carbon, nitrogen, and phosphorus) from wastewater in order to reproduce and grow [85]. They are mostly photoautotrophic organisms, making efficient use of CO₂ and sunlight. Additionally, depending on the energy and carbon sources that are available in their surroundings, they can effectively display both heterotrophic and mixotrophic modes [86]. They offer an additional choice because they are adaptable in a variety of climatic and environmental circumstances, economically efficient, and environmentally proficient for wastewater treatment [87]. Furthermore, the concentrated biomass recovered from microalgae-based wastewater treatment systems can be utilized as a biofertilizer or as a starting point for the synthesis of bioenergy [88].

Following a chemical adaption procedure, the degradation of sulfamethazine and sulfamethoxazole at various concentrations by S. obliquus was evaluated. High removals for high concentrations were observed (31.4–62.3% in 0.025–0.25 mg/L of sulfamethazine, and 27.7–46.8% in 0.025–0.25 mg/L of sulfamethoxazole) [89]. One of the potential algal strains for heavy metal biodegradation is Phacus sp. This strain is highly resistant to heavy metals. Phacus spp. exhibited a 75.17% absorption rate of the heavy metal nickel (Ni) at a concentration of 5 mg/L. Furthermore, the strain reduced the concentration of the heavy metal aluminum (Al) by 19% from 9.94 mg/L. Moreover, the concentration of the heavy metal lead (Pb) was decreased from 1 mg/L by 96.7 percent [90]. It has been established that the green filamentous algae Cladophora sp. can degrade arsenic from water at quantities of up to 6 mg/L, with incredible results. Because of their great sorption ability, they have been demonstrated to be able to absorb arsenic in inorganic forms (like As III and As V), organic forms (such methyl methacrylate and DMA), and arsenosugar forms [91]. Manganese (Mn) from tainted water was remedied by Spirogyra sp. and Richeterella sp. When compared to Spirogyra sp., the experimental investigation showed that Richeterella sp. had the best capacity to accumulate [92]. The degradation of industrial metals such as Cd and Zn from the brown alga Sargassum polycystum was investigated through optimization experiments. Under optimal conditions, the highest removal efficiencies of Cd and Zn are 86.20% and 92.90%, respectively [93].

However, the removal of various pollutants using indigenous microbial species to clean up the environment is considered an efficient method and supplying various kinds of nutrients by biostimulation and bioaugmentation processes stimulates the microbial species for the degradation of emerging pollutants [94,95].

2.2. Installation of Floating Wetlands for Wastewater Treatment

Floating treatment wetlands are extensively applied and well known due to their functional benefits, such as being highly efficient, easy to install, inexpensive, and ecofriendly for treating polluted water [96]. They contain macrophytes developing in a floating structure that keeps the plant roots in direct contact with the effluent regardless of the water flow variation over time, allowing the removal of pollutants by various processes [97]. The shoots and crowns of macrophytes develop at the water level while their roots are expanded beneath the water column [98]. A dangling setup of roots, rhizomes, and supported biofilm forms below the floating mat, which supplies a biologically active surface area for biochemical processes and physical processes, such as filtering and entrapment of particulates [99] (Figure 3). Floating treatment wetland technologies are designed and applied to remove various kinds of emerging pollutants from water, such as nutrients, petroleum hydrocarbons, and pharmaceutical products [100]. More interestingly, the treated water can be applied for irrigation purposes to crops and provide a sustainable and ecofriendly approach which is beneficial for the long-term removal of contaminants with minimal ecological involvement [101] (Table 2). To treat domestic sewage, constructed wetlands were installed by applying macrophyte Typha domingensis Pers. For one year, the average degradation of organic matter was investigated by chemical oxygen demand, 5-day biochemical oxygen demand, and total suspended solids. The results of this study revealed that 41% of nutrients and 31% of total phosphorus were removed efficiently. Finally, this study concluded that investigating various parameters in the floating wetlands treatment technique provides valuable data in enhancing the removal capability of macrophytes and improving the quality of water bodies [102]. On a large scale, nutrients and agrochemicals in the floating wetlands were removed for 16 weeks. Two different plant species (duckweed and water hyacinth) were applied, and their growth parameters and climatic conditions were measured. Five different pesticides, imidacloprid, thiacloprid, myclobutanil, chlorpyriphos, and dimethomorph, were used with the volumes of 0.75 mL, 0.63 mL, 3.3 mL, 0.31 mL, and 0.3 mL. In contrast, the volume of nutrients was 68.9 g, used in the tank to pollute the water artificially. The results of this study showed that both plant species could remove pesticides and nutrients in the ranges of 27.4% to 83.6% and 12.4% to 42.7%, respectively [103].

Steroid hormones and biocides are considered emerging sources of pollution in the urban environment, which are extensively applied and cause severe threats to living organisms in aquatic and terrestrial environments [104]. An integrated constructed wetland system was recently installed to treat wastewater with steroid hormones and biocides. The results of this study revealed that five kinds of steroid hormones and four biocides could be detected within a constructed wetland system. The concentrations of the effluents were 30.5 ± 1.25 ng/L to 105 ± 5.14 ng/L and from 63.4 ± 2.85 ng/L to 515 ± 19.7 ng/L, respectively. By installing a floating treatment wetland system, 97.4% of steroid hormones and 92.4% of biocides were removed from the wastewater efficiently [105]. Constructed wetland systems are applied to remove a wide range of pollutants from the wastewater, such as livestock wastewater, organic matter, nutrients, and metals called emerging pollutants [106]. A microcosm of Phragmites australis was used to clean livestock wastewater with 100 µg/L of enrofloxacin, ceftiofur, and two antibiotics commonly applied in the livestock industry. Results of this study demonstrated that after 8 weeks of installation, floating constructed wetlands could remove 90% of pollutants from the environment [107]. In another study, a constructed floating wetland system was built to remove various kinds of pollutants, including petroleum hydrocarbons, from wastewater. The plant Typha latifolia was grown for three months and various plant growth indexes, biofilm formation, and degradation rate of pollutants were measured. Results of this study indicated that the floating wetland mediated with the plant was able to remove petroleum hydrocarbon, phenol, oil and grease, chemical oxygen demand, and total suspended solids within the ranges of 45–99%, 99–100%, 70–80%, 45–91%, and 46–88%, respectively. Finally, this study concluded that Typha latifolia is a superior candidate that could be further used to remove other emerging pollutants from aquatic systems and save the diversity of living organisms in water bodies [108].

Table 2. Application of potential plant species for remediation of emerging pollutants in wastewater.

Name of Pollutants	Plant Species	Water Matrix	Degradation %	References
Iron, nickel, manganese, lead, and chromium	Phragmites australis and Brachia mutica	Polluted river water	79.05, 91.4, 91.8, 36.14, and 85.19	[109]
Ammonia, chromium, and total ammonia nitrogen	Chrysopogon zizanioides L.	Industrial wastewater	40.29–50	[110]
Sewage and industrial wastewater	Brachiaria mutica, Cannabis indica, Leptochloa fusca, Phragmites australis, Rhaphiolepis indica, and Typha domingensis	Ponds and industrial wastewater	60 and 40	[111]
Hexavalent chromium	Brachiaria mutica	Industrial wastewater	53	[112]
Copper, nickel, manganese, zinc, lead, and iron	Phragmites australis	Textile wastewater	77.5, 73.3, 89.7, 81, 70, and 65.5	[113]
COD, TN, ammoniacal nitrogen, nitrate nitrogen, TP, and phosphate ion	Canna sp.	Synthetic wastewater	91.3. 58.3, 58.3, 92, 79.5, and 67.7	[114]
COD, BOD, ammonia nitrogen, and orthophosphate	Cyperus sp. and Heliconia sp.	Polluted fishpond water	33.96, 29.41, 27.80, and 28.44	[115]
Nitrogen, phosphorus, organic matter, and coliform	Phragmites sp.	Domestic wastewater	93, 100, 99.6, and 99.9	[116]
COD, BOD, and TSS	Eichhornia crassipes, Eichhornia paniculate, polygonum ferrugineum, and Borreria scabiosoides	Dairy wastewater	74.8, 86.4, and 84.8	[117]
Hydrocarbons, COD, BOD, TOC, and phenol	Phragmites australis	Diesel-oil-contaminated water	95.8, 98.6, 97.7, 95.2, and 98.9	[118]
COD, BOD, colors, and trace metals	Phragmites australis	Textile industry wastewater	92, 91, 86, and 87	[119]
Oil, COD, and BOD	Brachiara mutica and Phragmites australis	Oil field wastewater	97, 93, and 97	[120]
BOD, TSS, nitrogen and phosphorus	Carex virgata	Domestic wastewater	100, 100, 93, and 93	[121]
Nitrogen and phosphorus	Agrostis alba, Canna generalis, Carex stricta, Iris ensata, and Panicum virgatum	Nursery wastewater	59.6 and 64.7	[122]
TP, TSS, BOD, TOC, turbidity, and DOC	Juncus maritimus	Saline wastewater	86, 82, 78, 55, 53, and 19	[123]
Total phosphorus (TP) and total nitrogen (TN)	Pontederia cordata and Juncus effusus	Agricultural runoff	90 and 84	[124]
Phenolic compounds, TOC, and TN	Cyperus alternifolius and Vetiveria zizanioides	Olive mill wastewater	98.8, 95.3, 82.7, and 98.8	[125]
Total nitrogen and total phosphorus	Iris wilsonii	Municipal wastewater	57.6 and 46.7	[126]
Ammonium, BOD, TN, TP, iron, lead, copper, and nickel	Eichhornia crassipes	Polluted lake water	97.4, 75, 82, 84.2, 62.5, 88.9, 81.7, and 80.4	[127]
BOD, COD, TN, ammonium, nitrate, phosphate, and sulfate	Spirodela polyrhiza	Septage effluent	68.43, 64.29, 66.41, 81.87, 58.02, 60.48, and 64.45	[128]

Table 2. Application of potential plant species for remediation of emerging pollutants in wastewater.

Name of Pollutants	Plant Species	Water Matrix	Degradation %	References
Iron, nickel, manganese, lead, and chromium	Phragmites australis and Brachia mutica	Polluted river water	79.05, 91.4, 91.8, 36.14, and 85.19	[109]
Ammonia, chromium, and total ammonia nitrogen	Chrysopogon zizanioides L.	Industrial wastewater	40.29–50	[110]
Sewage and industrial wastewater	Brachiaria mutica, Cannabis indica, Leptochloa fusca, Phragmites australis, Rhaphiolepis indica, and Typha domingensis	Ponds and industrial wastewater	60 and 40	[111]
Hexavalent chromium	Brachiaria mutica	Industrial wastewater	53	[112]
Copper, nickel, manganese, zinc, lead, and iron	Phragmites australis	Textile wastewater	77.5, 73.3, 89.7, 81, 70, and 65.5	[113]
COD, TN, ammoniacal nitrogen, nitrate nitrogen, TP, and phosphate ion	Canna sp.	Synthetic wastewater	91.3. 58.3, 58.3, 92, 79.5, and 67.7	[114]
COD, BOD, ammonia nitrogen, and orthophosphate	Cyperus sp. and Heliconia sp.	Polluted fishpond water	33.96, 29.41, 27.80, and 28.44	[115]
Nitrogen, phosphorus, organic matter, and coliform	Phragmites sp.	Domestic wastewater	93, 100, 99.6, and 99.9	[116]
COD, BOD, and TSS	Eichhornia crassipes, Eichhornia paniculate, polygonum ferrugineum, and Borreria scabiosoides	Dairy wastewater	74.8, 86.4, and 84.8	[117]
Hydrocarbons, COD, BOD, TOC, and phenol	Phragmites australis	Diesel-oil-contaminated water	95.8, 98.6, 97.7, 95.2, and 98.9	[118]
COD, BOD, colors, and trace metals	Phragmites australis	Textile industry wastewater	92, 91, 86, and 87	[119]
Oil, COD, and BOD	Brachiara mutica and Phragmites australis	Oil field wastewater	97, 93, and 97	[120]
BOD, TSS, nitrogen and phosphorus	Carex virgata	Domestic wastewater	100, 100, 93, and 93	[121]
Nitrogen and phosphorus	Agrostis alba, Canna generalis, Carex stricta, Iris ensata, and Panicum virgatum	Nursery wastewater	59.6 and 64.7	[122]
TP, TSS, BOD, TOC, turbidity, and DOC	Juncus maritimus	Saline wastewater	86, 82, 78, 55, 53, and 19	[123]
Total phosphorus (TP) and total nitrogen (TN)	Pontederia cordata and Juncus effusus	Agricultural runoff	90 and 84	[124]
Phenolic compounds, TOC, and TN	Cyperus alternifolius and Vetiveria zizanioides	Olive mill wastewater	98.8, 95.3, 82.7, and 98.8	[125]
Total nitrogen and total phosphorus	Iris wilsonii	Municipal wastewater	57.6 and 46.7	[126]
Ammonium, BOD, TN, TP, iron, lead, copper, and nickel	Eichhornia crassipes	Polluted lake water	97.4, 75, 82, 84.2, 62.5, 88.9, 81.7, and 80.4	[127]
BOD, COD, TN, ammonium, nitrate, phosphate, and sulfate	Spirodela polyrhiza	Septage effluent	68.43, 64.29, 66.41, 81.87, 58.02, 60.48, and 64.45	[128]

3. Physiochemical Methods for Wastewater Treatment

Different strategies are involved in remediating hazardous substances in water. The suitability of these techniques can be analyzed by various parameters such as the ability of a method to remove toxic contaminants from wastewater to an acceptable level, the stability and shelf life of the method, and, most importantly, its compatibility with the environment and human resources [129]. Physiochemical approaches for the remediation of emerging micropollutants in water matrices are mentioned in Table 3.

3.1. Physical Method

3.1.1. Sedimentation

This physical method is considered one of the most prominent for wastewater treatment. The principle of this strategy is to disperse waste particles from the liquid based on gravity and decrease the velocity of water, favoring the suspension of particles in motionless situations. After that, gravitational forces are used to separate the particles [130]. The efficiency of the sedimentation process depends on various parameters such as the size of wastewater particles, their density, the velocity of subsidence, and the volume of wastewater particles [131]. The water flow velocity plays a crucial role in removing suspended solids. In the primary sedimentation process, the travel time of pollutants is adjusted to be slower than the travel time of water. Suspended solids with low density or smaller size and greater density are efficiently removed in the primary sedimentation process [132].

This technique is also highly effective against various pollutants, including antibiotic-resistant bacteria and antibiotic-resistant genes. Anthony et al. [133] demonstrated the removal of antibiotic-resistant bacteria and genes using three distinct plants in an experiment. The study indicated that the primary treatment, which involves the remediation of suspended solids, could have been more efficient, while the secondary treatment process efficiently degraded antibiotic-resistant bacteria and genes. Furthermore, the sludge sedimentation technique effectively removed antibiotic-resistant bacteria and genes in all three plants [133]. An investigation was conducted to remove three different pollutants (phenolic compounds, turbidity, and suspended solids) from wastewater using the sedimentation process. The results revealed that sedimentation significantly reduced contaminant levels by up to 75% and lowered chemical oxygen demand and discoloration by about 90% [134]. In another study, the same method was applied to remediate antibiotics from pharmaceutical wastewater through sedimentation. The results showed that color reduction, chemical oxygen demand, and suspended solids were reduced by approximately 97.3%, 96.9%, and 86.7%, respectively, under optimal conditions [135]. Recently, Zhou et al. [136] developed a novel wastewater treatment method that combines chemically enhanced primary sedimentation with acidogenic sludge fermentation. This novel sedimentation technique not only recovers valuable resources like phosphorus and organics but also efficiently removes various pollutants in sewage sludge under laboratory conditions.

3.1.2. Degasification

In this method, the exclusion of suspended harmful gases and biological nutrients is achieved through physical methods, a process known as degasification [137]. The effectiveness of degasification depends on factors such as the temperature of the wastewater solution, the volume of the tank, ultrasonic power, and their frequency [138]. Degasification membranes have been widely utilized for removing various toxic gases from wastewater, offering an efficient alternative to vacuum towers, forced draft deaerators, and oxygen scavengers across multiple sectors including microelectronics, pharmaceuticals, power generation, food and beverages, photography, ink production, and analytical industries [139]. For instance, in the removal of CH₄ from water, a degassing membrane was used in conjunction with granular sludge for anaerobic wastewater treatment [140].

A study conducted by Saidou et al. [141] investigated pH and airflow factors for the removal of phosphorus gas. This study utilized the dissolved carbon dioxide degasification technique, where precipitation occurred due to carbon dioxide and atmospheric air. Below a pH of 6.5, no precipitation was recorded. Conversely, at pH levels above 6.5, phosphorus elimination reached approximately 78%, with precipitation observed upon increasing the airflow volume by about 25 L/min. In another study focusing on phosphorus removal from animal manure wastewater, carbon dioxide degasification and a continuous U-shaped bioreactor system were employed. The results indicated that without magnesium, the remediation rate exceeded 50%, whereas in the presence of magnesium, phosphorus removal ranged from 80% to 86% [142].

3.1.3. Filtration

There are two primary kinds of filtration processes used for wastewater treatment: particle filtration and membrane filtration processes [143]. Filtration is essential in wastewater treatment for removing solid contaminants up to several microns in size, and it depends on parameters such as the size, texture, quantity, and density of contaminated particles [144,145]. Membrane filtration is a highly complex method extensively used to remove various pollutants. It is often integrated with other physical, chemical, and biological removal methods to enhance overall efficiency [146]. Direct membrane filtration systems are compact, requiring a small footprint, and do not involve an additional activated sludge process, thereby reducing energy consumption [147]. Recently, a study investigated the filtration method for removing organic matter, suspended solid particles, nutrients, and pathogens from domestic wastewater. In this study, a pilot-scale reactor system with an up-flow anaerobic sludge blanket operated at 19 °C for six hours of hydraulic retention time. The results showed that the filtration reactor system effectively removed suspended solid particles by 93%, reduced chemical oxygen demand by up to 87%, and decreased fecal coliform levels by nearly 93% in the combined system. Furthermore, the study highlighted that combining the filtration system with an anaerobic reactor is a more efficient and cost-effective method for removing toxic pollutants in developing countries [148]. Many studies have concluded that wastewater treatment through filtration processes is effective due to reduced time consumption, filtering water with lower concentrations of solids and turbidity, and efficiently removing colloidal particles from liquid waste [149].

3.1.4. Aeration

The aeration technique involves bringing air and water into close contact for the remediation of emerging pollutants [150]. This method utilizes air blowers in combination with an air support system to supply oxygen to the aeration tank, facilitating the conversion of pollutants into various non-toxic or less toxic compounds such as ammonia, water, and carbon dioxide [151]. Another critical component is the pump system, supported by the air system, which consumes over 70% of electricity in wastewater treatment processes [152]. Aeration has proven effective in removing toxic gases, heavy metals, and volatile organic compounds and reducing odors [153]. Uggetti et al. [154] conducted a pilot-scale study on the aeration method for wastewater treatment. The results demonstrated that under anoxic and aerobic conditions, the aeration technique removed 66% of chemical oxygen demand, 99% of ammonium, and 79% of total nitrogen. Continuous aeration further accelerated pollutant removal, achieving 99% removal of ammonium starting from an initial concentration of 27 mg/L. The study highlighted the potential of intermittent aeration to enhance pollutant removal efficiency, offering new insights into energy and cost consumption. Many studies have emphasized that aeration is the primary large-scale physical treatment method for wastewater treatment, historically preceding chemical methods in efficiency for removing nutrients from domestic wastewater [155,156]. Even biological wastewater treatment in aerobic environments requires pure oxygen aeration [157]. Therefore, the aeration technique stands out as a superior physical treatment widely applicable on an industrial scale [158].

3.2. Chemical Methods

3.2.1. Adsorption

There are two kinds of adsorption processes: physical adsorption and chemical adsorption. In the physical adsorption process, van der Waals forces are applied to non-dependent substrates to enhance the adsorbate concentration. In the chemical adsorption process, different chemical reactions occur between the adsorbate and adsorbent, stimulating covalent and ionic bonding [159]. For the chemical process, adsorbents based on activated carbons are extensively applied for the remediation of toxic metals due to their distinguishing characteristics, such as well-established porous structures, large specific surface area, and various functional groups [160].

Recently, two nanocomposites (kaolin and kaolin zinc oxide) were studied to remove heavy metals, including chromium, iron, and chloride, and their chemical and biological oxygen demands in wastewater were investigated. Different characteristics were analyzed to optimize the batch adsorption experiment, including temperature, adsorbent concentration, and contact time. This study showed that the batch adsorption process significantly removes the pollutants within 15 min. Specifically, the action of both composites resulted in complete chromium degradation. In contrast, under similar conditions using only kaolin, chromium removal was 78%, iron 91%, chloride 73%, and chemical and biological oxygen demand were 91% and 89%, respectively [161].

In another study, a biomass adsorbent was used to remove dye contaminants from water. The adsorption capability of biomass such as graphene oxide aminated lignin aerogels was compared with malachite green by investigating various parameters such as pH, temperature, aerogel concentration, and contact time. The results of this study demonstrated that after optimizing the adsorbents, they were responsible for removing 91.72% of dyes with the highest adsorption efficiency of 113.5 mg/g [162].

3.2.2. Chemical Precipitation

The chemical precipitation method is often used and considered one of the most efficient techniques for removing different pollutants from wastewater, especially for eliminating heavy metals [163]. A study was conducted to remove sulfide from petroleum-refined wastewater using a chemical precipitation technique. Two coagulants, FeCl₃·6H₂O and FeSO₄·7H₂O, were used as partial precipitants, along with coagulant aids, Ca(OH)₂ and CaCO₃. The results showed that when Fe³⁺ ions were used, sulfide removal ranged from 62% to 95%, and chemical oxygen demand (COD) reduction ranged from 45% to 75%, depending on the pH of the treated water. In contrast, the combination of Fe²⁺ and Ca(OH)₂ under similar conditions achieved sulfide removal of 96% to 99% and COD reduction of 50% to 80% [164]. In another study, chemical precipitation is used to remove fluoride, phosphate, and total ammonia nitrogen simultaneously from semiconductor wastes. The outcomes of the laboratory experiment showed that the use of magnesium salts to remove fluoride led to good performance. The investigation conducted on a pilot scale showed that a two-stage precipitation procedure was capable of elimination of 97% of the phosphate, 58% of the total ammonia nitrogen, and 91% of the fluoride from semiconductor wastewater. The suggested approach has a treatment cost of about 1.58 USD/m³, according to an economic analysis [165].

Recently, a study investigated the application of chemical precipitation of calcium oxide and calcium hydroxide to remove chromium, sulfates, and chemical oxygen demand from industrial tannery wastewater. Low to high alkali concentrations were applied, and chromium was theoretically removed using 0.3–3.2 g alkali (Cr⁺³)⁻¹. The precipitation was conducted at room temperature, with vigorous stirring of 10 min at 200 rotations per minute for 1 day. The results of this study revealed that using a high concentration of alkalis boosts the removal of chromium and sulfates while the removal of chemical oxygen demand was not affected. The removal rate using calcium oxide precipitation for the removal of Cr, SO₄²⁻, ZnSO₄, FeSO₄, CN⁻¹, NiSO₄, and Fe⁺² [Fe (CN)₆] was 99.8%, 66.9%, 99.6%, 21.4%, 70.9%, 52.8% and 76.4%, respectively. In comparison, by using the precipitation of calcium hydroxide, 99.8%, 61.6%, 99.9%, 7.1%, 84.0%, 54.4%, and 90.5% were recorded, respectively [166].

3.2.3. Flocculation and Coagulation

Undermined contaminated elements are clustered into bigger particles by mechanical agitation for the flocculation method. In contrast, for the coagulation process, some materials stabilize the colloidal suspensions by neutralizing their charges, leading to the accumulation of minor particles [167,168]. Recently, the method of flocculation and coagulation was adopted to remove microplastics from secondary wastewater. In this study, two different sizes of polystyrene spheres, 1 µm and 6.3 µm, with wastewater effluent were spiked and the removal rate in a wide pH range was investigated. Moreover, ferric chloride, poly aluminum chloride, and polyamine were used as organic and inorganic coagulants. The results of this study revealed that coagulants play a vital role in removing microplastics. Ferric chloride and poly aluminum chloride efficiently almost completely removed microplastics compared to polyamine [169]. In another, a batch experiment was conducted for textile wastewater treatment. It evaluated the efficiency of four different coagulants, ferric sulfate, aluminum chloride, aluminum sulfate, and ferric chloride, at various ranges of pH (1–11) for the elimination of different pollutants such as chemical oxygen demand, total suspended solids, color, total nitrogen, and turbidity from industrial wastewater. Results of this study demonstrated that by using a high concentration of ferric chloride at pH 9, a fast-mixing speed of 150 rpm for 1 min, and a slow mixing speed of 30 rpm for 20 min with 30 min of settlement time, almost 90% of the pollutants were eliminated [170]. Heterogeneous photocatalysis was used to optimize the traditional coagulation–flocculation process and finish the removal of natural organic matter from drinking water. TiO₂-P25 suspended catalyst and TiO₂-P25/β-SiC supported materials were used in heterogeneous photocatalytic experiments [171]. Coagulation–flocculation and heterogeneous photocatalysis have been used alone and in combination to determine the most effective method for breaking down the most significant number of organic molecules. Total organic carbon, specific UV absorbance (SUVA254nm), and UV absorbance at 254 nm (UV254nm) were evaluated to quantify the number of humic compounds eliminated from each treatment. Findings indicated that at pH 5 for 110 mg/L of coagulant dosage, the coagulation–flocculation process conditions were optimized, and at this pH, 70% of humic compounds were eliminated. After 220 min of irradiation, the coupling of coagulation–flocculation and the supported photocatalytic process (with TiO₂-P25/β-SiC supported catalyst) reveals that around 80% of the mineralization of humic compounds is still present in water treated by coagulation–flocculation. As a result, these two procedures together eliminate around 90% of humic compounds [172].

3.2.4. Ion Exchange

The alteration of ions present in the wastewater for their treatment is called ion exchange, and the constituents used to detect ion pollutants are known as resins [173,174] (Figure 4). Mainly two types of resins are used for the ion-exchange process: synthetic and natural resins. Due to their distinguished characteristics and good efficiency, synthetic resins are extensively used [175]. Natural resins include clays, polysaccharides, proteins, and carbon materials. Synthetic resins used for ion exchange are heavy metal silicates, formaldehyde resins, Sephadex, and acrylic acid co-polymers [176].

Recently, for removing nitrite ions from the tailwater of dyeing wastewater, an ion-exchange polymer and modified carbonization bacterial cellulose were made using different concentrations of ion-exchange polymers such as glutaric acid and sulfosuccinate acid. Furthermore, the ion-exchange polymers are manufactured within an asymmetric capacitive deionization unit, and the efficiency of NO⁻² electroadsorption was investigated. Results of the study showed that the activated carbon and carbonization bacterial cellulose group efficiently showed adsorption capacity of salts upto 14.56 mg/g and effectively eliminated nitrates at the rate of 71.01% as compared to the activated carbonization bacterial cellulose and glutaric acid (10.72 mg/g, 47.83%) and activated carbon-based (4.81 mg/g, 12.74%) groups [177]. A study was carried out on removing the heavy metal chromium from wastewater using an ion-exchange technique. In this study, the resin used for ion exchange was Lewatit S 100. Results of the study showed that at lower pH (3.5), resin adsorption was maximum and performed efficiently to remove chromium metal [178].

3.2.5. Ozonation

Due to the excellent oxidation and disinfection efficiency of ozone, the ozonation process is extensively applied for wastewater treatment [179]. The most prominent characteristic of ozone gas is that it is unstable, which is why removing pollutants from wastewater can be performed directly by molecular ozone and indirectly via hydroxyl radicals’ formation [180]. Generally, the most used ozonation method has been applied to detoxify contaminants in wastewater as a disinfector and to reduce waste sludge. In addition, this method is also mainly applied for the decolorization of dyes, removing micro- and nanoscale contaminants, and eliminating chemical oxygen demand [181] (Figure 5).

Pulp and paper wastewater treatment using the ozonation method at a large scale in a medium-potentiality wastewater treatment plant (143,000 population equivalent) was recently investigated. To evaluate the efficiency of the ozonation technique, single wastewater lines, including bleaching and processing wastewater, and the mixture of wastewater before and after secondary biological treatment were carried out. Ozone demonstrated considerably greater efficiency on pulp and paper wastewater mixture following biological treatment (up to 81% COD removal) rather than before biological process (46% mean COD abatement). Ozone effectiveness was more noticeable in process water (60% COD removal) than in bleaching water (28% COD removal). A good TSS abatement (up to 20–30 mg/L) was also noted, and the COD elimination effectiveness at a dosage of 100 mg O₃/L was comparable to the current physicochemical treatment (mean 50%). [182]. In another study, various methods were applied to treat oily gas wastewater, such as hybridization of the electrochemical coagulation method, ceramic microfiltration membrane, and ozonation, and their efficiencies were compared. This study investigated different parameters, such as hydraulic retention time, aeration, current density, method of supply, and pH of samples. Results of this study revealed that the ozonated reactor eliminates chemical oxygen demand by up to 53.1% compared to the aerated electromembrane reactor. Moreover, this study explained that the ozonation-assisted elec −romembrane hybrid plays a vital role in removing pollutants in wastewater [183]. An indicative profile of the physiochemical characteristics for remediation of emerging micropollutants in water matrices is presented in Table 3.

Table 3. Physiochemical approaches for remediation of emerging micropollutants in water matrices.

Name of Treatment	Micropollutants	Water Matrix	Removal Efficiency (%)	References
Sedimentation	Phosphorus Nitrogen	Municipal wastewater	72.43 98.63	[184]
	Oils	Oily wastewater	82	[185]
	Phenolic compounds	Olive mill wastewater	76.2	[186]
	Phosphorus Volatile fatty acids	Organic wastewater	31	[187]
	Ferric chloride Phosphorus Nitrogen	Sewage effluent	80 70 40	[188]
	Colors	Antibiotic fermentation wastewater	97.3	[137]
	Toxic phenolic compounds	Olive mill wastewater	71	[186]
Degasification	Methane Hydrogen sulfide	Anerobic treated wastewater	94 88	[189]
	Phosphate	Animal manure wastewater	80–86	[142]
	Dust Carbon monoxide Nitrogen oxides	Industrial wastewater	20 59.4 55.1	[190]
	Nitrogen	Coal gasification wastewater	81.23	[138]
	Organic compounds	Anaerobic wastewater	90	[191]
	Chromium	Synthetic and industrial wastewater	92.6	[192]
	Organic matter	Sugar industry wastewater	79	[193]
Filtration	Phenol Sodium sulfate Ferrous sulfate Sulfuric acid Sodium hydroxide Potassium titanium	Synthetic and industrial wastewater	100	[143]
	Conventional pollutants	Swine wastewater	99	[194]
	Color Total Nitrogen	Textile wastewater	98.4 86.1	[195]
	Microplastics	Sewage wastewater	96	[144]
	Phosphorus Organic carbon Heavy metals	Urban road runoff	84.1–97.4	[145]
	Copper	Acid mine drainage	100	[146]
	Dye/salt mixtures	Textile wastewater	99.84	[147]
	p-chloroaniline	Industrial wastewater	50	[149]
	Free DNA Antibiotic resistance genes	Domestic wastewater	99.80	[196]
Adsorption	Manganese	Agricultural wastewater	99	[197]
	Heavy metal ions	Domestic wastewater	99	[198]
	Dyes (basic violet and red)	Textile wastewater	77 and 93	[199]
	TetrabromobispenolA	Industrial wastewater	90	[200]
	Bisphenol A	Hospital effluents	100	[201] [202]
	Estrone 17β-estradiol 17α--ethinylestradiol	Laboratory wastewater	86 94 94	[203]
	Cadmium	Industrial wastewater	86	[204]
	Chromium	Industrial wastewater	96	[205]
	Lead	Tannery wastewater	99.12	[206]
	Zinc	Domestic wastewater	93.3	[21]
	Copper Iron Lead Nickel Cadmium	Agricultural and industrial wastewater	98.54 99.25 87.17 96.95 73.54	[207]
Chemical precipitation	Chromium Copper Lead Zinc	Contaminated river water	99.8	[208]
	Zinc	Industrial wastewater	99–99.3	[209]
	Fluoride Ammonia nitrogen Phosphate	Synthetic wastewater	91 58 97	[165]
	Lead	Industrial wastewater	99.4	[210]
	Silicon	Pulping whitewater	93–95	[211]
	Polycyclic aromatic hydrocarbons Micropollutants	Domestic wastewater	80–100	[212]
	Copper	Textile wastewater	80.2	[213]
	Lead	Contaminated river water	94	[214]
	Cobalt	Industrial wastewater	99.9	[215]
	Copper	Textile wastewater	92	[216]
Flocculation and coagulation	Iron, phosphorus, and aluminum	Tannery wastewater	99	[217]
	Reactive and acid	Dye bath effluents	98	[218]
	Sulfur	Industrial dying wastewater	100	[219]
	Arsenic Mercury Lead	Mature landfill leachate	46 9 85	[220]
	Microplastics Humic acid	Synthetic wastewater	98.2 97.9	[221]
	Colors	Tannery wastewater	95	[222]
	Total organic carbon Color	Textile effluents	82 70	[223]
	Turbidity Total organic carbon	Vegetable oil refinery wastewater	100 98	[224]
Ion exchange	Arsenic	Domestic wastewater	100	[225]
	Nickel Zinc	Synthetic wastewater	98	[226]
	Chromium	Synthetic wastewater	93	[227]
	Chromium	Tannery wastewater	95	[228]
	Nickel Vanadium	Hospital effluents	98	[229]
	Hexavalent chromium	Tannery wastewater	98.5	[230]
	Cadmium Lead	Mango peel wastewater	72.46 76.26	[231]
	Thallium Chloride	Industrial wastewater	98 90	[232]
	Methylene blue	Textile wastewater	97.02	[233]
Ozonation	Colors	Tannery wastewater	100	[234]
	Nitrogenous heterocyclic compounds Total nitrogen	Coal gasification wastewater	95.6 80.6	[235]
	Ibuprofen	Synthetic wastewater	99	[236]
	Proteins Polysaccharides	Organic wastewater	100 42	[237]
	Non-polar pollutants	Synthetic wastewater	95	[238]
	Metolachlor	Organic wastewater	82	[239]
	Atrazine Metolachlor Nonylphenol	Organic wastewater	75 78 100	[240]
	Diclofenac Sulfamethoxazole	Pharmaceutical industrial wastewater	100 95	[241]
	Diclofenac Sulfamethoxazole 17-α-Ethynylestradiol	Pharmaceutical industrial wastewater	100	[242]
	Ibuprofen Ciprofloxacin	Pharmaceutical industrial wastewater	100 88	[243]
	2,4–Dichlorophenol 2,4,6–Trichlorophenol Phenazone	Synthetic wastewater	98 98 79	[244]

Table 3. Physiochemical approaches for remediation of emerging micropollutants in water matrices.

Name of Treatment	Micropollutants	Water Matrix	Removal Efficiency (%)	References
Sedimentation	Phosphorus Nitrogen	Municipal wastewater	72.43 98.63	[184]
	Oils	Oily wastewater	82	[185]
	Phenolic compounds	Olive mill wastewater	76.2	[186]
	Phosphorus Volatile fatty acids	Organic wastewater	31	[187]
	Ferric chloride Phosphorus Nitrogen	Sewage effluent	80 70 40	[188]
	Colors	Antibiotic fermentation wastewater	97.3	[137]
	Toxic phenolic compounds	Olive mill wastewater	71	[186]
Degasification	Methane Hydrogen sulfide	Anerobic treated wastewater	94 88	[189]
	Phosphate	Animal manure wastewater	80–86	[142]
	Dust Carbon monoxide Nitrogen oxides	Industrial wastewater	20 59.4 55.1	[190]
	Nitrogen	Coal gasification wastewater	81.23	[138]
	Organic compounds	Anaerobic wastewater	90	[191]
	Chromium	Synthetic and industrial wastewater	92.6	[192]
	Organic matter	Sugar industry wastewater	79	[193]
Filtration	Phenol Sodium sulfate Ferrous sulfate Sulfuric acid Sodium hydroxide Potassium titanium	Synthetic and industrial wastewater	100	[143]
	Conventional pollutants	Swine wastewater	99	[194]
	Color Total Nitrogen	Textile wastewater	98.4 86.1	[195]
	Microplastics	Sewage wastewater	96	[144]
	Phosphorus Organic carbon Heavy metals	Urban road runoff	84.1–97.4	[145]
	Copper	Acid mine drainage	100	[146]
	Dye/salt mixtures	Textile wastewater	99.84	[147]
	p-chloroaniline	Industrial wastewater	50	[149]
	Free DNA Antibiotic resistance genes	Domestic wastewater	99.80	[196]
Adsorption	Manganese	Agricultural wastewater	99	[197]
	Heavy metal ions	Domestic wastewater	99	[198]
	Dyes (basic violet and red)	Textile wastewater	77 and 93	[199]
	TetrabromobispenolA	Industrial wastewater	90	[200]
	Bisphenol A	Hospital effluents	100	[201] [202]
	Estrone 17β-estradiol 17α--ethinylestradiol	Laboratory wastewater	86 94 94	[203]
	Cadmium	Industrial wastewater	86	[204]
	Chromium	Industrial wastewater	96	[205]
	Lead	Tannery wastewater	99.12	[206]
	Zinc	Domestic wastewater	93.3	[21]
	Copper Iron Lead Nickel Cadmium	Agricultural and industrial wastewater	98.54 99.25 87.17 96.95 73.54	[207]
Chemical precipitation	Chromium Copper Lead Zinc	Contaminated river water	99.8	[208]
	Zinc	Industrial wastewater	99–99.3	[209]
	Fluoride Ammonia nitrogen Phosphate	Synthetic wastewater	91 58 97	[165]
	Lead	Industrial wastewater	99.4	[210]
	Silicon	Pulping whitewater	93–95	[211]
	Polycyclic aromatic hydrocarbons Micropollutants	Domestic wastewater	80–100	[212]
	Copper	Textile wastewater	80.2	[213]
	Lead	Contaminated river water	94	[214]
	Cobalt	Industrial wastewater	99.9	[215]
	Copper	Textile wastewater	92	[216]
Flocculation and coagulation	Iron, phosphorus, and aluminum	Tannery wastewater	99	[217]
	Reactive and acid	Dye bath effluents	98	[218]
	Sulfur	Industrial dying wastewater	100	[219]
	Arsenic Mercury Lead	Mature landfill leachate	46 9 85	[220]
	Microplastics Humic acid	Synthetic wastewater	98.2 97.9	[221]
	Colors	Tannery wastewater	95	[222]
	Total organic carbon Color	Textile effluents	82 70	[223]
	Turbidity Total organic carbon	Vegetable oil refinery wastewater	100 98	[224]
Ion exchange	Arsenic	Domestic wastewater	100	[225]
	Nickel Zinc	Synthetic wastewater	98	[226]
	Chromium	Synthetic wastewater	93	[227]
	Chromium	Tannery wastewater	95	[228]
	Nickel Vanadium	Hospital effluents	98	[229]
	Hexavalent chromium	Tannery wastewater	98.5	[230]
	Cadmium Lead	Mango peel wastewater	72.46 76.26	[231]
	Thallium Chloride	Industrial wastewater	98 90	[232]
	Methylene blue	Textile wastewater	97.02	[233]
Ozonation	Colors	Tannery wastewater	100	[234]
	Nitrogenous heterocyclic compounds Total nitrogen	Coal gasification wastewater	95.6 80.6	[235]
	Ibuprofen	Synthetic wastewater	99	[236]
	Proteins Polysaccharides	Organic wastewater	100 42	[237]
	Non-polar pollutants	Synthetic wastewater	95	[238]
	Metolachlor	Organic wastewater	82	[239]
	Atrazine Metolachlor Nonylphenol	Organic wastewater	75 78 100	[240]
	Diclofenac Sulfamethoxazole	Pharmaceutical industrial wastewater	100 95	[241]
	Diclofenac Sulfamethoxazole 17-α-Ethynylestradiol	Pharmaceutical industrial wastewater	100	[242]
	Ibuprofen Ciprofloxacin	Pharmaceutical industrial wastewater	100 88	[243]
	2,4–Dichlorophenol 2,4,6–Trichlorophenol Phenazone	Synthetic wastewater	98 98 79	[244]

4. Nanotechnology for Wastewater Treatment

Clean and safe water is one of the most fundamental elements needed for the survival of life on the planet [245]. The increasing population, industrialization, urbanization, and an imprudent number of agriculture procedures produce dirty and deadly wastewater [246,247]. Every year millions of people are affected due to harmful pathogens through the consumption of drinking water worldwide [248]. However, in the last few years, many techniques have been applied to wastewater treatment. However, their applications are confined by various limitations such as the use of chemicals, formation of secondary pollutants, time consumption, and high prices [249].

Nanoparticles incorporate a high surface-to-volume ratio, high sensitivity and reactivity, a high adsorption capacity, and ease of functionalization, making them suitable for wastewater treatment [250]. Nanoparticles have been proven efficient in removing different toxic contaminants from wastewater, such as heavy metals, organic and inorganic compounds, dyes, biological toxins, and pathogens that spread lethal diseases [251] (Figure 6).

Recently, Shkir et al. [252] investigated applications of novel Ni-mediated ZnO nanomaterials for removing methylene blue and tetracycline from wastewater. Ni- and ZnO-doped nanoparticles were synthesized at the wt% of 0.0, 0.5, 1.0, 2.0, and 3.0 by the high-combustion method at 550 °C. The morphology, homogeneity, and particle size were evaluated by scanning electron microscope analysis, and it was found that both particles were braced efficiently with each other at the range of 30–60 nm. In addition, this study explained that 3.0% wt of Ni doping in ZnO nanoparticles is more suitable, effective, and more rapidly removed both pollutants from the wastewater and reused several times. In another study, various kinds of emerging pollutants were removed from wastewater with the synthesis of silver and gold nanoparticles by using an extract of Crinum latifolium. The results of this study explained that the average diameters of unique and multishaped silver and gold nanoparticles were 20.5 and 17.6 nm, respectively. Moreover, the biosynthesized metallic nanoparticles efficiently removed dyes and antibiotics from the wastewater [253]. Nanoparticles and their preferential role in degrading different toxic compounds in wastewater are mentioned in Table 4. To remove secondary effluents from municipal wastewater, a comprehensive investigation was proposed and synthesized magnetic and silver nanoparticles had average dimensions of 41 and 34 nm, respectively, and the saturation magnetization was recorded as 62 and 67 emu/g, respectively. The findings of this study revealed that the dose of nanoparticles at 105 mg/L with a contact time of 70 min was able to effectively remove 55% of toxic pollutants and 30.40% of chemical oxygen demand. In addition, this study explained that increasing the dose of nanomaterials and contact time and decreasing the concentration of pollutants enhanced the removal rate, and nanoparticles could be reused several times [254]. For the removal of various cationic and anionic dyes such as malachite green, Congo red, methylene blue, and eosin Y from wastewater, the biosynthesis of flower-shaped zinc oxide (ZnO) nanoparticles from the extract of sea buckthorn fruit was carried out, and their external and internal properties were examined by using different microscopes. This study showed that by a photocatalyst mechanism, almost 99% removal of malachite green, methyl blue, Congo red, and eosin Y was achieved at the concentration of 15 mg/L with a contact time of 70, 70, 80, and 90 min, respectively. In addition, using 5 mg/L of green synthesized nanoparticles, all dyes were completely degraded with a contact time of 23, 25, 28, and 30 min, respectively. This study concluded that biosynthesized zinc oxide nanoparticles are faster, inexpensive, easy to synthesize, efficient, recyclable, ecofriendly, and non-toxic agents to degrade various kinds of emerging pollutants from wastewater [255].

Heavy metals are extensively released into the ecosystem by various industries, and their accumulation causes severe threats to terrestrial as well as aquatic organisms [256]. To remove chromium from tannery wastewater, green synthesis of titanium oxide nanoparticles (TiO₂ NPs) from Jatropha curcas leaf extract was carried out, and their efficiency was evaluated. The findings of this study explained that by photocatalytic treatment, complete removal of chromium metal and chemical oxygen demand (COD) was achieved, while by applying TiO₂ NPs in a parabolic trough reactor, 82.26% of COD and 76.48% of chromium were removed from tannery wastewater. This study concluded that biosynthesized TiO₂ NPs performed rapidly and could be used to remove other kinds of emerging pollutants from the environment at a pilot scale [257]. Another study studied the formation of novel magnetic nanoparticles modified by organodisulfide polymer to remove highly toxic metals, including lead, mercury, and cadmium, from high-salinity wastewater. The results of adsorption kinetics and isotherm thermodynamics followed the pseudo-second-order model. The Freundlich equation revealed that, by using inorganic salt in high-salinity water, removing all metals was efficiently achieved by applying nanoparticles for twenty seconds and they could be recycled five times [258]. The imprudent applications of pesticides and other organic chemicals in the agriculture system cause various diseases in living organisms, reaching the groundwater and contaminating drinking water. Due to the imperative need for a healthy natural environment, researchers are constantly seeking to maintain biodiversity by removal of toxic pesticide residues worldwide [259].

Recently, the removal of chlorpyriphos residues from the wastewater synthesis of green nanoparticles from the leaf extract of Moringa olivera was carried out and their efficiency was investigated. To gain the best degradation rate of chlorpyriphos residues in wastewater, wide ranges of chlorpyriphos concentrations (10–80 g/mL), doses of nanoparticles (0.05–0.5 g), pH (5–9), contact time (10–1440 min), and temperature (25–45 °C) were used. The outcomes of this study indicated that 81% removal of chlorpyriphos residues at the concentration of 80 µg/mL was achieved within 30 min at pH 7 and a temperature of 35 °C. The CPF sorption process was shown to be exothermic and spontaneous by the thermodynamic characteristics.

This study concluded that a novel nanobiosorbent could be an effective, inexpensive, ecofriendly, non-toxic, and superior candidate for removing chlorpyriphos and other organophosphate pesticides from polluted water [260].

Antibiotics are one of the fundamental components of pharmaceuticals that are extensively applied as a growth factor in fish farms, livestock, and other living organisms, including humans, for the treatment of various infectious diseases [261]. The secondary metabolites of various microbial species, such as bacteria, actinomycetes, archaea, fungi, and algae, could synthesize antibiotics. However, in recent years due to high demand, the synthesis of antibiotics changed and extended to synthetic and semisynthetic compounds [262]. Due to their injudicious use and high applications, their toxic residues are often detected in different compartments of water, including wastewater, surface water, groundwater, and even potable water, causing severe threats to non-target organisms [263,264]. To remove flumequine antibiotics from wastewater, green synthesis of zinc oxide nanoparticles (ZnO NPs) from pomegranate seed molasses was carried out and their external and internal characteristics were analyzed by using a scanning electron microscope, spectrometry, fluorimetry, and Raman spectroscopy. Findings revealed that green synthesized ZnO NPs indicated narrowed band gaps and more excellent absorption of visible photons that allow the maximum density of hydroxyl radicals during the solar illumination process and efficiently degraded 97.6% of flumequine from the wastewater. This study provides new insights into the biosynthesis of various nanoparticles to remove different emerging pollutants from the environment [265]. In another study, the biosynthesis of novel magnetic iron oxide nanoparticles (Fe₃O₄ NPs) from the extract of Excoecaria cochinchinensis to remove rifampicin antibiotics from polluted water and their degradation efficiency as well as other physiochemical properties were investigated. The outcomes of this study revealed that at the initial concentration of 20 mL of rifampicin, 98.4% removal was achieved by a 10 mg dose of Fe₃O₄ NPs at a temperature of 303 K. The scanning electron microscope analysis revealed that the size of nanoparticles was 20–30 nm, and the N₂ adsorption/desorption isotherms explained that the surface area of nanomaterials was 111.8 m²/g. In addition, this study demonstrated that after five reuses, Fe₃O₄ NPs could degrade 61.5% of rifampicin with a concentration of 20 mL [266].

Table 4. Nanoparticles and their preferential role to degrade different toxic compounds in wastewater.

Name of Emerging Pollutant	Name of Nanomaterials	Characteristics	Removal Efficiency %	References
Organic dyes	PVA/PAA/GO-COOH@AgNPs	High catalytic activity, easy to recycle, perform efficiently at room temperature, inexpensive	99.8	[267]
Dyes	Bismuth oxychloride	Controllable shape, perform at various temperatures (low–high), large surface area, ecofriendly	85.31	[268]
4-nitrophenol and 2-nitroaniline	PVA/PAA/Fe3O4/MXene@AgNP	Excellent structure, high thermal stability and good magnetic properties, able to be reused and high catalytic activity	72.55 and 88.8	[269]
Phosphorus and nitrogen	Carbon-based nanomaterials	Easy to synthesize, ecofriendly, high adsorption capacity, high enzymatic and catalytic activity	24.1–42.7	[270]
Organic matter and personal care products	TiO2 and ZnO	Diverse range of particle sizes, grow in clusters, inexpensive, high sorption capacity, and perform in different temperatures efficiently	43.8–55.3	[271]
Methylene blue	Rod-shaped manganese oxide	High adsorption capacity, perform efficiently at pH 8.0 and room temperature, ecofriendly, inexpensive, high degradation ability	99.8	[272]
Congo red dye	Silica composite (Si-IL) and silica-coated magnetite (Fe3O4-Si-IL) composites	Excellent adsorption capacity, high catalytic activity, diverse range of sizes, good magnetic and thermal properties	100	[273]
Chromium, arsenic, and lead	Single-walled carbon nanotubes	Reduced pore size, smoother surface, and high rejection ability	96.8, 87.6, and 30.3	[274]
Diazinon, phosalone, and chlorpyrifos	Modified magnetic chitosan nanoparticles based on mixed hemimicelle of sodium dodecyl sulfate	Excellent absorbance, easy to synthesize, inexpensive, ecofriendly, and easy to recycle	99, 98, and 96	[275]
Methomyl	Cu/Cu2O/CuO hybrid nanoparticles	Efficient in extreme environmental conditions, good reusability, ecofriendly, high adsorption ability, good catalytic activity, and easy to synthesize	91	[276]
Chlorpyriphos	ZnO	Highly dependent on pH, good thermodynamic properties, economical, and environmentally friendly	56	[277]
Ciprofloxacin	Fe3O4/red mud nanoparticles	High removal efficiency, depend on pH, contact time, and temperature, high adsorption capacity, and able to reuse	30–100	[278]
Naproxen	Silica and magnetic nanoparticle-decorated graphene oxide (GO-MNPs-SiO2)	Perform efficiently in optimum conditions, good adsorption ability, inexpensive, and environmentally friendly	83–94	[279]
Lead	TiO2	High catalytic activity, average crystalline size, large surface area, and easy to recycle	82.53	[280]
Dimethoate	Graphene-oxide-supported graphitic carbon nitride microflowers decorated by silver nanoparticles	Grow in crystals, high adsorption ability, good removal efficiency, and long reaction time	93	[281]

Table 4. Nanoparticles and their preferential role to degrade different toxic compounds in wastewater.

Name of Emerging Pollutant	Name of Nanomaterials	Characteristics	Removal Efficiency %	References
Organic dyes	PVA/PAA/GO-COOH@AgNPs	High catalytic activity, easy to recycle, perform efficiently at room temperature, inexpensive	99.8	[267]
Dyes	Bismuth oxychloride	Controllable shape, perform at various temperatures (low–high), large surface area, ecofriendly	85.31	[268]
4-nitrophenol and 2-nitroaniline	PVA/PAA/Fe3O4/MXene@AgNP	Excellent structure, high thermal stability and good magnetic properties, able to be reused and high catalytic activity	72.55 and 88.8	[269]
Phosphorus and nitrogen	Carbon-based nanomaterials	Easy to synthesize, ecofriendly, high adsorption capacity, high enzymatic and catalytic activity	24.1–42.7	[270]
Organic matter and personal care products	TiO2 and ZnO	Diverse range of particle sizes, grow in clusters, inexpensive, high sorption capacity, and perform in different temperatures efficiently	43.8–55.3	[271]
Methylene blue	Rod-shaped manganese oxide	High adsorption capacity, perform efficiently at pH 8.0 and room temperature, ecofriendly, inexpensive, high degradation ability	99.8	[272]
Congo red dye	Silica composite (Si-IL) and silica-coated magnetite (Fe3O4-Si-IL) composites	Excellent adsorption capacity, high catalytic activity, diverse range of sizes, good magnetic and thermal properties	100	[273]
Chromium, arsenic, and lead	Single-walled carbon nanotubes	Reduced pore size, smoother surface, and high rejection ability	96.8, 87.6, and 30.3	[274]
Diazinon, phosalone, and chlorpyrifos	Modified magnetic chitosan nanoparticles based on mixed hemimicelle of sodium dodecyl sulfate	Excellent absorbance, easy to synthesize, inexpensive, ecofriendly, and easy to recycle	99, 98, and 96	[275]
Methomyl	Cu/Cu2O/CuO hybrid nanoparticles	Efficient in extreme environmental conditions, good reusability, ecofriendly, high adsorption ability, good catalytic activity, and easy to synthesize	91	[276]
Chlorpyriphos	ZnO	Highly dependent on pH, good thermodynamic properties, economical, and environmentally friendly	56	[277]
Ciprofloxacin	Fe3O4/red mud nanoparticles	High removal efficiency, depend on pH, contact time, and temperature, high adsorption capacity, and able to reuse	30–100	[278]
Naproxen	Silica and magnetic nanoparticle-decorated graphene oxide (GO-MNPs-SiO2)	Perform efficiently in optimum conditions, good adsorption ability, inexpensive, and environmentally friendly	83–94	[279]
Lead	TiO2	High catalytic activity, average crystalline size, large surface area, and easy to recycle	82.53	[280]
Dimethoate	Graphene-oxide-supported graphitic carbon nitride microflowers decorated by silver nanoparticles	Grow in crystals, high adsorption ability, good removal efficiency, and long reaction time	93	[281]

5. Conclusions and Future Perspectives

Water systems around the world are facing significant accumulations of micropollutants. These primary contaminants largely stem from human activities, such as industrialization, urbanization, and poor wastewater management. The harmful effects of micropollutants on both terrestrial and aquatic ecosystems are unavoidable, with dire consequences for life in these environments. The heavy accumulation and biotoxicity of these pollutants pose severe environmental hazards. As a result, environmentalists emphasize the need for environmentally friendly, cost-effective, and biologically reliable strategies. Conventional physiochemical and biotechnological methods for removing micropollutants from aquatic environments are being re-evaluated, as biological approaches offer advantages in terms of energy efficiency and low costs, improving the efficacy of pollutant removal. Additionally, the integration of nanomaterials has proven to be a significant adjunct in sustainable wastewater management and effective micropollutant abatement. Furthermore, bio-monitoring methods utilizing microbiology, bioinformatics, omics technologies, big data analysis, and systems biology approaches are critical for the sustainable management of micropollutants. The use of novel microbes, innovative nanomaterial strategies, and advanced data management is essential for enhancing the efficiency of micropollutant removal. Holistic approaches, such as sustainable wastewater treatment using floating wetlands, show promise for practical application. Future research should focus on comprehensive assessments of technical stability, from pilot-scale to long-term implementations, for effective micropollutant removal and water body conservation. Additionally, practical applicability and economic feasibility analyses are necessary to develop a sustainable and appropriate wastewater management strategy