Environments

Editorial

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5 pages, 579 KiB

Open AccessEditorial

Advanced Technologies of Water and Wastewater Treatment

by Athanasia K. Tolkou and George Z. Kyzas

Environments 2024, 11(12), 270; https://doi.org/10.3390/environments11120270 - 28 Nov 2024

Viewed by 598

Abstract

With more than 2 billion people worldwide suffering from water scarcity, clean water is one of the most important natural resources on earth, whereas wastewater, which corresponds to spent water, can be considered a valuable natural resource if treated and reused [...] Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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Research

Jump to: Editorial, Review

23 pages, 2147 KiB

Open AccessArticle

Reducing Methane, Carbon Dioxide, and Ammonia Emissions from Stored Pig Slurry Using Bacillus-Biological Additives and Aeration

by Oumaima El bied, Martire Angélica Terrero Turbí, Melisa Gómez Garrido, Ángel Faz Cano and José Alberto Acosta

Environments 2024, 11(8), 171; https://doi.org/10.3390/environments11080171 - 12 Aug 2024

Viewed by 1969

Abstract

This study delves into the innovative application of a novel bacterial and enzyme mixture alone or combined with aeration in mitigating emissions from pig slurry storage and explores their impacts on the methane (CH₄), carbon dioxide (CO₂), and ammonia [...] Read more.

This study delves into the innovative application of a novel bacterial and enzyme mixture alone or combined with aeration in mitigating emissions from pig slurry storage and explores their impacts on the methane (CH₄), carbon dioxide (CO₂), and ammonia (NH₃) emissions from stored pig slurry. A dynamic chamber was used in this research to assess the efficacy of the treatments. Biological additives (HIPO-PURÍN) of specific microbial strains were tested (a mixture ofof Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Bacillus amyloliquefacien, and Bacillus thuringiensis) alone and combined with an aeration system (OXI-FUCH). Controlled experiments simulated storage conditions, where emissions of ammonia, methane, and carbon dioxide were measured. By analyzing the results statistically, the treatment with HIPO-PURÍN demonstrated a significant reduction in CH₄ emissions by 67% and CO₂ emissions by 60% with the use of biological additives, which was increased to 99% and 87%, respectively, when combined with OXI-FUCH aeration, compared to untreated slurry. Ammonia emissions were substantially reduced by 90% with biological additives alone and by 76% when combined with aeration. The study was driven by the need to develop sustainable solutions for livestock waste management, particularly in reducing emissions from pig slurry. It introduces techniques that significantly lower greenhouse gases, aligning with circular economy goals and setting a new standard for sustainable agriculture. Furthermore, there is a need to validate that farmers can independently manage pig slurry using simple and effective treatments techniques with profound environmental benefits, encouraging broader adoption of climate-conscious practices. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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14 pages, 5215 KiB

Open AccessArticle

Enhancing Swine Wastewater Treatment: A Sustainable and Systematic Approach through Optimized Chemical Oxygen Demand/Sulfate Mass Ratio in Attached-Growth Anaerobic Bioreactor

by Mehdi Lamssali, Shobha Mantripragada, Dongyang Deng and Lifeng Zhang

Environments 2024, 11(8), 162; https://doi.org/10.3390/environments11080162 - 1 Aug 2024

Viewed by 1170

Abstract

The swine industry generates millions of gallons (thousands of cubic meters) of wastewater every day, posing significant environmental risk due to high concentrations of organics and nutrients. This study aims to investigate the effectiveness of attached-growth anaerobic bioreactors for treating swine wastewater by [...] Read more.

The swine industry generates millions of gallons (thousands of cubic meters) of wastewater every day, posing significant environmental risk due to high concentrations of organics and nutrients. This study aims to investigate the effectiveness of attached-growth anaerobic bioreactors for treating swine wastewater by utilizing sulfate-reducing bacteria, focusing on the impact of chemical oxygen demand (COD)/sulfate mass ratios on organics degradation. A series of lab-scale anaerobic bioreactors were employed to treat swine wastewater for a 14-day period. The study evaluated changes in pH, acidity, alkalinity, COD, sulfate, and various nutrients along with total suspended solids (TSS) and volatile suspended solids (VSS) before and after treatment. At a COD/sulfate mass ratio of 2:1, the bioreactors achieved optimum removal efficiencies of 80% for TSS, 83% for VSS, 86–88% for COD, 82–87% for sulfate, 73% for sulfide, and 73% for sulfite. The nutrient removal efficiency was 67% for nitrate and 72% for nitrite. The acidity and alkalinity were effectively controlled, with alkalinity values reaching up to 2161 ± 92.5 mg/L and pH within the range of 7–7.24. The findings demonstrated that anaerobic bioreactor at a COD/sulfate mass ratio of 2:1 significantly enhanced the degradation of organic matter coupling with sulfate reduction in swine wastewater, providing an efficient and sustainable treatment method. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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25 pages, 2846 KiB

Open AccessArticle

Small Decentralized Technologies for High-Strength Wastewater Treatment and Reuse in Arid and Semi-Arid Regions

by Khaja Zillur Rahman, Shamsa Al Saadi, Mohamed Al Rawahi, Manfred van Afferden, Katy Bernhard, Jan Friesen and Roland A. Müller

Environments 2024, 11(7), 142; https://doi.org/10.3390/environments11070142 - 5 Jul 2024

Viewed by 1187

Abstract

Rural and semi-urban areas in arid/semi-arid regions are facing severe water scarcity and a series of environmental challenges nowadays, specifically due to rapid urbanization and economic development, climate change, population growth, increasing water demand, influxes of refugees caused by war and regional political [...] Read more.

Rural and semi-urban areas in arid/semi-arid regions are facing severe water scarcity and a series of environmental challenges nowadays, specifically due to rapid urbanization and economic development, climate change, population growth, increasing water demand, influxes of refugees caused by war and regional political conflict, etc. To solve the emerging problems, the safe reuse of treated wastewater in agriculture can provide an additional water resource for countries with high water scarcity. The aim of this study was to investigate the treatment performance and effectiveness of small decentralized wastewater treatment (DWWT) technologies treating high-strength wastewater with concentrations far beyond the European Union testing ranges of parameters such as five-day biochemical oxygen demand (BOD₅ > 500 mg/L), chemical oxygen demand (COD > 1000 mg/L), or total suspended solids (TSS > 700 mg/L). Four (4) commercially available DWWT technologies with a design capacity of 4–8 PE (population equivalent) were selected and operated with various wastewater compositions in Leipzig, Germany. The technologies were (i) the moving bed biofilm reactor (MBBR), (ii) the sequencing batch reactor (SBR), (iii) the membrane bioreactor (MBR) and (iv) the aerated vertical-flow constructed wetland (AVFCW). This study results clearly demonstrated that the EU-certified small DWWT technologies are quite capable of treating high-strength wastewater and can provide high-quality treated water for safe reuse in rural communities of arid and semi-arid regions. During operation with high-strength wastewater with a mean inflow BOD₅, COD and TSS concentrations of 1532 ± 478, 2547 ± 830 and 546 ± 176 mg/L, a low mean BOD₅ (<10 mg/L), COD (<70 mg/L) and TSS (<15 mg/L) in the outflow of the four systems showed removal efficiency of BOD₅ (>99%), COD (>97%) and TSS (>97%), and met the maximum allowable limit value of water quality class A for reuse in agriculture according to Jordanian and Omani standard. The MBR showed almost a complete removal of Escherichia coli (E. coli) in a range of 6.1–6.9-log removal in the outflow during all three experimental phases and performed best for BOD₅, COD, TSS and pathogen removal when treating high-strength wastewater if properly maintained to prevent potential fouling and clogging of the membrane. Before the final permitting process, long-term monitoring under local temperature and climatic conditions as well as guidelines based on local needs (e.g., in Jordan, Oman, etc.) should be developed to guarantee a minimum level of performance standards of such small DWWT technologies and requirements for operation and maintenance (O&M). Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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9 pages, 2586 KiB

Open AccessCommunication

TiO₂-Coated Meltblown Nonwoven Fabrics Prepared via Atomic Layer Deposition for the Inactivation of E. coli as a Model Photocatalytic Drinking Water Treatment System

by Alexander G. Aragon, Jaime A. Cárdenas Sánchez, Carlos Zimeri, Eunkyoung Shim, Xiaomeng Fang and Kyana R. L. Young

Environments 2024, 11(5), 92; https://doi.org/10.3390/environments11050092 - 30 Apr 2024

Viewed by 1908

Abstract

The controlled manufacturing of semiconductor photocatalysts is crucial to their development for drinking water treatment. In this study, TiO₂-coated meltblown nonwoven fabrics prepared via Atomic Layer Deposition (ALD) are applied for the inactivation of Escherichia coli (E. coli). It [...] Read more.

The controlled manufacturing of semiconductor photocatalysts is crucial to their development for drinking water treatment. In this study, TiO₂-coated meltblown nonwoven fabrics prepared via Atomic Layer Deposition (ALD) are applied for the inactivation of Escherichia coli (E. coli). It is observed that in the presence of an ultraviolet light-emitting diode (UV-LED) light source (255 nm), 1.35 log E. coli inactivation is achieved. However, exposure to catalyst-coated fabrics in addition to the light source resulted in >4 log E. coli inactivation, suggesting a much higher rate of hydroxyl radical formation on the surface, leading to cell death. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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34 pages, 3225 KiB

Open AccessArticle

Plant-Wide Models for Optimizing the Operation and Maintenance of BTEX-Contaminated Wastewater Treatment and Reuse

by Dániel Bencsik, Tanush Wadhawan, Ferenc Házi and Tamás Karches

Environments 2024, 11(5), 88; https://doi.org/10.3390/environments11050088 - 25 Apr 2024

Cited by 1 | Viewed by 2300

Abstract

Benzene, toluene, ethylbenzene and xylenes, collectively known as BTEX compounds, are significant emerging contaminants in municipal wastewater. Stricter effluent quality regulations necessitate their removal, especially with concerns about organic micropollutant concentrations. Water scarcity further underscores the need for wastewater treatment to ensure safe [...] Read more.

Benzene, toluene, ethylbenzene and xylenes, collectively known as BTEX compounds, are significant emerging contaminants in municipal wastewater. Stricter effluent quality regulations necessitate their removal, especially with concerns about organic micropollutant concentrations. Water scarcity further underscores the need for wastewater treatment to ensure safe agricultural or drinking water supplies. Although biological treatment partially reduces BTEX levels through processes like biodegradation and sorption, additional purification using physico-chemical methods is crucial for substantial reduction. This paper aims to outline plant-wide simulation methods for treating BTEX-contaminated sewage and facilitating reuse, adhering to IWA Good Modelling Practice Guidelines. The model, built upon the MiniSumo process model, incorporates equations detailing BTEX metabolism and removal kinetics, informed by an extensive literature review. Using a variant of the Benchmark Simulation Model with granular activated carbon for water reuse, the study examines strategies for improving effluent quality and minimizing operational costs. These strategies include adjusting the sludge retention time and airflow to enhance BTEX degradation and stripping, respectively, and comparing maintenance approaches for the GAC tower. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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21 pages, 4259 KiB

Open AccessArticle

BioWin Modeling of CalPrex Phosphorus Recovery from Wastewater Predicts Substantial Nuisance Struvite Reduction

by Donald Vineyard, K.G. Karthikeyan and Phillip Barak

Environments 2024, 11(3), 48; https://doi.org/10.3390/environments11030048 - 29 Feb 2024

Cited by 2 | Viewed by 2153

Abstract

The wastewater treatment industry could benefit from new technologies for the removal and recovery of phosphorus (P). The CalPrex precipitation reactor has the potential to recover P in a readily land-applicable form by treating organic acid digestate with calcium hydroxide to produce brushite. [...] Read more.

The wastewater treatment industry could benefit from new technologies for the removal and recovery of phosphorus (P). The CalPrex precipitation reactor has the potential to recover P in a readily land-applicable form by treating organic acid digestate with calcium hydroxide to produce brushite. Using data from a pilot-scale reactor at the local Nine Springs Wastewater Treatment Plant in Madison, WI, we modified the plant’s BioWin configuration using BioWin 6.2 to model the CalPrex technology and estimate performance under a variety of conditions. We produced dose/response curves for a range of possible lime dosages to estimate the impact of reagent dosage on the quantity and composition of precipitate produced by the CalPrex reactor and characterize the effects on downstream anaerobic digester performance. CalPrex was found to capture 46% of the plant’s influent P, reducing nuisance struvite precipitates by 57% and biosolid sludge production by 14%. The CalPrex module was also tested in two predesigned plant configurations in the BioWin cabinet with the intention of testing applicability to other configurations and searching for the impacts of CalPrex on treatment train performance. This is the first work simulating a full-scale implementation of CalPrex and the first to model interactions of CalPrex with other treatment processes. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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13 pages, 4330 KiB

Open AccessArticle

Statistical Characterization of Full-Scale Thermophilic Biological Systems to Inform Process Optimization

by Maria Cristina Collivignarelli, Stefano Bellazzi, Francesca Maria Caccamo, Marco Sordi, Barbara Crotti, Alessandro Abbà and Marco Baldi

Environments 2024, 11(2), 36; https://doi.org/10.3390/environments11020036 - 17 Feb 2024

Cited by 1 | Viewed by 1833

Abstract

This paper focuses on using a novel approach to assess the statistical variability of management data from an aerobic thermophilic biological plant (AWTP) utilizing a fluidized bed biological reactor. A proper statistical characterization of full-scale thermophilic biological systems, in fact, may inform process [...] Read more.

This paper focuses on using a novel approach to assess the statistical variability of management data from an aerobic thermophilic biological plant (AWTP) utilizing a fluidized bed biological reactor. A proper statistical characterization of full-scale thermophilic biological systems, in fact, may inform process optimization in the light of a future automation of treatment plants. We present a case study that spans the period from 2018 to 2023 and encompasses various high-strength aqueous waste (AW) in continuous mode. Key aspects of the proposed analytical approach include: (i) utilizing advanced descriptive statistics, such as violin graphs, to depict the variability of monitored parameters over five years; (ii) conducting correlation analyses (Spearman and Pearson correlation matrices) specifically focusing on nitrogenous forms within the AW; (iii) applying multivariate statistical analysis to assess the correlation between pollutants released and the plant’s energy and oxygen consumption; and (iv) reconstructing parameter trends by considering periodic and random components, thus enhancing the understanding of the system’s behavior over time. The findings presented in this paper offer valuable insights into the performance and optimization of AWTPs, potentially leading to a proper planning of the loads and consequent feeding of the plants. If properly enacted, our approach may provide a significant contribution to the field of aqueous waste management. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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19 pages, 2633 KiB

Open AccessFeature PaperArticle

Improving BioWin Modeling of Phosphorus Solubilization in Acid-Phase Digesters

by Donald Vineyard, K.G. Karthikeyan, Christy Davidson and Phillip Barak

Environments 2024, 11(2), 31; https://doi.org/10.3390/environments11020031 - 3 Feb 2024

Cited by 2 | Viewed by 2040

Abstract

BioWin 6.0 does not accurately predict phosphorus (P) speciation in acidogenic anaerobic digesters under default kinetics characterization and parameterization. The accurate modeling of acid-phase digestion is needed to predict the performance of novel nutrient recovery technologies that act on these digester effluents. The [...] Read more.

BioWin 6.0 does not accurately predict phosphorus (P) speciation in acidogenic anaerobic digesters under default kinetics characterization and parameterization. The accurate modeling of acid-phase digestion is needed to predict the performance of novel nutrient recovery technologies that act on these digester effluents. The main thrust of this work was to identify and correct the causes of inaccurate P partitioning and precipitation within BioWin models of acid-phase digestion reactors. A BioWin configuration including an organic acid digester was parameterized and recalibrated based on the known traits of acid-phase digestion and then validated against a full-scale digester in a municipal wastewater treatment plant. This digester, with pH 5.14 and 61–74% solubilized P, was predicted by BioWin default parameters to have only 27% soluble P and a net formation of P precipitates. Corrections to the polyphosphate-accumulating organism decay, endogenous product decay, hydrolysis rate, and brushite behavior resulted in 67% solubilization with no precipitate formation. Cabinet configurations showed similar behavior when modified to include an acid-phase digester under default parameters, but predictions were similarly amended by our parameter changes. This improved modeling technique should allow operators to effectively characterize acid digesters for their own treatment trains and allow engineers to predict the performance of novel nutrient recovery technologies acting on acidogenic digest. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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22 pages, 2901 KiB

Open AccessArticle

Assessment of the Impact of War on Concentrations of Pollutants and Heavy Metals and Their Seasonal Variations in Water and Sediments of the Tigris River in Mosul/Iraq

by Zena Altahaan and Daniel Dobslaw

Environments 2024, 11(1), 10; https://doi.org/10.3390/environments11010010 - 3 Jan 2024

Cited by 2 | Viewed by 2528

Abstract

The war-related contamination of water and sediment of the Tigris River within the urban area of Mosul leads to seasonally independent exceedances of the WHO limit values for Cd, Pb, Cr, and Ni in water and sediments. Furthermore, exceedances consistently occur for conductivity, [...] Read more.

The war-related contamination of water and sediment of the Tigris River within the urban area of Mosul leads to seasonally independent exceedances of the WHO limit values for Cd, Pb, Cr, and Ni in water and sediments. Furthermore, exceedances consistently occur for conductivity,

{P O}_{4}^{3 -}

, and

{S O}_{4}^{2 -}

, as well as sporadically for salinity and COD in water samples, and consistently for salinity in sediment samples, highlighting the direct impact of war (ammunition, ignition of sulfur fields), as well as indirect effects (destroyed wastewater infrastructure). Conflict-related emissions from the former conflict zone (S5–S7) are highlighted by the sudden increases in load from S4 to S5, although partially masked by the discharge of highly polluted water from the Khosr River (between S3 and S4). Due to the sorption of sediments and the presumed wind-borne discharge of highly polluted particles into the Tigris River, sediments at S10 on the southern edge of Mosul showed the highest pollutant loads. Significant statistical differences were observed through T-test analyses for E.C., TDS, salinity, COD,

{P O}_{4}^{3 -}

,

{N O}_{3}^{-}

,

{S O}_{4}^{2 -}

, Cd, Pb, Zn, Cr, and Ni for water samples, as well as salinity, Cd, Pb, Zn, and Cr for the sediment samples for seasonal comparison. Since the percentage difference of water samples at S4–S7 is smaller than upstream and downstream, contaminant input is not limited to rainwater but also occurs via the year-round infiltration of highly polluted wastewater from the surrounding valleys or suburban areas, as well as presumably polluted groundwater or windblown particulate input. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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21 pages, 6523 KiB

Open AccessArticle

Bacteria and Yeasts Isolated from the Environment in Biodegradation of PS and PVC Microplastics: Screening and Treatment Optimization

by Kristina Bule Možar, Martina Miloloža, Viktorija Martinjak, Matija Cvetnić, Vesna Ocelić Bulatović, Vilko Mandić, Arijeta Bafti, Šime Ukić, Dajana Kučić Grgić and Tomislav Bolanča

Environments 2023, 10(12), 207; https://doi.org/10.3390/environments10120207 - 29 Nov 2023

Cited by 2 | Viewed by 4232

Abstract

Biodegradation is the most environmentally friendly and, at the same time, economically acceptable approach to removing various pollutants from the environment. However, its efficiency in removing microplastics (MPs) from the environment is generally low. The successful biodegradation of MPs requires microorganisms capable of [...] Read more.

Biodegradation is the most environmentally friendly and, at the same time, economically acceptable approach to removing various pollutants from the environment. However, its efficiency in removing microplastics (MPs) from the environment is generally low. The successful biodegradation of MPs requires microorganisms capable of producing enzymes that degrade MP polymers into compounds that the microorganisms can use as a source of carbon and energy. Therefore, scientists are screening and characterizing microorganisms that can degrade MPs more efficiently. These microorganisms are often isolated from sites contaminated with MPs because the microorganisms living there are adapted to these pollutants and should be able to better degrade MPs. In this study, five bacterial strains and five yeast strains were isolated from various environmental samples including activated sludge, compost, river sediment, and biowaste. Among them, screening was performed for bacteria and yeasts with the highest potential for the biodegradation of polystyrene (PS) and polyvinyl chloride (PVC) MPs, and the bacterium Delftia acidovorans and the yeast Candida parapsilosis were identified as the best candidates. Optimization of biodegradation of the selected MPs by each of these two microorganisms was performed, focusing on the influence of cell density, agitation speed and pH of the medium. It was found that within the selected experimental ranges, high values of cell density, low agitation speed, and a slightly basic medium favored the biodegradation of PS and PVC MPs by Delftia acidovorans. In the case of Candida parapsilosis, favorable conditions also included high cell density followed by a slightly higher, but not maximum, agitation speed and a weakly acidic medium. Broad spectroscopic and imaging methods indicated that Delftia acidovorans and Candida parapsilosis better adapt to PVC MPs to use it as a carbon and energy source. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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14 pages, 2200 KiB

Open AccessArticle

The Effect of Foam-Recycle on Ammonium Removal by Aerobic Denitrification Using Alcaligenes faecalis No. 4

by Kwanyong Lee and Hung-Soo Joo

Environments 2023, 10(10), 184; https://doi.org/10.3390/environments10100184 - 18 Oct 2023

Viewed by 1711

Abstract

Aerobic denitrifier Alcaligenes faecalis No. 4 removes ammonium-nitrogen to nitrogen gas via denitrification in a single aerobic condition. In our previous studies, factors such as ammonium removal rate, denitrification ratio, and cell growth were tested in various conditions. The removal pathway from ammonium [...] Read more.

Aerobic denitrifier Alcaligenes faecalis No. 4 removes ammonium-nitrogen to nitrogen gas via denitrification in a single aerobic condition. In our previous studies, factors such as ammonium removal rate, denitrification ratio, and cell growth were tested in various conditions. The removal pathway from ammonium to nitrogen gas still needs to be determined in detail. To clarify this pathway of Alcaligenes faecalis No. 4, we in this study investigated the effects of several factors on ammonium removal, such as foam-recycle, initial pH, initial ammonium concentration, and airflow rate. Denitrification ratio was improved by up to 23% through foam-recycle. The improvement of the denitrification ratio was resulted by the higher enzyme activity of hydroxylamine oxidoreductase (HAO) in the produced foam, which was about 28 times higher than that in the culture broth (i.e., without foam-recycle). The stripped ammonia was significantly high (above pH 9). The initial ammonium concentration and airflow rate also influenced the denitrification ratio. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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14 pages, 2466 KiB

Open AccessArticle

Removal of Cadmium and Lead from Synthetic Wastewater Using Galdieria sulphuraria

by Hari Lal Kharel, Ina Shrestha, Melissa Tan and Thinesh Selvaratnam

Environments 2023, 10(10), 174; https://doi.org/10.3390/environments10100174 - 4 Oct 2023

Cited by 7 | Viewed by 2405

Abstract

The strain of red microalgae Galdieria sulphuraria CCMEE 5587.1 was evaluated in a controlled laboratory environment for its ability to tolerate and remove two heavy metal (HM) ions: cadmium [Cd(II)] and lead [Pb(II)] in aqueous solutions as a single metal species. Various concentrations [...] Read more.

The strain of red microalgae Galdieria sulphuraria CCMEE 5587.1 was evaluated in a controlled laboratory environment for its ability to tolerate and remove two heavy metal (HM) ions: cadmium [Cd(II)] and lead [Pb(II)] in aqueous solutions as a single metal species. Various concentrations (0 mg L⁻¹ to 5 mg L⁻¹) of Cd and Pb ions were added to the Cyanidium medium in which the chosen microalgae strain G. sulphuraria CCMEE 5587.1 was grown at an acidic pH of 2.5. The effectiveness of G. sulphuraria CCMEE 5587.1 in tolerating and removing these two metal ions was measured by analyzing its growth profile, growth rate, nutrient removal, and metal ion removal efficiency. The growth of G. sulphuraria CCMEE 5587.1 was inhibited during the initial days of incubation, and the growth rate decreased when the HM concentration in the media was increased. Nutrient removal in the HM-containing media is comparable to that in the control media at low metal concentrations but decreases as the metal concentration rises. G. sulphuraria CCMEE 5587.1 has the highest removal efficiency for Cd and Pb in a medium containing 2.5 mg L⁻¹ of metal ions, which is 49.80% and 25.10%, and the corresponding sorption capacity is 1.45 mg g⁻¹ and 0.53 mg g⁻¹ of dry biomass, respectively. These findings suggest that G. sulphuraria CCMEE 5587.1 holds potential as a viable bioremediation solution for extracting Cd and Pb from wastewater, alongside its capacity to remove nutrients concurrently. The study underscores the dual advantage of G. sulphuraria CCMEE 5587.1, making it a promising candidate for addressing heavy metal pollution in wastewater treatment processes. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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17 pages, 3747 KiB

Open AccessArticle

Magnesium/Silica/Lanthanum@Activated Carbon for the Remediation of As(III) from Water

by Athanasia K. Tolkou and George Z. Kyzas

Environments 2023, 10(10), 171; https://doi.org/10.3390/environments10100171 - 3 Oct 2023

Cited by 3 | Viewed by 1702

Abstract

In this study, activated carbon was suitably modified with Mg/Si/La and its effectiveness in removing As(III) was investigated. The structure of Magnesium/Silica/Lanthamum@Activated Carbon (Mg-Si-La@AC) was fully characterized and several parameters, such the dosage, pH, contact time, and initial As(III) concentration, were studied. Thus, [...] Read more.

In this study, activated carbon was suitably modified with Mg/Si/La and its effectiveness in removing As(III) was investigated. The structure of Magnesium/Silica/Lanthamum@Activated Carbon (Mg-Si-La@AC) was fully characterized and several parameters, such the dosage, pH, contact time, and initial As(III) concentration, were studied. Thus, the BET surface area, total pore volume, and micropore volume of Mg-Si-La@AC were measured to be 271.46 m²/g, 0.006 cm³/g and 0.52 cm³/g, respectively. The results showed that the optimal condition for the reduction in As(III) from the initial concentration of 100 μg/L to below 10 μg/L was the addition of 1.5 g/L of adsorbent at pH 7.0. Furthermore, 4 h of contact time showed >90% removal. The Langmuir isotherm model was best fitted to the experimental results, exhibiting a maximum adsorption capacity of 322 μg/g, and the PSO kinetic model was found to be the most applicable according to kinetics. Consecutive regeneration studies were carried out and the results showed that the adsorbent was effectively used up to four cycles. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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16 pages, 3146 KiB

Open AccessFeature PaperArticle

Heterogeneous Activation of Persulfate by Nickel Oxide/Strontium Carbonate Composite for Sulfamethoxazole Degradation in Water

by Despoina Jessica Skempi, Konstantinos Kouvelis, Athanasia Petala, Georgios Bampos and Zacharias Frontistis

Environments 2023, 10(8), 147; https://doi.org/10.3390/environments10080147 - 18 Aug 2023

Viewed by 1910

Abstract

The development of efficient heterogeneous persulfate activators is one of the main research topics in the wastewater treatment area. The present work deals with the heterogeneous activation of sodium persulfate (SPS) using nickel oxide/strontium carbonate (NiO/SrCO₃) for the degradation of sulfamethoxazole [...] Read more.

The development of efficient heterogeneous persulfate activators is one of the main research topics in the wastewater treatment area. The present work deals with the heterogeneous activation of sodium persulfate (SPS) using nickel oxide/strontium carbonate (NiO/SrCO₃) for the degradation of sulfamethoxazole (SMX), a representative compound from the group of antibiotics. Results showed that NiO/SrCO₃ exhibited high performance towards the activation of SPS, leading to SMX elimination in brief time spans. The impact of SPS (25–100 mg/L), NiO/SrCO₃ (50–250 mg/L), and SMX (0.25–3.00 mg/L) concentration, and initial pH on the decomposition of SMX was further examined. Experiments were also conducted in real matrices such as secondary effluent and bottled water, revealing the existence of retarding phenomena compared to ultrapure water. This behavior was further investigated with the addition of bicarbonates, chlorides, or humic acid in ultrapure water. It was found that organic matter significantly hampered SMX removal. The role of the main radicals (hydroxyl and sulfate radicals) was determined using appropriate radical traps (methanol and tert-butanol). These quenching experiments combined with the conducted electrochemical measurements revealed that both a radical and a non-radical mechanism contribute to the decomposition of SMX. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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13 pages, 2182 KiB

Open AccessArticle

Analysis of Siphonic Roof Drainage Systems with EPANET

by Gonzalo López-Patiño, Pedro L. Iglesias-Rey, Francisco Javier Martínez-Solano and Vicente S. Fuertes-Miquel

Environments 2023, 10(7), 123; https://doi.org/10.3390/environments10070123 - 17 Jul 2023

Viewed by 2255

Abstract

Analysis and design of siphonic roof drainage systems are usually performed with specific software developed by the system’s manufacturers. An experimental study was carried out to verify if a general software for the analysis of hydraulic pressurized pipe networks can be used to [...] Read more.

Analysis and design of siphonic roof drainage systems are usually performed with specific software developed by the system’s manufacturers. An experimental study was carried out to verify if a general software for the analysis of hydraulic pressurized pipe networks can be used to analyze a siphonic roof drainage system. A test model was built and tests were conducted to compare the prototype results with simulation runs in EPANET. A new EPANET data model was developed to overcome software limitations for the siphonic drainage systems analysis. Considering the results, less than 5% of average error was observed between the measures in the real test model and the simulation results, which can be attributed to measurement error. To validate the EPANET data model, it was compared with a specific software that analyzes siphonic roof drainage systems. It can be concluded that EPANET is a software that can be used to analyze and, therefore, to design, siphonic roof drainage systems in buildings. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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Review

Jump to: Editorial, Research

19 pages, 1462 KiB

Open AccessReview

Water Reuse: A Comprehensive Review

by Fivos Florides, Maria Giannakoudi, Giorgos Ioannou, Despoina Lazaridou, Elissavet Lamprinidou, Nikolaos Loukoutos, Maria Spyridou, Eleftherios Tosounidis, Maria Xanthopoulou and Ioannis A. Katsoyiannis

Environments 2024, 11(4), 81; https://doi.org/10.3390/environments11040081 - 13 Apr 2024

Cited by 3 | Viewed by 4360

Abstract

Water scarcity has emerged as a pressing global concern, driven by population growth, urbanization, and climate change. As freshwater resources dwindle, the imperative for water reuse becomes increasingly apparent. Reusing water presents a sustainable solution to mitigate scarcity, offering a way to maximize [...] Read more.

Water scarcity has emerged as a pressing global concern, driven by population growth, urbanization, and climate change. As freshwater resources dwindle, the imperative for water reuse becomes increasingly apparent. Reusing water presents a sustainable solution to mitigate scarcity, offering a way to maximize the efficiency of available resources. This review delves into the multifaceted landscape of water consumption and reuse, aiming to provide a comprehensive analysis and understanding of this critical issue. It explores the diverse implications of unregulated water consumption, spanning from its impacts on household routines to its profound influence on economic activities. Additionally, it scrutinizes the legislative framework surrounding water usage, shedding light on the policies and regulations in place. Furthermore, the review investigates the current status of water reuse practices in Europe, delving into various methods of water recovery. Finally, it examines public perceptions and attitudes toward recycled water, offering insights into the societal outlook on this increasingly vital aspect of water management. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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Open AccessReview

The Use of Constructed Wetlands to Treat Effluents for Water Reuse

by Sandro Xavier de Campos and Manuel Soto

Environments 2024, 11(2), 35; https://doi.org/10.3390/environments11020035 - 14 Feb 2024

Cited by 10 | Viewed by 3452

Abstract

Constructed wetland systems (CWs) are technologies based on natural processes for pollutant removal and have been more and more accepted in the treatment of domestic and industrial wastewater. This study selected and reviewed articles published in the last six years involving the use [...] Read more.

Constructed wetland systems (CWs) are technologies based on natural processes for pollutant removal and have been more and more accepted in the treatment of domestic and industrial wastewater. This study selected and reviewed articles published in the last six years involving the use of different CW conceptions and their association with other technologies to treat different effluents and evaluated the quality of the effluents for reuse. From a total of 81 articles reviewed, 41 presented quantitative data on the quality of the treated effluent in relation to the requirements of the reuse regulations in different countries of the world. CWs can be used to treat gray water and runoff water, as well as domestic and industrial effluents with the purpose of reusing them. While studies on the removal of new chemical and biological substances have increased, challenges are associated with the optimization of CWs to improve the removal of pathogens and new contaminants that have appeared more recently. The potential for the improved removal of those pollutants lies in the association of CWs with conventional and advanced technologies in new configurations. We concluded that studies related to the reuse of effluents using CWs are in constant evolution, with experiments at different scales. The perspectives are promising since CWs are an economic, environmentally friendly, and efficient technology to help in the mitigation of water scarcity problems imposed by climate changes. Full article

(This article belongs to the Special Issue Advanced Technologies of Water and Wastewater Treatment)

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