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18 pages, 6807 KiB

Open AccessArticle

Study on Properties of Micro-Nano Magnetic Composite Prepared by Mechanochemical Method of NdFeB Secondary Waste and Removal of As (V) from Mine Water

by Xiujuan Feng and Yicheng Rao

Water 2024, 16(9), 1234; https://doi.org/10.3390/w16091234 - 25 Apr 2024

Viewed by 419

Abstract

The secondary waste produced by NdFeB waste after rare earth recycling, with an annual output of more than tens of thousands of tons, is the largest solid waste emission source in the rare earth industry, and long-term storage causes land resource occupation and [...] Read more.

The secondary waste produced by NdFeB waste after rare earth recycling, with an annual output of more than tens of thousands of tons, is the largest solid waste emission source in the rare earth industry, and long-term storage causes land resource occupation and environmental pollution. Arsenic-containing mine wastewater has serious harm, wide distribution, and long duration of pollution. In this study, the mechanical ball milling method was used to activate NdFeB secondary waste to prepare micro-nano magnetic composite materials, the main components of which are Fe₂O₃, Fe₃O₄, and C. Under mechanical mechanochemical action, the particles are more dispersed, the particle size decreases, the specific surface area increases significantly, the crystal structure changes to amorphous structure, the degree of amorphous shape increases, and the content of Fe-OH increases. Applied to the treatment of As (V) in simulated mine water, it was found that the removal of As (V) by this material was mainly based on chemisorption and monolayer adsorption, and the maximum adsorption amount reached 10.477 mg/g. Zeta, FT-IT, and XPS characterization confirmed that the removal of As (V) was a coordination exchange reaction between the material and As (V) to form an inner sphere complex. The removal rate of As (V) decreased from 94.33% to 73.56% when the initial concentration of solution was 10 mg/L, pH value was 3.0, and material dosage was 1 g/L after 5 times of regrowth. This study provides a new way for the application of NdFeB secondary waste, which has low cost, green environmental protection, and wide application prospects. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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24 pages, 3047 KiB

Open AccessArticle

Evaluation of the Characteristics of Pollutant Discharge in Tomato Hydroponic Wastewater (HWW) for Sustainable Water Management in Korea

by Jinkwan Son

Water 2024, 16(5), 720; https://doi.org/10.3390/w16050720 - 28 Feb 2024

Cited by 1 | Viewed by 707

Abstract

In South Korea, the use of hydroponic cultivation has been on the rise. However, this system produces a large amount of wastewater. In this study, the amount of wastewater generated by hydroponic tomato cultivation is identified, and a management plan is proposed. Based [...] Read more.

In South Korea, the use of hydroponic cultivation has been on the rise. However, this system produces a large amount of wastewater. In this study, the amount of wastewater generated by hydroponic tomato cultivation is identified, and a management plan is proposed. Based on the analysis of 103 tomato HWW samples, it was found that the electrical conductivity (EC) was 4.25 ± 1.01 dS/m, the nitrogen (N) content was 411.21 ± 122.64 mg/L, and the phosphorus (P) content was 47.74 mg/L, which caused eutrophication. Therefore, agricultural reuse and HWW treatment were proposed. Regarding the annual HWW load, 1 ha of hydroponics discharges 964.26 kg/ha of N, 111.95 of P, 937.46 of K, 795.14 of Ca, 313.83 of Mg, and 405.40 of S. The trace elements were heavy metals, which were calculated as Fe—4.03, Mn—0.77, Zn—1.08, B—2.25, Cu—0.38, and Mo—0.05 kg/ha. Since wastewater is a national source of drinking water, it needs to be collected and treated. Inter-item correlation analysis showed that most of the fertilizer components were correlated with the EC concentrations. This study can be used to determine the concentrations required for agricultural reuse and to determine the treatment capacity in HWW management. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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15 pages, 3637 KiB

Open AccessArticle

A Newly Isolated Rhodococcus sp. S2 from Landfill Leachate Capable of Heterotrophic Nitrification and Aerobic Denitrification

by Xianglan Chen, Shuangfei Li, Wenxuan Zhang, Shaofeng Li, Yurong Gu and Liao Ouyang

Water 2024, 16(3), 431; https://doi.org/10.3390/w16030431 - 29 Jan 2024

Viewed by 866

Abstract

Nitrogen removal through heterotrophic nitrification–aerobic denitrification (HN–AD) has been acknowledged as one of the most efficient and cost-effective nitrogen removal processes. This study involved the isolation of a novel HN–AD bacterium (Rhodococcus sp. S2) from landfill leachate. Rhodococcus sp. S2 exhibited high [...] Read more.

Nitrogen removal through heterotrophic nitrification–aerobic denitrification (HN–AD) has been acknowledged as one of the most efficient and cost-effective nitrogen removal processes. This study involved the isolation of a novel HN–AD bacterium (Rhodococcus sp. S2) from landfill leachate. Rhodococcus sp. S2 exhibited high nitrogen removal performance under aerobic conditions without the accumulation of nitrite as an intermediate. The maximum removal efficiencies for NH₄⁺-N, NO₂⁻-N, and NO₃⁻-N were found to be 99.97 ± 0.3%, 99.79 ± 0.14%, and 83.53 ± 0.31%, respectively. Additionally, Rhodococcus sp. S2 demonstrated simultaneous nitrifying and denitrifying capabilities and showed a preference for utilizing NH₄⁺-N in mixed nitrogen sources. The optimal nitrogen removal conditions for Rhodococcus sp. S2 were as follows: sodium acetate as a carbon source, a C/N ratio of 16, a shaking speed of 200 rpm, a pH of 9, and a temperature of 35 °C. Genome sequencing results revealed the presence of nitrate reductases (NarG), nitrate oxidoreductase (NxrA), and nitrite reductase (NirBD) in Rhodococcus sp. S2, providing further evidence of its HN–AD capability. In treating raw wastewater under the aforementioned experimental conditions, S2 achieved a maximum TN removal efficiency of 57.16 ± 0.52% with the addition of sodium acetate as a carbon source. These results suggest that Rhodococcus sp. S2 might be a promising candidate for wastewater nitrogen removal. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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25 pages, 12402 KiB

Open AccessArticle

The Impact of Various Types of Cultivation on Stream Water Quality in Central Poland

by Krzysztof Stępniewski, Michał Karger and Maksym Łaszewski

Water 2024, 16(1), 50; https://doi.org/10.3390/w16010050 - 22 Dec 2023

Viewed by 1676

Abstract

Agricultural practices have a significant impact on stream water quality in rural landscapes; however, there is still little empirical evidence of how different types of cultivation alter the hydrochemistry of running water. Thus, the current study explored the spatial dynamics of selected ion [...] Read more.

Agricultural practices have a significant impact on stream water quality in rural landscapes; however, there is still little empirical evidence of how different types of cultivation alter the hydrochemistry of running water. Thus, the current study explored the spatial dynamics of selected ion concentrations and their land cover dependence in lowland agricultural catchments. From November 2021 to October 2022, water samples were collected from 30 sites located across small tributaries of the rivers Bzura, Pilica, and Radomka for chemical analysis of their NO₃, NO₂, NH₄, Ca, Mg, K, Na, As, Ba, Sr, and V concentrations. The results indicated a clear spatial heterogeneity of water quality, related to lithology and dominant land cover evaluated with the CORINE Land Cover 2018 dataset. Overall, sites representing agricultural land promoted increased concentrations of major and trace elements, while those with pepper cultivation were additionally contaminated with NO₃ and NO₂. The correlation performance for nitrogen compounds was the highest for narrower buffer zones, which was not documented for major and trace elements, which were linked more strongly with land cover at larger scales. Such new insights into the water quality dynamics of lowland agricultural catchments, being a simultaneous reflection of lithology, agricultural practices, and several municipal impacts, have significant implications for appropriate water management in rural landscapes. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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18 pages, 4672 KiB

Open AccessArticle

Application of the Monte-Carlo Method to Assess the Operational Reliability of a Household-Constructed Wetland with Vertical Flow: A Case Study in Poland

by Karolina Migdał, Krzysztof Jóźwiakowski, Wojciech Czekała, Paulina Śliz, Jorge Manuel Rodrigues Tavares and Adelaide Almeida

Water 2023, 15(20), 3693; https://doi.org/10.3390/w15203693 - 23 Oct 2023

Viewed by 1088

Abstract

The objective of this study was to model the operation of a vertical-flow constructed wetland (VF-CW) for domestic wastewater, using Monte-Carlo simulations and selected probability distributions of various random variables. The analysis was based on collected wastewater quality data, including the values of [...] Read more.

The objective of this study was to model the operation of a vertical-flow constructed wetland (VF-CW) for domestic wastewater, using Monte-Carlo simulations and selected probability distributions of various random variables. The analysis was based on collected wastewater quality data, including the values of the pollutant indicators BOD₅ (biochemical oxygen demand), COD_Cr (chemical oxygen demand), and TSS (total suspended solids), in the 2017–2020 period. Anderson–Darling (A–D) statistics were applied to assess the fit of the theoretical distributions to the empirical distributions of the random variables under study. The selection of the best-fitting statistical distributions was determined using the percentage deviation (PBIAS) criterion. Based on the analyses that were performed, the best-fitting statistical distributions for the pollution indicators of the raw wastewater were the generalised extreme value distribution for BOD₅, the Gaussian distribution for COD_Cr, and the log-normal distribution for TSS. For treated effluent, the log-normal distribution was the best fit for BOD₅ and COD_Cr; the semi-normal distribution, for TSS. The new data generated using the Monte-Carlo method allowed the reliability of the VF-CW operation to be assessed by determining the reliability indices, i.e., the average efficiency of the removal of pollutants (η), the technological efficiency index (R), the reliability index (CR), and the risk index of the negative control of the sewage treatment plant operation (Re). The obtained results indicate that only in the case of COD_Cr, the analysed treatment facility may fail to meet the requirements related to the reduction of organic pollutants to the required level, which is evidenced by the values of the indicators CR = 1.10, R = 0.49, and η = 0.82. In addition, the risk index of the negative operation of the facility (Re) assumes a value of 1, which indicates that during the period of its operation, the VF-CW system will not operate with the required efficiency in relation to this indicator. The novelty of this work is the implementation of the indicated mathematical simulation methods for analysing the reliability of the operation of the domestic wastewater treatment facility. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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30 pages, 6890 KiB

Open AccessArticle

Pharmaceuticals Removal by Ozone and Electro-Oxidation in Combination with Biological Treatment

by Francesca Audino, Judith Arboleda, Mira Petrovic, Ricard García Cudinach and Sonia Sanchis Pérez

Water 2023, 15(18), 3180; https://doi.org/10.3390/w15183180 - 6 Sep 2023

Viewed by 1129

Abstract

This study investigated the efficiency of two advanced oxidation processes (AOPs), ozonation (O₃), and electrochemical oxidation (EO), applied individually or in combination, in the removal of contaminants of emerging concern (CECs) contained in hospital wastewaters, focusing on pharmaceuticals. The optimisation of [...] Read more.

This study investigated the efficiency of two advanced oxidation processes (AOPs), ozonation (O₃), and electrochemical oxidation (EO), applied individually or in combination, in the removal of contaminants of emerging concern (CECs) contained in hospital wastewaters, focusing on pharmaceuticals. The optimisation of the single technologies was performed using synthetic wastewater composed of four refractory pharmaceuticals, (carbamazepine-CBZ, lorazepam-LZP, ketoprofen-KTP, 10,11-epoxicarbamazepine-E-CBZ), first alone and then in mixture, in an initial concentration of 1 mg L⁻¹ each. Once the best operational conditions for EO and O₃ were defined, their combination (both simultaneous and sequential) was evaluated for the mixture of the selected pharmaceuticals. The treatment solution that showed the best performance was the simultaneous combination of O₃ and EO. This treatment was validated using real hospital wastewater previously treated through a moving bed biofilm reactor (MBBR), evaluating its viability by testing the toxicity of the final effluent via Vibrio fischeri inhibition tests. The obtained results showed that the simultaneous combination of O₃ and EO as the polishing step after a biological treatment is a very promising solution for hospital wastewater treatment, allowing for obtaining a non-toxic effluent and full degradation of refractory compounds. The disinfection potential of the proposed AOP was also assessed by determining Escherichia coli inactivation potential. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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13 pages, 852 KiB

Open AccessArticle

Possibilities for Anaerobic Digestion of Slaughter Waste and Flotates for Biomethane Production

by Maximilian Philipp, Helene Ackermann, Nesrine Barbana, Jonas Pluschke and Sven Uwe Geißen

Water 2023, 15(10), 1818; https://doi.org/10.3390/w15101818 - 10 May 2023

Cited by 2 | Viewed by 1771

Abstract

Anaerobic digestion for biomethane production is an important tool regarding sustainable energy production. The objective of this study was to investigate the effects of the substrate composition and operating parameters on biomethane production during anaerobic digestion, focusing on the use of flotates and [...] Read more.

Anaerobic digestion for biomethane production is an important tool regarding sustainable energy production. The objective of this study was to investigate the effects of the substrate composition and operating parameters on biomethane production during anaerobic digestion, focusing on the use of flotates and slaughterhouse waste as substrates with a high organic content. A novelty here was the use of a moving bed biofilm reactor (MBBR) with circulation pump for the anaerobic treatment of flotates, slaughter waste (SW), and their mixture. Flotates and waste from slaughterhouses offer a substrate with a high organic content. In this work, it was shown that both substrates provide a high biochemical methane potential (BMP). The highest methane yield was achieved by mixing both substrates. In continuous operation, special challenges arose, due to the high nitrogen and fat content of the substrates. These could be overcome by mixing the substrates and using a circulation pump in the reactor for improved back-mixing. As a result, the highest average methane yield of 0.65 NLCH4·g_{TS eli}⁻¹ was achieved in mesophilic operation at an organic loading rate (OLR) of 4.2 g_TS·L⁻¹·d⁻¹. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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Review

Jump to: Research

34 pages, 1666 KiB

Open AccessReview

Integrated Process of Immediate One-Step Lime Precipitation, Atmospheric Carbonation, Constructed Wetlands, or Adsorption for Industrial Wastewater Treatment: A Review

by Luís Madeira, Fátima Carvalho, Adelaide Almeida and Margarida Ribau Teixeira

Water 2023, 15(22), 3929; https://doi.org/10.3390/w15223929 - 10 Nov 2023

Cited by 1 | Viewed by 1694

Abstract

The transition from the linear economy paradigm to the circular economy in industrial wastewater treatment systems is on the global agenda. The search for new simple, eco-innovative, and low-cost processes for treating industrial wastewater, which can also be used by small and medium-sized [...] Read more.

The transition from the linear economy paradigm to the circular economy in industrial wastewater treatment systems is on the global agenda. The search for new simple, eco-innovative, and low-cost processes for treating industrial wastewater, which can also be used by small and medium-sized industries, has been a constant challenge especially when environmental sustainability is considered. So, a new integrated industrial wastewater treatment system has been developed that includes the immediate one-step lime precipitation process (IOSLM) and atmospheric carbonation (AC), followed by constructed wetlands (CWs) or adsorption. The current review provides an overview of industrial wastewater treatment strategies for high- and low-biodegradable wastewater. A background on functionality, applicability, advantages and disadvantages, operating variables, removal mechanisms, main challenges, and recent advances are carried out for each process that makes up the IOSLM+AC+CW/adsorption integrated system. The prospects of the IOSLM+AC+CW/adsorption integrated system are also discussed. Not neglecting the improvements that still need to be made in the integrated treatment system as well as its application to various types of industrial wastewater, this review highlights that this treatment system is promising in industrial wastewater treatment and consequent by-product recovery. The IOSLM+AC integrated system showed that it can remove high amounts of organic matter, total suspended solids, oils and fats, phosphorus, and ammonium nitrogen from industrial effluents. On the other hand, constructed wetlands/adsorption can be alternatives for refining effluents still containing organic matter and nitrogen that were not possible to remove in the previous steps. Full article

(This article belongs to the Special Issue Water, Wastewater and Waste Management for Sustainable Development)

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