Wastewater Treatment Techniques Research Articles

Artificial intelligence integration in conventional wastewater treatment techniques: techno-economic evaluation, recent progress and its future direction

Artificial intelligence integration in conventional wastewater treatment techniques: techno-economic evaluation, recent progress and its future direction

Advances in Nanoparticles and Nanocomposites for Water and Wastewater Treatment: A Review

Addressing water scarcity and pollution is imperative in tackling global environmental challenges, prompting the exploration of innovative techniques for effective water and wastewater treatment. Nanotechnology presents promising solutions through the customization of nanoparticles and nanocomposites specifically designed for water purification applications. This review delves into recent advancements in nanoparticle-based technologies for water treatment, with a particular focus on their synthesis methodologies, intrinsic properties, and versatile applications. A wide range of nanoparticles, ranging from metal nanoparticles to carbon-based nanomaterials, along with hybrid nanocomposites such as metal/metal oxide-based nanocomposites, polymer-based nanocomposites, and others, were emphasized for eliminating contaminants from water and wastewater matrices. Furthermore, this review elucidates the underlying mechanisms governing pollutant removal processes, encompassing adsorption, catalysis, and membrane filtration, facilitated by nanoparticles. Additionally, it explores the environmental implications and challenges associated with the widespread deployment of nanoparticle-based water-treatment technologies. By amalgamating existing research findings, this review provides valuable insights into the potential of nanoparticles and nanocomposites in mitigating water-related challenges and presents recommendations for future research trajectories and technological advancements in this domain.

Artificial intelligence and machine learning for the optimization of pharmaceutical wastewater treatment systems: a review

AbstractThe access to clean and drinkable water is becoming one of the major health issues because most natural waters are now polluted in the context of rapid industrialization and urbanization. Moreover, most pollutants such as antibiotics escape conventional wastewater treatments and are thus discharged in ecosystems, requiring advanced techniques for wastewater treatment. Here we review the use of artificial intelligence and machine learning to optimize pharmaceutical wastewater treatment systems, with focus on water quality, disinfection, renewable energy, biological treatment, blockchain technology, machine learning algorithms, big data, cyber-physical systems, and automated smart grid power distribution networks. Artificial intelligence allows for monitoring contaminants, facilitating data analysis, diagnosing water quality, easing autonomous decision-making, and predicting process parameters. We discuss advances in technical reliability, energy resources and wastewater management, cyber-resilience, security functionalities, and robust multidimensional performance of automated platform and distributed consortium, and stabilization of abnormal fluctuations in water quality parameters.

Ultrafiltration of anaerobically digested sludge centrate as key process for a further nitrogen recovery process

In a wastewater treatment plant, the centrate generated in the dehydration process of the anaerobically digested sludge has a high potential for nutrients recovery because of its high nutrients concentration (specifically nitrogen and phosphorous). However, the high organic matter and solids content may make difficult its management. Membrane fouling is the most significant challenge limiting the application of membrane techniques for wastewater treatment. Results in this article highlight the potential of conventional filtration followed by ultrafiltration as pretreatment for further nutrients recovery using emerging membrane technologies (as membrane contactor, membrane distillation or forward osmosis). Thus, a conventional filtration (with 1, 5 and 60 μm filters) followed by an ultrafiltration process were tested. The UF membranes studied were two PES membranes (5kDa and 0.01 μm) and one PVDF membranes (100kDa). Results demonstrated that a conventional filtration with a cartridge filter of 60 μm and a subsequent UF process with a 0.01 μm RAY100 membrane (Orelis, France) achieved the best results in terms of the maximum organic matter (66% COD removal) and solids (over 97% suspended solids removal) separation, hardly varying nutrients concentration (13% NH4+ removal). Concerning membrane fouling, FESEM-EDX confirmed salt precipitation on the membrane surface, which has to be controlled to avoid loss of performance.

Investigation of the removal of diclofop methyl herbicide by peroxy electrocoagulation process and kinetic and cost analysis

Pesticides containing chlorine, which are released during agricultural activities, are chemical substances that mix with surface and underground waters and have toxic, carcinogenic, and mutagenic effects on the entire living ecosystem. Due to their chemically stable structure, conventional water and wastewater treatment techniques such as coagulation, flocculation, and biological oxidation do not entirely remove these chemical substances. Therefore, before releasing them into the environmental receptor, these chemical substances must be transformed into harmless products or mineralized through advanced oxidation processes. When we look at the literature, there are not many studies on methods of removing diclofop methyl from aquatic media. Our study on the removal of diclofop methyl herbicide from aquatic media using the peroxy electrocoagulation method will provide the first information on this subject in the literature. In addition, this treatment method will contribute significantly to filling an important gap in the literature as an innovative approach for diclofop methyl removal. Moreover, peroxy electrocoagulation, which produces less sludge, provides treatment in a short time, and is economical, has been determined to be an advantageous process. The effects of conductivity, pH, H2O2 concentration, current, and time parameters on the removal of diclofop methyl were investigated using a GC–MS instrument. Kinetics, energy consumption, and cost calculations were also made. Under the optimum conditions determined (pH = 5, H2O2 = 500 mg/L, NaCl = 0.75 g/L, current density = 2.66 mA/cm2), the peroxydic electrocoagulation process resulted in a diclofop methyl removal efficiency of 79.2% after a 25-min reaction. When the experimental results were analyzed, it was found that the results fitted the pseudo-second-order kinetic model.

Investigation on pulsed-electrocoagulation process for the treatment of wet coffee processing wastewater using an aluminum electrode

The use of conventional direct current-electrocoagulation in wastewater treatment is limited by its drawbacks, which include electrode passivation, high energy consumption, and significant sludge generation. Therefore, to address these issues, pulsed-electrocoagulation (PECP) has been developed. The PECP is an advanced wastewater treatment technique that uses intermittent electrical pulses to target and break down organic compounds in wastewater. It offers several benefits, including enhanced removal of organic compounds, reduced chemical consumption, energy efficiency, treatment of complex wastewater composition, pathogen inactivation, environmental compliance, and potential for water reuse. In this research, removal efficiency of % Chemical Oxygen Demand (COD), % Color, % Turbidity, % phosphate, and %nitrate was investigated for the wet coffee processing wastewater by using PECP and the obtained results as the COD-98.75%, color-99.92%, turbidity-99.00%, phosphate-99.02%, and nitrate-98.83%, respectively. Independent variables were the major significant factors and the optimum value was investigated and obtained at pH of 7, electrolyte dosage of 0.75 g L−1, electrolysis time of 45 min, and current of 0.45 Amp. As a result, PECP with NaCl and CaCl2 as an electrolyte is an effective treatment technique for pollutant removal from wastewater. As a consequence, the specific benefits may vary depending on the system design, operational parameters, and wastewater characteristics. The pilot-scale studies and optimization are essential for assessing PECP feasibility and performance.

Comparative study of wastewater treatment efficiency: ozone vs. atmospheric oxygen with a manganese dioxide catalyst

Abstract This study aims to validate the wastewater treatment technique and compare the effectiveness of applying an ozone mixture and atmospheric oxygen in the presence of a catalyst (manganese dioxide) with various dosages. A total of 540 replicates were performed, corresponding to different levels of manganese dioxide concentrations during oxygen and ozone delivery (270 repetitions for each of the experiments). The research was carried out using an experimental setup developed by the authors. The maximum efficiency of oxidation processes was observed within 15–30 min after the start of the treatment cycle. The decrease in the level of chemical oxygen demand within the first quarter-hour during ozone treatment was significantly greater compared to atmospheric oxygen treatment (p ≤ 0.05). The method's efficiency increased to 53% for ozone and 41% for oxygen after 30 min of purification (p ≤ 0.05). Lower catalyst consumption was observed when using an ozone mixture. The tested technology can be recommended for wastewater treatment with high hydrocarbon concentrations. The findings of the study indicated the potential application of ozone treatment with a manganese catalyst for treating wastewater with high hydrocarbon content, thereby fostering the development of more effective water purification methods in the industrial sector.

Pharmaceuticals in the Water: Emerging Concerns and Innovative Remediation Solutions

Abstract: Pharmaceutical contamination, resulting from the discharge of active pharmaceutical ingredients (APIs) and other related compounds into the water, has become a growing concern due to its potential adverse effects on ecosystems and human health. This review article aims to examine the many facets of pharmaceutical contamination and highlight the most recent developments in its remediation. The effects of pharmaceuticals, sources, and pathways of pharmaceutical contamination, as well as the difficulties in detecting and evaluating its toxicities, have been included in the present manuscript. Nowadays various remediation strategies are employed to mitigate pharmaceutical contamination in water. Conventional wastewater treatment techniques, including activated sludge processes and membrane filtration, are effective in removing a portion of the pharmaceutical compounds. However, advanced oxidation processes such as ozonation and photocatalysis have shown promising results in enhancing the degradation of recalcitrant APIs. Nanotechnology-based approaches, such as the use of nanoparticles for adsorption and degradation, and bioremediation methods utilizing microbial degradation, enzymatic processes, and phytoremediation, offer potential future directions for efficient and sustainable remediation. This review describes the most recent developments, current status, and potential research directions with the future prospects of pharmaceutical pollutants.

Optimizing Cr(VI) Reduction in Plastic Chromium Plating Wastewater: Particle Size, Irradiation, Titanium Dose

The preservation of the aquatic environment and water systems has been a fundamental objective that has led great scientists and researchers to seek new alternatives or techniques that allow the decontamination of water sources. The plastic chromium plating industries have been identified as important sources of contamination since their residues are characterized by having considerable amounts of hexavalent chromium Cr (VI), which alters the stability of water resources and can affect effluents on the surface and the subsoil. Given this problem, the need to improve the usual methods and techniques for wastewater treatment with more effective solutions, such as photocatalysis, which presents significant advantages over the inefficiency of traditional methods, is recognized. However, given the limited availability of research in the country that addresses the removal of hexavalent chromium from the wastewater of these industries, this work focuses on optimizing the process by varying conditions of variables such as particle size, catalyst dose, and irradiation time. The optimization of the photocatalysis process was evaluated using the Box-Behnken experimental design. The results show that contaminant removal occurred when the particle size was 0.177 mm. This particle size showed the highest photocatalytic activity, with 100% removal at 45 minutes. These findings represent a significant step towards solving the problem of contamination in this business sector by this pollutant and contribute to preserving our water resources. Doi: 10.28991/ESJ-2024-08-01-02 Full Text: PDF

Photodegradation of cationic and anionic dyes by ZnO and S/ZnO biosynthesized nano‐photocatalysts

Photocatalysis is considered a promising and efficient oxidation technique for wastewater treatment. Developing more environmentally biocompatible, simple, effective, and inexpensive photocatalysts enables photocatalysis technology to be at the forefront of wastewater treatments. As an alternative to harmful chemicals, this work focused on the biosynthesis of a variety of ZnO and doped ZnO based on the extract of the brown alga Cystoseira crinite. X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform‐infrared (FTIR) spectroscopy, and ultraviolet–visible (UV–vis) spectroscopy were used to characterize the structure, phase, morphology, and UV–vis properties of the biosynthesized samples. XRD showed the crystalline structure of ZnO and S‐doped ZnO. SEM analysis revealed agglomerated spherical particles of the prepared samples. EDX analysis confirmed the formation of S‐doped ZnO. FTIR spectra exhibited that phenolic compounds and protein molecules are present in the Cystoseira crinite extract. The photocatalytic efficiency of biosynthesized materials was examined by monitoring the degradation of crystal violet (CV) and methyl orange (MO) dyes, which serve as cationic and anionic dye models, respectively. The various factors that influence the efficacy of the photodegradation process were investigated. In total, 5% S‐doped ZnO decomposed 97.40% and 89.18% of CV and MO dyes, respectively. The dye degradation was most efficient in samples calcined at 500 °C. The photodegradation of CV dye was enhanced at high pH, while the highest photocatalytic activity of MO dye was observed at low pH values. The kinetic study confirmed that the photodegradation follows the first‐order reaction.

Degradation of direct red 23 dye in a plug flow reactor with adjustable angle baffles using nano-Fe3O4: modelling and optimisation

ABSTRACT Photocatalytic degradation is a key technique in wastewater treatment, particularly for toxic dye removal, yet challenges related to poor hydrodynamics and mass transfer limitations persist. This study addresses these challenges by innovatively employing an adjustable-angle baffle in a plug flow reactor (PFR) to enhance dye removal efficiency. A lab-scale PFR with an adjustable baffle was utilised to assess the impact of various factors, including baffle angle, catalyst concentration, hydraulic retention time (HRT), pH, and initial dye concentration, on the removal of direct red 23 dye. The experimental design employed a central composite design (CCD), with subsequent data analysis using response surface methodology (RSM) and artificial neural network (ANN) models. The findings demonstrate that the adjustable baffle significantly impacts dye removal, achieving maximum efficiency at an optimal angle of 77.5 degrees. The ANN model outperformed the RSM model, with a higher determination coefficient (R 2) of 0.994 compared to 0.928. Furthermore, RSM and genetic algorithms yielded closely aligned optimal conditions, validating their accuracy. The optimised conditions achieved a dye removal efficiency of 89.47%. Significantly, the study also identified degradation as the dominant mechanism over adsorption and highlighted the impressive stability of nano-Fe3O4 during the recycling process. Mineralisation analysis revealed the presence of lightweight organic residual molecules post-treatment. These outcomes demonstrate the effectiveness of adjustable baffles in PFRs, marking a significant advancement in wastewater treatment technologies and underscoring the critical role of baffle orientation and catalyst concentration in optimising dye removal processes.

Critical evaluation of electroactive wetlands: traditional and modern advances.

In the field of sustainable wastewater management, electroactive wetlands (EW), or constructed wetland-microbial fuel cells (CW-MFC), are an emerging technology. With the growing problem of untreated wastewater, the emphasis must shift to decentralisation of wastewater treatment infrastructure, and CW-MFC can be an excellent choice. This review provides a chronologically organized account of the design and configuration of CW-MFCs developed between 2010 and 2023. The research on CW-MFC has mainly focused on material, positioning and number of electrodes; use of electroconductive media and filler materials; flow regime; algal-based CW-MFC and multistage setups. Compared to traditional constructed wetlands (CW) and microbial fuel cells (MFC), CW-MFCs have a number of advantages, including better treatment efficiency, faster organic matter utilisation, lower capital and land requirements and a smaller carbon footprint. However, there are some limitations as well, such as upscaling and viable electricity generation, which are covered in more detail in the article. Moreover, the economics of this technology is also evaluated. The microbiology of a CW-MFC and its influence on its performance are also elaborated. Recent advancements in this field in terms of design, configuration and performance are discussed. Finally, the knowledge gaps that must be addressed before this technique can be successfully implemented on a large scale are highlighted, along with specific recommendations. This article aims to advocate for EWs as an ideal decentralised wastewater treatment technique, while also shedding light on the areas that still need to be worked on.

Conventional and Advanced Wastewater Treatment Techniques; Development of Sustainable Environment and Production of Biofertilizers

Conventional and Advanced Wastewater Treatment Techniques; Development of Sustainable Environment and Production of Biofertilizers

Water Contamination and Its Effects on Human Health: A Review

The study was done on the effect of water contamination on human health. The review revealed a complex network of factors contributing to water contamination, including home sewage, industrial discharges, pesticides, plastics, and systemic management deficiencies. The study highlighted the widespread effects on human health, including skin disorders, serious illnesses like cancer and diarrheal infections, particularly affecting children. It emphasized the need for synchronized efforts to alleviate pollution sources, focusing on sustainable farming methodologies and responsible waste management. The study also explored advanced wastewater treatment techniques, highlighting the urgent need for their widespread use worldwide. However, the study acknowledged limitations, such as geographical scope and contamination origins. Recommendations included a comprehensive strategy involving sustainable behaviors, strict laws, and advanced treatment technology. The study emphasized the need for governments, companies, and communities to work together to implement strong legislation, improve infrastructure, and increase knowledge about water quality. Addressing these challenges requires a holistic approach, focusing on mitigating constraints through ongoing research, innovation, and international collaboration.

Sustainable wastewater management in the brewing industry: Utilizing cellulose acetate membranes derived from brewers’ spent grain for enhanced treatment efficiency

Brewers’ spent grain (BSG), the primary by-product of the brewing industry, constitutes approximately 85.0% of the total by-products generated. BSG is known for its rich cellulose and non-cellulosic polysaccharide content, making it a valuable resource with significant potential for profitable recycling and reutilization. Given that the brewing sector is among the most substantial industrial consumers of water due to the water-intensive process of producing BSG, the effective management of wastewater in this industry is of paramount importance. This research focuses on investigating innovative wastewater management in the brewing sector. It employs the conversion of BSGs into a cellulose acetate membrane, thus enabling a physio-chemical treatment process utilizing the micro-filtration technique for wastewater treatment within the brewery industry. The results of this study demonstrate a substantial reduction in biochemical oxygen demand from the initial value of 16.65 mg/l (untreated) to 13.70 mg/l, 11.16 mg/l, 8.37 mg/l, 5.58 mg/l, and 3.14 mg/l after the first through fifth treatment cycles, respectively. Furthermore, the research indicates a high correlation with an R<sup>2 </sup>value of 0.999, affirming the viability and effectiveness of the treatment process. This is further substantiated by the results of chemical oxygen demand, total dissolved solids, total suspended solids, and hydrogen ion concentration analyses presented in this study. These findings not only validate the efficacy of utilizing BSG-derived cellulose acetate membranes but also emphasize the potential for revolutionizing wastewater treatment practices within the brewing industry. This research paves the way for sustainable, environmentally conscious strategies in industrial wastewater management, ensuring the optimal utilization of by-products while minimizing the environmental footprint of brewing operations.

Mechanistic insights and DFT analysis of bimetal doped styrofoam-like LaFeO3 perovskites with in-built dual redox couples for enhanced Photo-Fenton degradation of Tetracycline

The rising number of contaminants released into the environment and the inadequacies of traditional wastewater treatment techniques have led to the demand for enhanced oxidation technologies like photo-Fenton. In this study, bimetal co-doped lanthanum orthoferrite (BixLa1-xCuyFe1-yO3 (x = 0, 0.01, 0.05, 0.1; y = 0, 0.01, 0.05, 0.1, 0.15)) based photo-Fenton catalysts with the in-built redox couples Fe3+/Fe2+, Cu2+/Cu+ and oxygen vacancies have been successfully synthesised via a facile one-pot solution combustion route. Systematic studies show that the Bi0.05La0.95Cu0.1Fe0.9O3 (LFOBC) exhibits an optimal photo-Fenton degradation rate of 0.0497/min for Tetracycline (TC) removal, being ∼ 1.8 and ∼ 6.2 times greater than Bi0.05La0.95FeO3 (LFOB) and pristine LaFeO3 (LFO) respectively. DFT analysis confirmed the better adsorption and dissociation of H2O2 on a bimetal co-doped catalyst and identified the electron density difference in LFOBC, which can induce the H2O2 dissociation. A detailed investigation of various influencing reaction parameters is explored. The degradation pathway for the LFOBC catalyst with the toxicological characteristics of each intermediate is analysed. This study presents the Bi0.05La0.95Cu0.1Fe0.9O3 as a potential photocatalyst for enhanced photo-Fenton degradation with excellent efficiency observed for the degradation of various harmful pollutants for environmental remediation.

Magnetic recoverable Ag3PO4/Fe3O4/γ-Fe2O3 nanocomposite

The use of nanomaterials in water treatment is an alternative for the development of new systems to optimize the purification process. Heterogeneous photocatalysis is used for the treatment of wastewaters contaminated with recalcitrant pollutants that cannot be removed with conventional wastewater treatment techniques. Silver phosphate (Ag3PO4) can be used in visible-light driven photocatalysis. An important challenge of heterogeneous photocatalysis is to find a proper support for the photocatalysts to reduce the expense associated with the separation and reuse of these materials. However, the immobilization of the catalyst leads to lower reaction rates because the exposed surface area decreases and the material used as support can also interfere. In the last years, the use of magnetic materials to support photocatalysts has attracted special attention because it allows high surface areas to be exposed. Only few authors have reported the use of Ag3PO4/magnetic nanocomposites for photocatalysis and these need to be continued to improve their efficiency. In this work we synthesized Ag3PO4 and supported it on ferromagnetite (Fe3O4). In this study, Fe3O4 was synthesis following the Massart’s method. Ag3PO4 was synthesised over Fe3O4 from the reaction between silver nitrate (AgNO3) and disodium hydrogen phosphate (Na2HPO4). For characterization, DRS, SEM, XRD and magnetization studies were carried out. Ag3PO4 was synthesised and satisfactorily supported over magnetite (Fe3O423). The photodegradation of 10 mg·L−1 of methylene blue was achieved, although the apparent reaction rate constant was slightly lower for the magnetic composite than for bare Ag3PO4. This is explained because the composite contained 48% of the active Ag3PO4 material, as depicted form XRD studies.

Electrocoagulation as a Possible Treatment for Wastewater Contaminated with Microplastics - A Review

Microplastics (MPs) have arisen as an omnipresent pollutant that damages the aquatic ecosystem, raising serious concerns. It has become a massive challenge since MPs have the ability to biomagnify and thereby harm human health, biodiversity, aquatic species, and the environment. Therefore, innovative technologies are needed to efficiently remove MPs. Membrane technologies can be quite effective in the removal of MPs. Furthermore, hybrid membrane techniques such as advanced oxidation processes (AOPs), membrane fouling, electrochemical processes, and adsorption processes can be used to improve efficiency. Electrocoagulation is considered an effective wastewater treatment technique for MPs removal, with the advantages of low cost, independence of chemicals, and ease of operation. The main aim of this work is to demonstrate the potential of electrocoagulation to remove MPs from wastewater and provide an overview of the sources and toxicity of MPs found in wastewater. This study also evaluates various physical, chemical, and biological treatment methods for removing MPs from wastewater.

Application of Pseudomonas aeruginosa and Bacillus subtilis for Heavy Metal Bioremediation in Wastewater from Wupa Wastewater Treatment Plant, Abuja, Nigeria.

Water pollution is a huge issue on a global scale and is on the rise because of growing human activity and population, unsustainable farming methods, and quick industrialization. There is an increasing demand for innovative wastewater treatment techniques and there is also the need to establish rigorous operational guidelines in discharging wastewater into the environment. This study examined the application of Pseudomonas aeruginosa and Bacillus subtilis for heavy metal bioremediation in wastewater from Wupa Wastewater Treatment Plant, Abuja, Nigeria. Wastewater samples (Effluent) were collected from WUPA treatment plant, Abuja. The physiochemical parameters which include pH, Temperature, Conductivity, Turbidity, TDS, DO, BOD, COD wastewater was carried out and heavy metal analysis was carried out before and after treatment of the wastewater. The results showed the pH, conductivity BOD, DO and TDS of the wastewatewater;ered significantly (p<0.05) with the control and treated water, however the temperature of the wastewater does not differ significantly with the control and treated water. In the screen pump, the pH and temperature the untreated water shows no significant difference (p>0.05) with the control and treated water, however the conductivity, BOD5, DO and TDS of the wastewater differs significantly (p<0.05) with control and treated water. Inoculums of Pseudomonas aeruginosa and Bacillus species were prepared to aid the removal of heavy metals from wastewater. The removal of heavy metal was determined using AAS. The result revealed a significant reduction in the concentration of heavy metals in treated water samples compared to the untreated waters samples (p<0.05). In conclusion, Pseudomonas aeruginosa and Bacillus subtilis showed good remediation potentials as it reduces the heavy metals (Lead, cadmium, chromium, and zinc) within WHO specification against their initial concentrations and control. Finally, the findings of this study recommend the use of Pseudomonas aeruginosa and Bacillus subtilis for the remediation of heavy metals in wastewater.

Investigation Removal Efficiency of Electrocoagulation Process as A Slaughterhouse Wastewater Treatment Technique: Toxicity Assessment

Investigation Removal Efficiency of Electrocoagulation Process as A Slaughterhouse Wastewater Treatment Technique: Toxicity Assessment