Advanced Wastewater Treatment Technologies Research Articles

Techno-economic feasibility of photovoltaic solar electrodialysis with bipolar membranes

Electrodialysis with bipolar membranes (EDBM) can transform concentrated brines into acids and bases through the application of an electric field. Nevertheless, the widespread use of EDBM is limited by its high energy consumption, typically based on fossil fuels. Yet, the integration of EDBM with renewable energy sources, like solar photovoltaic (PV), remains unexplored. This study presents a techno-economic analysis of PV-EDBM to produce NaOH and HCl from seawater reverse osmosis (SWRO) brines. An integrated PV-EDBM model was developed and applied to a hypothetical PV-EDBM plant located in the SWRO facility of Lampedusa (Italy). Results revealed that PV has no negative impact on the performance in terms of product concentration, specific energy consumption and current efficiency. Meanwhile, the levelized cost of NaOH for PV-EDBM was reduced by 20 % in comparison to the electrical grid mix, achieving 210 €·ton−1 NaOH on an annual average for PV-EDBM. Therefore, the investment associated with PV is offset by the benefits of reduced electricity costs from the grid. Consequently, EDBM emerges as a feasible solution to address resource scarcity, representing a significant step towards integrating renewable energies with advanced wastewater treatment technologies, thus paving the path to a greener future.

Recent advances of membrane-based hybrid membrane bioreactors for wastewater reclamation

Membrane bioreactor (MBR) is an advanced wastewater treatment technology, which has been established for more than 3 decades. In MBRs, membrane separation allows not only rejecting microorganisms/greater-sized molecules but decoupling hydraulic retention time (HRT) and solid retention time (SRT). Low-pressure driven, porous membranes have been widely used in MBRs, but their performances are mainly limited for wastewater reuse applications. Recently, many attempts have been made to combine desalination technologies to advance hybrid MBR processes for wastewater reclamation. Nanofiltration (NF) and reverse osmosis (RO) have been applied with the MBRs to improve effluent quality, and their advantages and challenges have been well reported in terms of rejection efficiency, operational energy, fouling control and recovery of retentate stream. Alternatively, the direct introduction of non-pressurized desalination technologies such as forward osmosis (FO) and membrane distillation (MD) into MBR processes for wastewater reclamation or probably for microbial activity have been considered substantially due to their low energy consumption and excellent rejection efficiency of solid materials. However, several technical limitations still need to be resolved to commercialize hybrid FO- or MD-MBR processes. This paper reviews recent advances of MBR technology integrated with desalination technologies for wastewater reclamation and suggests perspectives to optimize membrane-based hybrid MBR process.

A review of advanced wastewater treatment technologies: USA vs. Africa

This research paper conducts a comprehensive comparative analysis of advanced wastewater treatment technologies in the USA and Africa, emphasizing infrastructure, regulatory frameworks, and socio-economic factors. The USA exhibits robust infrastructure, supportive regulations, and technological awareness, fostering the adoption of advanced solutions. In contrast, Africa faces limited resources and diverse regulatory landscapes. Affordability, accessibility, public awareness, and education are critical socio-economic factors influencing technology adoption. Prospects include innovations like AI integration and circular economy principles. Policy recommendations stress adaptive frameworks and international collaborations. The conclusion underscores the importance of inclusive strategies for global sustainable wastewater management, recognizing each region's unique socio-economic diversity. This research contributes valuable insights for policymakers, researchers, and practitioners working towards resilient and equitable wastewater treatment systems.

Determinants of efficient water use and conservation in the Colombian manufacturing industry using machine learning

Water is a fundamental aspect of achieving sustainable industries, and it is essential for firms to make efficient use of it. However, not all companies have sustainable water management practices in place. In this study, we aim to answer the research question: What factors influenced the efficient use and saving of water in the Colombian manufacturing industry in 2020? We used data from the Annual Manufacturing Survey and the Industrial Environmental Survey conducted by DANE to investigate this question. Our study grouped the variables into four categories: Environmental commitment, Risk mitigation, Innovation, and Location. We used two supervised learning machine-learning algorithms—decision tree and logit regression with LASSO regularization—to analyze the data. The results underscore those investments in wastewater treatment, total water consumption, and commitments to air and climate protection emerge as pivotal drivers for embracing sustainable practices. Moreover, the geographical location of companies significantly influences the likelihood of implementing water conservation initiatives. To enhance efficient water use and conservation in the Colombian manufacturing sector, several targeted public policies are recommended. These include offering fiscal and financial incentives to encourage investments in advanced wastewater treatment and reuse technologies. Additionally, advocating for specialized training and environmental education programs tailored for corporate personnel is crucial. Moreover, establishing initiatives for environmental certification and eco-labeling within the corporate sector can significantly promote sustainable water practices. Lastly, enforcing more stringent environmental regulations and standards, especially for industries like Textile, Metallurgy, and Manufacturing of rubber and plastic products, is essential to ensure responsible water management across the sector.

Autotrophic denitrification based on sulfur-iron minerals: advanced wastewater treatment technology with simultaneous nitrogen and phosphorus removal.

Autotrophic denitrification technology has many advantages, including no external carbon source addition, low sludge production, high operating cost efficiency, prevention of secondary sewage pollution, and stable treatment efficiency. At present, the main research on autotrophic denitrification electron donors mainly includes sulfur, iron, and hydrogen. In these autotrophic denitrification systems, pyrite has received attention due to its advantages of easy availability of raw materials, low cost, and pH stability. When pyrite is used as a substrate for autotropic denitrification, sulfide (S2-) and ferrous ion (Fe2+) in the substrate will provide electrons to convert nitrate (NO3-) in sewage first to nitrite (NO2-), then to nitrogen (N2), and finally to discharge the system. At the same time, sulfide (S2-) loses electrons to sulfate (SO42-) and ferrous ion (Fe2+) loses electrons to ferric iron (Fe3+). Phosphates (PO43-) in wastewater are chemically combined with ferric iron (Fe3+) to form ferric phosphate (FePO4) precipitate. This paper aims to provide a detailed and comprehensive overview of the dynamic changes of nitrogen (N), phosphorus (P), and other substances in the process of sulfur autotrophic denitrification using iron sulfide, and to summarize the factors that affect wastewater treatment in the system. This work will provide a relevant research direction and theoretical basis for the field of sulfur autotrophic denitrification, especially for the related experiments of the reaction conversion of various substances in the system.

Impacts of multi-pollutants on sulfonamide antibiotic removal from water matrices using layered double hydroxide sorbents

Remediation of sulfamethoxazole (SMX) present in the aqueous environment requires the development of new advanced wastewater treatment technologies, crucial to reduce the toxicity of such pollutants to the environment, supporting urban water reuse. Continuously synthesised layered double hydroxides (LDH) have been applied as a sorbent material for the removal of SMX from water. No equilibrium uptake of SMX was observed from any water matrix. However, an unusual sorption/release behaviour of SMX was observed in the presence of Mg2Al-NO3-LDH, influenced by the characteristics of the water matrix. A maximum SMX removal percentage of 34.7% was reached within 10 min, from ultrapure water, followed by release of SMX back into solution over the following 24 h. Further, Mg2Al-NO3-LDH is shown to release NO3- into all water matrices. It is proposed that NO3- disrupts the SMX-LDH interactions, resulting in release of SMX from the LDH. No initial SMX sorption was observed onto Mg2Al-NO3-LDH when wastewater effluent was the water matrix, likely due to competition for sorption sites on the LDH with multiple pollutants, including metals and additional anionic nutrients, present in the wastewater. This work illustrates the potential for relationships between the sorbent material and water matrix interactions on pollutant sorption behaviour. In addition, the findings highlight the importance of conducting removal experiments at realistic environmental conditions to ensure development of suitable sorbent materials for pollutant remediation.

Is constructed wetlands carbon source or carbon sink? Case analysis based on life cycle carbon emission accounting

Constructed wetlands (CWs) are widely used to polish the effluent of wastewater treatment plants and micro-polluted river or lake water. However, the impact of large-scale applications of CWs on carbon emissions is unclear. In this study, the carbon footprints of two full-scale hybrid CWs were determined based on life cycle assessment (LCA). Results showed that the carbon emission of CW ranged from 0.10 to 0.14 kg CO2-eq/m3, and was significantly correlated with the influent chemical oxygen demand loads and electricity consumption. However, CW would approach carbon neutrality during the service period when taking plant carbon sequestration into consideration. Compared with other advanced wastewater treatment technologies, CWs showed significant low-carbon emission and cost-effective benefits. This study clarified the role of CWs in the carbon cycle and would provide guidance for the construction and management of CWs.

Inactivation of antibiotic resistant bacteria and elimination of transforming ability of plasmid carrying single and dual drug resistance genes by electro-oxidation using Ti/Sb-SnO2/PbO2 anode

Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are one of the major components of environmental antimicrobial resistance (AMR). Wastewater treatment plant is an important source and a contributor of AMR components in environment. The existing tertiary treatment technologies viz., chlorination, ultraviolet treatment and ozonation are not effective in ARB disinfection or ARG removal. Therefore, it is important to evaluate the potential of advanced wastewater treatment technologies in removing ARB and ARGs. In this study, the potential of Ti/Sb-SnO2/PbO2 anode in disinfecting single ARB (pUC19-ampR), dual ARB (pBR322-ampR and tetR), regrowth inhibition, removal of intracellular and extracellular ARGs and loss of transformation efficiency were evaluated. Upto 7 log (99.99 %) removal of single ARB (0.212 min−1) and dual ARB (0.185 min−1) was achieved in 40 min and 35 min, respectively at an applied current density 30 mA cm−2. Scanning electron microscopy images confirmed extensive and irreparable cell damages. Therefore, no re-growth was observed upto 30 days. Agarose gel electrophoresis and qubit analysis confirmed degradation of intracellular and extracellular genetic material. Upto ∼7.5 log (53.14 ± 1.23 %) of intracellular and ∼5.3 log (41.43 ± 0.89 %) of extracellular ampR (pUC19) reduction was observed. Similarly, reduction of intracellular ampR and tetR (pBR322) were ∼6.5 log (55.19 ± 0.92 %) and ∼7.5 log (64.89 ± 2.39 %). While, extracellular ampR and tetR (pBR322) were ∼4.1 log (41.85 ± 1.62 %) and ∼4.9 log (52.49 ± 1.35 %), respectively. Despite low ARG removal efficiency, complete loss of transformation ability of intracellular and extracellular pUC19 and pBR322 was observed. From the results, it is evident that electro-oxidation is effective in disinfecting both the ARB, removal of intracellular and extracellular ARGs. Therefore, EOP is proposed as an effective and promising tertiary treatment technology.

Transforming Agriculture: Innovations in Sustainable Wastewater Reuse – A review

This scientific review delves into the crucial role of wastewater reuse in agriculture for sustainable water resource management, especially in the context of water scarcity. The paper examines innovative wastewater treatment methods like biofiltration, membrane bioreactors, and electrocoagulation, exploring their effectiveness and limitations. It emphasizes the significance of proper wastewater treatment in mitigating risks and maximizing benefits. Key considerations such as economic viability and social acceptance are highlighted, urging comprehensive cost-benefit analyses and active engagement with stakeholders. Drawing from case studies in Tshwane, Egypt, Valencia, and Sde Warburg, successful wastewater reuse practices underscore the importance of stringent water quality standards, public education, regulatory frameworks, and stakeholder involvement in achieving sustainable wastewater management. Despite global advancements, challenges persist in the adoption of these technologies in many African countries, necessitating collaborative efforts and targeted capacity-building for widespread implementation. Historical insights reveal the evolution of wastewater irrigation from European and American cities to its current global prevalence, impacting around 10% of the world’s irrigated land with untreated or partially treated wastewater. Technological advancements, such as biofiltration relying on microbial activities, membrane bioreactors integrating biological treatment with filtration, and electrocoagulation as an electrochemical process, offer sustainable solutions. Case studies highlight the economic, environmental, and social benefits of successful wastewater reuse programs. However, the review acknowledges the risks associated with wastewater reuse, including environmental contamination and public health hazards. To strike a balance between risks and benefits, the paper advocates for proper wastewater treatment, robust regulatory frameworks, and responsible farming practices. It concludes by stressing the need for collaborative efforts, international partnerships, and targeted capacity-building initiatives to overcome barriers to the adoption of advanced wastewater treatment technologies in African countries, fostering water management, ensuring food security, and contributing to social and economic development amid global challenges.

Indicators for the sustainability assessment of MBR technologies for wastewater reuse in Chile: The good, the bad, and the ugly

While Chile faces a mega-drought, wastewater reuse emerges as an alternative solution. In this study we develop a set of indicators for the comprehensive sustainability assessment for the application of advanced wastewater treatment technologies (e.g., MBRs) in a wastewater reuse project in Chile. The methodology is based on the Integrative Concept of Sustainable Development (ICoS) framework. A critical analysis of the set of indicators is presented in terms of the benefits (The Good), the difficulties (The Bad), and the barriers (the Ugly) for their development and potential application. The characterization of the environmental benefits constitutes the useful aspects (e.g., recovery of nutrients, energy, and water). Difficulties include economic aspects (e.g., continuous monitoring of emerging contaminants) and public acceptance. Political and administrative aspects were found to be the main barrier, including water rights in Chile and the absence of a clear regulatory framework for wastewater reuse. To our knowledge, this study is the first to present a detailed methodology for developing indicators for membrane-based water reuse projects in Chile.The steps to develop the indicators are: •Identification of the study zone or case study, characterization of treatment technology.•Identification and formulation of indicators for the specific case study, based on the ICoS framework.•Verification of the relevance of indicators for the case study according to data availability and expert reviews.

Metal Recovery and Electricity Generation from Wastewater Treatment: The State of the Art

The recovery of metal resources from wastewater is very important for both resource recovery and wastewater treatment. Compared with traditional metal-polluted wastewater treatment technologies, advanced wastewater treatment technologies with the functions of both recovering metals and generating electricity have been developed rapidly in recent years. These advanced technologies include microbial fuel cells, photo fuel cells, coupled redox fuel cells, etc. In this paper, these advanced technologies are elaborated from their principles to their applications in wastewater treatment for metals recovery and electricity generation. The recent progress of these technologies was also reviewed. The effects of different metal ions, cell configurations, and various operating parameters on their performance were also discussed. Although these technologies are promising, the challenges and the efforts needed to overcome them are also highlighted.

The fate of microplastics in wastewater treatment plants: An overview of source and remediation technologies

Microplastics (MPs) in everyday consumer products have paved the way for high MPs concentrations in wastewater. Wastewater treatment plants (WWTP)s are the significant focal points for MP pollution, as millions of MP particles with varying characteristics enter WWTPs through the sewage systems of urban areas. Although the units in the WWTPs are not primarily designed to target MPs specifically, researchers have reported a large amount of microplastic removal from various units of WWTPs. The scientific community has remarkably studied various conventional and advanced treatment methods to remediate MPs and nanoplastics (NPs) from wastewater. This review aims to provide comprehensive knowledge about the source of MPs and NPs in wastewater, their composition, toxic effects, and remediation from treatment units of the WWTPs. The WWTPs comprise several physical, chemical, and biological treatment processes broadly categorized into three key stages: primary, secondary, and tertiary. The interaction of MPs and NPs with these processes have also been reviewed. Literature indicates that the WWTPs can separate more than 90% of MPs from wastewater. However, despite low concentrations of MPs in the treated effluent, large discharge volumes contribute to millions of MPs/NPs into the environment. Also, the separated MPs/NPs re-enter the environment through sludge applied on land. The paper also discusses the application of various advanced wastewater treatment technologies and their efficacies in remediating microplastics. Finally, the paper also highlights the research gaps where additional exploration is required, providing a new perspective on developing policies for controlling microplastic pollution.

Membrane distillation bioreactor (MDBR) for wastewater treatment, water reuse, and resource recovery: A review

Membrane bioreactors (MBRs) have been well established as an advanced wastewater treatment technology that combines activated sludge with a pressure-driven membrane separation process. They have been widely applied in municipal and industrial wastewater treatment systems due to their advantages over conventional activated sludge systems. However, MBRs still face major issues hindering their widespread implementation such as poor effluent quality due to low retention of trace organic contaminants, instability due to changing operating conditions, and organic membrane fouling. Membrane distillation (MD) bioreactor (MDBR) is a novel wastewater treatment technology that combines MBRs with an MD unit either separated at a side stream or submerged in the bioreactor. The concept of hybrid MDBR configuration was firstly introduced in 2007 which was followed by numerous journal articles. These studies demonstrated the MDBR potential for water, nutrients, bioenergy, and other value-added product recovery from domestic and industrial wastewater; however, there is still a lack of a comprehensive study that shows the full MDBR potential. Hence there is a need for a dedicated review that summarize and critically analyse these research findings and highlight the research gaps to provide clear path for future research. This review presents system availability and applications of hybrid MDBR. In particular, the review presents brief introduction of MBR and MD technologies followed by covering the evolution of MDBR as a novel technology for municipal and industrial wastewater treatment. Several applications of MDBR systems are reviewed with a focus on system performance and removal efficiencies. The potential of MDBR to widen wastewater reuse and achieve nutrient and biogas recovery is also presented. Finally, the main challenges that hinder the development of MDBR are discussed while recommendations on future perspectives towards MDBR commercialization are suggested.

Advanced wastewater treatment of micropollutants – state of the art

PurposeMicropollutants in the aquatic environment pose threats to both ecosystems and human health. Traditional wastewater treatment plants (WWTP) reduce some micropollutants, especially those who adhere to sludge or suspended matter. The hydrophilic micropollutants, on the other side, which may be non-biodegradable and resistant to UV-treatment etc. are typically transported untreated into the water recipients. This paper contains a literature study on the state of the art of advanced wastewater treatment technologies for reducing micropollutants such as pharmaceutical degradation products, personal care products, surfactants and industrial chemicals including heavy metals.Design/methodology/approachThis literature study is completed using the most extensive and expansive literature database in the World to date, Google Scholar (GS). Published papers in recognized scientific journals are sought out in GS, and for relevance for this literature study, papers published here from 2016 and onwards (the last 5 years) have been chosen to eliminate irrelevant studies.FindingsThe result of the study is that there are many promising technologies on the market or emerging; however, no one solution treats every micropollutant equally well. Since advanced technologies often require expensive investments for municipalities and companies, it is important to identify which micropollutants pose the highest risk towards human health and the environment, because choosing systems to eliminate them all is not economically wise, and even choosing a system combining the existing technologies can be more expensive than states, municipalities and private companies are capable of investing in.Research limitations/implicationsThe research is limited to published papers on GS, which may omit certain papers published in closed databases not sharing their work on GS.Practical implicationsThe practical implications are that practitioners cannot find go-to solutions based on the conclusions of the research and thus need to use the results to investigate their own needs further in order to make the wisest decision accordingly. However, the paper outlines the state of the art in advanced wastewater treatment and explains the benefits and downsides of the technologies mentioned; however, more research in the field is required before practitioners may find a proper solution to their specific issues.Social implicationsThe social implications are that the consequences of introducing a removal of micropollutants from the water environment can ultimately effect the citizens/consumers/end-users through added costs to the tariffs or taxes on advanced wastewater treatment, added costs on everyday goods, wares and products and added costs on services that uses goods, wares and products that ultimately produces micropollutants affecting the water environment.Originality/valueThis paper presents a much needed state of the art regarding the current advanced technologies to mitigate micropollutants in wastewater. The overview the paper provides supports politics on national as well as international levels, where larger unions such as the EU has stated that advanced wastewater treatment will be the next step in regulating pollutants for aquatic outlet.

Industrial application of membrane distillation technology using palm oil mill effluent in Malaysia

The palm oil industry plays a vital role in the nation’s economy. Regardless of the high revenue generated, the main problem in the palm oil industry is its substantial amount of wastes including empty fruit bunches, oil palm trunks and in particular palm oil mill effluent (POME) which can be harmful to the environment if discharged without being treated. The objective of this work is to introduce advanced wastewater treatment technology, which is membrane distillation (MD) technology for the effluent treatment system. PVDF hollow fibre membranes were fabricated via wet spinning technique and characterized using Scanning Electron Microscope (SEM) and contact angle goniometer. The fabricated membranes were then tested in direct contact membrane distillation (DCMD) system using anaerobic POME as the feed solution. The effluent was analyzed before and after treatment with DCMD. The parameters included biological oxygen demand (BOD), chemical oxygen demand (COD), ammonia nitrogen (AN), nitrate-nitrogen (NN), total suspended solids (TSS), total dissolved solids (TDS), colour and turbidity. A preliminary test was carried out using distilled water before continuing with anaerobic POME as a feed solution. The average permeate flux obtained by the PVDF membrane is 2.509 kg/m2.hr with slight flux decline that is probably due to the attachment of biological compounds on the membrane pores. It was found that at least 90% rejection was obtained for almost all water quality parameters tested with the values were all lower than that of the standard set by the local authority. In a conclusion, it can be said that MD demonstrated excellent performance in treating palm oil wastewater to produce water of high quality.[copyright information to be updated in production process]

Performance evaluation of an integrated multi-stage poultry slaughterhouse wastewater treatment system

Poultry slaughterhouse wastewater (PSW) with a high fats, oil, and grease (FOG) content in South Africa (SA) is generally discharged into municipal wastewater systems. This is detrimental for municipal treatment plants since there is a limited number of these wastewater treatment works (WWTWs) that are operating optimally. Furthermore, increasingly stringent standards for effluent discharge have placed an urgency on the development of advanced wastewater treatment technologies. This study evaluated the performance of a lab-scale integrated multi-stage PSW treatment system consisting of an aerobic pre-treatment tank, an expanded granular sludge bed (EGSB) bioreactor coupled with a submerged ultrafiltration (UF) membrane. The possibility of treating PSW to a water quality standard compliant with discharge by-laws or the standards of effluent discharge was investigated. The EGSB was operated for 120 days at a hydraulic retention time (HRT) of 5.71 h and an organic loading rate (OLR) ranging from 200 to 700 mg COD/L·h, while the submerged membrane unit had OLR fluctuating between 50 and 450 mg COD/L·h. The integrated system achieved overall average removal efficiencies (REs) of 98% for chemical oxygen demand (COD), 97% for FOG, and 99% for total suspended solids (TSS); and reducing the pollutant content of the treated PSW to 101 mg/L COD, 8 mg/L FOG and 7 mg/L TSS, i.e. qualities which are comparable to inland surface water, rendering it safe for discharge into the City of Cape Town (CCT) WWTWs.

Comparative Life Cycle Assessment of two advanced treatment steps for wastewater micropollutants: How to determine whole-system environmental benefits?

Advanced wastewater treatment (AWT) technologies are now considered to target urban micropollutants (MPs) before discharge into receiving water bodies and to comply with specific criteria for reuse. Extra energy and/or resources are necessary to achieve the elimination of MPs. Using the Life Cycle Assessment framework, this study assesses net environmental efficiencies for two AWTs (i) ozone systems (air-fed and pure oxygen-fed) and (ii) granular activated carbon filter. Sixty-five MPs with proven removal efficiency values and toxicity and/or ecotoxicity potentials were included in this study building on results from recent research. Consolidated Life Cycle Inventories with data quality and uncertainty characterization were produced with an emphasis on operational inputs. Results show that the direct water quality benefits obtained from AWT are outweighed by greater increases in indirect impacts from energy and resource demands. Future research should include water quality aspects not currently captured in life cycle impact assessment, such as endocrine disruption and whole-effluent toxicity, in order to assess the complete policy implications of MP removal strategies.

Prevalence of human pathogenic viruses in wastewater: A potential transmission risk as well as an effective tool for early outbreak detection for COVID-19

Millions of human pathogenic viral particles are shed from infected individuals and introduce into wastewater, subsequently causing waterborne diseases worldwide. These viruses can be transmitted from wastewater to human beings via direct contact and/or ingestion/inhalation of aerosols. Even the advanced wastewater treatment technologies are unable to remove pathogenic viruses from wastewater completely, posing a serious health risk. Recently, coronavirus disease 2019 (COVID-19) has been urged globally due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has resulted in >4.1 million deaths until July 2021. A rapid human-to-human transmission, uncertainties in effective vaccines, non-specific medical treatments, and unclear symptoms compelled the world into complete lockdown, social distancing, air-travel suspension, and closure of educational institutions, subsequently damaging the global economy and trade. Although, few medical treatments, rapid detection tools, and vaccines have been developed so far to curb the spread of COVID-19; however, several uncertainties exist in their applicability. Further, the acceptance of vaccines among communities is lower owing to the fear of side effects such as blood-clotting and heart inflammation. SARS-CoV-2, an etiologic agent of COVID-19, has frequently been detected in wastewater, depicting a potential transmission risk to healthy individuals. Contrarily, the occurrence of SARS-CoV-2 in wastewater can be used as an early outbreak detection tool via water-based epidemiology. Therefore, the spread of SARS-CoV-2 through fecal-oral pathway can be reduced and any possible outbreak can be evaded by proper wastewater surveillance. In this review, wastewater recycling complications, potential health risks of COVID-19 emergence, and current epidemiological measures to control COVID-19 spread have been discussed. Moreover, the viability of SARS-CoV-2 in various environments and survival in wastewater has been reviewed. Additionally, the necessary actions (vaccination, face mask, social distancing, and hand sanitization) to limit the transmission of SARS-CoV-2 have been recommended. Therefore, wastewater surveillance can serve as a feasible, efficient, and reliable epidemiological measure to lessen the spread of COVID-19.

Reactive Green 19 degradation using O3/S2 O8(2-) process: Intermediates and Proposed Degradation Pathway

ABSTRACT The massive drawbacks of conventional wastewater treatment have led to a demand investigation about new advanced wastewater treatment technology. The issue can be addressed via advanced oxidation processes (AOPs) as witnessed recently. Therefore, the objective of this study was to investigate the performance of ozone/persulfate () process to assess its use as potential degradation of diazo dye which is Reactive Green 19 (RG19). In this work, efficiency, color, and COD removal were investigated over a range of initial pH, persulfate concentration and initial concentration of RG19. The amount of sodium persulfate () was varied at different levels (20–100 mM) relative to precursor radical to assess the optimum usage of persulfate concentration for RG19 degradation. Evidence that RG19 could degrade efficiently had occurred at 100 mg/L, initial pH 9, 60 mM persulfate concentration was identified by FTIR and GC/MS analysis. The results revealed that RG19 could achieve complete decolorization easily as compared to mineralization. In addition, RG19 degradation pathway gave the best representation of level degradation. The GC/MS and FTIR results exhibited the proposed RG19 degradation pathway that involved the characteristic of sulfonic group, accompanied with became as an indicator of their structure broken down one by one. The degradation products such as oxalic acid, formic acids and others were analyzed and finally converted to carbon dioxide and water. The diazo dye structure itself aided with has its superior characteristic as an aid for the efficient degradation process.

Investigation of microplastic removal from greywater by coagulation and dissolved air flotation

Microplastics (MPs) have recently become a controversial issue, mainly due to their eco-toxicological effects on aquatic environments. Although a typical wastewater treatment plant (WWTP) removes a large number of MPs from the wastewaters, final effluents are yet considered to be the primary sources of MP contaminations into the environment. Hence, there should be a tertiary treatment called advanced wastewater treatment technology for efficient MP removal. In the current research, Al-based and Fe-based coagulants were used in a dissolved air flotation (DAF) cell as an advanced wastewater treatment technology to remove polyethylene (PE) MPs from greywater, which is one of the most predominant types of MPs found in the greywater. PE reduction up to 96.10 % and 70.56 % were observed for Al- and Fe-based coagulants, respectively. The operative parameters, including pressure, pH, coagulant dosage, and water flow rate into the flotation cell, were identified. The experimental design was developed using Design-Expert software to investigate and maximize the PE removal efficiency. As a result, some sufficiently accurate statistical models were proposed to obtain the optimum quantities of the respective factors. It was determined that the most effective removal was achieved with 5.95 bar saturation pressure, pH 6, 14.46 mg/L coagulant concentration, and 680.5 mL/min water flow rate into the flotation cell using AlCl3·6H2O as the coagulant.