Technology For Municipal Wastewater Treatment Research Articles

Partitioning and inactivation of enveloped and nonenveloped viruses in activated sludge, anaerobic and microalgae-based wastewater treatment systems

Anaerobic and microalgae-based technologies for municipal wastewater treatment have emerged as sustainable alternatives to activated sludge systems. However, viruses are a major sanitary concern for reuse applications of liquid and solid byproducts from these technologies. To assess their capacity to reduce viruses during secondary wastewater treatment, enveloped Phi6 and nonenveloped MS2 bacteriophages, typically used as surrogates of several types of wastewater viruses, were spiked into batch bioreactors treating synthetic municipal wastewater (SMWW). The decay of Phi6 and MS2 in anaerobic and microalgae-based reactors was compared with the decay in activated sludge batch reactors for 96 h (Phi6) and 144 h (MS2). In each reactor, bacteriophages in the soluble and solids fractions were titered, allowing the assessment of virus partitioning to biomass over time. Moreover, the influence of abiotic conditions such as agitation, oxygen absence and light excess in activated sludge, anaerobic and microalgae reactors, respectively, was assessed using dedicated SMWW control reactors. All technologies showed Phi6 and MS2 reductions. Phi6 was reduced in at least 4.7 to 6.5 log10 units, with 0 h concentrations ranging from 5.0 to 6.5 log10 PFU mL−1. Similarly, reductions achieved for MS2 were of at least 3.9 to 7.2 log10 units, from starting concentrations of 8.0 to 8.6 log10 PFU mL−1. Log-logistic models adjusted to bacteriophages’ decay indicated T90 values in activated sludge and microalgae reactors of 2.2 and 7.9 h for Phi6 and of 1.0 and 11.5 h for MS2, respectively, all within typical hydraulic retention times (HRT) of full-scale operation. In the case of the microalgae technology, T99 values for Phi6 and MS2 of 12.7 h and 13.6 h were also lower than typical operating HRTs (2–10 d), while activated sludge and anaerobic treatment achieved less than 99 % of Phi6 and 50 % of MS2 inactivation within 12 h of typical HRT, respectively. Thus, the microalgae-based treatment exhibited a higher potential to reduce the disinfection requirements of treated wastewater.

Application of the sulfur-siderite composite filler: A case study of augmented performance and synergistic mechanism for low C/N wastewater treatment in constructed wetland

The urgent need to achieve sustainable development goals and address global climate change calls for innovative solutions in advanced low-carbon water treatment technologies. In this study, constructed wetlands (CWs), a sustainable and multifunctional wastewater treatment technology known for its low cost and energy efficiency, was focused. It was presented a novel approach that employs a sulfur-siderite composite filler in the constructed wetland (SSCF-CW), which demonstrated remarkable removal efficiencies for total phosphorus (TP) ranging from 81.14 % to 98.87 %, nitrate nitrogen (NO3−-N) ranging from 85.23 % to 99.82 %, and total nitrogen (TN) ranging from 91.65 % to 97.01 % in low C/N wastewater treatment. The electron resupply mode of the sulfur and iron cycles plays a pivotal role in enhancing denitrification efficiency. Furthermore, SSCF enhances the resilience of SSCF-CW against shock loadings, providing increased stability and performance with TN removal rate of 2.96 ∼ 3.42 g N·m−3·d−1 while HRT decreased from 48 h to 10 h. Notably, the majority of NO3−-N elimination occurs within the SSCF layer, where Thiobacillus species dominate the denitrification process in SSCF-CW. The introduction of SSCF promotes carbon fixation with the higher relative abundance of DLD gene (5.52 %) in SSCF-CW, benefiting microbial growth and accelerating electron transfer process. Co-precipitation and adsorption pathways in the SSCF layer primarily contribute to TP removal, while iron leaching from SSCF facilitates the formation of iron plaque on roots, establishing an iron reservoir and ensuring bioavailability. These findings highlight the significant potential of SSCF in constructed wetland systems, offering a cost-effective and sustainable low-carbon technology for municipal wastewater treatment.

Techno-economic and environmental assessment of different municipal wastewater treatment systems

A comprehensive economic evaluation and environmental assessment of wastewater treatment plants (WWTPs) is a precondition to ensure long-term economic, environmental, and social sustainability. In this study, a techno-economic feasibility analysis for different modern compact municipal wastewater treatment technologies including aerobic granular sludge (AGS), high rate activated sludge (HRAS) coupled with membrane bioreactor (MBR), HRAS + MBR process, was conducted. The findings were comparatively evaluated with the conventional anaerobic/anoxic/aerobic (A2O) process. Capital, operation and maintenance (O&M) costs for each system were investigated in detail. Environmental benefits for each system were assessed and an energy balance for each system was conducted. 21 % lower energy consumption was observed in the AGS system in comparison to the A2O system. This finding might be associated with the absence of mixers, return sludge pumping and recirculation of wastewater for nitrogen removal in AGS system. The unit total cost was found to be 0.113 €/m3, 0.091 €/m3, and 0.195 €/m3 for A2O process, AGS process, and HRAS + MBR process in order. Based on the energy balance and economic analysis, AGS system was found to have lower net energy consumption and total cost compared to A2O process and HRAS + MBR process. The results obtained from this study are of vital importance in the economic evaluation of the projected large new WWTPs.

Municipal Wastewater Treatment Technologies in Malaysia: A Short Review

The aim of this study was to evaluate different municipal wastewater treatment technologies for commercial use and develop an optimized system for a case study plant and future plant designs. Municipal wastewater, classified as a low-strength waste stream, can be treated using aerobic and anaerobic reactor systems or a combination of both. Aerobic systems are suitable for low-strength wastewaters, while anaerobic systems are suitable for high-strength wastewaters. Malaysia has actively implemented various wastewater treatment technologies to address the increasing demand for clean water and reduce environmental pollution. Some commonly used technologies in Malaysia include Activated Sludge Process (ASP), Membrane Bioreactor (MBR), and Moving Bed Biofilm Reactor (MBBR). These technologies show promise in removing emerging pollutants, such as pharmaceuticals and personal care products, which are not effectively eliminated by conventional treatment methods. Additionally, Malaysia could consider investing in renewable energy sources like solar and wind to power wastewater treatment plants, thereby reducing reliance on non-renewable energy and supporting sustainable development. It is also important to emphasize continued public awareness and education initiatives to promote responsible wastewater disposal practices and environmental stewardship.

Water-energy-greenhouse gas nexus of a novel high-rate activated sludge-two-stage vertical up-flow constructed wetland system for low-carbon wastewater treatment

Municipal wastewater treatment which is associated with high energy consumption and excessive greenhouse gas (GHG) emissions, has been facing severe challenges toward carbon emissions. In this study, a high-rate activated sludge-two-stage vertical up-flow constructed wetland (HRAS-TVUCW) system was developed to reduce carbon emissions during municipal wastewater treatment. Through carbon management, optimized mass and energy flows were achieved, resulting in high treatment efficiency and low operational energy consumption. The carbon emission of the HRAS-TVUCW system (i.e., 0.21 kg carbon dioxide equivalent/m3 wastewater) was 4.1-folds lower than that of the conventional anaerobic/anoxic/aerobic (A2O) process. Meanwhile, the recovered energy from the HRAS-TVUCW system increased its contribution to carbon neutrality to 40.2%, 4.6-folds higher than that of the A2O process. Results of functional microbial community analysis at the genus level revealed that the controlled dissolved oxygen allocation led to distinctive microbial communities in each unit of HRAS-TVUCW system, which facilitated denitrification efficiency increase and carbon emissions reduction. Overall, the HRAS-TVUCW system could be considered as a cost-effective and sustainable low-carbon technology for municipal wastewater treatment.

Eco-efficient Prototype of Wastewater Treatment Plant Applying Clean Development Mechanism Methodologies – Mediterranean Countries

Municipal wastewater treatment is committed reducing greenhouse gases emissions in line with United Nations Framework Convention on Climate Change (UNFCCC) norms in order to preserve Earth's blanket and lower climate acute changes. Greenhouse gases emissions reduction is the avant-garde of municipal wastewater treatment technologies; however, the process requires particular segmentation of all phases to contain the excessive energy required for treatment. Consequently, Energy analysis is endorsed as essential to sustain a thermodynamic equilibrium of the treatment plant with its environment. Decarbonization, denitrification & phosphorus removal urge the exploitation of sustainable energy whether recovered or renewable to engine the treatment facility. This literature values compile the eco-design of wastewater treatment plant with the avant-garde technologies of greenhouse gases emissions reduction, considering environmental aspects at all stages of treatment process, targeting the lowest possible environmental impact throughout the plant life cycle to create a CO₂-free facility prototype. UNFCCC introduced the greenhouse gases emissions definition in wastewater plants as a project design document for the Clean Development Mechanism (CDM) project AM00801 activity. The literature adopted this project and submitted it as a friendly user interface or a Software to model an Eco-efficient management strategy for wastewater treatment plant aerobic activated sludge type with the offset of environmental footprint measures based on decision making analysis, Input-output analysis, benchmarking and energy balance, net negative emissions including environmental declaration assessing the life cycle from costing, management, and sustainability perspectives.

The Influence of Municipal Wastewater Treatment Technologies on the Biological Stabilization of Sewage Sludge: A Systematic Review

Various wastewater treatment technologies are available today and biological processes are predominantly used in these technologies. Increasing wastewater treatment systems produces large amounts of sewage sludge with variable quantities and qualities, which must be properly managed. Anaerobic and aerobic digestion and composting are major strategies to treat this sludge. The main indicators of biological stabilization are volatile fatty acids (VFAs), volatile solids (VS), the carbon/nitrogen (C/N) ratio, humic substances (HS), the total organic carbon (TOC), the carbon dioxide (CO2) evolution rate, the specific oxygen uptake rate (SOUR), and the Dewar test; however, different criteria exist for the same indicators. Although there is no consensus for defining the stability of sewage sludge (biosolids) in the research and regulations reviewed, controlling the biological degradation, vector attraction, and odor determines the biological stabilization of sewage sludge. Because pollutants and pathogens are not completely removed in biological stabilization processes, further treatments to improve the quality of biosolids and to ensure their safe use should be explored.

A Novel Hybrid Reactor of Pressure-Retarded Osmosis Coupling with Activated Sludge Process for Simultaneously Treating Concentrated Seawater Brine and Wastewater and Recovering Energy.

As an attractive way to deal with fresh water shortage, membrane-based desalination technologies are receiving increased interest. However, concentrated seawater brine, in needing further treatment, remains a main obstacle for desalination via membrane technology. Here, a hybrid technology integrating pressure-retarded osmosis with activated sludge process (PRO-MBR) was applied for simultaneously treating concentrated seawater brine and municipal wastewater. Performance of the PRO-MBR, including water flux, power density, contaminants removal, and membrane fouling was evaluated and compared at two different membrane orientations (i.e., active layer facing feed solution (AL-FS) mode and active layer facing draw solution (AL-DS) mode). During the PRO-MBR process, the municipal wastewater was completely treated regardless of the membrane orientation, which means that there was no concentrated sewage needing further treatment, owing to the biodegradation of microorganisms in the bioreactor. In the meantime, the concentrated brine of seawater desalination was diluted into the salinity level of seawater, which met the standard of seawater discharge. Owing to the high rejection of forward osmosis (FO) membrane, the removal efficiency of total organic carbon (TOC), total phosphorus (TP), ammonia nitrogen (NH4+-N), and total nitrogen (TN) was higher than 90% at both modes in the PRO-MBR. In addition, the PRO-MBR can simultaneously recover the existing osmotic energy between the municipal wastewater and the seawater brine at both modes. Compared with the AL-DS mode, the AL-FS mode took a shorter time and achieved a bigger power density to reach the same terminal point of the PRO-MBR owing to a better water flux performance. Furthermore, the membrane fouling was much more severe in the AL-DS mode. In conclusion, the current study demonstrated that the PRO-MBR at the AL-FS mode can be a promising and sustainable brine concentrate and municipal wastewater treatment technology for its simultaneous energy and water recovery.

Anaerobic Membrane Bioreactors for Municipal Wastewater Treatment: A Literature Review.

Currently, there is growing scientific interest in the development of more economic, efficient and environmentally friendly municipal wastewater treatment technologies. Laboratory and pilot-scale surveys have revealed that the anaerobic membrane bioreactor (AnMBR) is a promising alternative for municipal wastewater treatment. Anaerobic membrane bioreactor technology combines the advantages of anaerobic processes and membrane technology. Membranes retain colloidal and suspended solids and provide complete solid–liquid separation. The slow-growing anaerobic microorganisms in the bioreactor degrade the soluble organic matter, producing biogas. The low amount of produced sludge and the production of biogas makes AnMBRs favorable over conventional biological treatment technologies. However, the AnMBR is not yet fully mature and challenging issues remain. This work focuses on fundamental aspects of AnMBRs in the treatment of municipal wastewater. The important parameters for AnMBR operation, such as pH, temperature, alkalinity, volatile fatty acids, organic loading rate, hydraulic retention time and solids retention time, are discussed. Moreover, through a comprehensive literature survey of recent applications from 2009 to 2021, the current state of AnMBR technology is assessed and its limitations are highlighted. Finally, the need for further laboratory, pilot- and full-scale research is addressed.

Reuse-focused selection of appropriate technologies for municipal wastewater treatment: a multi-criteria approach.

Wastewater treatment technologies (WWTTs) are employed across the world, and the selection is mainly based on ‘past experiences’ aimed at ‘pollution prevention’ in the receiving water bodies. This paper aims to develop a methodology for the selection of an appropriate wastewater treatment chain that produces effluent suitable for the defined reuse. Adopting the least weighted cost approach, four decision criteria: Capital cost, Operation and Maintenance cost, Land requirement, and Energy requirement, have been used and the Full Consistency Method (FUCOM) has been employed for obtaining weights. Quality expectations for 14 reuses have been enlisted, and 25 WWTTs have been evaluated in a total of 360 combinations. In Kanpur city, for water reuse in industrial cooling under restricted land and challenging influent quality conditions, a combination of Membrane Bioreactor (MBR) with Wuhrmann process (WP) is obtained as the most preferred suggestion. For non-potable domestic reuse, Anaerobic Anoxic Oxic (A2O) with Ultrafiltration (UF) and Reverse Osmosis (RO) is the most preferred combination. In Varanasi city, for vehicular washing operations and for flow augmentation (inland surface water), under energy-constraint scenario, high-rate activated sludge-based biological filtration and oxygenated reactor (BIOFOR-F) is suggested. For technology supplementation to existing ASP-based STPs in the city to obtain effluent for inland surface water augmentation, WP in combination with microfiltration (MF) and reverse osmosis (RO) is suggested. Thus, the developed model may be used as a decision-making tool for planning a reuse-focused water reclamation program or for upgradation of existing STPs as per resource availability and target reuse objectives.

Circular economy is game-changing municipal wastewater treatment technology towards energy and carbon neutrality

With gradual transformation of global linear economy to circular economy, the present municipal wastewater treatment processes designed with the philosophy of take-make-dispose are facing incredible economic and environmental pressures due to high energy consumption, emission of greenhouse gases, waste generation etc. In such a situation, “we cannot solve our problems with the same thinking we used when we created them” as said Albert Einstein. Therefore, this article intends to trigger discussion on how circular economy is to game-change municipal wastewater treatment technology towards energy and carbon neutrality. As illustrated with anaerobic MBR as an example, municipal wastewater indeed is a regenerative resource of freshwater, energy and mineral nutrients rather than a waste. This will lead to a paradigm shift of municipal wastewater engineering from simple treatment to recovery and reuse of multiple resources for synergistically addressing the water-energy-resource-greenhouse gases nexus in an environmentally and economically sustainable manner, with the ultimate goals of energy and carbon neutrality in municipal wastewater reclamation.

Microalgal-Bacterial Granular Sludge Process in Non-Aerated Municipal Wastewater Treatment under Natural Day-Night Conditions: Performance and Microbial Community

The microalgal-bacterial granular sludge (MBGS) process is expected to meet the future requirements of municipal wastewater treatment technology for decontamination, energy consumption, carbon emission and resource recovery. However, little research on the performance of the MBGS process in outdoor treatment was reported. This study investigated the performance of the MBGS system in treating municipal wastewater under natural alternate day and night conditions in late autumn. The results showed that the average removal efficiencies of Chemical oxygen demand (COD), NH4+-N and PO43−-P on daytime before cooling (stage I, day 1−4) could reach 59.9% ± 6.8%, 78.1% ± 7.9% and 61.5% ± 4.5%, respectively, while the corresponding average removal efficiencies at night were 47.6% ± 8.0%, 56.5% ± 17.9% and 74.2% ± 7.6%, respectively. Due to the dramatic changes in environmental temperature and light intensity, the microbial biomass and system stability was affected with fluctuation in COD and PO43−-P removal. In addition, the relative abundance of filamentous microorganisms (i.e., Clostridia and Anaerolineae) decreased, while Chlorella maintained a dominant position in the eukaryotic community (i.e., relative abundance > 99%). This study can provide a theoretical basis and technical support for the further engineering application of the MBGS process.

Analysing water-energy-GHG nexus in a wastewater treatment plant of Mumbai Metropolitan Region, India

Developing nations are advancing towards improving municipal wastewater treatment infrastructure. However, there have been limited efforts in these countries to understand Water-Energy-GHG nexus for sustainable wastewater treatment. This study evaluates operational energy, total embodied energy and corresponding GHG emissions of a widely implemented municipal wastewater treatment technology in Mumbai Metropolitan Region of India. Data for wastewater inflow, total energy consumption and materials used in the unit processes of the treatment plant were collected and analysed. Direct GHG emissions from the plant were estimated using the method proposed by the intergovernmental panel for climate change (IPCC). The energy embodied within the materials used in the construction and operations of the plant was estimated using country-specific information. The results show that the energy intensity for plant operation and chemical oxygen demand (COD) removal was 0.23 ± 0.05 kWh/m3 of wastewater treated and 1.12 ± 0.77 kWh/kg of COD removed, respectively. The embodied energy in chemicals and building materials during the plant's life cycle contributed 19% of the total embodied energy. Wastewater inflow with specific average energy consumption in wet-well pumping and blowers showed a negative and positive correlation, respectively. The total GHG emissions (direct and indirect) from the plant were ~0.22 kgCO2eq/m3 of wastewater treated. The study presents the energy accounting of a wastewater treatment system and extensive analysis of infrastructural data, which is scarcely accessible and available in developing countries.

Advances in anaerobic membrane bioreactor technology for municipal wastewater treatment: A 2020 updated review

The application of anaerobic membrane bioreactors (AnMBR) for mainstream municipal sewage treatment is almost ready for full-scale implementation. However, some challenges still need to be addressed to make AnMBR technically and economically feasible. This article presents an updated review of five challenges that currently hinder the implementation of AnMBR technology for mainstream sewage treatment: (i) membrane fouling, (ii) process configuration, (iii) process temperature, (iv) sewage sulphate concentration, and (v) sewage low organics concentration. The gel layer appears to be the main responsible for membrane fouling and flux decline being molecules size and morphology critical properties for its formation. The review also discusses the advantages and disadvantages of five novel AnMBR configurations aiming to optimise fouling control. These include the integration of membrane technology with CSTR or upflow digesters, and the utilisation of scouring particles. Psychrophilic temperatures and high sulphate concentrations are two other limiting factors due to their impact on methane yields and membrane performance. Besides the methane dissolved in the effluent and the competition for organic matter between sulphate reducing bacteria and methanogens, the review examines the impact of temperature on microbial kinetics and community, and their combined effect on AnMBR performance. Finally, the review evaluates the possibility to pre-concentrate municipal sewage by forward osmosis. Sewage pre-concentration is an opportunity to reduce the volumetric flow rate and the dissolved methane losses. Overall, the resolution of these challenges requires a compromise solution considering membrane filtration, anaerobic digestion performance and economic feasibility.

Consequences of fluctuating depth of filter media on coliform removal performance and effluent reuse opportunities of a bio-sand filter in municipal wastewater treatment

Abstract Due to the rapid urbanization attaining full coverage of proper wastewater treatment is a challenge in several developing nations. The conventional sanitattion approachpracticed in different countries does not satisfy the current wastewater treatment need of fastly growing cities. Also, the decentralized technologies practiced so far is interrupted by technical issues that ends in an extensive upsurge of maintenance cost and poor effluent quality. Thus, this study focuses on the applicability of low-cost bio-sand filters as a decentralized municipal wastewater treatment technology through testing pathogen removal efficiency and effluent reuse possibilities of different media depth bio-sand filters. Three setups of bio-sand filtercolumn were established each comprised of a specific sand, fine gravel and coarse gravel with different filter depths. The results orevealed geometric mean reductions for total coliforms of 99 %, 87 % and 30 % for a bio-sand filter with the top fine sand depth of 220 mm, 120 mm, and 20 mm, respectively. While the geometric mean for the reduction of fecal coliform was 99.9 %, 99.6 %, and 99 %. The effluent from three of the bio-sand filters does not achieve the requirements for unrestricted irrigation according to WHO and US-EPA guidelines. Whereas the quality of effluent from the first scenario of the bio-sand filter can meet WHO and US-EPA guidelines for restricted irrigation reuse option. Likewise, the effluent from the second scenario of the bio-sand filter achieves the US-EPA reuse standard for restricted irrigation.

Techno-economic analysis of combining forward osmosis-reverse osmosis and anaerobic membrane bioreactor technologies for municipal wastewater treatment and water production

The economic feasibility of combining forward osmosis (FO), reverse osmosis (RO) and anaerobic membrane bioreactor (AnMBR) technologies for municipal wastewater treatment with energy and water production was analysed. FO was used to pre-concentrate the AnMBR influent, RO for draw solution regeneration and water production, and AnMBR for wastewater treatment and energy production. The minimum wastewater treatment cost was estimated at 0.81 € m−3, achieved when limiting the FO recovery to 50% in a closed-loop scheme. However, the cost increased to 1.01 and 1.27 € m−3 for FO recoveries of 80% and 90%, respectively. The fresh water production cost was estimated at 0.80 and 1.16 € m−3 for an open-loop scheme maximising water production and a closed-loop scheme, respectively. The low FO membrane fluxes were identified as a limiting factor and a sensitivity analysis revealed that FO membrane fluxes of 10 LMH would significantly improve the competitiveness of FO-RO + AnMBR technology.

Moving forward in the use of aerobic granular sludge for municipal wastewater treatment: an overview

Activated sludge is one of the most widely implemented technologies for municipal wastewater treatment. Yet, more restrictive environmental standards demand for more efficient technologies. Aerobic granular sludge (AGS) is a promising alternative in this context since this technology has shown potential for simultaneous organic matter and nutrient removal using smaller bioreactors and consuming less energy. However, despite such engaging claims, only ca. 40 full-scale AGS systems have been installed worldwide after 30 years of development. This reduced implementation suggests the existence of significant bottlenecks for this technology, which currently only have partially been overcome. This overview aims to analyze the recent progress in R&D concerning aerobic sludge granulation for municipal wastewater treatment via the analysis of research articles and invention patents as well as to elucidate exiting technological gaps and development opportunities. Culturing methods aiming at fast granulation, long-term stability and excellent process performance are of utmost interest for promoting massive implementation of full-scale AGS systems. Moreover, the recovery of biomaterials from waste sludge could contribute to the implementation of the biorefinery paradigm in wastewater treatment plants.

Process schemes for future energy-positive water resource recovery facilities.

There are numerous successful studies on optimizing the performance of conventional activated sludge (CAS)-based wastewater treatment plants. However, recent studies have shown that a more significant improvement of the plant performance is achievable through integration of established technologies in novel process schemes. High-rate activated sludge system, chemically enhanced primary treatment, partial nitritation-anammox, partial nitrification-denitrification over nitrite and anaerobic digestion are integrated in two process schemes to determine to which extent energy savings and energy production can be achieved with these new process layouts compared to a CAS-based process scheme. The results presented in this paper show that there is potential for achieving future energy-positive water resource recovery facilities through novel integration of mature technologies for municipal wastewater treatment.

Direct filtration for the treatment of the coagulated domestic sewage using flat-sheet ceramic membranes

Direct membrane filtration (DMF) is considered as a promising technology for municipal wastewater treatment. We utilized an innovative application of flat-sheet ceramic membranes (FSCM) for DMF for the rapid treatment of domestic sewage. Coagulation was applied before FSCM filtration to increase the pollutant removal and to mitigate membrane fouling. This coagulation-FSCM filtration can significantly reduce the pollutant load on the downstream treatment and concentrate organics and nutrients into sludge to facilitate resource recovery. Using polyaluminum chloride (PACl) based FSCM filtration, approximately 90.0% of the chemical oxygen demand (COD) and 99.0% of the phosphorus (P) were removed from the sewage influent and retained in the concentrated sludge, with less than 25.0 mg/L COD left in the effluent. Long-term operation of the PACl-based FSCM filtration stably maintained a high flux of 41.7 L/m2-h (LMH, or 1.0 m/d). The fouled membranes were cleaned chemically every 3–5 d, and the membrane permeability could almost be completely recovered using chemical backwash for only 10 min with a diluted acidic, alkaline, chlorine or H2O2 solution. The novel FSCM process will fundamentally advance wastewater treatment technology. It can be readily modularized and installed as simple add-on units to upgrade and retrofit existing wastewater treatment systems.

Municipal wastewater treatment technologies: A review

Municipal wastewater is the most abundant type of wastewater that falls into the category of low-strength waste streams. It is characterized by low organic strength and high particulate organic matter content. Municipal wastewater treatment plants have the potential to become net producers of renewable energy, converting the chemically bound energy content in the organic pollutants of raw municipal wastewater to a useful energy carrier (biogas), while producing clean water for communities in the vicinity. This paper presents a review of the different technologies that can be deployed in the treatment of municipal wastewater. The focus is mainly on bioreactor technologies that are available for current and possible future implementation in the municipal wastewater treatment systems.