Decentralized Wastewater Treatment Systems Research Articles

Exploring transitions of sewer wastewater infrastructure towards decentralisation using the modular model TURN-Sewers

We present a new modular model called TURN-Sewers for exploring different adaptations of centralised wastewater infrastructure towards more decentralised wastewater systems under different urban development scenarios. The modular model is flexible and computationally efficient in exploring transitions at the city scale, allowing for the comparison of different policies and management strategies for sanitary wastewater infrastructure. TURN-Sewers includes independent modules that simulate the generation, dimensioning, deterioration, management, and calculation of performance indicators for different wastewater systems. This model can use readily available spatial information to support infrastructure planners and other stakeholders in exploring different transition pathways from centralised to decentralised wastewater infrastructure. An illustrative example demonstrates how TURN-Sewers can generate multiple future alternatives, define different infrastructure management strategies regarding system expansion, rehabilitation and transition, and assess the economic, hydraulic and structural impacts.

Monitoring SARS-CoV-2 RNA in wastewater from a shared septic system and sub-sewershed sites to expand COVID-19 disease surveillance

Abstract Wastewater-based epidemiology has expanded as a tool for collecting COVID-19 surveillance data, but there is limited information on the feasibility of this form of surveillance within decentralized wastewater systems (e.g., septic systems). This study assessed SARS-CoV-2 RNA concentrations in wastewater samples from a septic system servicing a mobile home park (66 households) and from two pumping stations serving a similarly sized (71 households) and a larger (1,000 households) neighborhood within a nearby sewershed over 35 weeks in 2020. Also, raw wastewater from a hospital in the same sewershed was sampled. The mobile home park samples had the highest detection frequency (39/39 days) and mean concentration of SARS-CoV-2 RNA (2.7 × 107 gene copies/person/day for the N1) among the four sampling sites. N1 gene and N2 gene copies were highly correlated across mobile home park samples (Pearson's r = 0.93, p < 0.0001). In the larger neighborhood, new COVID-19 cases were reported every week during the sampling period; however, we detected SARS-CoV-2 RNA in 12% of the corresponding wastewater samples. The results of this study suggest that sampling from decentralized wastewater infrastructure can be used for continuous monitoring of SARS-CoV-2 infections.

Smartphone-based colorimetric method for decentralized wastewater treatment monitoring by inexperienced users

Rural areas often rely on decentralized wastewater treatment systems, including individual sewage treatment systems (ISTS), for remote houses, farms, and other establishments. For practical and financial reasons, ISTSs are often exempt from routine monitoring of effluent quality. As a result, they cannot guarantee the same level of treatment performance as their large-scale counterparts. A smartphone-based colorimetric monitoring method has been developed and tested to address this issue. This method can be easily adopted by untrained system owners. It uses modified test strips with built-in color reference zones and fiducial markers, which simplifies data acquisition and interpretation, eliminating the need for positioning accessories or controlled lighting. The proposed method ensures reliable results even when using a regular smartphone with default picture quality settings. The method has been tested with test strips measuring five different relevant wastewater quality parameters: pH, phosphates, ammonium, nitrates, and nitrites. For each type of test strip, the software installed on a smartphone provides a correlation for interpolating the measurements. The R2-values ranged from 0.881 to 0.993 for different reagents. The accuracy of this method was verified using lab-grade reference sensors and was found to be sufficient for the intended purpose.

Eliciting expert judgements to underpin our understanding of faecal indicator organism loss from septic tank systems

Septic tank systems (STS) in rural catchments represent a potential source of microbial pollution to watercourses; however, data concerning the risk of faecal indicator organism (FIO) export from STS to surface waters are scarce. In the absence of empirical data, elicitation of expert judgements can provide an alternative approach to aid understanding of FIO pollution risk from STS. Our study employed a structured elicitation process using the Sheffield Elicitation Framework to obtain expert judgements on the proportion of FIOs likely to be delivered from STS to watercourses, based on 36 scenarios combining: (i) septic tank effluent movement risk, driven by soil hydro-morphological characteristics; (ii) distance of septic tank to watercourse; and (iii) degree of slope. Experts used the tertile method to elicit a range of values representing their beliefs of the proportion of FIOs likely to be delivered to a watercourse for each scenario. The experts judged that 93 % of FIOs would likely be delivered from an STS to a watercourse under the highest risk scenario that combined (i) very high STS effluent movement risk, (ii) STS distance to watercourse <10 m, and (iii) a location on a steep slope with gradient >25 %. Under the lowest risk scenario, the proportion of FIOs reaching a watercourse would likely reduce to 5 %. Expert confidence was high for scenarios that represented extremes of risk, while uncertainty increased for scenarios depicting intermediate risk conditions. The behavioural aggregation process employed to obtain a consensus among the experts proved to be useful for highlighting both areas of strong consensus and high uncertainty. The latter therefore represent priorities for future empirical research to further improve our understanding of potential pollution risk from septic tanks and in turn enable better assessments of potential threats to water quality in rural catchments throughout the world where decentralised wastewater systems are common.

Characterization of Low-Volume Meat Processing Wastewater and Impact of Facility Factors

Low-volume meat processing facilities often rely on decentralized wastewater treatment due to cost constraints and the lack of access to centralized treatment. Improved characterization of these facilities’ wastewater is crucial for meeting local groundwater discharge permits. This study also directly correlates treatment systems and facility characteristics to the results of the characterization. The total nitrogen (TN), biochemical oxygen demand (BOD), and phosphorus (P) reductions ranged from −15% to 83%, 43% to 95%, and −75% to 62%, respectively. Slaughtering and smoking were found to significantly increase nutrient concentrations. The average TN leaving the slaughterhouses and processing-only facilities was 519 mg/L-N and 154 mg/L-N, respectively. The average BOD produced by the slaughterhouses and processors was 3002 mg/L and 1660 mg/L, respectively. Filtration was found to reduce BOD, chemical oxygen demand (COD), and trace metals. Aeration in a treatment lagoon was found to significantly reduce BOD, COD, and N compounds. The results indicate that even simple decentralized wastewater treatment systems, combined with facility management practices, can substantially reduce permitted wastewater characteristics. The facility with the best BOD removal had an effluent value of 71.3 mg/L, representing a 96% reduction. The facility with the best TN removal had an effluent value of 20 mg/L, representing a 92% reduction prior to discharge.

Tracking performance and disturbance in decentralized wastewater treatment systems with fluorescence spectroscopy

Fluorescence spectroscopy holds promise as a rapid tracer of performance in decentralized wastewater treatment systems (DEWATS) that may reduce the monitoring burden on communities.

Contaminants of Emerging Concern in Minnesota Subsurface Sewage Treatment Systems

Highlights CEC are quantified in septic tank effluent, soil, and groundwater within septic systems. The success of septic system treatment of specific CEC is discussed. Treatment of CEC is compared between wastewater in septic systems and land-applied septage. Advanced treatment impact on CEC levels is analyzed. Abstract. Contaminants of Emerging Concern (CEC) are gaining attention as they continue to attract public awareness and more environmental and health consequences are recognized. This study showcases CEC concentrations within Minnesota’s Subsurface Sewage Treatment Systems (SSTS). The study identifies a broad range of CECs associated with subsurface sewage treatment at four sites. Three sites are Minnesota Department of Transportation rest area SSTS with high user inputs, and one site is a septage land application field that receives septage from residential and septic commercial tanks. The studied CEC include antibiotics, chronic disease prescriptions, veterinary medicine, stimulants, hormones, antihistamines, pain and fever relief prescriptions, and a plasticizer. CEC were quantified in the septage, septic tank effluent, advanced treatment effluent, soil, and shallow groundwater. The samples were analyzed via mass spectrometry coupled with light chromatography, revealing that CEC concentrations decrease as they move through the SSTS system. Septage had the highest concentrations of CEC, followed by septic tank effluent. Groundwater had the third highest concentrations, and soils had the lowest concentrations of CEC. CEC concentrations are being reduced through SSTS, but some persist in shallow groundwater. Keywords: Decentralized wastewater system, Groundwater, Pharmaceuticals, Septage, Septic system, Septic tank, Wastewater.

Conceptual Feasibility of a Portable Containerized and Decentralized Wastewater Treatment System for Rural Regions: A Case Study in Palestine

The necessary implementation of decentralized wastewater treatment systems in densely populated rural regions is a viable alternative to constructing a large centralized system. Therefore, this study aims to assess the conceptual feasibility of implementing a portable containerized and decentralized wastewater treatment system as a case study in Palestine that can help in treating wastewater in rural areas efficiently generated by up to 4,000 individuals. The conceptually proposed system is comprised of two stages. The initial stage includes a standalone primary sedimentation tank located outside the container. The subsequent stage consists of a container housing all the equipment utilized in the treatment process beginning with aeration, followed by secondary sedimentation, and ending with filtration and chlorination. Although the system is designed as a single container, in practice, it will consist of two containers with identical units. The second container will ensure continuous operation mode in case of maintenance in the first container. An initial cost evaluation was conducted, and the projected cost for one container is roughly $9,800, which is reasonable. Indeed, adopting this proposed system would result in a significant cost-saving of approximately 40 million dollars compared to the current west wastewater treatment plant in Nablus. Additional research can be undertaken to explore the running cost and the level of efficacy attained

Investigation of Decentralized Wastewater Treatment System in Urban Wastewater Management: Case Study in Yangon, Myanmar

Urban wastewater management in rapidly growing cities presents a significant challenge. Traditional centralized systems are unable to keep pace with increasing urbanization and wastewater generation. This manuscript presents a case study conducted in Yangon, aimed at investigating the feasibility and potential benefits of approaching the decentralized wastewater treatment system (DEWATS) as an alternative solution. DEWATS and centralized wastewater treatment system (CWTS) cases were observed for performance, operational efficiency, and environmental benefits. Field studies, interviews with municipal personnel, and discussions with residents were also conducted. Residents using DEWATS in Yangon value its environmental advantages and are willing to invest in sustainability. Those who use centralized systems are concerned about high costs and unreliability. Results from sustainability assessments showed that DEWATS obtained higher total scores than CWTS. Based on Weighted Sum Methods in three sustainability scenarios, DEWATS ranked first and has been shown to be a sustainable solution for Yangon across environmental, social, economic, and technical aspects. This study provides an alternative strategy for urban planners and decision-makers to use DEWATS as an option for urban wastewater management. The evidence could support accelerating provision of wastewater treatment plants and encourage willingness to pay.

Phosphate Recovery from Urine-Equivalent Solutions for Fertilizer Production for Plant Growth.

This study presents a proof of concept for the recovery of phosphate from aqueous solutions with high phosphorus (PO4-P) initial contents to simulate the concentration of streams from decentralized wastewater systems. Solutions with ∼500 ppm phosphorus enable phosphate adsorption and recovery, in contrast to the highly diluted inlet streams (<10 ppm) from centralized wastewater treatment plants. In this work, Mg-Fe layered double hydroxide is used as a phosphate adsorbent, demonstrating its separation from aqueous streams, recovery, and use as a fertilizer following the principles of circular economy. We demonstrate that the mechanism of phosphate adsorption in this material is by a combination of surface complexation and electrostatic attraction. After the loss of crystallinity in the presence of water in the first cycle and its associated decrease in adsorption capacity, the Mg-Fe layered double hydroxide (LDH) is stable after consecutive adsorption/desorption cycles, where desorption solutions were reused to substantially increase the final phosphate concentration demonstrating the recyclability of the material in a semicontinuous process. Phosphate recovered in this way was used to complement phosphate-deficient plant growth medium, demonstrating its efficacy as a fertilizer and thereby promoting a circular and sustainable economy.

Lesson Learned from Yangon to Mandalay on Wastewater Treatment Systems

This paper presents a comparative analysis of wastewater management practices in Myanmar’s major cities, Yangon and Mandalay, with a focus on drawing valuable lessons from Yangon’s experiences and proposing recommendations for the improvement of Mandalay’s domestic wastewater management, drawing insights from a SWOT analysis. Both cities are facing challenges due to rapid urbanization, leading to untreated discharge into the environment. The study identifies common challenges in both Yangon and Mandalay, such as limited treatment capacity, environmental concerns, and funding gaps. The decentralized-centralized strategy is a successful approach for Yangon even though the capacity is not high. Results showed that 17.5% of Decentralized Wastewater Treatment Systems (DEWATS) users were highly satisfied and 45% were somewhat satisfied. Yangon’s experience with centralized systems showed that it took several years to cover the entire city for treatment, resulting in issues to cover revenue expenditures. If Mandalay adopts a similar, it will likely encounter the same issues. A recommended approach would be to implement an integrated system with DEWATS, which offers a better solution. The recommendations for sustainable wastewater management in Mandalay include active stakeholders’ involvement in decision-making, promoting community participation, and providing training. Transparency and shared responsibility are crucial for success. Addressing membrane fouling, sludge disposal, and implementing monthly fees are essential for sustainable implementation. An integrated approach along with environmental and social impact assessments are necessary to develop a cost-effective and efficient wastewater treatment system while safeguarding public health and the environment. These insights offer broader implications, guiding developing countries towards more effective and environmentally responsible wastewater management practices.

Using walnut shells as low-cost adsorbent materials in an anaerobic filter medium of a De-centralized wastewater treatment system (DEWATS)

The flow of unprocessed sewage through municipal sewers is a great source of water contamination. This study aims to observe the pollutants removal efficiencies of walnut shells as an efficient low-cost adsorbent material compared to gravel materials as an anaerobic filter medium. Two models of the De-Centralized Wastewater Treatment System (DEWATS) were constructed. The wastewater flowing from toilets and handwashing places was connected to anaerobic filters filled with walnut shells and gravel. The efficiency of both filter media in the removal of biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS), nitrate (NO3), and phosphate (PO43), pH and temperature were observed at the influent of the settler tank and then at the effluent of the collection tank (CT). Temperature and pH were within the acceptable limit of wastewater discharge. The results also indicated that the walnut shells filter media was more efficient at removing organic pollutants (TSS 94%, BOD5 88%, COD 85%, Nitrate 57%, phosphate 46%, and TDS 29%) than the gravel (TSS 81%, BOD5 82%, COD 84%, Nitrate 35%, phosphate 38%, and TDS 26%) at the successive stages. The average removal efficiency of the walnut shell was 88% while in the gravel case, it was 83%. The removal efficiency of walnut shell filters was extensively better over the complete experiment compared to gravel filters for the removal of pollutants, representing the high sorption capability of the walnut shell material. The results of this study show that the walnut shells may be a very useful substitute for other conventional fillers for anaerobic treatment in the anaerobic filter of DEWATS.

Linking Urban Water Management, Wastewater Recycling, and Environmental Education: A Case Study on Engaging Youth in Sustainable Water Resource Management in a Public School in Casablanca City, Morocco

The management of water resources is crucial for sustainable development, necessitating innovative solutions to address the increasing demand for safe water. Alternative approaches must be adopted to effectively engage young generations in understanding the importance of water resources. This chapter reports on an experiment that aimed to promote sustainability education by linking wastewater treatment and reuse with an educational garden. In particular, an undertaking was executed to establish a decentralized wastewater treatment system wherein purified water was employed for the purpose of irrigation. The study’s primary focus is on the association between urban water management, wastewater recycling, and environmental education. The study has two distinct components. The first segment discusses three examples of projects that have employed urban wastewater treatment and reuse to generate environmental education materials using various approaches. The second component features a case study of a public high school in Casablanca, where students participated in a questionnaire and participatory workshops to design an educational garden. The study’s outcomes include a proposed educational garden design that will be presented to the relevant authorities and project partners.

A survey on constructed wetland publications in the past three decades.

Decentralised wastewater treatment systems, such as constructed wetlands, are becoming increasingly popular these days because they are more economical and cost-effective than conventional plants. The primary objective of this review paper is to determine the number of studies that have been conducted on constructed wetlands, specifically 'free water surface flow constructed wetlands', 'horizontal subsurface flow constructed wetlands', 'vertical subsurface flow constructed wetlands', and 'hybrid constructed wetlands'. In addition, the paper examines the status of research publications on constructed wetlands by country, author, and journal. Based on the review, it has been found that although constructed wetland technology is economical and cost-effective, it is still not among the top 10 effluent treatment methods. Compared to other constructed wetland systems, 'hybrid constructed wetlands' have received minimal attention. Based on the search results, 4639 documents published between 1989 and 2021 have been extracted from the online edition of SCI-EXPANDED, Web of Science. The documents associated with constructed wetlands are divided into eight main document types. Articles and proceedings papers are the most common document type, accounting for 93% of all publications, followed by reviews (4%), meeting abstracts (1.3%), corrections (0.56%), editorial materials (0.38%), news items (0.2%), letters (0.04%), and book reviews (0.02%).

Enhancement of a Decentralized Wastewater Treatment System by Applying a Bio-tower - A Project for Improving our Environmental Footprint

To investigate if decentralized wastewater treatment systems impact on the environment performance can be improved, a Field Bio-tower Tank Septic system was designed, installed on an existing 1,500-gal (5678 l) decentralized wastewater treatment system. The system was started up during a 14-day start-up phase, followed by a 130-day test phase. The system was operated at an average hydraulic retention time of 16.7 days based on a 90 gal (204.4 l) daily influent wastewater flow.&#x0D; The systems recirculation flow for the bio-tower was 22.6 l/min (6 gal/min) for the start-up phase and 40.0 l/min (10.6 gal/min) for the test period with a corresponding recirculation of the entire septic tank from 5.7 to 10.1 times a day respectively.&#x0D; During the testing period a daily average temperature of 19.3°C (66.7°F) and an average rainfall of 5 l/m² was observed. The FBST system operated at an average influent pH level and temperature of 8.6 and 22.0°C. The average effluent pH and temperature was 8.5 of 20.9°C.&#x0D; The installed system reduced on average the influent TS from 79151 mg/l to 43021 mg/l and showed an average reduction of the TDS from 36424 mg/l to 21965 mf/l. The TSS and VSS was reduced on average from 94.1 mg/l to 69.9 mg/l and 89.0 mg/l to 64.9 mg/l.&#x0D; NH3-N content was reduced from 57.5 mg/l in the influent to 53.4 mg/l in the effluent. The average BOD and COD was reduced from the average influent value of 88.2 mg/l and 318.2 mg/l to 66.8 mg/l and 256.2 mg/l respectively. However, at the end of the 130-day test period BOD and COD values were the lowest at 15.5 mg/l and 56.0 mg/l respectively, indicating bacteria cultures are well established and the system operation of the FBTS system is mostly constant.&#x0D; This research showed that the FBST system can improve operations of a DWWTS system significantly reducing the effluent load over 10 times compared to the influent load of the system.

Water treatment and reclamation by implementing electrochemical systems with constructed wetlands

Seasonal or permanent water scarcity in off-grid communities can be alleviated by recycling water in decentralized wastewater treatment systems. Nature-based solutions, such as constructed wetlands (CWs), have become popular solutions for sanitation in remote locations. Although typical CWs can efficiently remove solids and organics to meet water reuse standards, polishing remains necessary for other parameters, such as pathogens, nutrients, and recalcitrant pollutants. Different CW designs and CWs coupled with electrochemical technologies have been proposed to improve treatment efficiency. Electrochemical systems (ECs) have been either implemented within the CW bed (ECin-CW) or as a stage in a sequential treatment (CW + EC). A large body of literature has focused on ECin-CW, and multiple scaled-up systems have recently been successfully implemented, primarily to remove recalcitrant organics. Conversely, only a few reports have explored the opportunity to polish CW effluents in a downstream electrochemical module for the electro-oxidation of micropollutants or electro-disinfection of pathogens to meet more stringent water reuse standards. This paper aims to critically review the opportunities, challenges, and future research directions of the different couplings of CW with EC as a decentralized technology for water treatment and recovery.

Stakeholder evaluation of sustainability in a community-led wastewater treatment facility in Jakarta, Indonesia

Indonesia’s severely flawed centralized wastewater treatment system has caused economic and socioeconomic losses for decades. An alternative system has been called for under a national-scale program called Sanimas or Community-Led Total Sanitation (CLTS), which would cater to 50–100 urban families in every intervention with urgent needs through the operation of a decentralized wastewater treatment system. Through household participation, this program features a co-production system wherein the national-level government initiates and provides initial funding until construction, after which a community-appointed social organization takes over. This study implemented a multicriteria approach to assess sustainability in Sanimas communities in Jakarta: 67 in Menteng (Central Jakarta) and At-Taubah in Koja (North Jakarta). Connected households and facility-operating committees were questioned separately for their opinions on six aspects that explained the survival of the establishment of a facility: technical, management, community participation, financial, institutional, and environmental. We found that although the facility’s excellence and overall satisfaction with the program were unanimous, Koja and Menteng showed substantial differences in management, institutional, and financial aspects, largely due to administrative policies, payment contributions, and committee commitments. Interviews revealed that periodic testing of the treated water was neglected, against the provided guidance. In conclusion, communities have come to focus more on the technical functionalities of the installation, regardless of the state of the management, which is indisputable not only in Menteng but also in Koja. Finally, we argue that although decentralized systems can substitute centralized systems, they still require stringent and adequate support in quality control and troubleshooting.

Life Cycle Assessment of Black and Greywater Treatment Solutions for Remote and Sensitive Areas

Sensitive and remote areas have come under pressure from growing populations and tourism, often resulting in improper wastewater management. Efficiency, durability, the use of renewable construction materials, and the minimization of environmental impacts must be conformed to a sustainable paradigm. A life cycle assessment (LCA) was applied to compare three different decentralized wastewater treatment systems built at tourist facilities: a source separation sanitation system with a hybrid constructed wetland (S1), a sequential batch reactor (SBR) with a hybrid constructed wetland (S2), and a solar-powered composting toilet (S3). Benchmarking showed that S1 was preferred over S2. The differences were up to a factor of two, except for eutrophication, which was significantly higher for S2 (10×). S3 had the lowest environmental impact, but S3 treated only the blackwater fraction, i.e., urine, faeces, and toilet paper, and excluded greywater treatment, i.e., handwashing and/or kitchen wastewater. The scenario analysis showed that the environmental performance could be improved by installing solar panels, but this would increase the impact on the abiotic depletion of elements by 83% for S2. The LCA indicated the advantages, disadvantages, flexibility, and potential for design improvements to meet the environmental sustainability and market demands for system diversity.

The potential of decentralised wastewater treatment in urban and rural sanitation in South Africa: lessons learnt from a demonstration-scale DEWATS within the eThekwini Municipality

The design principles of decentralised wastewater treatment systems (DEWATS) make them a practical sanitation option for municipalities to adopt in fast-growing cities in South Africa. Since 2014, a demonstration-scale DEWATS with a modular design consisting of a settler, anaerobic baffled reactor (ABR), anaerobic filter (AF), vertical down-flow constructed wetland (VFCW) and horizontal flow constructed wetland (HFCW) has been in operation in eThekwini. A performance evaluation after the long-term operation was undertaken in 2019 by comparing the final effluent with national regulatory requirements. Despite limitations in characterising the raw wastewater, a comparison of the settler and final effluent quality indicated high (≥ 85%) removal efficiencies of total chemical oxygen demand (CODt), ammonium-N (NH4-N) and orthophosphate-P (PO4-P), 75% removal of total suspended solids (TSS) and 83.3% log10 removal of Escherichia coli. Lack of exogenous and endogenous carbon and high dissolved oxygen (DO) concentrations (&gt; 0.5 mg‧L−1) inhibited denitrification in the HFCW, resulting in 12.5% of the effluent samples achieving compliance for nitrate-N (NO3-N). Moreover, mixed aggregate media and low residence times in the HFCW may have also contributed to poor NO3-N removal. During the COVID-19 lockdown, an unexpected shutdown and subsequent resumption of flow to the DEWATS indicated a 16-week recovery time based on achieving full nitrification in the HFCW. Although design modifications are necessary for the HFCW, the installation of urine diversion flushing toilets at the household will reduce the nutrient loading to the DEWATS and potentially achieve fully compliant effluent. Alternatively, the application of two-stage vertical flow constructed wetlands to improve denitrification should also be explored in the South African context. With an improved design, DEWATS has the potential to fill the gap in both urban and rural sanitation in South Africa, where waterborne sanitation is still desired but connections to conventional wastewater treatment works (WWTWs) are not possible.

Feasibility Study of Anaerobic Baffled Reactor Coupled with Anaerobic Filter Followed by Membrane Filtration for Wastewater Treatment.

The performance of a Decentralized Wastewater Treatment System (DWTS) comprising an Anaerobic Baffled Reactor (ABR) and an Anaerobic Filter (AF) and Membrane Filtration (MF) module was studied for domestic wastewater treatment. The efficiency of the system was evaluated by running ABR at four different HRTs (14, 12, 10, and 8 h) resulting in COD removal efficiencies of 74, 72, 69, and 65%, respectively. The performance of AF using four different filtration media, i.e., PVC pipe (25 mm), PVC pipe (20 mm), PVC pipe (15 mm), and Kaldnes K3, was determined at optimized HRT (12 h). Among all the filtration media tested, the highest performance efficiency of the system was found with the PVC pipe (20 mm), which showed COD, TP, and TKN removal of 79, 32, and 63%, respectively. The efficacy of the system was proven via significant COD and turbidity removal of 94.6 and 87.2%, respectively, by the combined system.