Domestic Wastewater Treatment Systems Research Articles

Pepper mild mottle virus as an effective tool in microbial source tracking for deficient domestic on-site water treatment systems

Pollution from domestic on-site wastewater treatment systems (OWTS) is a significant contaminant pressure in many rural catchments. However, due to their design, and dispersed proliferation, it is difficult to assess their impact. Water testing methodologies employ bacterial culturing methods and chemical analysis which may lose resolution and/or specificity being confounded by diffuse agricultural sources within a rural environment. In this study, we successfully assessed the applicability of Pepper Mild Mottle Virus (PMMoV) as a human faecal source tracker for deficient on-site wastewater treatment systems. The transport of PMMoV was first studied in the effluent of a 30 cm deep soil column which was dosed for 510 days with primary influent from a conventional septic system. The removal of PMMoV through the 30 cm deep soil column was quantified with a 5-day seeding trial employing primary influent mixed with PMMoV sourced from Tabasco pepper product ®. The trial was then carried out at field scale with the seeding solution dosed into an operational percolation trench receiving septic tank effluent which had been instrumented for porewater sampling. Samples were taken at depths of 10 cm, 30 cm, and 50 cm across the length of the trench at distances of 1 m, 7.5 m, and 17.5 m from the inlet of the trench. PMMoV was detected on all days of the trial, with a peak concentration of 1 × 106 found at the rear of the trench on day 2 of the seeding trial. Finally, to assess the effectiveness of PPMoV as a microbial source tracking tool from a water receptor perspective, three rural catchments with high densities of OWTSs were sampled and analysed for hourly variations in biological parameters which included total coliforms, Escherichia coli, PMMoV, and chemical parameters total organic carbon, total nitrogen, and total carbon. PMMoV was detected in all river samples over a 24-hour period, thereby indicating its suitability as a tracer of human wastewater effluent in such environments with multiple diffuse sources.

An Integrated Modified Anaerobic/Slow Sand Filter Tertiary Treatment System for Domestic Wastewater Treatment at a Single Family Level

An Integrated Modified Anaerobic/Slow Sand Filter Tertiary Treatment System for Domestic Wastewater Treatment at a Single Family Level

［Joint Seminar by Younger Researcher's Associations at JSMCWM and SECE］ Design of Onsite Domestic Wastewater Treatment Systems toward Decarbonization

［Joint Seminar by Younger Researcher's Associations at JSMCWM and SECE］ Design of Onsite Domestic Wastewater Treatment Systems toward Decarbonization

Filtration of Grey Water Using Herbs in a Columnar Evaluation

Filtration of Grey Water Using Herbs in a Columnar Evaluation

Evaluation of the role of urban domestic wastewater treatment systems for greenhouse gases emissions in China

Rapid urbanization has exacerbated the dual challenge of mitigating water pollution and reducing greenhouse gas (GHG) emissions. The present study offers insights into the actual role of urban domestic wastewater treatment systems by shedding light on their capacity to act as GHG emitters. We introduce a modelling framework to calculate GHG emissions from wastewater treatment systems in China over the past two decades. Our analysis showed that treated wastewater volume increased by over 4.5 times, but GHG emissions also increased by 2.9 times. The annual emissions from wastewater treatment were -on average- nearly 60 Tg CO2-eq over the past two decades, accounting for <1% of the total national emissions. We also found a significant spatial variability with thirteen developed areas contributing >70% of the GHG emissions. Constructions and operations of wastewater treatment systems approximately accounted for 17% and 83% of the GHG emissions, respectively. Our study also proposes a hierarchical governance framework based on ten major regions that could maximize the efficiency in mitigating water pollution and GHG emissions in China.

Analysis of fecal pollution load factor from septic tanks of residential area (study case: Bandung City, Indonesia)

According to the Ministry of Environment and Forestry, 2017, domestic waste is the most significant contributor to pollution sources in the Citarum watershed (62.16%) and Bandung City (94.15%). To overcome the problem, planning for infrastructure development and improvement of the domestic sewage treatment system is necessary. One of the essential characteristic parameters, which is the subject of this study, is the pollutant load factor parameter in the city of Bandung. Compared to sewage pipelines, the domination of domestic wastewater treatment in Bandung is the On-site Sanitation System (OSS) (38.47%), and the most widely used type of OSS is a septic tank. For this reason, thirty fecal sludge samples were taken from two fecal disposal points in Bandung City, and the concentrations of TSS, COD, BOD, and Ammonia were then analyzed. Based on the results of the study, the range of fecal sludge pollutant load factor for TSS in Bandung City is 57.28 g / person/day – 1,064 g / person/day with an average value of 546.39 g / person/day, the range for total COD is 30.06 g / person/day – 294.99 g /person/day with an average of 294.99 g / person/day, the total BOD range is 14.05 g /person/day – 504.97 g / person/day with an average of 175.5 g / person/day, and ammonia range 1.61 g/person/day – 3.11 g/person/day with an average of 2.62 g/person/day. Based on fecal sludge data, the result can be considered a recommendation to re-determine the main domestic wastewater pollution indicator generation. The new suggestions can be used to design an adequate domestic wastewater treatment system, especially in Bandung. The pollutant load factors can also be used to estimate the pollution loading of wastewater generated by present and future populations. It is important in urban growth planning.

Communication Strategy for Spald-T Development via YouTube in Haurwangi Village, Cianjur Regency

Domestic wastewater is a complex problem, but it is almost neglected and not managed, let alone a priority by the public and the government. This does not mean that there is no attention or treatment at all, but its management can still be identified as being carried out in inadequate achievements. This study aims to identify how the development communication strategy becomes an innovation that is beneficial for the surrounding community to solve a problem in terms of health that is packaged in development. The Centralized Domestic Wastewater Treatment System (SPALD-T) must begin with determining the right strategy, determined by considering the conditions of the planning area. This research method uses an approach technique with the results of an interview, observation, documentation and with the results obtained, namely the results of development and innovation that are obtained running smoothly. The results in this study that need to be taken are to seek onsite wastewater management because it is considered relevant, while to increase community participation in the development of domestic wastewater it needs to be coordinated by the KSM

Exploration of sustainable driving path of rural domestic wastewater treatment-from the perspective of life cycle assessment

Most rural wastewater treatment facilities require electricity to maintain operation. Traditional fossil energy consumption increases the environmental load and greenhouse gas emissions. Wind-solar power generation is widely recognized as a renewable energy technology. However, conventional wind-solar power systems need batteries to store energy, which can lead to secondary pollution. Additionally, the alternating aerobic and anaerobic process were crucial for nitrogen and phosphorus removal, and some distributed wastewater treatment systems do not require continuity operation. Therefore, this study reports on a wind–solar power generation mode without batteries (Mode-II) to control and drive a bioecological rural domestic wastewater treatment system with a scale of 0.5 m³/day. By logic control, the inspired combination of power generation capacity and treatment process requirements was realized. The effluent CODcr, NH4+-N, and TN concentrations were 14.63 ± 7.02, 1.39 ± 1.63, and 8.65 ± 4.02 mg/L, with removal rates of 89.01 ± 4.15%, 88.58 ± 2.28%, 75.47 ± 8.84%, respectively. From the perspective of environmental load and carbon emissions, based on life cycle assessment theory, this novel approach was compared with the traditional wind–solar power generation driven mode with battery storage (Mode-I) and mains power driven mode (Mode-III). The environmental load and carbon emissions of Mode-II were 1.08 kPt and 2836 kg CO2 eq by end-of-life (25 years), the lowest of the three modes. Compared with the mains power drive mode, the environmental load and carbon emissions of Mode-II can be repayment until years 6 and 2. The supercapacitors and solar panels were the main source of environmental load and carbon emissions for Mode-II. Overall, Mode-II was found to be the most environmentally friendly mode all over the China, which is expected to be promoted in the field of rural wastewater treatment.

Risk Assessment of Domestic Wastewater Treatment System Based on Constructed Wetlands

Risk assessment methods vary and have been applied to areas such as environmental, technological, and occupational safety, adapting to the complexities of the subjects under study. The objective of this work is to conduct a risk analysis of a domestic wastewater treatment system based on constructed wetlands (CW) and to evaluate actions to reduce the operational risk of the studied installation. The approach used is the three-dimensional risk matrix, which is a simplified version of the probabilistic risk evaluation method, making it more accessible and allowing for broader application. To apply the risk matrix method to a wastewater system based on CW, it was necessary to modify a risk model. This modification involved creating a process map and identifying accidental scenarios or sequences within each stage, including their initiating events, defenses, and consequences. The results enabled the identification of the most critical initiating events and defenses. Notably, human factors emerged as the primary contributors to the risk associated with wetland operation. The findings from this study can be used to enhance wetland security, including the prioritization of controls for the most critical defenses identified in this research.

Cost benefit analysis of integrated constructed wetland microbial fuel cell system for sustainable and economic domestic wastewater treatment

Wastewater treatment with integrated constructed wetland–microbial fuel cell technology has attracted serious attention from researchers. The economic sustainability of any potential technology is the key to its commercialization from laboratory to field application, which is fulfilled through an exhaustive assessment of the related costs and benefits. This article presents a comparative cost-benefit analysis of three reactors: constructed wetland (R1), integrated CW-MFC (R2), and unplanted CW-MFC (R3) for domestic wastewater treatment and economic sustainability assessment. The study was conducted with 36 h and 24 h hydraulic retention times of the reactors and the respective cost-benefit ratio was determined. Results revealed that R2 was the most sustainable option with maximum economic benefits during Phase 1 and Phase 2 without effluent disinfection. With effluent disinfection in place, R1 emerged with the best cost-benefit ratio due to less investment cost and low revenue from electricity production in R2 and R3. Sensitivity analysis with net investment cost, power density, electrode area, effective reactor volume, and hydraulic retention time; showed power density was the most influential parameter affecting the cost-benefit ratio. Revenue from wastewater treatment was found essential for economic sustainability which shows the importance of producing high-quality effluent and greater power density to make CW-MFC technology economically attractive.

Energy, exergy, economic and environment analysis of standalone forward osmosis (FO) system for domestic wastewater treatment

Energy, exergy, economic and environmental analysis is applied to a novel FO system. The system is designed to achieve minimal/zero liquid discharge with low specific energy consumption. Up to 43 % recovery is obtained with desired output in terms of salinity of diluted draw solution and concentrated feed solution. The specific energy required to produce diluted draw and concentrated feed solutions for the proposed application is as low as 0.0285 kWh/m3. In this study, DS-Lumen/AL-DS mode shows specific energy savings of 49.5 % in performed cases compared to FS-Lumen/AL-FS mode using a less flow rate of draw solution. The process design is done to reach the appropriate salinity level at the system outlet. The feed solution connection is in the series between membranes, which helps to dilute the draw solution, while the draw solution connection is in parallel between membranes to achieve desired salinity level at the outlet. The influence of the feed and draw solution temperature and flow rate on the membrane performance is observed. Capital and operating costs of the membrane and other costs, such as tank and chemical solution costs, are significant contributors to the total cost. The specific solution (total output of FO system) cost is estimated at 0.23 $/m3. Environmental analysis suggests that the deployment of solar energy as an energy source of the system reduces 93.06 % of CO2 emissions compared to fossil fuel (coal).

Efficiency and effectiveness of systems for the treatment of domestic wastewater based on subsurface flow constructed wetlands in Jarabacoa, Dominican Republic

Constructed wetlands (CW) are well known nature-based systems for water treatment. This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa, the Dominican Republic. The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand (BOD5) and chemical oxygen demand, but not for the removal of phosphorus and fecal coliforms. In addition, a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions. The concentrations of heavy metals, such as zinc, copper, chromium, and iron, were found to decrease in the effluent of the wetland, and the concentrations for nickel and manganese tended to increase. The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards. The construction cost of these facilities was around 200 USD per population equivalent, similar to the cost in other countries in the same region. This study suggested some solutions to the improved performance of CWs: selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen, use of endemic plants that bioaccumulate heavy metals, combination of constructed wetlands with filtration on activated carbon, and inclusion of water purification processes that allow to evaluate the reuse of treated water.

Impact of maintenance on domestic wastewater treatment systems

AbstractWastewater treatment systems are important sources of contaminants of emerging substances, including pharmaceuticals, and personal care products. Onsite wastewater treatment systems provide alternative solutions to centralized systems; although they are becoming increasingly popular, little is known about the effect of maintenance on their performance. In the current study, chemical and microbiological parameters in the effluents from two identical on-site wastewater treatment systems were analyzed, one being properly maintained while the other not maintained at all. Taxonomic profiles vastly differed from each other, and organic micropollutants are present at higher concentrations in the effluent of the non-maintained unit. The results highlight the importance of proper maintenance.

Pengawasan Dinas Lingkungan Hidup Provinsi Jawa Timur Terhadap Limbah Cair Industri Baja dan Pengolahannya

An internship is an independent student activity carried out on campus to gain practical work experience in accordance with their field of specialization through observation and participation methods. The method used in this study is a quantitative-descriptive method. This method combines empirical research in which the data is in the form of numbers and research that seeks to describe a symptom, event, event that is happening at the present time. The wastewater treatment for the steel industry uses the Sewage Treatment Plant process, which is a domestic wastewater treatment system that aims to reduce the content of parameters that have the potential to pollute the environment. These parameters include BOD, COD, Ammonia, TSS, Total Coliform, pH, and others. The decrease in parameter levels occurs due to physical, chemical and biological processes that occur at the Compliance Point Well (STP). Domestic waste testing is carried out with a frequency of once a month, with monitoring well monitoring test results showing no contamination of groundwater by heavy metal content (key parameter) as a result of the production process as indicated in the monitoring discussion. The results of this study aim that the industry can be responsible for treating the waste water produced in accordance with existing regulations.

Environmental assessment of on-site source-separated wastewater treatment and reuse systems for resource recovery in a sustainable sanitation view

Sustainable sanitation solutions are necessary for promoting public health and environmental security. In this study, on-site domestic wastewater treatment (WWT) systems used for households in rural and peri-urban areas of Brazil were compared in different scenarios from a life cycle assessment (LCA) perspective. The evaluated scenarios represented different practices in wastewater management, such as direct discharge into the soil, rudimentary treatment, septic tank, public sewerage system, and source separation of wastewater streams for water, nutrient, and organic matter recovery. The WWT technologies considered in the proposed scenarios of source-separated wastewater streams were as follows: an evapotranspiration tank (TEvap) and composting toilet for blackwater, a modified constructed wetland (EvaTAC) for greywater, and a storage tank for urine. LCA was performed in this study according to the ISO standards to assess the environmental impacts at both midpoint and endpoint levels. The results show that on-site source-separated wastewater treatment systems with resource recovery result in significant reductions in environmental impacts compared to scenarios with precarious conditions or ‘end-of-pipe’ solutions. For example, regarding the human health damage category, the scenarios involving resource recovery, including systems such as EvaTAC, TEvap, composting toilet, and urine storage tank, demonstrate significantly lower values (−0.0117 to −0.0115 DALY) compared to scenarios with rudimentary cesspits and septic tanks (0.0003 to 0.001 DALY). We conclude that the focus should be beyond mere pollution aspects and instead concentrate on the benefits of the co-products, which are: avoiding the extraction and consumption of valuable and increasingly scarce raw materials, such as potable water, and production of synthetic fertilizer. Furthermore, it is highly recommended that an LCA of sanitation systems synergistically integrates the WWT process, the constructive aspects, and the resource recovery potential.

Sludge Treatment Wetland for Treating Microalgae Digestate Grown in Agricultural Runoff: A Technical, Economic, and Environmental Assessment

The management and disposal of wastewater treatment sludge can be a costly and resource-intensive process. To provide a cost-effective and sustainable alternative, Sludge Treatment Wetlands (STW) have emerged as a viable solution for enhancing sludge quality through dewatering and biodegradation. In this study, the effectiveness of a full-scale STW for stabilizing and dewatering digested microalgal biomass from a domestic and agricultural wastewater treatment system was evaluated. The properties of the treated digestate in the STW were assessed after 35 weeks of operation and a resting period of 4 weeks. The dry matter content was found to be 12.8%, and the average macronutrient content was K: 3.8 mg/g DW, P: 4.9 mg/g DW, and Ca: 95 mg/g DW. The highest contents of micronutrients were for Fe: 7.8 mg/g DW and Mg: 7.6 mg/g DW, while heavy metals and pathogen contents were below the EC limits for sewage sludge reuse in agriculture. The STW was found to be a cost-effective and environmentally friendly option for treating mixed wastewater-based sludge for land application. The STW outperformed reference systems using centrifuge dewatering techniques, particularly in terms of eutrophication potential and acidification potential. However, the STW’s economic performance was slightly worse than that of the dewatering system in terms of unit production cost. This study is the first in the literature to investigate the use of STW for treating digested microalgae and its possible reuse in arable land, suggesting that STW infrastructures have great potential for the development of sustainable and eco-friendly sludge treatment technologies.

Unload control - efficiency strategy and rainfall control in urban wastewater systems

Controlling the influx of rainwater to domestic wastewater transport and treatment systems, aims to reduce its economic impact on energy and the interference in the treatment process, taking into account the technical and legal issues associated with its upstream rejection of such infrastructure. In order to guarantee safety in the flow thinning, we will have to monitor the quality of the effluent, basically in terms of COD, which directly indicates the degree of dilution and consequent influx of rainwater, and the flow rates upstream and to be discharged. This pilot project intends to implement the digitization of the process with automatic monitoring and control equipment with information sent to SCADA and availability of information to the Portuguese Environment Agency.

The antimicrobial resistance profiles of Escherichia coli and Pseudomonas aeruginosa isolated from private groundwater wells in the Republic of Ireland

The role of the natural environment in the dissemination of antimicrobial resistant bacteria has been increasingly recognised in the literature. However, knowledge surrounding the critical factors and mechanisms mediating their occurrence is still limited, particularly in relatively ‘pristine’ groundwater environments. In the Republic of Ireland (RoI), a country characterised by high groundwater reliance, household-based (unregulated) wells provide drinking water to 11% of the population. These private wells are generally located in rural areas, where the risk of microbiological contamination is high due to intensive agricultural practices and high reliance on domestic wastewater treatment systems; both of which are also potential sources of antimicrobials and antimicrobial resistant bacteria. Accordingly, the current research sought to elucidate current rates of antimicrobial resistant bacteria and the principal factors associated with their presence in private wells in the RoI. A total of 250 samples (from 132 wells nationwide) were assessed for the presence of faecal (Escherichia coli) and environmental (Pseudomonas aeruginosa) bacteria, with single isolates from each contaminated sample tested phenotypically against 18 and 9 antimicrobials, respectively. Findings show that while 16.7% of E. coli (n = 8/48) were categorically resistant to ≥1 antimicrobial, with a further 79.2% classified as intermediately resistant, no categorical resistance was found among P. aeruginosa isolates (n = 0/6), with just one intermediately resistant isolate detected. Multivariate regression modelling indicates significantly higher odds of resistant E. coli detection in concurrence with elevated cattle density (OR = 1.028, p = 0.032), aligning with findings of highest resistance rates to veterinary antimicrobials (e.g., streptomycin = 14.6%, tetracycline = 12.5%, and ampicillin = 12.5%). Multivariate model results also suggest overland flow culminating in direct wellhead ingress as a primary ingress mechanism for resistant E. coli. Study findings may inform groundwater source protection initiatives and antimicrobial resistance surveillance moving forward.

Environmental assessment of the water quality of the Kaniv reservoir

Safe drinking water is a basic requirement for good health. Fresh water is already a limited resource in many parts of the world. In the next century, it will become even more limited due to population growth, urbanization and climate change. Purpose. Provide a comprehensive assessment of the water quality of the Kaniv Reservoir based on the calculation of the Water Quality Index (WQI). Methods. Analytical-synthetic method, geo-information (cartographic modeling), analysis of information sources, mathematical modeling. Results. There is an increase in BOD, COD and dissolved oxygen content in the area of the Kaniv Reservoir from the hydropost 500 m above the Bortnytsky Aeration Station (BAS) to the hydropost 2 km below the Kanivska Hydropower Station’s dam. The only exception is the hydropost 500 m below the BAS, for which the corresponding values are the largest, and the BOD indicator exceeds the established standards by 1.5 times. Ammonium content 500 m below BAS exceeds the standards established by Directive 98/83/EC by almost 3 times. Exceeding the normative values for the content of sulfates and chlorides and suspended substances were not recorded. The least polluted water is observed at hydrostations located below Ukrainka and Pereyaslav-Khmelnytskyi. The highest value of the water quality index is 242, which is typical for the hydropost 500 m above the BAS and corresponds to the value of the worst quality. Conclusions. It was in the immediate vicinity of the city of Kyiv that the water turned out to be the most polluted. This may indicate the imperfection of industrial, domestic and agricultural wastewater treatment systems. For the hydropost 500 m below the BAS, excesses of the normative values for the parameters of ammonium and BOD content were also recorded, while other parameters are either at the limit of the norm or approaching it. Studies of the water quality of the Kaniv Reservoir showed that its quality according to the WQI indicator varies from 59 to 242 (from low to the worst). Accordingly, such water, in the absence of another source, can be used for drinking after passing proper multi-stage purification.

A pilot-scale study of a down-flow hanging sponge reactor as a post-treatment for domestic wastewater treatment system at short hydraulic retention times

This study proposes a down-flow hanging sponge (DHS) reactor as a post-treatment process for sewage treatment systems. A pilot-scale DHS reactor was operated over 1000 days under relatively short hydraulic retention times (HRT) of 1–3 h to evaluate its effectiveness as a post-treatment technology. The DHS reactor consistently achieved superior effluent water quality with total suspended solid <10 mg/L, biochemical oxygen demand < 10 mg/L, and ammonium nitrogen < 5 mg/L. The effective removals (> 2-log10 reduction) of Escherichia coli, a fecal contaminant indicator, and Arcobacter spp., a potentially pathogenic bacterial group, were achieved. The treatment performance was compared with the previous operation treating raw domestic wastewater under long HRTs of 4 and 5 h. As a result, the DHS reactor under short HRT conditions showed advantages for biological oxidation and fecal contaminant removal. These results indicate that the DHS reactor could be a compact post-treatment technology.