Domestic Wastewater Treatment Research Articles

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

Sewage Sludge Plasma Gasification: Characterization and Experimental Rig Design

The treatment of wastewater worldwide generates substantial quantities of sewage sludge (SS), prompting concerns about its environmental impact. Various approaches have been explored for SS reuse, with energy production emerging as a viable solution. This study focuses on harnessing energy from domestic wastewater treatment (WWT) sewage sludge through plasma gasification. Effective syngas production hinges on precise equipment design which, in turn, depends on the detailed feedstock used for characterization. Key components of plasma gasification include the plasma torch, reactor, heat exchanger, scrubber, and cyclone, enabling the generation of inert slag for landfill disposal and to ensure clean syngas. Designing these components entails considerations of sludge composition, calorific power, thermal conductivity, ash diameter, and fusibility properties, among other parameters. Accordingly, this work entails the development of an experimental setup for the plasma gasification of sewage sludge, taking into account a comprehensive sludge characterization. The experimental findings reveal that domestic WWT sewage sludge with 40% humidity exhibits a low thermal conductivity of approximately 0.392 W/mK and a calorific value of LHV = 20.78 MJ/kg. Also, the relatively low ash content (17%) renders this raw material advantageous for plasma gasification processes. The integration of a detailed sludge characterization into the equipment design lays the foundation for efficient syngas production. This study aims to contribute to advancing sustainable waste-to-energy technologies, namely plasma gasification, by leveraging sewage sludge as a valuable resource for syngas production.

Enhancing pollutant removal efficiency in urban domestic wastewater treatment through the hybrid multi-soil-layering (MSL) system: A case study in Morocco.

This paper evaluates the performance and potential of a full-scale hybrid multi-soil-layering (MSL) system for the treatment of domestic wastewater for landscape irrigation reuse. The system integrates a solar septic tank and sequential vertical flow MSL and horizontal flow MSL components with alternating layers of gravel and soil-based material. It operates at a hydraulic loading rate of 250 L/m2/day. Results show significant removal of pollutants and pathogens, including total suspended solids (TSS) (97%), chemical oxygen demand (COD) (88.57%), total phosphorus (TP) (79.93%), and total nitrogen (TN) (88.49%), along with significant reductions in fecal bacteria indicators (4.21 log for fecal coliforms and 3.90 log for fecal streptococci) and the pathogen Staphylococcus sp. (2.43 log). The principal component analysis confirms the effectiveness of the system in reducing the concentrations of NH4, COD, TP, PO4, fecal coliforms, fecal streptococci, and fecal staphylococci, thus supporting the reliability of the study. This work highlights the promising potential of the hybrid MSL technology for the treatment of domestic wastewater, especially in arid regions such as North Africa and the Middle East, to support efforts to protect the environment and facilitate the reuse of wastewater for landscape irrigation and agriculture.

Microbial community structure and diversity attached to the periphyton in different urban aquatic habitats.

Periphyton is a complex community composed of diverse prokaryotes and eukaryotes; understanding the characteristics of microbial communities within periphyton becomes crucial for biogeochemical cycles and energy dynamics of aquatic ecosystems. To further elucidate the community characteristics of periphyton across varied aquatic habitats, including unpolluted ecologically restored lakes, aquaculture ponds, and areas adjacent to domestic and industrial wastewater treatment plant outfalls, we explored the composition and diversity of prokaryotic and eukaryotic communities in periphyton by employing Illumina MiSeq sequencing. Our findings indicated that the prokaryotic communities were predominantly composed of Proteobacteria (40.92%), Bacteroidota (21.01%), and Cyanobacteria (10.12%), whereas the eukaryotic communities were primarily characterized by the dominance of Bacillariophyta (24.09%), Chlorophyta (20.83%), and Annelida (15.31%). Notably, Flavobacterium emerged as a widely distributed genus among the prokaryotic community. Unclassified_Tobrilidae exhibited higher abundance in unpolluted ecologically restored lakes. Chaetogaster and Nais were enriched in aquaculture ponds and domestic wastewater treatment plant outfall area, respectively, while Surirella and Gomphonema dominated industrial sewage treatment plant outfall area. The alpha diversity of eukaryotes was higher in unpolluted ecologically restored lakes. pH and nitrogen content ( , , and TN) significantly explained the variations for prokaryotic and eukaryotic community structures, respectively. Eukaryotic communities exhibited a more pronounced response to habitat variations compared to prokaryotic communities. Moreover, the association networks revealed an intensive positive correlation between dominant Bacillariophyta and Bacteroidota. This study provided useful data for identifying keystone species and understanding their ecological functions.

Solar-powered single-stage distillation and complex conductivity analysis for sustainable domestic wastewater treatment.

This study investigates the efficacy of a solar-powered single-stage distillation system for treating domestic wastewater, supplemented with complex conductivity analysis. Domestic wastewater samples were collected from a municipal manhole in El Jadida, Morocco, over a 24-h period. The single-stage distillation system, designed for domestic wastewater treatment, utilizes heat to vaporize the wastewater, followed by condensation to produce pure liquid water. The system demonstrated increased distilled water production with rising temperatures, with domestic wastewater outperforming seawater as a feed water source. Physical and chemical testing of the treated water revealed significant improvements in water quality, meeting, or exceeding Moroccan irrigation water standards. Reductions in parameters such as biological oxygen demand (BOD), chemical oxygen demand (COD), suspended matter, and heavy metals underscored the effectiveness of the distillation process. Complex conductivity analysis provided insights into the electrical properties of untreated wastewater and distilled water. Deconvolution of complex conductivity data using an equivalent electrical circuit model elucidated the electrochemical processes during treatment, highlighting the efficiency of the distillation process. The integration of solar energy addresses water scarcity while promoting environmental sustainability. Complex conductivity analysis enhances process understanding, offering avenues for monitoring and control in wastewater treatment.

Pollution Load Reduction from Domestic Wastewater with Electrocoagulation Process for Agricultural Reuse

Objectives: The present study is aimed to investigate electrocoagulation of domestic wastewater and assessment of pollutants removal efficiency for potential reuse in agriculture. Methods: The electrocoagulation treatment of domestic wastewater with Fe – Fe electrodes was performed under optimal conditions of pH (8.0), current density (0.6 mA/cm2), treatment time (45 minutes), and NaCl dose (2.8 g/L) in a slurry type of reactor. The primary clarified and biotreated domestic wastewaters were subjected to electrocoagulation with Direct Current (DC) as power source. Findings: There was observed higher pollutants removal efficiency from the biotreated wastewater as compared with the primary clarified wastewater after electrocoagulation. The treated wastewaters showed significant removal of pollutants in terms of BOD (79.5% – 87.9%), COD (86.8% – 89.5%), TDS (87.4% – 89.9%), TSS (66.7% – 75.3%), conductivity (77.8% – 78.4%), turbidity (74% – 81.2%), colour (77.7% – 86.2%), nitrates (44.1% – 51.7%), and phosphates (48.7% – 55.9%) after electrocoagulation treatment. Electrocoagulation considerably improved the biodegradability index of the primary clarified (0.59 to 0.92) and biotreated (0.69 to 0.8) wastewaters. This indicates easy removal of the pollutants further by biological processes in the aquatic ecosystems. Electrocoagulation demonstrated potential for removal of pollution from the domestic wastewater for productive reuse in agriculture and urban areas. Novelty: There exist few studies of use of electrochemical process for treatment and reuse of domestic wastewater. The treated waters complied with the regulatory standards and had satisfactory quality for reuse in agriculture and urban activities. Keywords: Electrocoagulation, Domestic wastewater, Biodegradability index, Agricultural reuse, National Green Tribunal

Pilot–scale vertical continuous–flow reactors applied to treat rural domestic wastewater at low temperature via aerobic granular sludge

A pilot–scale vertical–flow continuous flow reactors (VF–CFR) was investigated for the treatment of rural domestic wastewater in the cold areas of Northeast China. VF–CFR helps in the creating of aerobic granular sludge (AGS), which improves the sludge concentration and removal efficiency of pollutants. VF–CFR achieved a high removal efficiency of Chemical Oxygen Demand (COD), Ammonia Nitrogen (NH3−N), Total Nitrogen (TN) and Total Phosphorus (TP) with 90 %, 94 %, 75 % and 93 % under the condition of sharp fluctuation of influent quality and temperature. The high–throughput sequencing analysis of the AGS revealed that Flavobacterium was a functional bacterium in the AGS process that had the function of heterotrophic nitrification and denitrification. The field–scale experiment confirmed the superiority of VF–CFR in wastewater treatment efficacy and stability. During the experiment, the concentrations of COD, TP and NH3–N in effluent at different temperatures were well met with the first–class A discharge standard of China (GB 18596–2001). However, there was a risk of exceedance exists in the reduction of TN removal under low temperature conditions.

A comparative study with vermifilter and geofilter for domestic wastewater treatment and its Phyto-toxicity efficacy

The present study investigated the role of earthworms in pollutant removal and toxicity assay of domestic wastewater. An indigenous reactor (vermigratings as an active layer) was set up for 60 days with a hydraulic loading rate of 1 m3 / m2 -d and hydraulic retention time of 3.5 h to evaluate its performance. Removal of total suspended solids, total dissolved solids, biochemical oxygen demand, chemical oxygen demand, and sulfate was found to be 92 %, 93 %, 89 %, 86 %, and 63.43 %, respectively. The Phyto-toxicity test reveals a higher germination rate and plant growth with vermifilter effluent than with geofilter effluent and raw wastewater. Additionally, vermifilter achieved heterotrophic bacteria removal by 1.54-fold. Hence, treated effluent can be used for irrigation purposes. Overall, this study will establish a potential alternative to the conventional wastewater treatment system and achieve Sustainable Development Goals 6.

The Radiation Graft Copolymerization of Allylmethacrylate to Polyvinylidene Fluoride to Prepare of Membrane and Its Affordability for Domestic Wastewater Treatment

The Radiation Graft Copolymerization of Allylmethacrylate to Polyvinylidene Fluoride to Prepare of Membrane and Its Affordability for Domestic Wastewater Treatment

The Domestic Wastewater Treatment Installation's Performance Study of Technical Aspects in Cahaya Abadi Housing, Palembang City

<p><em>The comprehensive treatment of rural water pollution was pioneered by developed countries, and many nations now have a variety of sewage treatment facilities and process technology that are suitable for their rural features. Domestic sewage is handled differently at sewage treatment facilities in cities than it is in rural areas. Its distributed drainage sites make it difficult to collect. The Indonesian government is implementing domestic wastewater treatment (DWWT) to reduce water pollution in areas without separate residential waste processing. The results of this analysis show that an extensive amount of maintenance is needed to ensure that the DWWT and its distribution system run as efficiently as possible. The Cahaya Abadi Housing in Sri Mulya Village, Sematang Borang District, Palembang City, is where the study is being carried out. DWWT Cahaya Abadi processes domestic liquid waste from household activities, although even though the facility has room for 169 dwellings, only 31 homes use it. As a result, capacity is not being used. The results of identifying the technical factors show that the use of pumps results in differences in flow discharge that affect the outcomes of the DWWT output. The extremely rapid pump that is being used has an impact on the processing process and the current detention time.</em></p>

Domestic wastewater treatment by Pistia stratiotes in constructed wetland

The objective of the study was to evaluate the performance of Pistia stratiotes for treatment of domestic wastewater in a free surface water flow constructed wetland. The objective of the study was to evaluate contaminants removal efficiency of the constructed wetland vegetated with P. stratiotes in treatment of domestic wastewater against Hydraulic retention time (HRT) of 10, 20 and 30 days was investigated. This asks for newer and efficient low-cost nature-based water treatment system which along with cost takes into consideration the sustainability of the ecosystem. Five constructed wetland setups improved the wastewater quality and purify it significantly by reducing the TDS by 83%, TSS by 82%, BOD by 82%, COD by 81%, Chloride by 80%, Sulfate by 77%, NH3 by 84% and Total Oil and Grease by 74%. There was an increase in pH of about 11.9%. Color and odor of wastewater was also improved significantly and effectively. It was observed that 30 days’ HRT was optimum for the treatment of domestic wastewater. The final effluent was found to be suitable as per national environmental quality standards and recycled for watering plants and crop irrigation but not for drinking purposes. The treatment in constructed wetland system was found to be economical, as the cost of construction only was involved and operational and maintenance cost very minimal. Even this research was conducted on the sole purpose of commuting the efficiency of pollutant removal in short span time.

［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

Effects of competitive cations and dissolved organic matter on ammonium exchange and up-concentration properties of ion exchangers from domestic wastewater under multicycle exchange - regeneration operation

This study aimed to investigate the impact of competitive cations and dissolved organic matter (DOM) on ammonium exchange and up-concentration properties of ion exchangers for domestic wastewater treatment during the multicycle exchange - regeneration operations. Three ion exchangers, including zeolite, strong acid cation resin and 4A molecular sieve (MS), all showed good NH4+ separation and up-concentration properties in 30 exchange - regeneration cycles. The exchange capacities of zeolite, resin, and MS decreased by 8.2 %, 10.4 %, and 4.8 % in the presence of Ca2+ and Mg2+, while DOM only impaired the exchange ability of zeolite. The up-concentration factors of zeolite, resin, and MS were 5.1, 11.5, and 5.0, respectively. Isothermal tests and breakthrough curves confirmed that long-term salt regeneration slightly reduced the exchange capacity, and the presence of competitive cations and DOM shortened the breakthrough time. Elemental mass balance further demonstrated that Ca2+ and Mg2+ were easily trapped by ion exchangers and could be released into the regeneration solution, which should be precipitated to avoid accumulation for long-term cyclic operation. Morphological analysis indicated that the presence of Ca2+ and Mg2+ would cause the resin to crack. Overall, for domestic wastewater treatment, the resin exhibited the highest NH4+ capture ability and up-concentration properties with low resistance to Ca2+ and Mg2+ contamination, while silicate exchangers with a regular and compact structure had higher durability but lower up-concentration properties.

Feasibility of sulfated BPA and BPS as wastewater-based epidemiology biomarkers: Insights from wastewater and reported human urine analysis

In wastewater-based epidemiology (WBE), the selection of appropriate biomarkers presents a significant challenge. Recently, sulfated bisphenols have garnered attention as potential WBE biomarkers due to their increased stability in wastewater compared to glucuronide conjugates. This study aims to comprehensively assess the feasibility of employing sulfated BPA and BPS as WBE biomarkers by analyzing both WBE and human biomonitoring data. To conduct this research, wastewater samples were collected from six domestic wastewater treatment plants in Guangzhou, China, and urinary concentration of BPA and BPS were obtained from peer-reviewed literature. The results revealed that mean urinary concentrations of BPA and BPS, calculated using Monte Carlo simulations, significantly exceeded those reported in human biomonitoring studies. Furthermore, the per capita mass load ratio of sulfated BPA and BPS in human urine to the mass load in wastewater was found to be below 10 %. This outcome suggests that the excretion of BPA-S and BPS-S in urine does not make a substantial contribution to wastewater, hinting at the existence of other notable sources. Consequently, our study concludes that sulfated BPA-S and BPS-S are not suitable candidates as WBE biomarkers. This work provides a referenceable analytical framework for evaluating the feasibility of WBE biomarkers and emphasizes the necessity for caution when utilizing WBE to assess human exposure to chemicals.

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.

Enzymatic Activities in the Rhizosphere Soil as Influenced by Filterbeds and Hydrophytes in the Vertically Constructed Wetland

An experiment with different filter beds and macrophytes was carried out to study their phytoremediation capacity on the efficiency of domestic wastewater treatment through constructed wetland (CW) at the University of Agricultural Sciences, Dharwad campus, Karnataka, between November 2017 and March 2018. Twenty treatment combinations involving five types of filter beds (FB-1: gravel, FB-2: gravel-sand-gravel, FB-3: gavel-sand-brick-gravel, FB-4: gravel-sand-charcoal-gravel and FB-5: gravel-sand-(charcoal+brick)-gravel) and four macrophytes (MP-1: Typha latifolia, MP-2: Brachiaria mutica, MP-3: Canna indica and MP-4: Phragmites sp.) were evaluated for treating domestic waste water. After 120 days from the start, across treatment combinations, the plant in each column was uprooted, and the soil adhered to the root was collected in a polyethylene cover. The samples were brought to the laboratory, refrigerated, and then analysed for dehydrogenase, phosphatase, and urease activities, as well as for biofilm formation. Results revealed that the highest biofilm growth was observed on brick (1.18 and 0.05 mg g-1) had the maximum biofilm formation, followed by sand (0.68 and 0.04 mg g-1), charcoal (0.67 and 0.02 mg g-1), and gravel (0.31 and 0.01 mg g-1) at depths ranging from 0 to 5 and 5 to 15 cm, respectively. Since the CW can be implemented with flexibility, it can be used as the primary, secondary or tertiary treatment stage depending on the site and its configuration.

Comparative evaluation of activated sludge and aerobic granular sludge for biological treatment of real domestic wastewater with oxytetracycline dosing

Aerobic granular sludge technology is an emerging choice for effective and sustainable wastewater treatment. The aim of this study was to determine the effect of antibiotics such as oxytetracycline on biological nutrient removal pathways in aerobic granular sludge and activated sludge sequencing batch reactors treating real domestic wastewater. The aerobic granular sludge and activated sludge reactors were operated in parallel for evaluating treatment of domestic wastewater and its response to 50–300 µg/L oxytetracycline dosing. The aerobic granular sludge and activated sludge sequencing batch reactors were dominated by compact granules (sludge volume index (SVI): 60 mL/g) and flocs (SVI: >100 mL/g), respectively, during treatment of real wastewater. Aerobic granular sludge has significantly outperformed activated sludge in achieving high phosphate removal of ∼99% against just 57%. This was corroborated with higher abundance of polyphosphate accumulating organisms and enhanced bio-P removal in the aerobic granular sludge system. In contrast, phosphate removal was achieved through normal bio-P removal in the activated sludge reactor. Oxytetracycline removals were distinct at 90% and 23%, respectively, in the aerobic granular sludge and activated sludge systems. High total nitrogen and phosphate removals of 97% and 96%, respectively, were maintained in the aerobic granular sludge system even during OTC dosing. In contrast, the total nitrogen and phosphate removals have dropped to 78% and 16%, respectively, in the activated sludge system due to oxytetracycline stress. Efficient biological nutrient removal and process stability along with environmental sustainability are critical for choosing aerobic granular sludge technology in wastewater treatment plants.

Is Africa Ready to Use Phycoremediation to Treat Domestic Wastewater as an Alternative Natural Base Solution? A Case Study

This review outlines the potential of phycoremediation as a natural, cost-effective solution for domestic wastewater treatment in Africa, particularly focusing on its application in less densely populated and rural areas. The urgency of improving sanitation access, a key objective in both the Millennium Development Goals (2000–2015) and the Sustainable Development Goals (2015–2030), is underscored by the fact that half of Africa’s population suffers from diseases linked to inadequate water and sanitation facilities. South Africa, a focal point of this study, faces significant challenges in wastewater management. These include the limited capacity of wastewater treatment plants to handle the burgeoning wastewater volumes due to population growth, unregulated discharges causing fluctuating pollution levels, and high operational costs leading to improper sludge disposal and odor issues. Compounding these problems are frequent power outages, financial constraints impacting wastewater treatment plant operations and maintenance across Africa, and a lack of skilled personnel to manage these facilities.

Performance evaluation and application of host-specific Bacteroidales and mitochondrial DNA markers to identify sources of fecal contamination in river water in Japan

Microbial source tracking (MST) using host-specific Bacteroidales and mitochondrial DNA (mtDNA) markers is an efficient tool to identify the sources of fecal contamination in environmental water. This study evaluated and updated the previously reported performances of seven host-specific Bacteroidales markers (three human-, two cattle-, and two pig-specific). Additionally, the performance of a cattle-specific Bovine mtDNA and a pig-specific Swine mtDNA marker were evaluated and then applied to MST of river water samples collected in Yamanashi Prefecture, Japan. We collected 48 fecal-source samples, including raw sewage, secondary-treated sewage, an effluent of a domestic wastewater treatment tank, pig feces, pig wastewater, and cattle feces, which were quantitatively analyzed using host-specific Bacteroidales and mtDNA markers. BacHum and gyrB markers (human-specific), BacR and Bovine mtDNA markers (cattle-specific), and Pig2Bac and Swine mtDNA markers (pig-specific) were judged the best-performing markers. Then, these selected markers were applied to MST to identify the sources of fecal contamination in 59 river water samples collected at 21 sites. Of them, 20 (95%), 21 (100%), and 16 (76%) sites were positive for at least one human, cattle, and pig marker, respectively, indicating the need for immediate action and monitoring to control fecal pollution.