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Phytodepuration is one of the most widely used techniques for treating wastewater, thanks to its specific characteristic of simplicity of design. The main objective of this study is the treatment of domestic wastewater from a district in Nouakchott, using a macrophyte lagooning system. Several physico-chemical parameters were measured before and after treatment. Average abatement rates were recorded for biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and suspended solids (SS), with progressive acceptable values of 26.57%, 28.60% and 59.45%. Treatment efficiencies for nitrogen and ortho-phosphate (P-PO4) are generally low. In general, our results show that this natural lagoon achieves a good purification efficiency of organic pollutants, which indicates the importance of the role of purifying plants in reducing the organic and particulate pollutant load. As well as the role of the various substrates used in the experimental set-ups. [ABSTRACT FROM AUTHOR]

The rapid development of the residential and industrial sectors produces a huge amount of treated domestic wastewater. The treated wastewater is discharged and could affect the environment in the long term. Improving the quality of treated domestic wastewater for water reclamation would benefit both sectors. This study aims to determine the efficiency of the biofilm-phytoremediation integration process in reclaiming domestic wastewater. A cuboid-shaped reactor was filled with 15 L of domestic wastewater, utilizing water hyacinth and a polyethylene carrier as supporting media for the process. The integrated reactor is tested in two phases: the initial adaptation of bacteria with domestic and synthetic wastewater (Phase I) and the integration process of biofilm-phytoremediation, based on the factors of NH3-N concentration and hydraulic retention time (HRT), for 24 to 48 h (Phase II). In Phase II, pollutant removal was observed at varying NH3-N concentrations: C1 (11–13 mg/L), C2 (9–11 mg/L), and C3 (3–5 mg/L). The study's findings indicate a consistent performance in the first phase, with removal rates for COD and NH3-N ranging between 86.7–100.0% and 79.0–99.6%, respectively. The reactor effectively removed pollutants at varying concentrations of NH3-N, with average removal up to 100% (COD), 99% (NH3-N), and 80% (PO43−). This integrated reactor shows the finest treated water quality outcomes for non-potable water recovery, as well as offers an alternative to resolve water scarcity for use in various sectors. [ABSTRACT FROM AUTHOR]

The presence of antibiotics in the environment is of significant concern due to their adverse effects on aquatic ecosystems. This study provides an assessment of potential ecological risks (RQ) associated with the concentrations of eight antibiotics and antiparasitics (amoxicillin—AMO, azithromycin—AZI, ciprofloxacine—CIP, ofloxacine—OFL, oxfendazole—OXF, lincomycin—LIN, sulfacetamide—SCE and sulfamethoxazole—SME) in the surface water of 13 urban lakes in Hanoi city, Vietnam during the period 2021–2023. The findings revealed considerable variations in the total concentrations of these 8 substances (TAB), ranging from below the method detection limit (< MDL) to 2240 ng L−1 with an average of 330.4 ng L−1. Among the 8 antibiotics and antiparasitics examined, OXF, AMO, and SCE were undetectable, while the others were present at a range of concentrations (in ng L−1): OFL: 129 (< MDL-1530); CIP: 87.1 (< MDL-608); LIN: 72.7 (< MDL-676); SME: 41.5 (< MDL-504); AZI: 0.03 (< MDL-1). The calculated RQ values for these antibiotics in the Hanoi lakes indicated a high ecological risk for OFL and CIP to bacteria, a medium to high risk for SME for phytoplankton, a high risk for LIN to phytoplankton, while the risk for invertebrates was deemed negligible for all antibiotics across all lakes. The strong, positive correlation between TAB concentrations and different microbial and environmental variables (Escherichia coli, ammonium, phosphate, and chemical oxygen demand) suggests that untreated domestic wastewater is the primary pollution source in these Hanoi lakes. These results should be used to raise public awareness and to encourage the implementation of strategies targeted at managing antibiotic use. They also underscore the need to reduce inputs of untreated, antibiotic-containing wastewater into urban lakes, such as those in Hanoi and advocate for the establishment of national limits for antibiotic concentrations in surface water. [ABSTRACT FROM AUTHOR]

Heavy metal bioremediation from wastewater has gained great attention due to their high toxicity and non-biodegradable nature. They should be treated before discharge to water bodies. Assessment and evaluation of the impact of different concentrations of a mixture of heavy metal ions, namely Zn2+, Pb2+, Cu2+and Cr6+on the efficiency of a pilot plant hybrid up-flow anaerobic sludge blanket packed with novel packing media treating real municipal wastewater was investigated. The packing media is a novel non-woven polyester fabric (NWPF) that entraps heavy metal ions, subsequently reducing their toxicity on anaerobic sludge that affects the performance of UASB. It promotes faster biomass propagation and organic matter removal due to their unique characteristics and morphology. The size of the reactor was 1.81 m3 and was continually fed with different heavy metal ions at a flow of 5.76 m3/day. Incremental increase of the concentrations of metal ions from 1200 to 13,300 mg/m3 was carried out at different experimental runs. Results indicated that the use of NWPF enhanced the removal efficiency of the mixture of metal ions compared with the conventional UASB. The removal rates of chemical and biological oxygen demands were 67.65 and 77.35% at a total metal concentration of 1200 mg/m3. Further increases in the total concentrations of metal ions to 11-fold decreased the organic removal by 15.43% for COD and 10.58% for BOD. In conclusion, the use of NWPF as a packing material proved to be a promising media for mitigating the effect of heavy metals on UASB performance. [ABSTRACT FROM AUTHOR]

Growing industrialization and urbanization have led to increased water pollution due to the inadequate treatment and disposal of domestic wastewater (DW) and wastewater produced by industries such as tanneries (TW). These wastewaters are characterized by high concentrations of organic matter, nutrients, sulphates, chlorides and high microbial load. TW also contains phenols and chromium, which disturb and harm the ecosystem the local. The decontamination of wastewater prior to their discharge through biological tools, especially the use of species that are native to the site in need of treatment, has been described as effective and advantageous. This study evaluated the ability of Schoenoplectus americanus, a native plant species from Cordoba (Argentina), to phytoremediate local DW and TW samples at a laboratory scale. The aim was to ascertain whether this system could potentially be considered for the remediation of wastewater in real-world scenarios. S. americanus was able to tolerate pure DW and a 1/20 (v/v) dilution of TW for 30 days under hydroponic conditions. Removal rates ranging from 50% to 89% were obtained for residual organic matter (determined as chemical oxygen demand or COD), total nitrogen (TN) and total phosphorus (TP). Significant removal of total chromium (TCr) and total phenols (TPhs) was also observed in TW (85% and 98%). The number of total coliforms (TC), was reduced by about 96% and 99%. These results indicate that S. americanus is a good candidate for the phytoremediation of regional DW and TW. For this reason, it may be considered for full-scale applications in the future. [ABSTRACT FROM AUTHOR]

Biochemical methane potential tests using water hyacinth (WH), pretreated water hyacinth (PWH), and Hydrilla verticillata (HV) as substrates using sewage media were explored. This study replaced the freshwater required to prepare the slurry for AD of organic solid waste with domestic sewage. Cow dung was used as the inoculum. WH (241.5 mL CH4/g VSadded), PWH (200.5 mL CH4/g VSadded), and HV (212 mL CH4/g VSadded) produced significant amounts of methane in the sewage medium. 16S-rRNA analysis showed that, in sewage, ~ 85% of the microbes were hydrolytic bacteria, and 7% were methanogens. This abundant quantity of hydrolytic microbes from sewage accelerated lignin degradation, achieving 28.32% and 38.34% degradation for WH and HV, respectively, within 14 days. Field emission-scanning electron microscopy images visually confirmed the enhanced substrate degradation in the presence of sewage. The net energy produced from the AD of WH and HV was significant (4664 J/g VSadded and 4109 J/g VSadded), but for PWH, it was negative, indicating that using sewage medium may be better than costly pretreatment techniques. This study demonstrated the potential of using sewage as an alternative to freshwater in AD, offering a sustainable solution for freshwater conservation and the possible utilisation of sewage for improved methane production, especially for substrates with lignin that are difficult to degrade. [ABSTRACT FROM AUTHOR]

Domestic wastewaters have a significant concentration of nutrients that can be utilised as alternative sources of phosphorus and nitrogen for agriculture applications. Chemical precipitation is one of the processes found to be an efficient way for nutrient recovery from various wastewater feedstock. However, not all nutrients are in a form that can be readily recovered. Therefore, a pre-treatment process may be necessary for an efficient recovery of nitrogen and phosphorus. In this research, acid hydrolysis was performed as pre-treatment to release phosphorus from synthetic septage into soluble forms for the subsequent precipitation as struvite (MgNH4PO4·6H2O) which is known as a slow-release fertiliser for application in agriculture. Results show that acid hydrolysis increases the phosphate concentration (PO4-P) to 148.07 ± 1.78 from 61.50 ± 0.07 mg/L, showing the potential of hydrolysis as pre-treatment to efficiently recover nutrients in the form of struvite. The result can inform further research to develop efficient processes for the recovery of nutrients from domestic wastewater. [ABSTRACT FROM AUTHOR]

Cultivating microalgae for biomass production is a prospective method to treat wastewater and recover nutrients simultaneously. The aim of this study was to evaluate the growth and nutrient removal efficiency of Chlorella vulgaris NIES-227 in unsterilized domestic wastewater. The results showed that removal efficiencies of COD, total nitrogen, ammonia nitrogen, nitrite, and total phosphorus by NIES-227 reached 87.69%, 97.52%, 95.51%, 100% and 100% in domestic wastewater. NIES-227 grew better with higher OD680 and total carbohydrate content in domestic wastewater than that in BG11 medium. However, the contents of protein and Chlb were lower than those in BG11 medium group. The results indicated that NIES-227 had huge potential in domestic wastewater treatment, production of renewable biomass and high-value compounds. This study also suggested that cultivating NIES-227 using unsterilized domestic wastewater was feasible. [ABSTRACT FROM AUTHOR]

Microalgae cultivation utilizing urine can extract valuable nutrients from the urine while also producing beneficial by-products. Phosphorus (P) and nitrogen (N) are nutrients vital to all living organisms. When wastewater rich in these elements is dumped into surface waterways, it leads to eutrophication. Urine contributes the bulk of the nutrients found in residential wastewater, including 10%–20% of the potassium (K), 30%–50% of the P, and 60%–80% of the N. Urine is thought to be far more effective and energy-efficient at recovering nutrients when separated from other household wastewater streams than when huge amounts of highly diluted domestic wastewater are treated. The purpose of this study was to produce microalgae using human urine as a source of nutrients. Because of the high N:P ratio of microalgal biomass, it was projected that all of the P and a significant portion of the N could be used from human urine for algal biomass growth. From this study, it was found that when Scenedesmus obliquus was grown in undiluted human urine, its specific growth rate was 0.99/day, and its ammonium and phosphate consumption were 70.10% and 75.58%, respectively. The effects of urine dilution rate on ammonium and phosphate recovery were also studied in real human urine and synthetic urine. [ABSTRACT FROM AUTHOR]

Hospital wastewater is composed of different types of chemical substances with scarce information about its biodegradability and environmental toxicity. This study characterized hospital effluents generated in the city of Belo Horizonte (Brazil) through data compilation provided by the local sanitation company and statistical analysis associated with parameters established by a technical rule which proposes the regulation and monitoring of liquid effluents discharge from industrial and commercial activities in the public sewer systems. Data covered a total of 78 small, medium-sized, and large establishments, presenting 395,586 results of monitored parameters from 10/09/2007 to 01/30/2019. Statistical analysis included normality test, Principal Components Analysis and variance comparison using software R. The analysis of correlograms showed a positive correlation between the parameters chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in the analyzed hospitals, which also showed a strong correlation with the surfactants agents. Regarding the biodegradability effluent, 13.21% of samples obtained a BOD/COD ratio lower than 0.3. Among the nonconformities, 73% of records were found for total suspended solids, 25% for BTEX (benzene, toluene, ethylbenzene, xylenes), and for metals, the values were close to zero. The metals parameter showed less relevance. The analyzes also indicated that there was no seasonality evidence of nonconformities over the years. At last, the multiple comparisons indicated significant differences between the profiles of liquid emission effluents depending on the hospital's classification. Small size hospitals had the least impact. [ABSTRACT FROM AUTHOR]

Filtration is a method for controlling water pollution. This study aimed to engineer a filtration system using a combination of Melaleuca cajuputi (galam) wood charcoal and zeolite to process domestic wastewater. The research focused on domestic wastewater from Sungai Pinang Village, Samarinda, East Kalimantan, an area with significant water pollution issues. The samples were divided into three groups, each containing zeolite and galam wood charcoal in different ratios: Group 1 (1:1), Group 2 (1:2), and Group 3 (2:1). Each sample was exposed to contact times of 30, 60, and 90 minutes. Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Ammonia (NH3), and pH were measured for each treatment group at each contact time. Results showed that prolonged contact with the filtration method significantly reduced all parameters except pH (P0.05). Group 2 was found to be the most effective in improving water quality. In conclusion, this study demonstrates that the filtration method can reduce pollutant levels, with the combination of galam wood charcoal and zeolite in a 2:1 ratio being the most effective.

Partially Saturated Vertical Constructed Wetlands (PSV-CWs) are novel wastewater treatment systems that work through aerobic and anaerobic conditions that favor the removal of pollutants found in high concentrations, such as rivers contaminated with domestic wastewater and landfill leachate. The objective of the study was to evaluate the efficiency of PSV-CWs using monocultures and polycultures of Typha latifolia and Heliconia psittacorum to treat river waters contaminated with leachates from open dumps and domestic wastewater. Six experimental units of PSV-CWs were used; two were planted with Typha latifolia monoculture, two with Heliconia psittacorum monoculture and two with polycultures of both plants. The results indicated better organic matter and nitrogen removal efficiencies (p < 0.05) in systems with polycultures (TSS:95%, BOD5:83%, COD:89%, TN:82% and NH4+:99%). In general, the whole system showed high average removal efficiencies (TSS:93%, BOD5:79%, COD:85%, TN:79%, NH4+:98% and TP:85%). Regarding vegetation, both species developed better in units with monocultures, being Typha latifolia the one that reached a more remarkable development. However, both species showed high resistance to the contaminated environment. These results showed higher removals than those reported in the literature with conventional Free Flow Vertical Constructed Wetlands (FFV-CWs), so PSV-CWs could be a suitable option to treat this type of effluent. NOVELTY STATEMENT: The research addresses the contamination of water resources in developing countries by landfill leachate and domestic wastewater discharges. It proposes treatment through Partially Saturated Vertical Constructed Wetlands (PSV-CWs), which, despite the limited information available, have been shown to be effective in removing pollutants in effluents with high concentrations. In addition to evaluating PSV-CWs, the study examines the impact of different types of vegetation on pollutant removal efficiency, concluding that PSV-CWs are a promising and viable option for the treatment of these effluents. [ABSTRACT FROM AUTHOR]

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Integrated fixed-film activated sludge (IFAS) technology greatly enhances nitrogen removal effectiveness and treatment capacity in municipal wastewater treatment plants, addressing the issue of limited land availability. Hence, this method is appropriate for treating household wastewater from office buildings. The research was conducted at the wastewater treatment plant in an office building in Ho Chi Minh City, Vietnam. Experiments were conducted to ascertain the most favorable working conditions, including hydraulic retention time (HRT), alkalinity dosage, and dissolved oxygen (DO). According to the study, the IFAS system had the highest nitrogen removal effectiveness when operated at a hydraulic retention time (HRT) of 7 h, an alkalinity dose of 7.14 mgCaCO3/mgN-NH4+, and a dissolved oxygen (DO) value of 6 mg/L. The nitrification efficiency ranges from 89.2% to 98.8%. The N-NO3− concentration post-treatment is within the range of 27–45 mgN-NO3−/L, which is lower than the allowable discharge limit of 60 mg/L as per Vietnam's wastewater discharge requirements. The research findings have enhanced the efficiency of the office building management process, thereby promoting the sustainable growth of society. [ABSTRACT FROM AUTHOR]

The management of wastewater remains a challenge, particularly in developing countries. The potential use of constructed wetlands to treat wastewater is promising but their contaminant removal efficiencies, particularly in a tropical country such as Zimbabwe, are not fully understood. A pilot-scale study was undertaken in Zimbabwe to evaluate the efficiency of vertical-flow constructed wetlands planted with Typha latifolia in the treatment of domestic wastewater. Four pilot subsurface vertical-flow constructed wetland units (measuring 1 m × 1 m × 1.1 m) were built from concrete. The units were filled with waste rock from a nickel mine. Three units were planted with Typha latifolia while the fourth one was left unplanted, acting as the control. Each unit was loaded with wastewater at a rate of 220 dm3/day. Physico-chemical and bacteriological parameters were analyzed during the winter season. Physico-chemical and bacterial contaminant concentrations were significantly lower in the effluent than in the influent, and the system achieved maximum removals for BOD5, COD, TDS, TSS, nitrates, phosphates, phosphate pentoxide, phosphorus, and E. coli of 56.01%, 82.87%, 30.61%, 90.40% 17.26%, 35.80%, 36.19%, 40.64%, and 90.28%, respectively. The study shows that constructed wetland systems can be successfully established for the removal of physical, chemical, and microbial contaminants from domestic wastewater. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions, particularly anthropogenic emissions, are the primary drivers of climate change. The cultivation of microalgae represents a highly promising strategy for mitigating atmospheric GHG levels. The growth characteristics and GHG mitigation capabilities of Tetradesmus obliquus PF3 were investigated in domestic wastewater at a thermal power plant. The maximum cell density and productivity were 1.52 ± 0.01 g L−1 and 0.33 ± 0.01 g L−1 day−1, respectively. Utilizing a serial configuration of two reactors, the elimination efficiency of NO and CO2 attained values of 78 ± 4% and 14 ± 4%, respectively. NO concentration at the outlet was less than 24.6 ± 2.9 mg m−3, meeting the latest Chinese discharge limits. Besides, the recovery efficiency of NO and CO2 increased to 77 ± 8% and 2.24 ± 0.04%, respectively, compared to that of the single reactor (40 ± 3%, 0.9 ± 0.0%). A removal efficiency of over 90% was achieved for TN and TP in domestic wastewater. The concentrations of COD (76.5 mg L−1), NH4+-N (0.9 mg L−1), TN(6.31 mg L−1), and TP (0.35 mg L−1) in effluent were below the thresholds of 100 mg L−1, 25 mg L−1, none data, and 3 mg L−1, respectively, complying with the Chinese Discharge Standard (Class II criteria set forth) for Municipal Wastewater Treatment Plants Pollutants. The harvested biomass exhibited a high content of carbohydrates and proteins, making it a viable feedstock for biofuels and bio-fertilizers. Our results demonstrate that Tetradesmus obliquus PF3–based flue gas treatment technology can simultaneously realize GHG removal, wastewater bio-remediation, and biomass recovery. [ABSTRACT FROM AUTHOR]

Aceh Selatan is the oldest district in Aceh Province, located on the edge of the Banda Aceh - Medan west cross highway consisting of mountainous areas, lowlands, and water areas (Hindia Ocean). The problem at this time is that 54% of the people of South Aceh Regency do not have proper access to latrines and drainage channels, which are the target for receiving domestic wastewater. There is no public awareness of the importance of providing and maintaining domestic wastewater facilities and infrastructure. This research aims to sustainably carry out regional-scale domestic wastewater management based on Maqashid Syari'ah. The method used in the research is to determine the target of wastewater handling in South Aceh Regency until 2040 to determine the development model and strategy. Meanwhile, the zoning method was used to determine the planning area. Labuhan Tarok Village, Meukek District, South Aceh Regency, is one of the villages in urgent priority scale wastewater treatment with the An Aerobic Baffled Reactor (ABR) model. The reduction of BOD, COD, and TSS can be made with this treatment model in accordance with the Quality Standard of Peraturan Menteri Lingkungan Hidup dan Kehutanan No. 68 of 2014 and accordance with Permen PUPR No.4 of 2017, concerning the Implementation of Domestic Waste Water Management Systems. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Small islands with high population density are facing various environmental problems such as domestic wastewater pollution. Generally, in small islands lacking adequate wastewater management, pollution from domestic sources can severely affect the health of marine ecosystem. Therefore, this study was conducted on one of the most densely populated islands, namely Bungin Island, in Sumbawa Regency, West Nusa Tenggara Province, Indonesia. This study sought to analyze the state of surface seawater as influenced by the pollution stemming from domestic wastewater contamination.METHODS: Water samples were collected from April to August 2024 during rainy and dry seasons. Three locations along marine area were tested ex-situ using six parameters for seawater, including physical, chemical, and microbiological. The assessment of marine water quality status was conducted through the application of the pollution index formula, which facilitated calculation and analysis. Alongside the analysis of surface seawater samples, this study incorporated domestic wastewater samples, employing seven parameters to evaluate and predict the pollution load affecting the aquatic ecosystem.RESULTS: The results showed that, in general, indications of light pollution were found at three test points in seawater of Bungin Island. Major pollution was influenced by the contribution of domestic activities. The key parameters identified during the dry season were the levels of dissolved oxygen and the values of total suspended solids. Meanwhile, the critical parameters in rainy season were salinity and orthophosphate values. Testing of domestic wastewater indicated that several quality indicators, such as chemical oxygen demand, total suspended solids, oil and grease, and total coliform, were below the acceptable quality thresholds. Consequently, this may lead to an escalation in the daily pollution load as time progresses. This pollution load was certainly a problem for marine ecosystem on Bungin Island.CONCLUSION: The increase in population over time on densely populated islands will cause problems in the future related to domestic wastewater problems that threaten marine ecosystem. To prevent the escalation of environmental problems in the future, it is imperative to undertake appropriate mitigation strategies. This study provides a real picture concerning the threat of environmental damage that threatens one of the most densely populated islands in the world. Additionally, the results present further information that is beneficial for the worldwide sustainability of aquatic ecosystems.

The paper aims to determine the effectiveness of several alternative technologies that have been applied in centralized domestic wastewater management systems, especially in West Java and Banten provinces, in the removal of domestic wastewater pollutant parameters. The study was conducted in SPALD-Ts, including the Anaerobic Baffle Reactor (ABR) system, the Anobic Filter (AF) system, the combined ABR + AF system, and the Extended Aeration. The analysis was performed by sampling at the inlet and outlet points of the system for three consecutive years with sampling times from 2021 - 2023. The results of the research show that the efficiency of pollutant parameter separation based on the best technology in the separation of domestic wastewater pollutant parameters is the SPALDT extended aeration technology, where this technology can separate pollutant parameters up to an average of 88.25%, but in this technology requires more cost and periodic maintenance.

BACKGROUND AND OBJECTIVES: Domestic wastewater pollution in Thailand presents challenges due to limited space and a high concentration of point source effluents. This phenomenon often leads to domestic wastewater exceeding the capacity of local treatment systems. This study aims to expand the knowledge gained from The King’s Royally Initiated Laem Phak Bia Environmental Research and Development Project by evaluating the treatability of municipal wastewater. It utilizes a constructed wetland system in conjunction with a transfer and point source system. After the implementation of this primary system, the reduction in highly contaminated domestic wastewater could enhance the treatment loading of other secondary treatment systems or even facilitate its release into natural pathways.METHODS: In the sampling collection process, the dynamics of the collection points were categorized into three different zones: 1) the point sources of domestic wastewater within a municipality, where 15 sample points were selected to represent the municipality; 2) the collection pond within the municipality and the transfer pipeline, comprising three collection points of the system; 3) the constructed wetland treatment system, where five water samples were collected in relation to the length of the existing 100-meter plot. The water samples were collected using four 1-liter polyethylene bottles. The analysis parameters were the biological oxygen demand, total nitrogen, nitrate, total phosphorous and phosphate, and other parameters related to domestic wastewater treatment efficacy.FINDING: This study reveals that the domestic wastewater in Phetchaburi Province initially has a high organic content, leading to a biochemical oxygen demand: nitrogen: phosphorous ratio of 100:2.5:0.2 favoring anaerobic degradation. This ratio shifts in the constructed wetland system, located 18.5 kilometers away, to 100:10.5:2.3, promoting anaerobic treatment. The system shows high efficacy, with 81.4, 50.0, and 58.3 percent removal rates for biochemical oxygen demand, nitrogen, and phosphorus, respectively. This efficacy corresponds to a notable reduction in average biochemical oxygen demand from 740.0 to 9.7 milligrams per liter. Moreover, changes are observed in total nitrogen content, shifting from 20.8 to 2.8 milligrams per liter, in the system’s effluent. While lastly, the total phosphorous decreased from 2.75 to 0.60 milligrams per literCONCLUSION: This treatment method can be effectively applied to small-scale constructed wetland systems within households. The recommended hydraulic retention time is between 29 and 60 hours under anaerobic conditions and 3 days under aerobic conditions. The changes in the composition of municipal wastewater, which is highly organic, support the use of both degradation processes. The knowledge and application of the constructed wetland system could be suggested for the primary treatment system of domestic wastewater within municipalities, given that this system would provide support to the central wastewater treatment system for enhanced efficacy.

BACKGROUND AND OBJECTIVES: Community domestic wastewater contains organic substances that can be decomposed through natural processes. Treatment using oxidation pond systems is popular in tropical zones because these locations provide a climate suitable for the growth and organic decomposition activities of various bacteria that remove organic contaminants from wastewater. Given that bacteria play an important role in the biodegradation of organic substances in wastewater treatment plants, their degradation activity is used as an indicator of water quality. The purpose of this study is to examine the vertical variability of bacteria in natural treatment oxidation ponds in tropical zones.METHODS: Wastewater samples were collected from an oxidation pond at 3 different depths (0–0.6, 0.6–1.5 and more than 1.5 meter), and their chemical, physical and biological qualities were analysed. Next-generation sequencing techniques were used to identify bacterial diversity, and the water quality at each depth was applied as an indicator of bacterial degradation activities.FINDINGS: Community domestic wastewater contained 10 major bacterial phyla that differed at different depths. Amongst these phyla, the Actinobacteriota dominated (25.35 to 28.23 percent), followed by Cyanobacteria (19.49 to 21.57percent), Planctomycetota (15.50 to 17.41 percent), Firmicutes (9.97 to 10.79 percent), Proteobacteria (9.73 to 10.79 percent), Verrucomicrobiota (6.47 to 7.69 percent), Chloroflexi (2.79 to 2.99 percent), Bacteriota (0.96 to 1.41 percent), Acidobacteriota (0.70 to 0.80 percent) and SAR324 clade (marine group B) (0.69 to 0.61 percent). Four organic substances were found in contaminated domestic wastewater. 1) Photosynthetic cyanobacteria and phytoplankton performed aerobic degradation and accounted for the dissolved oxygen levels of 7.76, 7.45 and 7.42 milligrams per liter, respectively at various depths along the vertical profile. 2) Bacteria and archaeans that participate in carbon compound treatment included Planctomycetes, Verrucomicrobiota, Bacteroidota and Euryarcheota. These bacteria exhibited a treatment efficiency for biochemical oxygen demand and low abundance at all depths. Biological oxygen demand increased to 23.11, 24.27 and 34.48 milligrams per liter with depth. 3) Nitrogen-cycling bacteria included nitrifying and denitrifying bacteria. They belonged to the Actinobacteriota, Planctomycetota, Firmicutes, Verrucomicrobiota, Chloroflexi, Bacteriota, Protrobacteria and Acidobacteriota phyla. They exhibited an ammonia-nitrogen treatment efficiency of 91.73 percent. 4) Phosphorus cycling–related bacteria in the Actinobacteriota phylum presented the orthophosphorus treatment efficiency of 65.41 percent.CONCLUSION: The results of this study suggested that bacterial communities did not significantly differ along oxidation depth because they work together with chemotrophs, which participate in organic substance decomposition, and phototrophs, which are involved in oxygen generation and nutrient removal. All of the bacteria found in domestic wastewater benefit and support oxidation pond systems in tropical zones. Anaerobic bacteria can be found in wastewater and used in treatment systems due to their protective mechanisms against oxygen toxicity and self-repair mechanisms. The knowledge gained from this study can be used as a reference in future works on natural wastewater treatment systems.

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.

The endocrine-disrupting compounds (EDCs) have high-risk implications for public health and the environment due to their potential to interfere with endocrine system functions. This study is based on an evaluation of the applying the UV-assisted Fenton process for the removal and degradation of 17β-estradiol and estrone in aqueous medium. The simple and affordable UV irradiation system was developed and applied to accelerate the Fenton reaction. High performance liquid chromatography (HPLC) was employed for the quantitative measurements of estrogenic hormones at 230 nm, which is highly sensitive and capable of accurately measuring hormones within 15 min. The LOD/LOQ values of HPLC system were recorded to be 0.03/0.11 mg/kg and 0.05 /0.15 mg/kg for estrone and 17β-estradiol, respectively. Fe3O4 magnetic nanoparticles and iron (II) sulfate solution were evaluated as appropriate iron sources under fixed UV irradiation to assess the Fenton process. The main parameters, namely hydrogen peroxide (H2O2) amount, iron (II) sulfate amount, pH, and UV irradiation period, were optimized univariately for determining the optimum conditions. The optimum conditions were recorded to be: 0.70 mL of pH 3.0 buffer solution, 1.25 mL of H2O2, 0.80 mL of 100 mg/L Fe2+ solution, and an irradiation time of 60 min. The removal experiments were also carried out on domestic wastewater to validate the system's applicability. The percent removal efficiencies of both estrogenic hormones were calculated at higher than 99%. These results showed that high efficiency was achieved within the detection limits of the HPLC system. This proves the possibility of complete degradation of the analytes and their efficiency and practicality for pollution control and water quality improvement in future studies. [ABSTRACT FROM AUTHOR]

Untreated domestic wastewater from rural areas poses significant risks to ecosystems and human health. Constructed wetlands (CWs) are a viable alternative for this wastewater treatment, enhancing nitrogen removal using substrates as carbon sources. This process is particularly beneficial for wastewater with low carbon-to-nitrogen (C/N) ratios, making the treated water suitable for agricultural irrigation. In this study, a Horizontal Subsurface Flow CW (HSF-CW) was evaluated using Canna hybrids and a mixed substrate of gravel and endocarp from oil palm fruit (EOP) as a carbon source to leverage its abundance in the region. It was also determined that the effluent complies with the permissible limits set by Resolution 1207 of 2014 from the Colombian Ministry of Environment and Sustainable Development, which establishes environmental standards for wastewater treatment to ensure environmental protection and enable safe reuse in agricultural irrigation. The key parameters analyzed included organic contaminants, heavy metals, nutrients, and microbiological indicators. Removal efficiencies of up to 91%, 94%, 98%, 52%, 73%, 78%, and 75% were achieved for BOD, TSS, total phosphorus, nitrates, nitrites, ammonium, and total nitrogen, respectively, demonstrating the CW's strong performance in contaminant removal and meeting most standards for agricultural irrigation. Although the carbon source was not highly efficient, the overall system performance supports its viability for improving water quality and promoting sustainable agricultural practices in rural areas. [ABSTRACT FROM AUTHOR]

Anaerobic and membrane technologies are a promising combination to decrease the energy consumption associated with wastewater treatment, allowing the recovery of resources: organic matter as biomethane, nutrient assimilation by microalgae and reclaimed water. In this study, domestic wastewater was treated using a combination of an upflow anaerobic sludge blanket sludge reactor (UASB) and a membrane photobioreactor (MPBR). The outdoor facilities were operated continuously for three months under unfavourable environmental conditions such as lack of temperature control, winter season with lower solar irradiation and lower daylight hours which was a challenge for the present work, not previously described. The energetic valorisation of the organic matter present in the wastewater by biomethane produced in the UASB would contribute to reducing overall facilities' energy requirements. The ultrafiltration (UF) membrane facilitated the harvesting of biomass, operating at 10 L·h−1·m−2 during the experimental period. Although the main contribution to fouling was irreversible, chemical cleanings were not necessary due to effective fouling control, which prevented the final TMP from exceeding 25 kPa. In addition, microalgae-bacterial consortium developed without prior inoculation were harvested from the MPBR using membrane assistance. The obtained biomass was also successfully tested as a biostimulant for corn germination/growth, as well as a biopesticide against Rhizoctonia solani and Fusarium oxysporum. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As global urbanisation, industrialisation, and population growth escalate, the production of wastewater also increases, leading to significant water pollution on a global scale. This pollution poses severe threats to environmental health, wildlife, and human communities. In rural areas where centralised sewage systems are often absent, septic tanks play a crucial role in managing wastewater. They separate solids from liquids and facilitate the biological decomposition of organic matter. This paper utilises a Patent Landscape Review (PLR) to analyse the scope and direction of innovations in septic tank technology. Conducted on 23 September 2022, the patent search targeted filings from January 2001 through June 2022 to identify prevailing trends and advancements within this field. Through a detailed examination of 889 patents, categorised by keywords, processes, materials, and designs, this study offers a comprehensive overview of the patent landscape for septic tanks. Key findings indicate that fibreglass cylindrical tanks dominate the market due to their durability and efficiency. This review also highlights a growing trend towards modular septic systems, which offer scalable solutions adaptable to specific environmental conditions. Furthermore, some patents propose the repurposing of various objects as septic tanks, demonstrating a move towards sustainability by reducing waste and enhancing environmental conservation. This paper emphasises the importance of continued innovation in septic tank technology to address the challenges of effective wastewater management in underserved rural communities. [ABSTRACT FROM AUTHOR]

Copyright of Global Journal of Environmental Science & Management (GJESM) is the property of Global Journal of Environmental Science & Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Global Journal of Environmental Science & Management (GJESM) is the property of Global Journal of Environmental Science & Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper studied the characteristics of the carbon emission of an industrial wastewater treatment plant (IWWTP) and a domestic WWTP (DWWTP) located in a high-tech industrial park of Shaanxi Province, China. The results showed that the total carbon emissions of the IWWTP and DWWTP were 10.13 kg/t and 1.84 kg/t in 2020, respectively. Indirect carbon emissions play a dominant role in the total carbon emission of the IWWTP, which accounts for about 97.6% of the total amount. The direct carbon emissions of greenhouse gases (e.g., CH4, N2O) account for about 62% of the total carbon emissions in the DWWTP, followed by the indirect carbon emissions generated by electricity consumption (31.06%) and chemical consumption (6.94%). Additionally, the centralized recycling and re-utilization of the wastewater could achieve 1.06 kg/t and 1.16 kg/t of carbon emission reduction in the IWWTP and DWWTP, respectively, while the carbon emissions of the DWWTP are inversely proportional to the treatment capacity. Therefore, it is of great value to collect and utilize intensively the recycled water to achieve the goal of regional carbon emission reduction and carbon neutralization of WWTPs in industrial parks. [ABSTRACT FROM AUTHOR]