Untreated Domestic Wastewater Research Articles

Occurrence of forever chemicals in Chennai waters, India

BackgroundPer- and polyfluoroalkyl substances (PFAS) are considered ‘contaminants of emerging concern’ due to their environmental persistence, bio-accumulative potential, and adverse effects on human health. They are widely employed in producing various goods used in daily life, such as non-stick cookware, cleaning agents, and many industrial applications in aerospace, automotive, construction, electronics, and military, all of which ultimately end up in different environmental matrices. India’s rapid economic growth necessitates a comprehensive understanding of its PFAS contamination levels and potential human and ecological exposure.ResultsThe present study reports the quantification of one long-chain and two short-chain perfluoroalkyl acids and three long-chain and two short-chain perfluorosulfonic acids and qualitative analysis using suspect screening in the waters of Chennai, Tamil Nadu, India. Samples were collected from surface and groundwater sources, including the Adyar river, Buckingham canal, Chembarambakkam lake, and the water treatment plant. The concentrations analyzed in all the samples ranged from 0.10 ng/L to 136.27 ng/L. Groundwater had some of the highest concentrations of PFAS. L-PFBS (up to 136.27 ng/L) and PFOA (up to 77.61 ng/L) are present in all the samples. The concentrations of all the target PFAS increased in the 5 to 103% range in the final treated water compared to the raw water of the water treatment plant. This treated water is distributed as a source of drinking water for the residents of Chennai. Additionally, the dominance of short-chain compounds (4–7 carbons) over long-chain compounds (> 7 carbons) was observed. Suspect screening revealed numerous precursors and other fluorinated compounds abundantly present in the samples.ConclusionsOur study revealed PFAS levels up to 136.27 ng/L in both surface and groundwater samples from Chennai. These findings raise concerns about potential risks to ecosystems and human well-being. The dominance of short-chain PFAS coupled with abundant precursors and unidentified fluorinated compounds indicates an ongoing shift toward alternatives. Conventional water treatment is ineffective in eliminating these chemicals from the water system; rather, increasing the PFAS concentrations from raw water to treated water necessitates advanced polishing steps. Industrial emissions, untreated domestic wastewater discharge, and open dump sites have been suspected as the significant sources of contamination, highlighting the need for further investigation to fully assess the extent of PFAS contamination in Chennai.Graphical

Effect of catholyte on performance of photosynthetic microbial fuel cell for wastewater treatment and energy recovery

The performance of photosynthetic microbial fuel cell (PMFC) was assessed for wastewater treatment and energy recovery using two different catholytes; untreated domestic wastewater (UDW) and wetland treated wastewater (WTW). The performance was investigated under continuous light and 12/12 h light/dark cycle, employing Scenedesmus sp. as a biocatalyst. The results showed that PMFC with UDW as the catholyte outperformed the WTW under both types of illumination. Under continuous illumination, the PMFC with UDW achieved a maximum working voltage 33 % higher than that of WTW. The rates of chemical oxygen demand (COD) and nutrient removal in the cathode chamber were significantly higher for PMFC with UDW catholyte. Maximum dissolved oxygen (DO) reached 10 and 8.4 mg/L for UDW and WTW, respectively, with corresponding algae concentrations of 5165 and 3130 mg/L. Under the light/dark cycle, both the working voltage and DO concentration exhibited a diurnal pattern. The maximum algal growth, DO and power output in UDW were higher than WTW under 12/12 h light-dark cycle; however, these values remained lower compared to continuous illumination. These results demonstrate the feasibility of PMFC for both untreated and secondary treated domestic wastewater as catholytes.

Cross-Sectional Study of Soil-Transmitted Helminthiases in Black Belt Region of Alabama, USA.

We conducted a cross-sectional study to determine the prevalence of soil-transmitted helminthiases (STH) in areas of rural Alabama, USA, that have sanitation deficits. We enrolled 777 children; 704 submitted stool specimens and 227 a dried blood spot sample. We microscopically examined stool specimens from all 704 children by using Mini-FLOTAC for helminth eggs. We tested a subset by using molecular techniques: real-time PCR analysis for 5 STH species, TaqMan Array Cards for enteric helminths, and digital PCR for Necator americanus hookworm. We analyzed dried blood spots for Strongyloides stercoralis and Toxocara spp. roundworms by using serologic testing. Despite 12% of our cohort reporting living in homes that directly discharge untreated domestic wastewater, stool testing for STH was negative; however, 5% of dried blood spots were positive for Toxocara spp. roundworms. Survey data suggests substantial numbers of children in this region may be exposed to raw sewage, which is itself a major public health concern.

Study on Nutrients Concentration Trends in Tukad Badung River Toward Nutrient Recovery Potential

This study addresses the urgent concern of water quality degradation resulting from untreated domestic wastewater discharge, with a specific focus on nutrient trends within an aquatic ecosystem. The investigation centres on ammonium (NH4 +) as a significant contaminant sourced from residual foods, hygiene practices, and fertilizers, known for its association with eutrophication—characterized by excessive algae growth and oxygen depletion. The study aims to offer comprehensive insights by meticulously analysing water quality parameters across six distinct sampling points. Data collection encompassed total suspended solids (TSS), ammonia (NH4 +), nitrite (NO2 −), nitrate (NO3 −), total phosphate (PO4 −), and total nitrogen (TN). Notable variations were observed: TSS concentrations ranged from 9.00 mg/L to 20.00 mg/L, NH4 + concentrations spanned 0.00 mg/L to 1.96 mg/L, NO2- and NO3 − levels varied from 0.00 mg/L to 0.16 mg/L and 1.19 mg/L to 1.91 mg/L, respectively, PO4 3- content ranged from 0.01 mg/L to 0.65 mg/L, and TN concentrations fluctuated between 1.36 mg/L and 3.31 mg/L. These findings underscore the complexity of water quality dynamics and highlight the need for integrated management strategies to mitigate nutrient pollution’s impact on aquatic ecosystems.

Applicability of hybrid treatment to reduce the footprint of domestic and industrial wastewater of developing countries

Wastewater pollution is a serious concern, especially in developing countries such as Pakistan. The untreated domestic and industrial wastewater is typically discharged into sewers, natural drains, or water bodies. There is a dire need to evaluate the applicability of low-cost treatment technologies. Hybrid wastewater treatment (HWWT), comprising of chemically enhanced primary treatment (CEPT) and intermittent sand filter (ISF), was adopted to treat domestic, process and manufacturing, and food industry wastewaters. The wastewater pollution and contamination were assessed in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS). The removal efficiency (RE) performance of HWWT was compared with the CEPT system only. Considering the CEPT only, the RE of BOD was ≈70 % for domestic, >80 % for process and manufacturing, and ≈50 % for the food industry. For COD, the RE was high in process & manufacturing (RE ≈ 81 %), followed by food (RE ≈ 55 %) and domestic wastewater (RE ≈ 17 %). Furthermore, the CEPT provided >95 % TSS removal in all wastewater types. The HWWT increased TSS removal by ≈2 %, BOD removal by ≈13 %, and COD removal by ≈27 % compared to the CEPT system. Therefore, HWWT proved more efficient in treating both domestic and industrial wastewater. The HWWT reduced the greywater footprint (GWF) by 50–60 % when compared to the CEPT system. This study provided knowledge of the characteristics of domestic and industrial wastewater. Furthermore, provides a basis to assess the applicability and performance of various wastewater treatment systems under given settings.

Biohythane Production from Domestic Wastewater Sludge and Cow Dung Mixture Using Two-Step Anaerobic Fermentation Process

The current study explored bioenergy, particularly biohythane (a combination of biohydrogen (bioH2) and biomethane (bioCH4)), production from cow dung and untreated domestic wastewater sludge to valorize the waste into a value-added product. The experimental study consisted of a two-step process: dark fermentation (DF) and anaerobic digestion (AD) with a range of processing conditions varying the temperature and pH (acidic, neutral, and basic). The study maintained thermophilic conditions (55 °C) for bioH2 production and mesophilic conditions (35 °C) for bioCH4 production. The highest yields of bioH2 and bioCH4 were obtained at a pH of 5.5 (108.04 mL H2/g VS) and a pH of 7.5 (768.54 mL CH4/g VS), respectively. Microorganisms, such as Lactobacillus brevis and Clostridium butyricum, in the wastewater sludge accelerated the conversion reaction resulting in the highest bioH2 yield for an acidic environment, while Clostridium and Bacilli enhanced bioCH4 yield in basic conditions. The maximum cumulative yield of biohythane was obtained under basic pH conditions (pH 7.5) through DF and AD, resulting in 811.12 mL/g VS and a higher volumetric energy density of 3.316 MJ/L as compared to other reaction conditions. The experimental data were modelled using a modified Gompertz’s model at a 95% confidence interval and showed the best-fitting data from experimental and simulation results for biohythane production. The regression coefficient R2 value was highly significant at 0.995 and 0.992 for bioH2 and bioCH4 with the change in pH during biohythane production. Thus, this study presented an effective pathway to utilize untreated domestic wastewater sludge as an inoculum, showcasing the potential of biohythane production and the generation of valuable metabolic end-products across a broad range of pH conditions.

Assessment of the current state of the hydrochemical regime and water-environmental problems of the basin of the Gavaraget River flowing into Lake Sevan

The results of studies of the current hydro-chemical state and water-ecological problems of the Gavaraget River basin, which flows into Lake Sevan from the north-west, are presented. Extreme water discharge, ten-day flow, ecological output have been determined, water-ecological features have been identified, long-term dynamics of the main indicators characterizing the ecological state of the Gavaraget River, spatial-temporal changes in winter and summer-autumn ten-day flow have been shown, the hydro-chemical state has been presented, the main water-ecological problems of this basin and ways to solve them were proposed, the physical and chemical state of Gavaraget water was clarified in accordance with the standards and requirements for water quality, and the level of risk was indicated. It has been clarified that the annual runoff in the basin basically follows the general features of the annual precipitation regime: the minimum amount falls in winter, and the maximum in spring. It is shown that Gavaraget is one of the most polluted rivers in the Lake Sevan basin. It was revealed that it is mainly contaminated with untreated domestic wastewater and agricultural return water. It was found that as the impact of anthropogenic load increases, river water pollution increases from the source to the mouth of the river. The water quality in the upper part of Gavaraget (0.5 km upstream from the village of Tsaghkashen) is excellently characterized as “excellent” (I) and “good” (II), in the lower part (at the river mouth) with “moderate” (III) and “unsatisfactory” (IV) class. The research results can be useful in solving geo-ecological problems, managing aquatic ecosystems, determining ecological flow, assessing risks, predicting water disasters, protecting river ecosystems from degradation, etc.

Spatio-temporal variations of groundwater quality index using geostatistical methods and GIS

A groundwater quality map serves as a deterrent mechanism that provides insight into likely environmental health predicaments. The objective of this study was to create map and evaluate the quality and changes in groundwater during the study period in Erbil, Iraq. Based on the 13 groundwater parameters, the water quality index (WQI) was calculated for 61 wells from 2015 to 2017 for wet and dry seasons. To generate WQI maps, two geostatistical analyst tools in Geographical Information Systems, including Kriging and Inverse Distance Weighted (IDW) were used. For determining the most suitable method, statistical indices were applied to the obtained data. The results showed that the Kriging method increases the prediction accuracy compared to the IDW method. The water quality in 2017 was decreased compared to the previous years and the WQI was increased from 1.64% to 11.47%. Untreated domestic and industrial wastewater causes groundwater pollution which was the main reason for the decrease in the water quality of Erbil city.

Antibiotic resistance in wastewater: Indian scenario

The surge of Antibiotic Resistant Bacteria (ARB) in the environment is poised to be the next health threat. World Health Organisation's (WHO's) Global Antimicrobial Surveillance System (GLASS) report indicates that developing countries may be at a greater risk. Among various factors, the major driver here could be untreated wastewater and poor sanitation. Bacteria are extremely adaptable to their surroundings and develop Antimicrobial Resistance (AMR) when exposed to antibiotics and other pollutants that cause microbial stress. Thus, untreated domestic wastewater drains could easily become hotspots for the occurrence of ARBs. This study reports surveillance of sewage-carrying drains across four urban cities in India and demonstrated the presence of ARBs in the bacterial community against 7 classes of antibiotics, namely, β-Lactams, Chloramphenicol, Glycopeptides, Macrolides, Tetracycline, Third Generation Cephalosporin, and Quinolones. Untreated domestic wastewater flowing in target drains was collected twice a month, for a period of six months and the microbial community was subjected to Antibiotic Susceptibility Testing (AST) by plate assays. The zone of inhibition was recorded and interpreted as per the interpretive chart of The Clinical & Laboratory Standards Institute (CLSI) & The European Committee on Antimicrobial Susceptibility Testing (EUCAST). The total number of samples showing resistance against antibiotics was used to define an Antibiotic Resistance Index (ARI), calculated for all 20 sampling sites (drains). Results demonstrated that the highest ARI was observed in Delhi and Mumbai, ranging from 0.81 to 0.92 in Delhi and 0.49–0.56 in Mumbai. This surveillance study reveals the antibiotic resistance pattern of the representative bacterial community in the drains and goes beyond few targeted bacterial species. The alarming presence of antibiotic resistant bacterial community highlights the concern of ARBs being the next looming health threat. This report aims to demonstrates the importance of considering sewage surveillance on routine basis by state authorities.

Epilithic biofilms of the Eastern Caspian (Aktau region, Kazakhstan) under conditions of falling sea level

Communities of microorganisms that form biofilms on the rocky shores of the Middle Caspian are capable of maintaining the integrity of the coastal landscape in the conditions of sea retreat associated with the ongoing drop in sea level since 1995. Algal-bacterial biofilms developing on rocky substrates of the East Caspian coast within the City of Aktau were studied in autumn (October 2022) and spring (April 2023) seasons. Communities in biotopes with different structure were investigated. It has been established that the most stable and diverse communities with a pronounced vertical structure live in the areas with high sheer cliffs on capes. On flat areas of the coast, which have undergone recent shallowing and are protected from surfing waves by ridges of large stones, less diverse cenoses, demonstrating clear spatial organization. In the shallow open areas of the shore, which are subject to intense wave action, live communities of two types were observed. Both cenoses contained a relatively small number of species, but differed in structure and potential for protecting the coast from erosion. The first of them live in biotopes outside the impact of urban domestic sewage, and are able to protect coastal marl from destruction due to the development of stable, rapidly regenerating complex structural elements. The latter were noted in the conditions of along-shore spreading of untreated domestic wastewater from new city developments located close to the coast. Such biofilms were no longer able to protect marls from being destroyed by waves, and took the form of constantly renewed patches with minimum diversity of components and unstable spatial organization.

A Novel Study on Anionic Surfactant Degradation Potential of Psychrophillic and Psychrotolerant Pseudomonas spp. Identified from Surfactant-contaminated River Water.

The Yamuna River, a tributary of the holy Ganga, is heavily polluted in the Delhi-NCR region, India and has been gaining attention due to the excessive foaming of the river over the past few years. This can be directly or indirectly related to the overuse of surfactants and the discharge of untreated domestic and textile wastewater into the river. To determine the surfactant load and investigate potential surfactant-degrading bacteria in the region, 96 water samples from four sites in the Okhla Barrage stretch of the river were collected and analysed. The results showed that the selected sites have surfactant concentrations more than the permissible limit (1.00 mgL-1). Also, at most of the sites, the concentration crossed the desirable limit of BIS (0.2 mgL-1) during the period of analysis. The concentration of anionic surfactant reported in the region was found in the range of 0.29 mgL-1 and 2.83 mgL-1. A total of 38 different bacteria were isolated using selective media from the same water samples, out of which 7 bacterial isolates were screened for sodium dodecyl sulphate (SDS) tolerance activity. Based on 16S rRNA gene sequencing, 2 species, namely Pseudomonas koreensis YRW-02 and Pseudomonas songnenensis YRW-05 have been identified and their degradation potential was assessed at different SDS concentrations. The results showed that our strains YRW-02 and YRW-05 degraded 78.29 and 69.24% of SDS respectively. Growth optimization was also performed at different substrate concentrations, pH, and temperature to investigate optimum degradation conditions. This study plays a significant role in assessing the surfactant load and also gives a promising background for future use in in-situ bioremediation experiments.

Restoration of Qaraoun Lake aquatic life based on wetland treatment concept

Qaraoun Lake, the largest artificial lake in Lebanon, suffered severe environmental issues due to discharging untreated domestic and industrial wastewater into it, throwing garbage, which transformed this lake into waste storage instead of using the water for agricultural purposes and making the surrounding places attractive for tourists as was before. Moreover, the violations on Litany River, Lebanon's main artery, also affected Qaraoun Lake. Therefore, this main reservoir suffers from annual blooms of potentially toxic cyanobacteria. Recently, tons of fish are washed up at the surface of the water, agricultural areas are irrigated with polluted water and the Qaraoun Lake is no longer an attractive touristic place. Besides, the climate change represented in lower precipitation and higher evaporation rates in the past few years in addition to the increase in the water demand due to the growth in the local population and the refugees from nearby countries have affected the vulnerability of the water sector in Lebanon. All these issues have resulted in the deterioration of the water quality, generating environmental issues, and seriously affecting the ecosystem. The purpose of this research is to investigate possible remediation strategies, which could help in the restoration of the Qaraoun reservoir. For this purpose, the Litani River water quality and hydrological data are collected from the Litani River Authority (LRA). Moreover, a hydrodynamic water quality model has been developed using Mike21 in order to restore the lake's aquatic life by eliminating the Litani River nutrients through constructed wetland concept, which reasonably simulated the water quality parameters of Qaraoun Lake. Consequently, the wetland could remarkably reduce the Litani River pollutants by 85%, 43.7%, 57%, and 56% for BOD, Phosphorous, Nitrate, and Ammonia, respectively. The resulted treated water, after passing the wetland, successfully improved the lake water quality and may lead to re-originate its ecosystem.

Uncovering the Dominant Contribution of Untreated Domestic Wastewater to Antimicrobials in the Lower Reach of the Lhasa River on the Tibetan Plateau

A major tributary of the Yarlung Tsangpo River on the Tibetan Plateau, the Lhasa River, flows through Lhasa, one of the world’s highest-altitude cities. Along with the fast urbanization and booming tourism industry in Lhasa, pollution of its aquatic environment receives growing concerns. This study quantified the spatiotemporal distributions and potential ecological risk of common antimicrobials in the lower reach of the Lhasa River for the first time and found untreated domestic wastewater to be a key source of pollution. Thirty-four antimicrobials were detected, with concentrations spanning 4 orders of magnitude (0.01–629 ng/L). Spatial variations of antimicrobials were observed, with tetracyclines and macrolides dominated at the upstream and downstream sites of Lhasa city, respectively, due to varying source inputs and different attenuation of antimicrobials. Although only a few antimicrobials pose medium–high ecological risk individually, the simultaneous occurrence of multiple antimicrobials may result in significant ecological toxicity. While the treated wastewater effluent and agricultural runoff combined contributed to 14.2 and 23.5% of the total antimicrobials in the Lhasa River during wet and dry seasons, respectively, the untreated domestic wastewater discharge accounted for the rest. These findings indicate the urgent need for improving the collection system and treatment technology of domestic wastewater in Lhasa.

Effect of pH, Dissolved Organic Carbon, and Sodium Dodecyl Sulfate to Degradation of Fenobucarb Insecticide in Paddy Soil-Water System

ABSTRACT In paddy rice farming systems, the degradation of insecticides from the soil reduces their occurrence as well as their levels in surface and groundwater. Degradation of insecticide fenobucarb in the paddy soil-water system was carried out by surface soil collected from paddy rice in the Hue province of Vietnam. Experiments were conducted using a batch technique, the fenobucarb-spiked paddy soils were shaken end-over-end with solutions of pH 7, pH 9, 25 mg L−1 DOC, and 1 critical micelle (cmc) sodium dodecyl sulfate (SDS). After each period (24, 48, 72, … 144 hours), the soil solutions were separated into the aliquot and the solid phase to analyze fenobucarb and intermediate metabolic products 2-sec-butyl phenol. The decrease of fenobucarb and the appearance of (2-sec-butyl-phenol) were the result of hydrolysis and biodegradation by fenobucarb-acclimatized microorganisms that were capable of degrading fenobucarb in the paddy soil. The degradation of fenobucarb in both the soil and water phases in the paddy soil-water system was enhanced in the experiment with pH 7, followed by those with pH 9, 25 mg L−1 DOC, and 1 cmc SDS. With pH 9, in addition to decomposition by bacteria present in the soil, fenobucarb was hydrolyzed under basic conditions. The presence of 25 mg L−1 DOC and 1 cmc SDS in the aqueous solution increased desorption and microbial activity in the soil and increased the biodegradation efficiency of fenobucarb in the paddy soil-water system. However, the degradation of fenobucarb in the 1 cmc SDS solution was inhibited because SDS solution may be preferentially utilized by microorganisms, and fenobucarb would have a competitive effect with SDS. Irrigation water for paddy fields often receives untreated domestic and industrial wastewater that may contain multiple compounds such as DOC and SDS. Therefore, it contributes to the elimination of fenobucarb insecticide in the paddy soil-water system.

A low-cost optofluidic platform for the colorimetric assessment of bacterial activity in domestic wastewater.

Optofluidic chips represent a cost-effective platform for the development of miniaturized devices to perform biochemical reactions at a microscale. The dye reduction-based electron-transfer activity monitoring (DREAM) assay is a colorimetric approach that has been adopted for the rapid assessment of bacterial activity in bioreactors used in bioremediation and industrial biotechnology. A three-layered PMMA-based optofluidic chip having laser-machined microchannels coupled with a detection system comprising an LED source and a photodiode interfaced with a microcontroller for automation constituted the experimental setup. Data acquisition was executed using a user-friendly graphical user interface (GUI) that enabled real-time monitoring of bacterial activity. A performance comparison study was performed to assess the viability of replacing expensive spectrophotometers with an inexpensive photodiode for optoelectronic automation. Bacterial activity across different growth phases of a bacterial culture, initiated using untreated domestic wastewater, was assessed by the detector on the basis of voltage readings corresponding to the rate of decrease in the blue color intensity. The highest activity observed corresponded to the log phase of the growth curve. The optimal time for measurement of bacterial activity within the log phase of the growth curve was identified using different dilutions of untreated domestic wastewater. Furthermore, the device showed comparable sensitivities for samples from different time points in a bacterial growth curve and for different dilutions of untreated domestic wastewater samples. The device also demonstrated a linear response in the assessment of bacterial activity as a function of the change in strength of untreated domestic wastewater. This is the first report on colorimetric assessment of bacterial activity using a low-cost photodiode-based device at the microscale constructed using off-the-shelf components.

ГИДРОХИМИЯ МАЛЫХ РЕК У ГОРОДА ВЯЗЕМСКИЙ

The paper provides characteristics of small rivers water chemical composition in the Vyazemsky area. The assumption is made that river waters were polluted by biogenic and organic nutrients due to to the discharge of untreated domestic wastewater.

Per- and polyfluoroalkyl substances (PFASs) in groundwater from a contaminated site in the North China Plain: Occurrence, source apportionment, and health risk assessment.

Per-and polyfluoroalkyl substances (PFASs) are manmade chemicals that have wide industrial and commercial application. However, little research has been carried out on PFASs pollution in groundwater from a previously contaminated site. Here, we investigated 43 PFASs in a monitoring campaign from two different aquifers in the North China Plain. Our results revealed that total PFASs concentrations (∑43PFASs) ranged from 0.22 to 3,776.76ng/L, with no spatial or compositional differences. Moreover, perfluorooctanoic acid (PFOA) and perfluoroheptane sulfonate (PFHpS) were the dominant pollutants with mean concentrations of 177.33ng/L and 51ng/L, respectively. ∑43PFAS decreased with well depth due to the adsorption of PFASs to the aquifer materials. Water temperature, total organic carbon, dissolved oxygen, and total phosphorus concentrations were correlated to the PFAS concentrations. Principal component analysis indicated that the main sources of PFASs in groundwater were untreated industrial discharge, untreated domestic wastewater, food packaging, aqueous film forming foams and metal plating, and surface runoff, which overlapped with the industries that previously existed in a nearby city. Human health risks from drinking contaminated groundwater were low to the local residents, with children aged 1-2 years being the most sensitive group. One specific site with a high PFOA concentration was of concern, as it was several orders higher than the 70ng/L recommended by US Environmental Protection Agency health advisory. This study provided baseline data for PFASs in a previously-contaminated site, which will help in the development of effective strategies for controlling PFASs pollution in the North China Plain.

DOMESTIC WASTEWATER TREATMENT USING VERMIFILTER COMBINED WITH CANNA INDICA

Untreated domestic wastewater can pollute the aquatic ecosystem. Vermifilter integrated with the Canna indica plant is one of the technological alternatives that can be used to treat domestic wastewater. One of affecting the performance of vermifilters is the vermibed media. Aim: This study aims to examine the effect of vermibed material on the concentration of COD, TP, DO, and the pH value of domestic wastewater treated with vermifilter combined with Canna indica plants. Methodology and Results: The research was conducted on a laboratory scale with a a continuous system using a plastic reactor dimension of 59 x 38 x 29 cm, which is filled with sand filter media, coconut fiber, gravel, and vermibed. The vermibed reactor consists of 4 reactors including reactor 1 (R1) vegetable vermibed, reactor 2 (R2) sawdust, reactor 3 (R3) banana peel, and reactor 4 (R4) cow dung. The results showed that at the end of the research, the best performance is showed by reactor R2 that able to decrease COD 94.81%, TP 92.07%, DO increase 320.00%, pH 6.30±0.10. Vermibed sawdust (R2) can lower COD, TP and raise DO higher to treat domestic wastewater by combining vermifilter with Canna indica plant. Conclusion, significance, and impact study: Vermifilter with Canna indica plant is an effective wastewater treatment in reducing COD, TP, increasing DO and pH value. This treatment is easy processing of operation and maintenance, does not require large land, can be done on an individual scale, and is environmentally friendly.

Modelling of a novel near zero energy for a wastewater treatment plant with OXY-Biogas power cycle

With the increase of population in the world, there have been tremendous increases in energy and water consumption which has made the Water Energy Nexus (WEN) an important consideration in the past several years. Moreover, energy consumption increased by a factor nine in the last century, and there is a close connection between water and electricity production – electricity production is one of the main sources of CO2 emissions in the world. In order to conserve water, energy, and CO2 emissions, a novel multigeneration net zero energy wastewater treatment plant has been modelled and developed by integrating an oxy-biogas power cycle with a wastewater treatment plant (WWTP). The proposed system is a combination of an activated sludge, anaerobic digester, oxy-biogas power cycle, and a Rankine cycle. The final product of the activated sludge is used to feed the power cycles in order to produce energy. The produced CO2 from the combustion chamber has been recycled and combusted in the combustion chamber with the biogas and pure oxygen. Several parametric studies have been conducted to investigate their effects on the thermodynamic efficiencies and self-sufficiency ratio. While wastewater strength, effluent biochemical oxygen demand, and dissolved oxygen concentration have been varied in the WWTP, turbine inlet temperature, combustion pressure, and CO2 return ratio have been chosen as the decision variables for the power cycle since they play key roles in both power requirement for wastewater treatment and power production from the oxy-biogas turbine cycle. The strength of untreated domestic wastewater has been found to be the most important factor among the decision variables. In addition, combustion pressure has shown to play a significant role, with the maximum self-sufficiency ratio and efficiencies occurring with combustion pressures in the range of 15 to 20 bars. Overall exergy efficiencies varied from 19.38% to 32.59%, and self-sufficiency ratios changed from 82.29 to 132.4%. Moreover, more than 95% of the CO2 has been captured and recycled in the combustion chamber.This work is the first study which evaluated the integration of an oxy-biogas combustion model not only to produce power but also a nearly zero emission free WWTP. Furthermore, a fundamental analysis of energy and CO2 saving for each state in the US have been calculated using the proposed system. It was found that, if the system outlined in this study was utilized in all activated sludge based WWTPs in the US, a total energy and CO2e emission savings of 10,409 GWh/yr and 3,553 kilotons/yr, could be obtained, representing 0.28% and 0.24% of the total electricity supply and annual CO2e emissions from electricity production. This study suggests that an energetically self-sufficient WWTP with near zero emission is plausible.

EVALUATION OF WATER QUALITY THROUGH WATER QUALITY INDEX (WQI), GOMTI RIVER, JAUNPUR CITY, INDIA

Jaunpur is an ancient city situated on the bank of River Gomti which bisects the municipal area of Jaunpur city (located between 25°44’ to 25°46’ North latitude and 82°40’ to 82°43’ East longitude) in the north and south directions. Population growth and urbanisation rate in the city is very high during the last few decades. The rate of environmental degradation has accelerated due to the population growth and the process of urbanisation and industrialisation has increased the level of pollutants. All the sources of water in Jaunpur city have been deteriorated with the growth of population, urbanisation and industrialization. The river serves as a major source of domestic water supply of the Jaunpur city, subsequently; the river receives back the untreated domestic wastewater from Jaunpur city (about 450 mld) directly during its course. It causes the river water quality deterioration. While entering the city Gomti river water quality can be seen less polluted but it increases as it run in the city core. The study aims to determine the water quality of river Gomti in Jaunpur city. Water quality variables are integrated to determine the water quality index value along the river. In order to determine the water quality, seven stations were selected along the stretch of river. Data have been collected on the water quality from Gomti river through sampling and analysis for pre and post monsoon, 2015 and 2016. The Water Quality Index (WQI) was calculated using the Weighted Arithmetic Index method. This method appears to be more systematic and gives comparative evaluation of the water quality of sampling stations. It is also helpful for public to understand the quality of water as well as being a useful tool in many ways in the field of water quality management.