TSS Removal Research Articles

Removal of pharmaceuticals and organic matter from municipal wastewater using two-stage anaerobic fluidized membrane bioreactor

The aim of present study was to treat municipal wastewater in two-stage anaerobic fluidized membrane bioreactor (AFMBR) (anaerobic fluidized bed reactor (AFBR) followed by AFMBR) using granular activated carbon (GAC) as carrier medium in both stages. Approximately 95% COD removal efficiency could be obtained when the two-stage AFMBR was operated at total HRT of 5h (2h for AFBR and 3h for AFMBR) and influent COD concentration of 250mg/L. About 67% COD and 99% TSS removal efficiency could be achieved by the system treating the effluent from primary clarifier of municipal wastewater treatment plant, at HRT of 1.28h and OLR of 5.65kg COD/m3d. The system could also effectively remove twenty detected pharmaceuticals in raw wastewaters with removal efficiency in the range of 86–100% except for diclofenac (78%). No other membrane fouling control was required except scouring effect of GAC for flux of 16LMH.

Performance of an anoxic reactor proposed before BAF: Effect of ferrous sulfate on enhancing denitrification during simultaneous phosphorous removal

Abstract A coagulant dosed pre-anoxic activated sludge reactor is proposed to configure prior to the BAF reactor to reduce the contents of phosphorus and suspend solids in wastewater, efficiently utilize the carbon source for denitrification, and avoid the problems caused by direct addition of coagulant into BAF reactor. A series of laboratory experiments were carried out to examine the feasibility and suitability of using Fe(II) as a coagulant. The performance on phosphorus removal and dinitrification, the determination of an optimal Fe(II), and any adverse effect brought by dosing Fe(II) are of interests. Base on the results of the continuously operated experiment, it was observed that dosing Fe(II) in the proposed pre-anoxic reactor demonstrated fair effectiveness in phosphorous removal and simultaneous denitrification. Enhanced denitrification efficiency was observed in the presence of Fe(II), probably resulting from the increased returned sludge amount and the promoted denitrification related to microbial Fe(II)-dependent nitrate reduction after dosing Fe(II). Overdosing Fe(II) would however result in suppressed TSS, TCOD and TP removal in the settling tank effluent due to the formation of fine microbial flocs. A Fe(II) dose with Fe:P molar ratio of 2–2.2:1 was selected as an optimal dose, which showed good performance in phosphorus removal, denitrification, and COD reduction, as well as, avoided the adverse effects caused by Fe(II) overdosing. Besides enhancing wastewater treatment in pre-anoxic reactor, dosing Fe(II) also improved sludge sedimentation and dewaterability, which were beneficial for the subsequent operation of dealing with excessive sludge.

Efficiency of Tibia Wetland in Treatment of Waste Water

Information on wetland function in waste water treatment is very important as the information can be used to remove undesirable qualities of water. The aim of the study was to assess the effectiveness of natural wetlands in the treatment of waste water. The study was carried out for a period of four months (November 2012 to February 2013). Four sampling site were selected within the wetland and water samples were collected twice every week. Standard methods for sampling, storage and analysing according to APHA were used. Statistical analysis informs of T-test (2-tailed) and ANOVA were used to summarize the findings. The study revealed that the wetland played a role in the removal of pollutants where the best performance was obtained at TSS removal efficiency of 97.67%. BOD, Chromium, Nitrate, Total Solids, and Phosphate ranged between 50- 96% while conductivity and Total Dissolved Solids were less than 50%. DO increased by 23.4% and pH changed by -0.79% hence the effluent water was less acidic as compared with influent water. The study concluded that Tibia wetland was effective and had potential in treatment of the waste water from the discharging facilities. It is recommended that wetlands can be conserved and used as waste water treatment facility instead of regarding them as waste land. Measures should be put in place to improve the final effluent quality to ensure that the levels of the parameters in the effluent are within the permissible limits.

Treatment of Rice Mill Wastewater Using Continuous Electrocoagulation Technique: Optimization and Modelling

Removal of COD and TSS from rice mill wastewater was investigated using continuous electrocoagulation method (CEC). The electrical energy consumption (EEC) of the process was also examined in order to evaluate the economic viability. The Box-Behnken statistical experiment design (BBD) and response surface methodology (RSM) were used to investigate the effects of major operating variables. Initial pH, current density, electrode distance and flow rate were selected as independent variables in BBD while COD removal, TSS removal and EEC were considered as the response functions. The predicted values of responses obtained using the response function was in good agreement with the experimental data. Optimum operating conditions were found to be pH of 7, current density of 15 mA <TEX>$cm^{-2}$</TEX>, electrode distance of 5 cm and flow rate of 70 ml/min. Under these conditions, greater than 89% removal of COD and TSS were obtained with EEC value of 7 KWh.

The combined UASB and MBR system to COD and TSS removal and excess sludge reduction for the treatment of high strength wastewater in various operational temperatures

There are many activated sludge plants (ASP) in Iran. Most of them are overloaded and as a result their efficiency is very low. A combined laboratory-scale system (5 L reactors) consisting of an up-flow anaerobic sludge blanket (UASB) and aerobic membrane bioreactor (MBR) was operated at 20 and 30°C with pH between 7.6 and 8.4. The experiment was run to optimize treatment of high-strength enriched municipal wastewater of the Ekbatan treatment plant located in west Tehran. The chemical oxygen demand (COD) of the wastewater was enriched due to the addition of molasses and milk powder. To prevent pH fluctuation of the influent, NaHCO3 and K2HPO4 were added to the wastewater. The excess sludge from the MBR was recirculated into the UASB. The system treated fortified municipal wastewater with a volumetric COD loading rate of 600, 1,200, 1,800, and 2,400 mg/L, and temperatures at 20 and 30°C. The results of the present work indicate an optimum organic loading (7.2–10.8 kg m−3 d−1) with COD removal efficiency (RE) between 74 and 85% in both examined temperatures in UASBR. The total combined system efficiency was, approximately, 98% in COD removal and 100% in total suspended solids removal. Furthermore, the nitrate RE was about 80%. Also, excess sludge reduction was over 90%, and the optimum hydraulic retention time for influent COD concentration of 1,200 mg l−1 is shown to be 4 h. This upgraded system increases the treatment capacity by factor of 5.

Tratamento de esgoto sanitário em sistemas alagados construídos cultivados com lírio-amarelo

Neste artigo, avaliou-se a eficiência de quatro sistemas alagados construídos (SACs) no tratamento de esgoto sanitário após ser submetido a tratamento preliminar e, no caso de alguns SACs, a tratamento primário (tanque séptico). Os SACs foram cultivados com lírio-amarelo (Hemerocallis flava), tendo a brita #0 como meio suporte, e submetidos às taxas de carregamento orgânico (TCO) de esgoto sanitário, em termos de DBO (kg ha-1 d-1), de 44; 98; 230 e 395 kg ha-1 d-1 e tempos de detenção hidráulica (TDH) de 3,9; 2,0; 1,0 e 0,75 dias, respectivamente. Para avaliar a eficiência dos sistemas, foram realizadas, no afluente e no efluente aos SACs, análises de DBO, DQO, SST, N-total, P-total, K e Na durante 6 meses de funcionamento do sistema. Nos SACs, houve predominância do ambiente anóxico/aeróbio, com remoção de SST, DBO e DQO, suficiente para atender aos padrões de lançamento de efluentes estabelecidos na legislação ambiental do Estado de Minas Gerais.

The role of eutrophication reduction of two small man-made Mediterranean lagoons in the context of a broader remediation system: Effects on water quality and plankton contribution

In order to meet the requirements of the European Union Water Framework Directive for the Albufera de València (AV) Natural Park, in 2009, several areas of free water surface constructed wetlands (FWSCWs) planted with emergent vegetation and two small shallow lagoons planted with submerged macrophytes were created over a 40-ha area formerly occupied by rice fields. This area is currently a reserve known as Tancat de la Pipa. The dual goal of this programme was to improve the quality of the hyper-eutrophicated waters of the AV lagoon, the largest littoral lagoon in the Iberian Peninsula, and to restore former lost habitats to increase the biodiversity of the area. The lagoons were mainly fed with the outflows of the FWSCWs. The submerged macrophytes covered both lagoons and sustained a diverse waterfowl community. In this study, the nutrient reduction between the inflows and the outflows of the lagoons was evaluated, along with the change in the composition and biomass of plankton (i.e., phytoplankton and zooplankton), over the first four years of operation of the two lagoons. The nutrient reduction contribution of the lagoons to the overall Tancat de la Pipa system was also quantified. The results indicated that 42% of the total suspended solids, 30% of the total nitrogen and 49% of the total phosphorus were retained in the lagoons. An increase in the zooplankton and phytoplankton richness was observed in the outflows of both lagoons. These aquatic systems served as a site for zooplankton production and large cladocerans played a significant role in water clearing by consuming microalgae. Submerged vegetation was also critical for reducing nutrient loads, although macrophytes disappeared after the second year. Despite the macrophyte loss, the lagoons continued to act as nutrient sinks. Both lagoons facilitated over 30% mass removal of TP, TSS and Chl a and over 20% mass removal of DIN and TN for the overall Tancat de la Pipa system. Therefore, these lagoons represent a new sustainable aquatic ecosystem for improving water quality and promoting biological development. We recommend the configuration of this ecosystem as a complement to FWSCWs for managing eutrophicated waters in protected sites.

Treatment of municipal wastewater using horizontal flow constructed wetlands in Egypt

The aim of this study was to evaluate the performance of two pilot horizontal flow constructed wetlands (HFCWs) with and without vegetation. Three types of plants namely Canna, Phragmites australis and Cyprus papyrus were used. The surface area of each plant was 654 m(2). The flow rate was 20 m(3) d(-1) and the organic loading rate range was 1.7-3.4 kg BOD d(-1) with a detention time of 11 days. The results obtained showed that planted HFCW produced high quality effluent in terms of reduction of chemical oxygen demand (COD; 88%), biochemical oxygen demand (BOD; 91%) and total suspended solids (TSS; 92%) as well as nutrient removal. In addition, 4 logs of total coliform were removed from the planted unit compared with only 3 logs in the unplanted one. The phosphate uptake by the plants reached 29, 30.91 and 38.9 g P m(-2) for Canna, Phragmites and Cyprus, respectively, with 60% removal rate in the treated effluent. The nitrogen uptake by the same plants reached 63.1, 49.46 and 82.33 g N m(-2). Although, the unplanted unit proved to be efficient in the removal of COD, BOD and TSS, it lacks efficiency in pathogen and nutrient removal. The reclaimed wastewater, after disinfection, could be reused for non-restricted irrigation purposes.

Modelling the coag-flocculation kinetics of cashew nut testa tannins in an industrial effluent

The coagulant behaviour of tannins of Anacardium occidentale (CANTETA) testa was assessed for the removal of suspended solids from a fibre-cement industry effluent. A series of flocculation experiments were conducted to examine the optimal concentration of the coagulant together with the pH of the effluent needed to obtain the best results. The results showed that CANTETA have significant flocculation properties particularly at lower doses and in alkaline medium. Optimum efficiency for TSS removal was 84% with 100mg/L CANTETA at initial effluent pH of 12. The kinetics of the coagulation process suitably fits the second order kinetic model.

Evaluation of herbaceous crops irrigated with treated wastewater for ethanol production

The competition for freshwater between agricultural, industrial, and civil uses has greatly increased in Mediterranean basin characterized by prolonged dry seasons. The aim of this study was to evaluate biomass production and the potential ethanol production of promising “no-food” herbaceous crops irrigated with low quality water at different ETc restitutions (0%, 50 and 100%). The research was carried out, in 2011 and 2012, in an open field near the full-scale constructed wetland (CW) municipal treatment plant located in the Eastern Sicily (Italy). The CW effluent has been applied in a experimental irrigation field of Vetiveria zizanoides (L.) Nash, Miscanthus x giganteus Greef et Deu. and Arundo donax (L.). Physical, chemical and microbiological analyses were carried out on wastewater samples collected at inlet and outlet of CW and pollutant removal efficiencies were calculated for each parameter. Bio-agronomical analysis on herbaceous species were made with the goal to evaluate the main parameters such as the plant dimension, the growth response and the biomass production. Biomass dry samples were processed with a three-step chemical pretreatment, hydrolysed with a mix of commercial enzymes and next fermented to obtain the yield of ethanol production. Average TSS, COD and TN removal for CW were about 74%, 67% and 68%, respectively. Although the satisfactory Escherichia coli removal, about 3.5 log unit for both beds on average, CW didn’t achieve the restrictive Italian law limits for wastewater reuse. As expected, irrigation was beneficial and the full ET replenishment increase the biomass productivity as compared to the other two treatment. The mean productivity of Vetiveria zizanoides and Myscanthus x giganteus were about 9, 26 and 38 t ha–1 and 3, 7 and 12 t ha–1 respectively in 0%, 50% and 100% ETc restitutions. Arundo donax gave higher values of dry biomass (78 t ha–1 in 100% ETc restitution in 2011 season), and potential ethanol production (about 3,744 kg ha–1). These results suggest the interest in the use of constructed wetland effluents for the irrigation of energy crops to obtain second generation ethanol, particularly in semiarid regions such as the Mediterranean area.

Development of Rainwater Purification and Reclaimed Water Treatment Systems Using a High-Efficiency Air-Cooled Ozone Generator

The objective of this study is to improve water quality resulting from rainwater purification treatment and to utilize reclaimed water purification system and high-class treatment purification system. This can be done by developing a purification treatment technique through resolution of discharged ozone problems by circulation-type of ozone treatment method with the use of a high-efficiency air-cooled cylindrical ozone generator. While the final removal rate of BOD showed the highest rate of 96% for 12g without showing a great difference for the ozone injection amount of 9g and 12g, the final removal rate of COD upon treating for 12 minutes showed 73%, 66%, 93% and 96% for 3g, 6g, 9g and 12g, respectively, exhibiting similar treatment results to that of BOD. The removal of TSS and VSS due to ozone treatment was indicated not to have occurred. Also, upon passage of the magnetized water device, the removal rate of colon bacterium and general bacteria was shown to be about 35%, while a high removal rate exceeding 70% was indicated during the initial 3 minutes. Upon final treatment for 12 minutes, sterilization power above 99% was exhibited. Upon treatment using the magnetized water device and the OH- radical generator, not only dissolved suspended materials but also excellent sterilization power appeared to be identifiable.

Cork boiling wastewater treatment at pilot plant scale: Comparison of solar photo-Fenton and ozone (O3, O3/H2O2). Toxicity and biodegradability assessment

Remediation of cork boiling wastewater was studied as an example of complex industrial wastewater treatment by applying a protocol based on a combination of advanced technologies and chemical–biological assays. Solar photo-Fenton and ozone (alone or in combination with hydrogen peroxide at different pH conditions), at pilot plant scale have been used as chemical oxidation step. Additionally, the effect of a physic-chemical pre-treatment using different flocculants (FeSO4 and FeCl3) was evaluated. Although physic-chemical pre-treatment with Fe3+ provided good removals of COD, DOC and TSS, it was found that it did not enhance solar photo-Fenton post-treatment. On the contrary, ozone-based process was improved after physic-chemical pre-treatment with Fe3+, attaining higher degradation efficiencies with lower ozone consumptions for the combination with O3 at initial pH 7. Toxicity and biodegradability assays were performed to evaluate possible variations along the oxidation processes. After solar photo-Fenton treatment, toxicity and biodegradability remained constant at their initial values. Then, Zahn–Wellens test was carried out to study long term biodegradability and possible biomass adaptation to the partially photo-treated effluent. Decrease in toxicity values and short term biodegradability enhancement were observed for cork boiling wastewater treated by ozonation systems.

The removal of COD, TSS and colour of black liquor by coagulation–flocculation process at optimized pH, settling and dosing rate

Pulp and Paper mills are generating millions of tons of wastewater and are major source of water pollution. In this research work, pulping wastes have been characterized and found to contain very high COD, TSS and colour. Coagulation–flocculation process was performed to find out the performance of different coagulants and flocculants like alum, ferric chloride, aluminium chloride, ferrous sulphate, poly aluminium chloride (PAC), cationic and anionic polyacrylamide polymers in individual form as well as in different combinations. The effects of dosing rate, settling time and pH were examined for reduction of COD, TSS and colour. Coagulants used in combinations were found to be more effective in reducing COD, TSS and colour instead of using individual form. The initial pH of the effluent for coagulation process was found to have remarkable effect on COD, TSS and colour removal. The most effective results were found using cationic and anionic polyacrylamide combination with ferric chloride and aluminium chloride and reduction of 76% COD, 95% TSS and 95% colour were observed at pH<3.

Improving the performance of stormwater detention basins by real-time control using rainfall forecasts

Dry detention ponds are commonly implemented to mitigate the impacts of urban runoff on receiving water bodies. They currently rely on static control through a fixed limitation of their maximum outflow rate. Real-Time Control (RTC) allows optimizing their performance by manipulation of an outlet valve. This study developed several enhanced RTC scenarios of a dry detention pond located at the outlet of a small urban catchment near Québec City, Canada. The catchment's runoff quantity and TSS concentration were simulated by a SWMM5 model with an improved wash-off formulation. The control procedures rely on rainfall detection, on measures of the pond's water height, and in some of the RTC scenarios on rainfall forecasts. The implemented RTC strategies allow a substantial improvement of the pond's performance - the TSS removal efficiency increases from 46% (current state) to about 90% - while remaining safe and taking a mosquito-breeding risk constraint into account.

Reduction of sludge generation by the addition of support material in a cyclic activated sludge system for municipal wastewater treatment

An innovative biomass carrier (Biobob®) was tested for municipal wastewater treatment in an activated sludge system to evaluate the pollutant removal performance and the sludge generation for different carrier volumes. The experiment was carried out in a pilot-scale cyclic activated sludge system (CASS®) built with three cylindrical tanks in a series: an anoxic selector (2.1 m(3)), an aerobic selector (2.5 m(3)) and the main aerobic reactor (25.1 m(3)). The results showed that by adding the Biobob® carrier decreased the MLVSS concentration, which consequently reduced the waste sludge production of the system. Having 7% and 18% (v/v) support material in the aerobic reactor, the observed biomass yield decreased 18% and 36%, respectively, relative to the reactor operated with suspended biomass. The addition of media did not affect the system's performance for COD and TSS removal. However, TKN and TN removal were improved by 24% and 14%, respectively, using 18% (v/v) carrier.

A new method of biological start-up in Arak activated sludge wastewater treatment plant

Starting up a wastewater treatment plant (WWTP) is one of the most important stages of operation. A new method was used to start Arak activated sludge WWTP up, which took in advantages of the other methods. Primarily just one of the basins was in the lane and wastewater entered the plant part by part. At first 1/30, second week 1/15, third week 1/6, and fourth week 1/3 of total inflow came to the plant. Observing little progress of biomass gain, some sludge from a similar treatment plant was added to the system, as seed. This procedure continued so the MLSS of the system, attained the 1/3 total design MLSS which was design MLSS of one basin. In the next two weeks, by using developed sludge of the self-system the second and third basins came in the lane and inflow increased to 2/3 and total flow, respectively. Finally after two months of beginning the start-up and one month after adding the seed total desired biomass was developed and the plant started to waste sludge. Because of cold weather start-up period took a longer time than expected. But even before developing biomass environment friendly results were achieved. After attaining design MLSS, BOD5 and COD removal from 40% and 60% increased to 90% and TSS removal from 70% reached to 96%. Less loading, less foam forming, no bacteriologic and chemical problems, better process control, using less seed, saving costs in sludge transport and avoiding relevant problems were the main advantages of this method.

Quality assessment of treated wastewater in Kuwait and possibility of reuse it to meet growing water demand

Kuwait’s water resources are insufficient and will become the limiting factor for sustainable development in the future. The need for water supplies in Kuwait is extremely high and expected to be growing due to increasing population growth. To face this challenge Kuwait has introduced a new element in water management system by considering and reusing treated wastewater. Currently, huge amounts of municipal wastewater are treated in four main treatment plants located at Regga, Jahra, Um Al-Haiman and Sulaibiya. In general overview on Kuwait’s water resource, water demand and wastewater treatment plants (WWTPs) is presented. In addition, data of treated effluent quality was collected from three main sources; namely; available publications and records within Kuwait, and the results of a wastewater-monitoring program involving survey, collection and analysis of samples from selected wastewater streams. Data reveal that the treatment plants at Jahra, Regga and Um Al-Haiman provide wastewater treatment up to a tertiary level with sand filters following the conventional activated sludge process. All three plants produce excellent effluent quality at a tertiary level of treatment. The advanced WWTP at Sulaibiya treats wastewater beyond tertiary level with advanced facilities of ultrafiltraion and, reverse osmosis producing super quality of effluent with insignificant traces of pollutants. The COD and TSS removals are above 90% for all the plants. Sulaibiya in particular achieved almost 100% COD and TSS removal. The utilization of Sulaibiya plant effluent for recharging ground-aquifers is a viable option to store treated effluent for future need.

Dynamic Performance Analysis and Simulation of a Full Scale Activated Sludge System Treating an Industrial Wastewater Using Artificial Neural Network

Due to changeable nature of the industrial wastewaters, proper operation of an industrial wastewater treatment plant is of prior importance in order to keep the process stability at the desired conditions. In this mean, simulation of the treatment system behavior using artificial neural network (ANN) can be an effective tool. This paper evaluates long term performance and process stability of a full-scale integrated industrial wastewater treatment system (Faraman’s industrial estate, Kermanshah) in removing organic matter over a 2-year operation. The wastewater treatment system is composed of static screens, an equalization tank, an aerobic biological tower (TF) and an activated sludge (AS) reactor. Multilayer Feed-forward Networks of ANN was used to forecast the process performance of AS system. In this study, mixed liquor suspended solids (MLSS) (mg/l) and organic loading rate (OLR) (kg COD/m 3 .d) were selected as input parameters and TSS removal, COD removal and sludge volume index (SVI) as output parameters. The results showed a very good agreement between the actual and modeled data (R 2 > 0.9). The ANN models provided a robust tool for predicting the performance of wastewater treatment plants and as a result, the online monitoring parameters could be applied for prediction of effluent characteristics.

Quantitative and qualitative greywater characterization in Greek households and investigation of their treatment using physicochemical methods

Data for the quantity of greywater produced in Greek households was collected from two different cities, while samples from different residences were taken for greywater's quality characterization. Laboratory experiments were also performed to investigate the use of coagulation on COD and TSS removal from two different types of greywater, while a combined treatment consisting of coagulation, sand filtration and adsorption on granular activated carbon (GAC) was applied to achieve adequate quality for greywater reuse. According to the results, average greywater production in Greek residences was 82.6±49.3L per inhabitant and day, while the major sources were shower/bathtub and laundry, contributing to 41% and 26%, respectively. On the other hand, blackwater production was estimated at 59.4±29.6L per inhabitant and day. Greywater produced in shower/bathtub and hand basin had similar quality characteristics, while kitchen sink's greywater were more contaminated, presenting lower pH values and higher concentrations of TSS and total COD. Coagulation experiments with FeCl3 and Al2(SO4)3 showed that process efficiency was differentiated significantly according to the type of greywater and the coagulant used. The highest removal efficiency (COD: 81%; TSS: 79%) was achieved for greywater that did not contain wastewater from the laundry and for Al2(SO4)3×14 H2O dosage of 800mgL−1. The application of coagulation, sand filtration and GAC adsorption resulted to average concentrations of COD and TSS equal to 28±11 and 11±3mgL−1, respectively, in treated greywater.

Case study on evaluation of the performance of waste stabilization pond system of Jodhpur, Rajasthan, India

The objective of this study is to find out physico-chemical and microbiological characteristics of influent and effluent generated by the sewage treatment plant of Jodhpur city. The treatment plant was constructed in the year 2003–2004 and based on waste stabilization pond (WSP) system. The treatment capacity of the plant is 45 ML/d. Relationship between different physico-chemical and microbiological parameters were studied. After the treatment of wastewater in WSP, average removal of BOD, COD, TSS and TKN were 84.1, 53.4, 79.7 and 61.7% respectively. Average removal of Total Coliforms (TC), Fecal Coliforms (FC), E. coli and Fecal Streptococci (FS) were 2.79 logs, 2.47 logs, 1.65 logs and 1.58 logs respectively. Maximum efficiency of fecal bacteria removal was found during the summers (2.7 to 4.0 log units) and minimum in winters (1 to 1.8 log unit). Further correlation of temperature, pH and biological oxygen demand with TC, FC, E. coli and FS were studied. Among all these parameters temperature shows highest correlation with microbiological parameters as follows: TC (−0.85), FC (−0.62), E. coli (−0.65) and FS (−0.75). High ambient temperature, long photoperiod and high intensity of light can be considered as the major factor for the removal of fecal indicators during the sewage treatment. After treatment pH, BOD, COD, TSS and TKN were found within the permissible limit of Central Pollution Control Board, India. The observed values of fecal indicator organisms are higher than the permissible limit of World Health Organization (WHO). There are no maturation ponds in the treatment plant; construction of maturation ponds will provide better removal of fecal coliforms.