Efficiency Of Sewage Treatment Plants Research Articles

Efficiency evaluation of sewage treatment plants in Delhi, India, using tolerance-based data envelope analysis.

Correct and effective performance evaluation of wastewater treatment plants is a tough task because of the complex biological, physico-chemical, and biochemical processes and associated variables affecting their performance. Conventionally, the efficiency of sewage treatment plants (STPs) are obtained using some index relating pollutant removal efficiency with energy used or costs. These indicators consider only one variable at a time. This leads to incorrect assessment of efficiency, which in turn could adversely affect decision-making of the regulatory authorities. The data envelope analysis (DEA) method utilizes a Linear programming technique which can handle multiple input/output variables without requiring the cost function. This makes it an appropriate tool for assessing the relative efficiency of treatment plants. The present study assess the efficiency of 30 STPs in Delhi, India, using the tolerance-based DEA model utilizing the variable return of scale (VRS). The uncertainty was incorporated into the model using the tolerance measure. The model is solved using the "Add on" option in spreadsheet toolbox of excel solver. Results reveal that out of the 30 plants considered for the study, 6 are performing well (20%). Further, it was observed that a slight change in the input data leads to instability of the efficiency results. Lastly, the ranking is used to determine the treatment plant with best efficiency under all scenarios for the larger period of the year. Such studies will help in chalking out the best management practices that could be adopted by other regulatory authorities.

A Review on Ecopharmacovigilance and their Major Impact on Bio-Diversity

Ecopharmacovigilance (EPV) included science and activities associated with the detection, evaluation, understanding, and prevention of adverse effects of pharmaceuticals in the environment. These drugs enter the environment in a variety of ways, creating negative impacts. Vultures dying after eating the carcasses of animals treated with Diclofenac sodium, Ethinyl oestradiol negatively affecting fish through "feminization" of males, Ivermectin negatively affecting dung beetle growth, Fluoxetine causing behavioural changes in shrimps, and bacterial resistance are just a few examples of drugs that have harmful effects on the environment. Some corrective methods that can be expected to reduce the number of pharmaceuticals entering the environment include lowering pharmaceutical waste, enhancing the efficiency of sewage treatment plants, green pharmacy, and developing better medication disposal systems. Regulatory agencies have tried a variety of approaches to mitigate the environmental impact of pharmaceuticals, including Environmental Risk Assessment (ERA) of drugs, Resource Conservation and Recovery Act (RCRA), and Risk Mitigation Measures. Drug effects must be monitored not only for medical reasons, but also to protect the environment.

Improving the Efficiency of Sewage Treatment Plants on the Example of Treatment Plants in the Cities of Artem and Vladivostok

Fugate water, when it enters the beginning of sewage treatment plants (STP), increases the load on the biological treatment system. Methods of purification of the STP return water are considered. A new composite composition has been developed for the reagent precipitation of ammonium and phosphates from water, which is formed as a result of thickening and dewatering of sludge. On the basis of the experimental data obtained, a technological scheme for the treatment of water formed after mechanical dewatering of excess activated sludge and sludge from the operation of treatment plants at biological wastewater treatment plants has been developed. The developed technological solution makes it possible to exclude the effect of aluminum on activated sludge and minimize the negative effect of ammonium and phosphates, with minimal construction and operating costs. The proposed cleaning method is applicable to both existing treatment facilities and newly designed ones.

The efficiency of sewage treatment plant: A case study at the main campus of Universiti Malaysia Sabah (UMS)

The aquatic nature, including streams, rivers, marine, and groundwater, becomes susceptible to most contaminants’ effects through various pathways known as point and non-point sources. Point source pollution from inefficient sewage treatment plants (STP) will likely produce effluents that could deteriorate the environment. Therefore, this study assesses the efficiency of STP at Universiti Malaysia Sabah (UMS) based on the Malaysian Sewerage Industry Guidelines (MSIG). The design parameters of the STP and its influent and effluent physicochemical parameters are evaluated and compared between usage peak time (lecture-week) and non-peak (semester-break) conditions. The measurement was based on the Standard Methods of Examination of Water and Wastewater. The permissible limits of influent and effluent from Malaysia Sewerage Industry Guidelines (MSIG) are referred. In contrast, the efficiency of the STP is calculated as the percentage reduction of pollutants. The findings revealed that the current STP’s design parameters complied with the MSIG standard. The suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), oil and grease (O&G) at influent during peak time is typically higher than during the non-peak time, albeit a timely sudden increase can be observed. The effluent quality is inconsistent but is still within permissible limits, except for O&G, which occasionally exceeds the allowable value. As for the BOD, a consistent 80% removal efficiency is observed. Hence the effluent reuse for agricultural purposed and landscape irrigation is proposed due to the environmental quality potential and reduction to direct released toward the receiving water streams.

Survival Ability of the COVID-19 Causative Agent in Aquatic Environment: A Literature Review

Background: The article presents an overview of foreign and Russian scientific data on possible natural reservoirs of the COVID-19 causative agent, SARS-CoV-2 transmission routes, and measures taken to combat it in an aquatic environment. The objective of this review is to determine the possibility and features of SARS-CoV-2 dissemination through the aquatic environment, taking into account statistical significance of the results obtained and the compliance of scientific research with the criteria of evidence-based medicine. Methods: We used keywords “COVID-19”, “wastewater”, “treatment facilities”, and “river water” to search the electronic databases, including Web of Science, Scopus, PubMed, eLIBRARY, and ResearchGate, for journal articles on the topic. Out of 109 search results, we chose 85 papers and, having analyzed them, selected 55 most relevant articles for this review. The presence of the COVID-19 causative agent has been shown in various environmental objects including water supply systems, wastewater, and surface waters. Methods for detecting SARS-CoV-2 particles based on the detection of strains of other viruses in environmental objects have been determined. They demonstrated that the independent entry of the virus into the ecosystem occurs due to its absorption by various fomites. The review presents the results of studies conducted in a number of countries during the pandemic, confirming the presence of SARS-CoV-2 in river water. Some studies indicate the resistance of viral particles present in environmental objects to disinfectants, which, in its turn, determines the relevance of in-depth studies from the standpoint of ensuring sanitary and anti-epidemic regimen at water treatment plants. Conclusions: The analysis of the world experience enabled us to establish the SARS-CoV-2 survival ability in the aquatic environment of urbanized areas and to identify its alternative transmission routes in the environment. In modern conditions, due to a poor efficiency of sewage treatment plants in terms of virions, the spread of SARS-CoV-2 in the environment posing a potential risk of the coronavirus disease is quite possible. Our findings will help develop new preventive measures to maintain safety of water bodies and sanitary protection zones. Their implementation will contribute to improvement of the epidemic situation in our country.

Retechnologization of biological sewage water treatment facilities using mathematical modelling

The efficiency of sewage treatment plants is an urgent problem of the designed and operating stations. In modern conditions, efficiency is understood as the operation of facilities in which operating costs are minimized, facilities provide standard cleaning, and the company implements measures to modernize and improve energy efficiency and trouble-free operation. The article deals with the comparative analysis and selection of the most optimal scheme of biological sewage water treatment of existing sewage water treatment plants. The indicators of the efficiency of functioning and permissible loads on treatment facilities in the design of aeration tanks for biological sewage water treatment are determined. The results served as the basis for the creation of a mathematical model, with the help of which it is possible to calculate the parameters of the biological treatment system and optimize the process of biological sewage water treatment at existing treatment facilities. Mathematical modeling allows you to reduce the cost of designing and operating treatment facilities, to guarantee the degree of treatment in accordance with the requirements and standards for the discharge of treated sewage water into a reservoir for fisheries purposes.

Efficiency evaluation of sewage treatment technologies: implications on aquatic ecosystem health

Abstract This research paper tries to identify and address issues related to efficiency of sewage treatment plants (STPs) and their implications on the Dal Lake ecosystem in Srinagar city, Kashmir, India. Fluidized aerobic bioreactor (FAB) and sequential batch reactor (SBR) technologies having been recently installed along the periphery of Dal Lake were evaluated for efficiency for a continuous period of 24 months from December 2016 to November 2018. Apart from chemical quality, total coliform (TC), fecal coliform (FC), and fecal streptococci (FS) analyses were also carried out. Major highlights of our work using one-way ANOVA (analysis of variance) revealed significant variations (p < 0.05) in total suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia (NH3-N), total phosphorus (TP), TC, FC, and FS. Our findings indicate that both technologies are struggling for removal efficiency, which is very low, especially in FAB during three to four months of winter season where a very high drop in the working efficiency of the STP was observed. The treatment facilities did not meet the prescribed standards in respect of TSS, BOD, NH3-N, TP, TC, FC, and FS thereby having the potential to compromise public health and trophic status of Dal Lake.

ANALISIS LOGAM BERAT (Mn, Fe , Cd), SIANIDA DAN NITRIT PADA AIR ASAM TAMBANG BATU BARA

Coal mining of PT. Mifa Brothers in Aceh Barat produces liquid waste containing hazardous heavy metals. Research conducted at PT. Mifa Brothers located in Sumber Batu Village, Meureubo Subdistrict, West Aceh Regency, Aceh Province. The coal mining activities by the PT. Mifa Brothers used open-cast mining systems with open method. From the resulting liquid waste, the PT. Mifa Brothers made two ponds used as liquid waste treatment. Efficiency of Sewage Treatment Plant (STP or IPAL) conducted by the industry, can be known through the analysis of he avy metals content (Fe, Mn and Cd), cyanide and nitrite on inlet and outlet of liquid waste shelter. This 
 analysis was determined using the atomic absorption Spectropotemer (SSA) for metal Fe, Mn and Cd, while CN-and NO2-analysis-using UV-Vis spectrophotometry methods. Test result of heavy metal ions of iron ion, manganese ions, cadmium ions, nitrite, and cyanide on each inlet is 8.24; 0.223; < 0.01; 0.034 mg/L and 0.321 on each outlet are 3.03; 0.189; < 0.01 mg/L; 0,016 and undetectable for cyanide. Sewage treatment at PT. Mifa Brothers using Dolomite method as adsorbent has not been efficient and efficient in the reduction of pollutant levels.
 
 Keywords : SSA, UV-Vis spectrophotometry, Inlet and outlet, Fe, Mn, Cd,NO2, CN-

Study on Adequacy of Functional Characteristics of a Typical Urban Waste Water Treatment Plant

This study examines the presence of pollution of river Yamuna in the city of Delhi. The condition of river Yamuna is deteriorating day by day. The main cause of this is the poor standard treated sewage from the sewage treatment plants being dumped into drains which directly meet into river Yamuna. In this study I audited Keshopur 40 MGD sewage treatment plant which works on activated sludge process in which Mixed Liquor Suspended Solids (MLSS) is the prime concern for the proper functioning of plant and checked the adequacy of the various functional units by comparing the detention time of each and every unit with the standard detention time given by code. Activated Sludge Process involves aeration and a biological flock composed of bacteria and protozoa to convert non settle particles into the settle one.ASP provides one of the highest degree of treatment within the limited cost involved. In this study various recommendations are also given for increasing the efficiency of sewage treatment plant.

Study on Adequacy of Functional Characteristics of a Typical Urban Waste Water Treatment Plant

This study examines the presence of pollution of river Yamuna in the city of Delhi. The condition of river Yamuna is deteriorating day by day. The main cause of this is the poor standard treated sewage from the sewage treatment plants being dumped into drains which directly meet into river Yamuna. In this study I audited Keshopur 40 MGD sewage treatment plant which works on activated sludge process in which Mixed Liquor Suspended Solids (MLSS) is the prime concern for the proper functioning of plant and checked the adequacy of the various functional units by comparing the detention time of each and every unit with the standard detention time given by code. Activated Sludge Process involves aeration and a biological flock composed of bacteria and protozoa to convert non settle particles into the settle one.ASP provides one of the highest degree of treatment within the limited cost involved. In this study various recommendations are also given for increasing the efficiency of sewage treatment plant.

Efikasnost pogona za galvansko tretiranje otpadnih voda "Frad" Aleksinac

The technological process of Galvano-chemical protection, according to qualitatively-quantitative characteristics, represents one of the most complex contaminants in wastewater. A large number of contaminants (metal ions, cyanides, acids, bases, grease and oils, organic solvents, surfactants, phosphates, etc.), found in galvanic wastewater are treated through conventional methods (chemical oxidation and reduction, neutralization, sedimentation, coagulation and flocculation). The reason why galvanic wastewater treatment systems in the Republic of Serbia are conventional is of economic nature. The present study has been undertaken to evaluate the performance of Sewage Treatment Plant located at Aleksinac, Company of "Frad" district which is based on Sequential Batch Reactor process. Performance of this plant is an essential parameter to be monitored as the treated effluent is discharged into the Moravica River. The Performance Evaluation will also help for the better understanding of design and operating difficulties (aeration, blowers, etc.) in Sewage Treatment Plant. Research goal: The efficiency of sewage treatment plants can be illustrated by a study on the evaluation of pollutant levels of the influent and the effluent at the treatment plant of sewage treatment plants discharging into the environment.

합류식 하수관거 월류수 오염 부하량 산정

This study has estimated the pollutant load from combined sewer overflows due to rain events by analyzing daily water quality and operation status of a sewage treatment plant. Because considerable amount of pollutant was overflowing into riverine and coastal ecosystem in short time frame, it was apparent that the combined sewer overflows are giving critical affect to ecosystems. To minimize the damage, policies supporting construction of separate sewer system which eliminates the overflow and enhances the efficiency of sewage treatment plants, should be promoted.

Management of sewage sludge energy use with the application of bi-functional bioreactor as an element of pure production in industry

The increase in sewage sludge makes it necessary to improve the direction of sewage sludge management policy and disposal, which requires a larger amount of incineration or land reclamation. It was shown that the result of methane fermentation, which is a more complex process of extracting energy contained in waste. High costs of implementation of sludge processing technology and low efficiency of sewage treatment plants in which sewage sludge is insufficient to recover energy from them, have a negative impact on the development of energy generation from sediments. The model waste system for energy is characterized, which includes two stages. The proposed solution can be applied to small wastewater treatment plants and it is justifiable to use the concept of bi-functional bioreactors in which anaerobic and aerobic processes can be carried out with much lower construction and maintenance costs. The use of bioreactors allows to exclude the energy demand needed to stabilize sewage sludge at a low cost compared to the expenditure that is currently incurred by disposal. The proposed solution works perfectly with industrial plants, due to the possibility of their creation in the time of the creation and application of a circular economy.

Efficiency of Sewage Treatment Plants in the Sequential Batch Reactor

The article analyzes the effectiveness of individual Actibloc wastewater treatment plants (produced by Sotralentz) working in the technology of low-rate activated sludge in the Sequential Batch Reactor (SBR) system. The assessment of the effectiveness of household wastewater treatment plants was made on the basis of pollutants: BOD<sub>5</sub>, COD, total suspended solids, total nitrogen and total phosphorus. The research objects were four household sewage treatment plants located in: Lubań, Kłębanowice, Stara Rzeka and Kościan. The efficiency of removing pollutants in the examined facilities was in the range of: BOD<sub>5</sub> 92.2 ÷ 97.2%, COD 82.6 ÷ 89.9%, total suspended solids 90.2 ÷ 96.2%, total nitrogen 50.8 ÷ 83.1%, total phosphorus 46.5 ÷ 73.6%. The treated wastewater met the requirements set out in the Regulation of the Minister of the Environment on the conditions to be met when discharging sewage into water or soil, and on substances particularly harmful to the aquatic environment (Journal of Laws 2014, item 1800) in terms of indicators such as BOD<sub>5</sub>, COD, total suspended solids and total nitrogen. The effectiveness of phosphorus removal in the studied treatment plants was much lower.

Export of microplastics from land to sea. A modelling approach

Quantifying the transport of plastic debris from river to sea is crucial for assessing the risks of plastic debris to human health and the environment. We present a global modelling approach to analyse the composition and quantity of point-source microplastic fluxes from European rivers to the sea. The model accounts for different types and sources of microplastics entering river systems via point sources. We combine information on these sources with information on sewage management and plastic retention during river transport for the largest European rivers. Sources of microplastics include personal care products, laundry, household dust and tyre and road wear particles (TRWP). Most of the modelled microplastics exported by rivers to seas are synthetic polymers from TRWP (42%) and plastic-based textiles abraded during laundry (29%). Smaller sources are synthetic polymers and plastic fibres in household dust (19%) and microbeads in personal care products (10%). Microplastic export differs largely among European rivers, as a result of differences in socio-economic development and technological status of sewage treatment facilities. About two-thirds of the microplastics modelled in this study flow into the Mediterranean and Black Sea. This can be explained by the relatively low microplastic removal efficiency of sewage treatment plants in the river basins draining into these two seas. Sewage treatment is generally more efficient in river basins draining into the North Sea, the Baltic Sea and the Atlantic Ocean. We use our model to explore future trends up to the year 2050. Our scenarios indicate that in the future river export of microplastics may increase in some river basins, but decrease in others. Remarkably, for many basins we calculate a reduction in river export of microplastics from point-sources, mainly due to an anticipated improvement in sewage treatment.

Use of activated sludge biomass as an agent for advanced primary separation

Conventional primary settling is a physical process of solid-liquid separation, normally presenting low removal efficiencies. Improvement of this separation process would result in energetic advantages: lower aeration requirements and higher biogas production form primary and secondary sludges. Secondary sludge has been proposed as a potential agent promoting an increase in primary separation efficiency. Few processes have been proposed, based on the cultivation of sludge under special conditions. However, one can speculate that regular sludge may have a similar effect. The aim of this research was to study that possibility. Sludges from different activated sludge reactors were tested. Results showed that COD removals were up to 55%, 2 times higher than that for simple settling. Under that condition, COD balances showed that aeration requirements would reduce 40%, and biogas production from primary and secondary sludges would increase 50%. It is inferred then that the application of activated sludge as an external agent represents an interesting alternative that have the potential to significantly improve energetic efficiency of sewage treatment plants.

Low efficiency of sewage treatment plants due to unskilled operations in India

Centralized sewage treatment plants may not be a sustainable solution for a developing country such as India. Therefore, we conducted for the first time an integrated assessment of the different technologies currently used for sewage treatment in the state of West Bengal, India. Five decentralized sewage treatment plants and one centralized sewage treatment plant located in different parts of Kolkata were evaluated. We compared influent and effluent water quality, energy consumed, capital and operating costs, and treated wastewater reuse potential. F test was used to validate results on the effect of working days and holidays and seasons on treated water quality. Wastewater management strategy was assessed by performance indicators. Our results show that treatment efficiency was lowest in anaerobic plants not because of faulty technology but due to unskilled operation. Therefore, performance improvement of plants is expected if factors such as monitoring, training of staff, regular and scrupulous desludging, reuse aspects, and rational water tariff are implemented earnestly.

Sewage Treatment Plants Efficiencies in Removal of Sterols and Sterol Ratios as Indicators of Fecal Contamination Sources

This study assessed the efficiency of sewage treatment plants (STPs) in removing sterols based on chemical analyses of both influents and effluents. Samples from 3s and three tertiary plants were collected and analyzed by gas chromatography mass spectrometry for 23 individual sterols including mestranol, norethindrone, equol, estrone, equilin, norgestrel, 17α-ethinylestradiol, 17α-estradiol, 17β-estradiol, estriol, dihydrocholesterol (cholestanol), coprostanol, epicoprostanol, cholesterol, desmosterol, campesterol, stigmasterol, β-sitosterol, coprostanone, cholestanone, epicholestanol, stigmastanol, and 24-ethylcoprostanol. The percentage of sterols remaining in effluent samples (compared to influent samples) ranged from 0% to 80% and varied among sterol compounds and with STP location and treatment type. Differences in the efficiency of sterol removal for secondary and tertiary STPs were statistically significant. Although the concentration of sterol compounds differed between influents and effluents, sterol abundances remained the same. The most abundant sterol detected was cholesterol, followed by the fecal sterol coprostanol, and the plant sterols 24-ethylcoprostanol and β-sitosterol. For three STPs, the hormone estrone was detected in effluents at concentrations of 0.03–0.05 μg L−1. Ten sterol ratios specific for human fecal contamination and eight sterol ratios for differentiating among multiple sources of fecal contamination were calculated and showed that 12 ratios for influent and nine ratios for effluent were successful for human fecal source tracking. Based on sterol ratio values in this study, new criteria for identification of human fecal contamination were suggested.

Pilot survey monitoring pharmaceuticals and related compounds in a sewage treatment plant located on the Mediterranean coast

A one-year monitoring study was performed to evaluate the occurrence, persistence and fate of a group of 14 organic compounds in a sewage treatment plant (STP) located in the south of Spain. These results are part of a more extensive study, financed by the Spanish Ministry of Research with the aim to evaluate the traceability of new pollutants on the Mediterranean coast and to determine the removal efficiency of sewage treatment plants (STP) for these pollutants. The compounds which have been analyzed include pharmaceuticals of various therapeutic categories (ibuprofen, acetaminophen, dipyrone, diclofenac, carbamazepine and codeine), pesticides (chlorfenvinfos and permethrin), caffeine, triclosan, bisphenol A and three of their more relevant metabolites (1,7-dimethylxanthine, carbamazepine 10,11-epoxide and 2,7/2,8-dichlorodibenzo- p-dioxin). An SPE/GC–MS multi-residue analytical method was developed and validated to facilitate simultaneous determination of these compounds in both influent and effluent wastewater. The method provided mean recoveries higher than 75%, with the exception of 2,7/2,8-dichlorodibenzo- p-dioxin, dipyrone and permethrin which exhibited recoveries lower than 22%. The overall variability of the method was below 14%. The method detection limit (LOD) was between 1 and 100 ng l −1 and precision, which was calculated as relative standard deviation (RSD), ranged from 1.8% to 11.2%. The application of the proposed method has allowed the identification of all the target compounds at mean concentrations which ranged from 0.12 to 134 μg l −1 in the influent and from 0.09 to 18.0 μg l −1 in the effluent. The removal efficiencies of the STP for these compounds varied from 20% (carbamazepine) to 99% (acetaminophen), but in all cases resulted insufficient in order to avoid their presence in treated water and subsequently in the environment.

Monitoring of endocrine disruptors in surface waters by the yeast recombinant assay

AbstractEndocrine disruptors exert physiological effects at very low concentrations. Surface waters present often a mixture of high concentrations of low‐potency disruptors and low amounts of very powerful ones, making their chemical analysis complicated and expensive. We developed a recombinant yeast assay (RYA) for estrogenic compounds using 96‐well microtiter plates. This assay is based on three yeast strains, transformed with self‐propagating plasmids. One strain contains an expression plasmid for the human estrogen hormone recéptor and an appropriate reporter; it detects estrogenic and antiestrogenic activities. The two other yeast strains, one expressing the human progesterone receptor and a second based on the yeast activator Gal4p, served to analyze the nature of antiestrogenic activities. We applied this technique to water samples from two tributaries of the Llobregat river (NE Spain) as well as from four sewage treatment plants discharging on them. Our results indicate that the efficiency of sewage treatment plants for eliminating estrogenic compounds varied notably, being in at least one case completely inefficient. We also observed a prevalence of an inhibitory activity all through the two rivers; this inhibition was hormone specific. These results were consistent to previously obtained chemical analyses of the same samples, although chemical and in vivo analyses showed rather different levels of sensitivity for some compounds. Our findings demonstrate the utility of the yeast recombinant assay for analyzing complex natural samples; at the same time, they stress the necessity of a panel of different yeast systems to adequately describe endocrine‐disruptor activities.