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Introduction. The level of water pollution in Ukraine continues to grow, despite the strengthening of requirements for the treated water, so the existing approaches to the water treatment processes control need to be revised and improved. Materials and methods. Mathematical Programming methods for formalization and solving the optimization problem are used. Computer simulation research using the program developed by the authors are applied to verify the compliance of the obtained results with the normative values and data of normal operation. Results and discussion. The optimization of processes control was performed on the example of a typical process of secondary wastewater treatment, which is used for wastewater treatment in Kyiv and nearby settlements. The secondary treatment unit consists of an aeration tank, into which air is forcibly supplied and evenly distributed, and a secondary settling tank with recycling. The problem of optimization of biological wastewater treatment control process is formalized: minimization of pollutant concentration in treated water is chosen as the main aim of optimization, air flow to aeration tank is chosen as control parameter, quadratic deviation of current concentration values from normative ones is chosen for target function. To solve the optimization task, a software module in JavaScript was developed using a client-server architecture that works in real time and allows to obtain such values of oxygen consumption in the aeration tank, which provide a minimum deviation of the concentration of pollutants from the normative values. The simulations showed that the calculated control values provide a reduction in the concentration of pollutants to the normative values within 6-10 hours, which corresponds to the data of normal operation, and the difference between the calculated and actual data does not exceed 5%. Conclusions. The obtained results allow to find a set of technological influences to ensure optimal control according to the selected criterion, and are also the basis for calculating the control system. The results of calculations can be used for short-term - up to 8 hours - forecasting of water quality indicators.

The textile industry is one of the industries that discharge an enormous quantity of highly colored wastewater because of the large amount of water used in the process. Textile wastewater is the potential to polluting the environment due to the high color contained in it. One of the problems in processing textile wastewater with conventional treatment methods is the ineffectiveness of color removal. A post-treatment is needed for treated wastewater to remove the color. One of the methods is by using the ozonation method. In this preliminary study, the decolorization of artificial textile wastewater containing azo dye reactive-black 5 (RB5) from secondary treatment was investigated in a batch system. Artificial treated textile wastewater from secondary biological treatment was made using 5,26 mg/L azo dye RB5 in 16 L volume of the reactor. The preliminary batch study showed that the optimum color removal achieved in 24.66 mg/minute ozone dose in a batch system with 20,89 mg/minute ozone consumption. Within 5 minutes of ozonation, color removal achieved was 100%, and COD removal achieved was 75%.

Water from cattle farming operations that is not properly managed and discharged directly into the environment can cause unpleasant odors and increase the risk of contamination of surrounding water bodies. The purpose of this study was to determine an effective management system in solving odor problems and the risk of contamination of water bodies. The method in this research includes the design of a management system and laboratory-scale processing experiments involving the oxidation pond as the processing unit. The cattle farm liquid waste management system consists of 3 stages, namely pre-treatment, primary treatment, and secondary treatment, where there is a processing unit (oxidation pond) for secondary treatment. Wastewater is treated in the oxidation pond with a variation of the injected oxygen discharge of 6 L / minute, 8 L / minute, and 11 L / minute with residence time during the calculation time according to EPA / 600 / R-11/008 of 2011 (respectively 0.256 days, 0.1356 days, 0.1096 days), 3 days, 7 days, and 14 days were equipped with control of oxidation-reduction potential (ORP) values. The parameters observed were odor, Biochemical Oxygen Demand (BOD) and Total Ammonia (NH3-N). Where the wastewater after the treatment process is yellowish with low turbidity and has no smell. While the test results after the study showed that the average BOD level had met the quality standard. With the highest final BOD level was 152 mg / L and the lowest was 98 mg / L. Meanwhile, the highest total ammonia levels after research were 0.0088 mg / L and the lowest was 0.00032 mg / L. Management with an oxidation pond as a processing unit is effective in overcoming odor problems and reducing levels of BOD and ammonia pollutants.

The purification of the primary treated domestic sewage was performed in the present study through the horizontal sub-surface flow constructed wetland (CW) of 10 × 3.5 m dimension. The study was performed using three setups of CW 1 (Unplanted CW), CW 2 (CW planted with macrophyte Typha latifolia), and CW 3 (CW planted with two species of macrophyte T. latifolia and Commelina benghalensis). The purification experiments were performed by converting one type of CW into the other form sequentially, i.e., CW 1 was built first and after the experiments, it was converted into CW 2 and then CW 3. The CW was filled with a layer of coarse and fine gravel of 70 cm depth as filter media in 1:2 ratio. Each set of wetland was operated for 3 months (12 wk) during which the treatment performance of wetlands for basic physicochemical parameters was evaluated. The CW was operated in continuous mode at an average hydraulic loading rate of 250 L h− 1 and the treated effluent was analysed twice every week at four different sampling points having hydraulic retention times (HRT) of 12, 24, 36 and 48 h for important sewage quality parameters All the three setups of CW were able to clean the primary treated sewage significantly. Among the three sets of wetlands used, CW 3 was the best performer removing 79, 77, 79, 79, and 78% of biochemical oxygen demand, chemical oxygen demand, nitrate, ammonia, and phosphate respectively in 48 h HRT. Among the three sets of wetlands, the CW 3 removed the highest percent of total coliforms, fecal coliforms, and E. coli as 64, 61 and 52% respectively.

On-site small-scale sanitation is common in rural areas and areas without infrastructure, but the treatment of the collected fecal matter can be inefficient and is seldom directed to resource recovery. The aim of this study was to compare low-technology solutions such as composting and lactic acid fermentation (LAF) followed by vermicomposting in terms of treatment efficiency, potential human and environmental risks, and stabilization of the material for reuse in agriculture. A specific and novel focus of the study was the fate of native pharmaceutical compounds in the fecal matter. Composting, with and without the addition of biochar, was monitored by temperature and CO2 production and compared with LAF. All treatments were run at three different ambient temperatures (7, 20, and 38°C) and followed by vermicomposting at room temperature. Materials resulting from composting and LAF were analyzed for fecal indicators, physicochemical characteristics, and residues of ten commonly used pharmaceuticals and compared to the initial substrate. Vermicomposting was used as secondary treatment and assessed by enumeration of Escherichia coli, worm density, and physicochemical characteristics. Composting at 38°C induced the highest microbial activity and resulted in better stability of the treated material, higher N content, lower numbers of fecal indicators, and less pharmaceutical compounds as compared to LAF. Even though analysis of pH after LAF suggested incomplete fermentation, E. coli cell numbers were significantly lower in all LAF treatments compared to composting at 7°C, and some of the anionic pharmaceutical compounds were detected in lower concentrations. The addition of approximately 5 vol % biochar to the composting did not yield significant differences in measured parameters. Vermicomposting further stabilized the material, and the treatments previously composted at 7°C and 20°C had the highest worm density. These results suggest that in small-scale decentralized sanitary facilities, the ambient temperatures can significantly influence the treatment and the options for safe reuse of the material.

Wastewater treatments are often expensive, and the resulting effluent can still harm the environment. Floating treatment wetland is an alternative low-cost eco-technology in which a hydroponic root network remediates polluted waters. This system has been broadly studied as a secondary treatment to remove nutrients and pollutants, but its application to improve raw wastewater quality is still incipient. Moreover, few studies have assessed acute ecotoxicity toward fish after treatment. Thus, this study aimed to evaluate the efficiency of a mesocosm floating treatment wetland to improve the raw wastewater quality from a university campus in South Brazil. Efficiency was assessed based on the improvement of physicochemical parameters (conductivity, pH, turbidity, color), nutrients (nitrogen and phosphorus), and heavy metals (zinc, chromium, copper, lead, and cadmium); Typha domingensis adaptability; and acute fish ecotoxicity reduction after wastewater treatment. Influent was treated with macrophytes tanks and their respective controls. T test was used to compare influent versus effluent samples, and macrophytes tanks versus controls. A Principal Component Analysis identified the main explanatory variables on the system, and a Two-way Cluster Analysis grouped samples before and after treatment. The results show floating mats efficiency in reducing most parameters compared to the influent, except phosphorus and zinc. Control tanks were also effective in improving wastewater quality due to microalgae and duckweed proliferation. In conclusion, floating treatment wetlands with Typha domingensis have the potential to treat raw wastewater. Further nitrogen removal in wastewater might improve acute ecotoxicity toward fish.

Challenges of wastewater treatment concerning high construction cost of the wastewater treatment plants and operation and maintenance, also the requirements of highly qualified operators, specially with the mechanical biological treatment systems, made investigation to suit simple systems of low costs and easy operation and maintenance of great importance. Slow sand and rough filtrations were effective systems when applied in water treatment, due to these filters being easy to construct and operate, with their high filtrate quality. Investigation herein was conducted to study the ability of both the rough and slow sand filters to secondarily treat the sullage wastewater, which primarily treated through interceptor tanks. The rough filter used in this study mainly was 100 cm gravel of 6-8 mm size operated at filtration rates of 20 and 30 m.d -1 . While the slow sand filter used was 60 cm sand of 0.2 mm effective size operated at rates of 4.5 and 8.0 m.d -1 . Studies continued for two stages of four and two months for the first stage and second stage, respectively. BOD5 removal of 35% and 61% was achieved through the rough filter and the slow sand filter, respectively. Also, removal of suspended solids was of 45% and 82% through the rough filter and slow sand filter, respectively. Runs of the rough filter usually extended between 38 and 17 days, while that of the slow sand filter was between 12 ‐ 6 days, according to the filtration rates.

This work presents a bibliographic review of the literature regarding the simultaneous removal of contaminants of emerging concern (CECs) and disinfection in domestic wastewater matrices. These two responses are usually evaluated independently, as most attention has been centered on the discussion over the removal of CECs in the last 10 years. However, the simultaneous removal of CECs and pathogens from wastewater has been recently brought to the spotlight, especially considering the removal of antibiotics and antibiotic-resistant bacteria. Aiming at a reproducible and nonbiased methodology, a combination of the construction of a bibliometric portfolio with systemic analysis was performed with peer-reviewed manuscripts published between 2008 and 2019 in five distinct databases. Several keyword combinations were necessary to achieve a relevant portfolio according to strict criteria. As a result, five highly cited papers and authors were selected. Among the advanced oxidation processes (AOPs) explored for simultaneous removal of CECs and disinfection in these papers, detailed results have been elucidated mainly for ozonation. Thus, revealing the broad range of questions that have yet to be investigated in depth for new technologies such as irradiated solar processes. In addition, there is a lack of information associated with simultaneous assessment of CEC removal and disinfection in real samples and in wastewater matrices originated from different secondary treatment technologies in diverse locations.

Natural zeolites have a high purification capacity in wastewater due to their porosity, specific surface, cation exchange capacity and they are a product available in nature. In Tabasco, Mexico, river and hill zeolites were evaluated to see their potential in wastewater treatment. First, an experimental system of three upflow fixed-bed bioreactors (UFBB) with a height of 1.5 meters and diameter of 4 inches was designed and built, then the potential of native zeolites and a commercial control in the field were evaluated. sewage treatment. The UFBB were started with a 3x3 factorial design, operating with river zeolite, hill zeolite and commercial zeolite (control), all with ? inch particles, using three different bed heights (0.75, 0.90 and 1.10 m) and three times. hydraulic retention (6, 12 and 24 hours). The response variables were evaluated by means of a multifactorial ANOVA and to discriminate between the means the Fisher's least significant difference (LSD) method (p < 0.05, 95 % confidence) was used. The closed zeolite presented (average, N=10) the best physicochemical characteristics with are real and apparent density of 2700 and 1470 kg/m3 respectively, specific weight 2240 kg/m3, porosity of 62 %, absorption of 15.20 %, solubility in hydrochloric acid of 29.96 %, pH of 7.4 and electrical conductivity of 70 mS/cm. The residual water with which the treatments were developed was applied prior to the experiment a primary treatment (grid, sand trap, skimmer and septic tank) and presented temperature values (average, N = 9) of 25.26 ? C, pH of 8.63, Total dissolved solids with 950.50 mg/L, color of 1305.10 UC, turbidity 96.37 NTU and chemical oxygen demand of 373 mg/L. Of the zeolites evaluated (N = 81) in the UFBB, the one that presented the best treatment was the hill zeolite operating with a bed height of 0.9 m and with 24 hours of hydraulic retention time, obtaining the best removal efficiencies with 71.42 % in total dissolved solids, 84.34 % for turbidity, 96.33 % for color and 97.28 % for the chemical oxygen demand, followed by the commercial zeolite that had very similar responses and finally the river zeolite treatment that also presents good results in comparison with other means of support. The optimal height in the UFBB was 0.9 m, an important factor to evaluate since the higher the elevation costs are increased and the efficiencies are not relevant to justify the investment and the lower the performance in quality of the treated water falls. Finally, native zeolites have ideal properties to be used in the treatment of domestic wastewater and we can recommend the implementation of UFBB in the secondary treatment of domestic effluents in decentralized systems in the southeast of Mexico as a viable alternative in the treatment of their domestic wastewater.

Two hundred 10- weeks old golden Hubbard grower chickens were randomly assigned to four water treatments: tap water (TW). alum treated domestic sewage (ATDS), secondary treatment domestic sewage (STDS) and raw domestic sewage (RDS). Each treatment was replicated twice with 25 birds per replicate. The trial lasted for 9 weeks. The experimental waters were analysed to determine their quality, water consumption by the chickens in each treatment was measured to assess their acceptability and the effects of water treatments on hematological and serum biochemical constituents over time were evaluated. The sequence of water quality in decreasing order is TW: ATDS, STDS and RDS. The effect of the water treatments on water consumption of the chickens was not significant (p>0.05). The packed cell volume, haemoglobin, serum total protein, serum albumin, serum globulin, serum calcium and serum phosphorus of the birds were not significantly different (p>0.05) at each bleeding throughout the experiment. While the blood constituents evaluated all had values within the normal limits, the concentrations of calcium in the sera of the bird receiving ATDS were slightly lower at weeks 5 and 9. The chickens on any of the treatments suffered no apparent harm. The physiological constitution of the chickens at this stage of growth appears to be able to accommodate the differences in the chemical and physical compositions of the domestic sewage effluents without disrupting the animal health. Keywords: Domestic sewage effluents, blood constituents, grower chickens.

Secondary wastewaters from the dairy industry may causeeutrophication of water bodies when not properly treated, mainlybecause they contain nutrients such as phosphorus and nitrogen.Tertiary treatment using microalgae could be an adequate solutionfor Minas Gerais State, the largest Brazilian milk producer,contributing to the reduction of environmental impacts, as wellas providing biomass for oil extraction, and obtaining activecompounds and inputs (including proteins) for animal feeding.In this work, dilutions (with distilled water) of the secondarywastewater from the dairy industry were evaluated to cultivateChlorella vulgaris in a bench-scale tubular photobioreactor.Theresults indicate the feasibility of using wastewater from thedairy industry, after secondary treatment, to cultivate microalgae,showing cell growth like that obtained in control cultures (Boldbasal medium). The secondary wastewater without dilution (100%wastewater) provided the best condition for biomass production.The biomass obtained in wastewater showed no differences fromthe biomass obtained in the Bold basal medium (control) in termsof protein, lipid content, or fatty acid profile. Efluentes secundários da indústria de laticínios, quando não tratadosadequadamente, podem provocar eutrofização de corpos d’água,principalmente por conter nutrientes como fósforo e nitrogênio.O tratamento terciário empregando microalgas poderia ser umasolução adequada para o estado de Minas Gerais, maior produtorbrasileiro de leite, contribuindo na redução de impactos ambientais,bem como fornecendo biomassa para extração de óleos e obtençãode compostos ativos e insumos (incluindo proteínas) para nutriçãoanimal. Neste trabalho, avaliaram-se diluições (com água destilada) doefluente secundário da indústria de laticínios para cultivo de Chlorellavulgaris em fotobiorreator tubular em escala de bancada. Os resultadosencontrados indicam a viabilidade do uso de efluente de indústria delaticínios, pós tratamento secundário, para o cultivo de microalgas,apresentando crescimento similar àquele obtido em cultivos padrões(meio basal Bold). O efluente secundário sem diluição (100% efluente)foi o que apresentou melhor desempenho na produção de biomassa.Além disso, a biomassa obtida em efluentes não apresentou diferençasem relação àquela obtida em meio basal Bold (controle), no que serefere a teores de proteínas, lipídios ou perfil de ácidos graxos.

The dyes and chemical additives, present in the wastewater produced in the teaching laboratories of Microbiology, generate high contamination, are difficult to degrade and according with the Colombian regulation should be treated before final disposing. In this article, a pilot plant was used to treat a synthetic wastewater (SWW) containing a mixture of dyes. Initially, the capacity of a fungal/bacterial sludge to remove this type of contaminants on a 1L scale was determined. Subsequently, the operating conditions that favor tertiary treatment were selected by using TiO2/UV photocatalysis and finally the complete treatment plant was integrated and evaluated (Pre-treatment, secondary treatment and tertiary treatment). The SWW that entered the plant had the following characteristics: Chemical Oxygen Demand (COD): 4033 mg/L, Biochemical Oxygen Demand (BOD5): 2750 mg/L, Unit Color (UC): 2010, BOD5/COD ratio: 0.68 and a pH of 7.0. At 37 hours of plant operation, overall removals were 98 ± 3 %, 99 ± 6 % and 99 ± 8 %, for COD, BOD5 and UC. Proving that the integration of unitary operations in a sequential and orderly manner, are a novel alternative for the treatment of this type of wastewater.

Performance of Shell and Tube Heat Exchanger for treatment of textile industry wastewater as a secondary treatment process is reported. An Adaptive Neuro-Fuzzy Inference System and Artificial Neura...

Many technologies have been developed to treat the rubber effluent, but the quality of the treated effluent after the secondary treatment still does not meet the requirements for releasing it back to water bodies. This treated effluent becomes one of the most challenging problems for the Vietnamese rubber industry. Therefore, the present paper studied two applications as a potential solution for this issue. The first one is an advanced technology using membrane ultrafiltration, for a higher quality of the treated effluent that meets the disposal requirements. The second application is a direct reuse of the effluent for agricultural irrigation. For investigation of the effectiveness of the membrane filtration, a small-scale ultrafiltration apparatus with polyacrylonitrile membrane was used to conduct experiments on synthetic wastewater. The obtained results indicate that the membrane significantly reduced the COD concentration of the treated effluent to a level below the limit of 50 mg/L set by the Vietnamese Regulatory for discharge to water bodies. Kinetics of membrane ultrafiltration was also discussed. For the reuse of the treated effluent for irrigation, the effluent must have no negative impact on the groundwater. In order to investigate this aspect, a large-scale penetration test was conducted using a column filled with soil samples collected from rubber plantations in Binh Duong. The column penetration test results show that the irrigated effluent posed no harmful effect on groundwater. All COD, total nitrogen and phosphorous concentrations at a depth higher than groundwater were lower than the discharge limits for treated wastewater to water bodies.

Over the past 20 years, various new filter technologies have been developed that can be used to (a) enhance the performance of or (b) replace conventional primary treatment facilities. To enhance the performance of a primary sedimentation facility, primary effluent is filtered to further reduce the constituent concentrations discharged to the secondary treatment facilities. This form of primary enhancement is known as primary effluent filtration (PEF). In the second case, where some type of filter technology is used to replace primary sedimentation, the process application is known as primary filtration (PF). The principal focus of this paper is on the performance of the first full-scale PF project using a fine pore cloth media disk filter to maximize the diversion of carbon for the production of energy and to reduce energy usage. Performance data from related pilot-scale cloth disk primary filter (CDPF) systems are included for process verification. The removal performance for total suspended solids (TSS) from the three CDPF installations varied from 83% to 85%, as compared to 55%-60% typically achieved with primary sedimentation. The total overall TSS removal performance achieved with PF is essentially the same as that achieved with PEF, without the need for a primary sedimentation tank. The removal performance for five-day biochemical oxygen demand (BOD5 ) from the three CDPF installations varied from 46% to 58%, as compared to 32%-38% BOD removal typically achieved with primary sedimentation. The full-scale CDPF results reported in this paper are from an on-going research and demonstration project, conducted for the California Energy Commission (CEC), to demonstrate the potential energy savings that can be achieved through the implementation of PF. PRACTITIONER POINTS: The performance of the first full-scale primary filtration system using a fine pore cloth disc filter is evaluated in this project. Design and operational criteria of the primary filtration technology were established in this project to implement in full scale installations. Primary filtration was demonstrated to increase the diversion of carbon for the production of energy and to reduce energy usage. Significant decrease in aeration power requirement and increase in digester gas production are possible with primary filtration. Footprint reduction (both for primary and secondary treatment) are other important attributes of primary filtration.

This study investigated the impact of each treatment stage of the activated sludge process on the fate of antibiotic resistant bacteria (ARB) in wastewater treatment plants (WWTPs). Wastewater and sludge samples were collected monthly at each stage of a commercial-scale WWTP. After 20–25 strains of indicator Escherichia coli were isolated from each sample on Chromocult Coliform Agar, antibiotic resistance of the isolates to amoxicillin (AMX), ciprofloxacin (CIP), norfloxacin (NFX), kanamycin (KM), sulfamethoxazole/trimethoprim (ST) and tetracycline (TC) were tested with the Kirby–Bauer disk diffusion method. As a result, activated sludge in the aeration tank and return sludge had higher abundance of antibiotic resistant E. coli than influent wastewater and secondary treatment effluent. AMX resistant E. coli was enriched in return sludge at the secondary clarifier. Higher temperature was also likely to cause an increase of AMX resistant E. coli in sludge. The antibiotic resistance profile of E. coli in secondary treatment effluent was more dependent on activated sludge than influent wastewater. These results suggested that activated sludge in WWTP possibly serves as a reservoir of ARB, and that behavior of ARB in WWTP differs by antibiotic classes.

Different selenium species released into the environment by anthropogenic activities pollute surface and ground water resources and can cause severe damage to the environment and ecosystems due to bio-accumulation. Though several physico-chemical methods are available to treat selenium oxyanion-containing wastewater, biological methods have gained significant importance due to their capability to convert selenium oxyanions to elemental selenium nanoparticles. The purpose of this review is to summarize the literature available on biological removal of selenium oxyanions and their recovery as elemental selenium nanoparticles. In recent times, the capability of several bacterial and fungal strains to reduce selenate and selenite to form elemental selenium nanoparticles has been reported. The shape, size and location of these selenium nanoparticles along with the selenium oxyanion removal efficiency depend on the operating parameters. Moreover, bioreactor configurations and operation strategies greatly influence the selenium removal and recovery efficiency. Several conventional bioreactor systems can be used to remove selenate and selenite from wastewater and form selenium nanoparticles. However, the selenium nanoparticles are mostly entrapped in the biomass and require a secondary treatment to recover them. On the other hand, some novel bioreactors, viz. inverse fluidized bed bioreactor, rotating biological contractor, horizontal rotating packed bed bioreactor, moving bed biofilm reactor, and hybrid bioreactor, can possibly recover selenium nanoparticles following bioreduction of selenium oxyanions in a single stage system. Thus, this review will help in finding research gaps in this area and providing solutions for resource recovery from selenium oxyanion-containing wastewater.

Azo dyes are widely used in textile industry due to their easy production, high stability during washing and variety of colors. It raises concern over the ecosystem because of its structural features. Some advanced oxidation process that is tertiary treatment is one of the conventional treatment methods. Pollutants that cannot be removed by primary and secondary treatment are treated by tertiary treatment methods. Primary and secondary treatment methods are not generally sufficient for removal of azo dyes. For this reason, it has an important place in its treatment with advanced oxidation processes. The aim of this study is to investigate the effect of different parameters on color and COD removal yields of triple dye mixtures by Fenton method and to optimize with the Taguchi method. Moreover, the aim is to examine the relationship between these parameters and ORP by regression analysis, and the change of organic groups by FTIR analysis in the effluent. As a result of the study, it was observed that the parameters considered had different effects on COD and color removal. There was an increase in both color and COD removal only with the increase in H2O2 concentration. The highest COD and color removal yields were 95.8% and 99.3%, respectively. As a conclusion, Fenton process is a method that can be preferred in the treatment of textile dyestuffs since the chemicals used are non-toxic, abundant and economical, and therefore, the operation cost of the system is quite favorable, providing advantages to compete with other advanced oxidation processes.

An evaluation process on the validity of wastewater treatment plants effluents for irrigation was done. Chemical and microbial pollutants were measured occasionally in five WWTPs spread in great Cairo, Egypt. The results revealed that WWTPs used secondary treatment (Chlorination) were had the capability to scrape much amount of microbial pollutants, while the units that have only primary treatments were unable to eliminate the microbial organisms. Although the processes used at WWTPs were unspecific for inorganic contaminants removal, metals were reduced in effluents to more than 50 % about the influents. This reduce was attributed to the adsorption of metals on activated sludge which used in aeration stage. In spite of low concentration values of heavy metals in the effluents, these values were conducted to cause hazard effects for aquatic organisms especially Cd, Cu, Pb and Zn based on predict no effect concentration criteria. Water quality index was calculated to identify the applicability of WWTPs effluents for sign in irrigation. The results cleared that the effluents of all units studied weren’t applicable for irrigation purpose. These consequences can affect directly on biological cycles. Thus it seems that more consideration of bio conservation protocols is so important.

Background “Chemically enhanced primary treatment” (CEPT) is an approach to wastewater treatment. It can be utilized as a specially designed step in “biological” secondary treatment processes. The aim of this study is to create an empirical model of separation efficiency for wastewater chemically enhanced primary treatment. Methods The empirical model is undertaken using the simulation of the data obtained from pilot plant experimental studies using different types of coagulant (FeCl3, alum, lime, and Magna-floc155). The empirical modeling techniques used multivariate regression model. Different values of BOD5, COD, TSS, as well as separation efficiencies for COD and TSS were investigated in accordance to achieve final effluent results that would meet the Egyptian standards limit. Results Multiple regression analysis showed that removal efficiencies of COD and TSS can be predicted to be (R2 = 0.973 and 0.978, respectively). Conclusion The present work provides an approach for using chemically enhanced primary treatment of wastewater. The obtained results showed that the empirical model can predict removal efficiencies with R2 = 0.973, and 0.978 for COD and TSS. The advantage of this model is that it would allow better process control and treatment efficiency. The results show that chemically enhanced primary treatment method can be used as an efficient method in conventional municipal wastewater treatment plants to reduce the organic load of biological treatment and enhance nutrients removal.

In the process of completion gas-condensate fields is observed an intensive increase of lifted out produced water and its mineralization influencing the process of regeneration of hydrate development inhibitors. The presence of mineral salts in the system of “hydrate development inhibitor – produced water” results in the decrease of saturated vapor pressure upon the solvent. The decrease of saturated vapors significantly influences the phase balance of the system. Moreover, the presence of salts changes the boiling temperature of water solutions of hydrate development inhibitors. This factor was not considered in the calculation and designing of existing regeneration set. The paper presents the data on the pressure of saturated vapor under the produced water with various mineralization based on which the correction coefficients were calculated and boiling temperature depending on the salt content specified as well.

The present study evaluates the performance efficiency of a wastewater treatment plant. A sewage treatment plant operating on biological treatment method (Rotating Media Bio-Reactor) with an average wastewater inflow of 6 MLD has been considered for the case study. Wastewater samples were collected at different stages of treatment units and analyzed for the major waste water quality parameters such as biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and biodegradability. The performance efficiency of waste water treatment plant along with the major secondary treatment unit as Rotating Media Bio-Reactor (RMBR) was calculated. The performance analysis on above two aspects was studied over 17 weeks. Overall performance was found to meet the design and discharge/effluent criteria as prescribed by the authorities. The studies of six units of Rotating Media Bio-Reactor (RMBR) over a period of 13 weeks have shown the reduction profile of the unit in treatment of wastewater with parameters of BOD and COD. The RMBR treatment profile is useful for the design and operation of the unit.

According to the statistical analysis results of the samples from the Kabd WWTP obtained over four years from January 2013 to December 2016 and four seasons (winter, spring, summer and fall), the following conclusions are obtained in this study. 1. Variations in the water temperature affect the treatment system, especially the biological treatment system and microorganism population. The sudden temperature rise in summer causes problems for aerobic digestion and nitrification. In addition, the DO of warm water is usually less than that of cold water, and if the temperature suddenly drops during winter, then the bacterial population will be affected. 2. Seasonal variations are observed in the physicochemical parameters. A small variation in pH occurs during all seasons. pH affects the microbial activity in the biological treatment, and an extreme value indicates the presence of toxic material in the wastewater. The electrical conductivity increased as the temperature increased. The maximum average removal of suspended solids, including VSS, depends primarily on the treatment quality process during fall and winter but also depends on the temperature. The removal efficiency is better during fall than that during summer because high temperatures improve the reproduction of nitrifying bacteria and the production of nitrogen in sludge in the final effluent. The SVI in the aeration tanks increased as the temperature increased; however, a value of 95% for BOD, COD, TSS, VSS, O&G and % 72 < for NH3-N and PO4-3. 5. The Kabd WWTP followed the KEPA and project contract water standards for irrigation use. All the parameters meet the KEPA and project contract standards, with F. coli and salmonella exceeding the project contract standards.

HighlightsSand bioreactors can effectively treat organic matter at salt levels at least up to 13 g L-1 NaCl.Acclimation of the systems for ammonia removal can take >4 weeks.Clogging and reduction in treatment efficacy can be alleviated through resting of sand bioreactors. Abstract. The treatment of high salt (>1%) wastewater is an issue in several food industries, including meat curing, vegetable pickling, and fish processing. Novel solutions involving biological treatment of saline wastewaters are increasingly important as companies strive to minimize waste production. Sand bioreactors are a secondary treatment option that do not produce secondary sludge. The purpose of this study was to assess the feasibility of treating high salt content poultry processing wastewater with sand bioreactors. Twelve laboratory-scale sand bioreactors consisted of 14.5-cm diameter columns with three layers composed of 15 cm of gravel, 15 cm of coarse sand, and 46 cm of fine sand. The columns were dose fed at 4 cm day-1 turkey processing wastewater with 0, 6, and 13 g L-1 NaCl. Removal of chemical oxygen demand (COD) and ammonia were monitored for over an 11-month period. Each bioreactor successfully removed >90% COD and ammonia during steady state after 4 to 5 week of acclimatization. Clogging caused a decrease in treatment in three sand bioreactors after 6 to 7 months, but was alleviated with rest periods. Keywords: Ammonia removal, Clogging, High salt wastewater, Organic matter removal, Sand bioreactor, Turkey processing wastewater.

The presence of micropollutants, such as pharmaceuticals and personal care products, in surface and ground water has escalated globally, leading to adverse effects on aquatic organisms in receiving waters. Untreated or inadequately treated wastewater is the main source of micropollutants entering the environment. In South Africa, the consumption of antibiotics and antiretroviral drugs is relatively higher than other nations; however, little data exists on the identification and remediation of micropollutants in domestic wastewater. In this study, a novel method to detect and measure 71 micropollutants using online solid phase extraction liquid chromatography coupled to tandem mass spectrometry was developed. To test the method in the South African context, grab samples of the influent and anaerobically treated effluent (AF effluent) from a demonstration-scale decentralised wastewater treatment system in eThekwini (Durban) were taken over 3 consecutive days at 2 time points. The presence of 24 micropollutants was detected in the raw wastewater, with analgesics/anti-inflammatory drugs, antiretrovirals, and antibiotics showing the highest concentrations and with the majority of compounds still present in the AF effluent. One antibiotic, ciprofloxacin, exceeded its predicted no-effect concentration in all influent and AF effluent samples. This suggests that the anaerobic treatment of the raw wastewater was not effective in removing micropollutants. Preliminary data from lab-scale adsorption experiments using biochar produced from a set of 4 feedstocks – olive residues, tomato residues, rice husks, and the African palm tree Raphia farinifera – showed average removal rates for 4 compounds of up to 62%. The application of biochar is thus recommended as a secondary treatment step in decentralised wastewater treatment for the removal of micropollutants in South Africa.

Despite last decades’ interventions within local and communitarian programs, the Mediterranean Sea still receives poorly treated urban wastewater (sewage). Wastewater treatment plants (WWTPs) performing primary sewage treatments have poor efficiency in removing microbial pollutants, including fecal indicator bacteria, pathogens, and mobile genetic elements conferring resistance to antimicrobials. Using a combination of molecular tools, we investigated four urban WWTPs (i.e., two performing only mechanical treatments and two performing a subsequent conventional secondary treatment by activated sludge) as continuous sources of microbial pollution for marine coastal waters. Sewage that underwent only primary treatments was characterized by a higher content of traditional and alternative fecal indicator bacteria, as well as potentially pathogenic bacteria (especially Acinetobacter, Coxiella, Prevotella, Streptococcus, Pseudomonas, Vibrio, Empedobacter, Paracoccus, and Leptotrichia), than those subjected to secondary treatment. However, seawater samples collected next to the discharging points of all the WWTPs investigated here revealed a marked fecal signature, despite significantly lower values in the presence of secondary treatment of the sewage. WWTPs in this study represented continuous sources of antibiotic resistance genes (ARGs) ermB, qnrS, sul2, tetA, and blaTEM (the latter only for three WWTPs out of four). Still, no clear effects of the two depuration strategies investigated here were detected. Some marine samples were identified as positive to the colistin-resistance gene mcr-1, an ARG that threatens colistin antibiotics’ clinical utility in treating infections with multidrug-resistant bacteria. This study provides evidence that the use of sole primary treatments in urban wastewater management results in pronounced inputs of microbial pollution into marine coastal waters. At the same time, the use of conventional treatments does not fully eliminate ARGs in treated wastewater. The complementary use of molecular techniques could successfully improve the evaluation of the depuration efficiency and help develop novel solutions for the treatment of urban wastewater.

Increasing attention is being paid to the environmental impacts of wastewater treatment plant (WWTP) effluent. In this study, comprehensive environmental impact analyses (EIAs) were performed for the secondary treatment processes, tertiary treatment processes, and entire plants at five full-scale WWTPs in Kunming, China. The EIAs took into account greenhouse gas (GHG) emissions, potential for the effluent to cause eutrophication, ecological risks posed by endocrine disrupting compounds (EDCs) in treated effluent, and the risks posed by heavy metals in excess sludge. A comprehensive assessment toward environmental sustainability was performed using a fuzzy approach. The results indicated that the biological treatment process made the largest contribution (>68% of the total) of the secondary treatment processes to GHG emissions and that electricity consumption made the largest contribution (>64% of the total) of the tertiary treatment processes to GHG emissions. Large numbers of EDCs were removed during the secondary treatment processes, but the potential ecological risks posed by EDCs still require attention. High mercury concentrations were found in excess sludge. The plant that removed the largest proportion of pollutants and produced effluent posing the least ecological risks gave the best comprehensive EIA performance.

The fate of Coronaviruses (CoVs) and in particular SARS-CoV-2 in wastewater treatment plants (WWTPs) has not been completely understood yet, but an adequate knowledge on the removal performances in WWTPs could help to prevent waterborne transmission of the virus that is still under debate. CoVs and SARS-CoV-2 are discharged from faeces into the sewer network and reach WWTPs within a few hours. This review presents the fate of SARS-CoV-2 and other CoVs in the primary, secondary and tertiary treatments of WWTPs as well as in sludge treatments. The viral loads decrease progressively along with the treatments from 20 to 3.0E+06 GU/L (Genomic Units/L) in the influent wastewater to concentrations below 2.50E+05 GU/L after secondary biological treatments and finally to negative concentrations (below detection limit) in disinfected effluents. Reduction of CoVs is due to (i) natural decay under unfavourable conditions (solids, microorganisms, temperature) for relatively long hydraulic retention times and (ii) processes of sedimentation, filtration, predation, adsorption, disinfection. In primary and secondary settling, due to the hydrophobic properties, a partial accumulation of CoVs may occur in the separated sludge. In secondary treatment (i.e. activated sludge) CoVs and SARS-CoV-2 loads can be reduced only by about one logarithm (∼90%). To enhance this removal, tertiary treatment with ultrafiltration (Membrane Bioreactors) and chemical disinfection or UV light is needed. CoVs and SARS-CoV-2 in the sludge (1.2E+04–4.6E+08 GU/L) can be inactivated significantly in the thermophilic digestion (55 °C), while mesophilic temperatures (33–37 °C) are not efficient. Additional studies are required to investigate the infectivity of SARS-CoV-2 in WWTPs, especially in view of increasing interest in wastewater reclamation and reuse.

The objective of this paper is to present an overview of state regulations and guidelines for wastewater reuse for irrigation. Land application of wastewater in the U.S. began in the 19th century when it was considered the safest and best method for wastewater disposal. According to the Environmental Protection Agency (EPA), 27 states have regulations for wastewater reuse and 11 states have guidelines for reuse. Some states have no regulations or guidelines for wastewater reuse. For urban wastewater reuse for irrigation where public access is not restricted and for irrigation of food crops, many of the states require additional levels of treatment beyond secondary treatment, which may include oxidation, coagulation, and filtration and high levels of disinfection. California, Arizona, Texas, and Florida were the earliest states to establish water reuse programs and account for the majority of wastewater reuse for irrigation in the U.S. Several of the challenges to increase wastewater reuse are water rights in the western states and a lack of funding for new projects.

Increasingly stringent regulations for leachate discharge call for leachate treatment plants (LTPs) to increase their treatment capacity by adopting membrane treatment processes to remove nitrogen and organics beyond conventional biological treatment processes. This study developed four common treatment strategies based on the existing operation and construction conditions of seven representative LTPs in China. We evaluated the LTPs' environmental impacts using life cycle assessment (LCA) following the International Organization for Standardization (ISO 14040 and ISO 14044). Compared with conventional secondary treatment processes, implementing high-level technologies to meet the strict standards could reduce an average of 59% of the eutrophication potential while increasing other environmental impacts resulting from both direct and indirect emissions by an average of 146%. We propose advanced technologies that integrate both midpoint and endpoint LCA results to meet stringent standards in areas sensitive to eutrophication.

There have been multiple reports of COVID‐19 virus, SARS‐CoV‐2 RNA presence in influent wastewater of water reclamation facilities (WRFs) across the world. In this study, the removal of SARS‐CoV‐2 RNA was investigated in a WRF by collecting samples from various stages relayed to hydraulic retention time (HRT) and analyzed for viral RNA (N1 and N2) gene markers and wastewater characteristics. SARS‐CoV‐2 RNA was detected in 28 out of 28 influent wastewater and primary effluent samples. Secondary effluent showed 4 out of 9 positive samples, and all tertiary and final effluent samples were below the detection limit for the viral markers. The reduction was significant (p value, The graphical abstract demonstrates the collection locations of the samples across the treatment train, followed by the step by step pretreatment and virus concentration methods required based on sample type.