Aeration Tank Research Articles

Do PFAS changes in landfill leachate treatment systems correlate with changes in physical chemical parameters?

Per- and polyfluoroalkyl substances (PFAS) have been found at relatively elevated concentrations in landfill leachates. Some landfill facilities treat physical-chemical parameters of their leachates using on-site leachate treatment systems before discharge. The objective of this study was to evaluate whether changes in physical-chemical parameters of leachate at on-site treatment systems (including bulk measurements, oxygen demanding components, and metals) were associated with concentration changes in PFAS. Leachates were evaluated at 15 on-site treatment facilities which included pond systems, aeration tanks, powdered activated carbon (PAC), sand filtration, reverse osmosis (RO) and combination treatment processes. Results show that most physical-chemical parameters and PFAS were significantly reduced in RO systems (over 90 %). For pond systems, statistically significant correlations (rs > 0.6, p < 0.05) were observed between ∑26PFAS changes and the changes in pH, alkalinity, ammonia, and some metals. Significant correlations were also found between ∑8PFAAs precursors changes and specific conductivity (SPC), pH, alkalinity, ammonia, and metals changes. For aeration tank systems, significant correlations (rs > 0.6, p < 0.05) were observed between ∑26PFAS changes and changes in total dissolved solids and zinc, and between the changes of ∑8PFAAs precursors and field pH. These correlations are believed to be associated with rainfall dilution and precipitation of calcium carbonate and other metals as leachate is introduced to the atmosphere.

Economic performance index assessment of an industrial wastewater treatment plant in terms of the European Green Deal: effect of greenhouse gas emissions

Abstract This study aims to determine the effect of greenhouse gas (GHG) emissions on economic performance in terms of energy costs for an industrial wastewater treatment plant. Also, the mitigation of GHG emissions aimed at using process modification to obtain possible reductions in energy costs. Optimum energy consumptions were reported for the minimum GHG emission using the Data Envelopment Analysis (DEA) and Monte Carlo simulation model. In this paper, a new empirical approach has been developed depending on the GHG emissions for estimating the economic performance of the wastewater treatment plants. The results revealed that nitrous oxide (N2O) emissions led to the highest energy costs among direct emissions. In the second stage of the study, the effects of design conditions on GHG emissions and energy costs were investigated. If the aeration tank is operated at 24 h of hydraulic retention time (HRT) and 22 days of solid retention time (SRT), then, on average, 27, 27.9, and 30.7% of reduction in energy costs in terms of direct carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions, respectively, is observed in the plant. These reductions corresponded to approximately 17.33 €/kWh of cost-saving in this plant.

Improving the Performance of Biological Tanks in Wastewater Treatment Plants by Modifying the Conventional Ceramic Aerator

The purpose of the article is to study the process of aeration of wastewater using an aerator with an air-lift effect to ensure a uniform distribution of the concentration of suspended solids in the aeration tank of the model installation. Based on the result of the work carried out, experimental data were obtained and a theoretical description of the parameters of the aeration process, which increase the coefficients of mass transfer and the use of the reactor volume, and the costs of the process. The airlift effect increases the concentration of sludge. The airlift also helps in the spread of suspended solid in the tank, as mass transfer reactions during aeration increase by an average of 11.8%. Also, an increase in dissolved oxygen concentration from 3.02 mg / L to 3.5 mg / L, i.e., by 15%, which indicates an improvement in mass transfer and, accordingly, a decrease in energy consumption for aeration. However, the existing technological potential requires the introduction of variable equipment. An example of an alternative air dispersion system can be aerators with airlift effect.

Impact of varying hydraulic retention time for treating distillery effluent in activated sludge system to combat the environmental and health hazards

Ethanol-distilleries are the key supporter to the world's economy, but these are moreover one of the major sources of environmental pollution that can impact the human heath if the effluents are not treated in proper manners. Distillery effluents with high biological oxygen demand (BOD) and chemical oxygen demand (COD) contains toxic chemicals which are reported to be of carcinogenic and mutagenic in nature. One of the widely used technology for the distillery wastewater treatment is based on up-flow anaerobic sludge blanket (UASB) technology along with activated sludge process. This technology has fulfilled a need for high efficiency treatment of wastes from various distilleries. With the increasing demands of distillery units and strict guidelines by government agencies for the environment protection, more efforts are required to achieve the zero liquid discharge (ZLD). The research reported in this paper is an effort to perform the in-situ study for evaluating the impact of varying retention times on the efficiency of the condensate Polishing Unit (CPU) based on UASB technology along with activated sludge process for ZLD. The primary objective was to determine pH, BOD and COD after increasing the HRTs in the aeration tank.

Effects of denitrifying granular sludge addition on activated sludge and anaerobic–aerobic systems for municipal sewage treatment

Conventional activated sludge (AS) systems are widely used to treat domestic sewage worldwide. However, the removal of nitrogen in the AS system is limited, and its concentration in the effluent exceeds the recommended values in the discharge standards. In this study, a pilot experiment was conducted to improve nitrogen removal during municipal sewage treatment by operating AS and anaerobic–aerobic (AO) systems under low dissolved oxygen (DO) conditions of less than 0.5 mg L−1 and by adding denitrifying granular sludge. The low DO operation of the AS and AO systems led to the sludge washout and increased the organic content and ammonia and nitrate concentration of the effluent. In contrast, the nitrate concentrations of the effluents produced by the AS and AO systems were 9.4 ± 3.6 and 8.4 ± 0.7 mg-N L−1, respectively, indicated that denitrifying granular sludge addition enhanced denitrification during sewage treatment. The total nitrogen (TN) removal efficiency increased by 13% and 9% for the AS and AO systems despite a decrease in the temperature of 6 °C for the water in the aeration tank. Thus, adding denitrifying granular sludge to the aeration tank is a simple and effective approach to improve organic and nitrogen removal during wastewater treatment.

ANAEROBIC BIOLOGICAL WASTEWATER TREATMENT OF SUGAR PRODUCTION

Water usage of sugar beet factories is characterized by a high level of consumption and a large volume of generated wastewater with a high concentration of mineral and organic pollution. Artificial biological purification facilities are mainly used for purification of sugar production effluents. While a scheme with two-stage aeration tanks is the most widespread in our country,anaerobic-aerobic regimens are frequently used abroad. It is more cost-effective, since the oxidation of large amounts of organic substances exclusively under aerobic conditions is associated with high energy consumption. The use of anaerobic digestion at the first stage allows reducing the concentration of organic substances in effluents by 60-90%, while the post-purification of remaining contaminants is carried out in stage-two aeration tanks with lower energy consumption. To assess the appropriateness of using a digester in the system of purification facilities of a particular enterprise, it is necessary to have information on the effectiveness of digestion and the optimal purification regime of the wastewater of that particular enterprise. This work studies the process of anaerobic digestion of wastewater at one of the beet sugar factories in Ukraine. The experiments were carried out in a bioreactor with an upward flow of activated sludge. The method of mathematical planning of an experiment was used in order to shorten the duration of the research. As a result, data was obtained regarding the influence of determining factors (flow rate, pH, temperature) on biogas yield and substrate fermentation depth. Received data proves the effectiveness and prospects of using anaerobic digestion in the first stage of biological fermentation of wastewater at a sugar beet production.

MLVSS / MLSS ratio’s standard value obtained from different aeration tank samples of different capacity sewage treatment plant - A case study

Waste water treatment system plays a vital role in controlling pollution of natural water bodies like lake, pond, river etc., by Municipal and Industrial effluents. Different industrial effluents play its own role in contaminating the water bodies which in turn creates huge impact for aquatic and terrestrial life. From past studies we understood that, all the sewage treatment systems have a secondary treatment step which are mainly driven by Bacterial oxidation or in other terms can be pronounced as Biological augmentation, Biological calcification etc., In environmental engineering term this bacterial growth will be pronounced as MLSS (Mixed Liquor Suspended Solids) and MLVSS (Mixed Liquor Volatile Suspended Solids). MLVSS will be an inclusive part of the MLSS and also can be sorted as live bacterial cells which can really does the oxidation process in the secondary treatment step of Sewage treatment plant. Hence, this study was performed to evaluate the percentage or concentration of MLVSS available in the total value of MLSS. For this study aeration tank water samples were collected from 6 different STP capacities from 6 different areas. All the samples were tested for MLSS and MLVSS concentration with the available standard method of drying. Drying with 105° C in oven gives the value of MLSS and drying with 550° C in furnace gives the value of MLVSS. With all the tested samples the concentration of MLVSS from the total MLSS was evaluated and standardized.

Determination of alpha factors for monitoring of aeration systems with the ex situ off-gas method: experience from practical application and estimation of measurement uncertainty

Performance of aeration systems in wastewater treatment plants (WWTP) under process conditions can be monitored with off-gas tests. The ex situ off-gas method transfers activated sludge from an adjacent aeration tank into aerated columns to determine oxygen transfer parameters (e.g., the α-factor). This method is an alternative to in situ off-gas testing with hoods at the tank surface; however, its application and measurement uncertainty have not been examined yet. We outline our experience from long-term off-gas testing with two pilot-scale test reactors (8.3 m3 volume). Global variance-based sensitivity analysis using Sobol’ indices revealed oxygen concentration in off-gas and dissolved oxygen as the most important input quantities to determine α-factors accurately. Measurement uncertainty of other instruments was negligible. These findings are transferable to in situ off-gas hoods because the methods are similar. Random measurement error of α-factors was estimated with uncertainty analysis and comparison measurements to a relative standard deviation of about ± 2.8% for our ex situ pilot setup. Diffuser fouling, biofilm growth, or sensor drift caused systematic errors avoidable by maintenance. Additional mixing of bubble column due to sludge inflow into ex situ tanks led to a systematic overestimation of α-factors at lower airflow rates. Hence, the ex situ off-gas method is not suitable to determine α-factors for the design of aeration systems but offers unique possibilities for research of oxygen transfer dynamics and development of aeration equipment because ex situ columns can be operated independently from a full-scale activated sludge tank.

Efficient removal of reactive red 24 from aqueous solution through electron beam and aeration tank using response surface methodology

The present work examines the decolorization of reactive red 24 (RR24) from an aqueous solution via the electron beam (EB) and aeration method. Response surface methodology (RSM) with central composite design (CCD) was used to optimize the treatment with the four selected variables, i.e., absorbed dose, H2O2 concentration, initial pH (in EB system), and operation time (in the aerobic reactor). The predicted optimized conditions for the color removal were 4.5 kGy for absorbed dose, 4.0 mM for H2O2 concentration, 6 for initial pH, and 7.5 days for operation time. The experimental response of 97.14% color removal from these optimized conditions was in agreement with the value predicted by the model to within an error of 2.24%. The closeness of the predicted values and experimental results indicated that the quadratic model is adequate for predicting the decolorization process of coupled EB and aeration. Besides, modern density function theory (DFT) and natural bond orbital (NBO) calculations are also used to predict the decomposition reaction mechanism of RR24 under the influence of EB irradiation. This study demonstrated a practical method of eliminating reactive dyes by the hybrid of EB and biological methods.

Design of Sustainable STP for Geeta University, Naultha

Abstract: Sample for the test which is required in designing units was collected from the backyard of the hostels of university where all the waste water meets. Various quality parameters of wastewater were determined in the campus lab and also in third party lab located in Panipat. After analysis of wastewater samples it is found that influent standards are more than the permissible limit prescribed by CPCB. There is an urgent need for a sewage treatment plant in the campus with a capacity for forecast of 30 years population. In this paper we have designed a sustainable sewage treatment plant for the university wastewater. The units have been designed based on the experimental data Such as; Screen unit, Grit chamber, PST, Aeration tank and SST Keywords: CPCB, Grit Chamber, PST, SST

A Study on Deriving Operation Conditions for Biological Treatment of Dry Condensate Generated in The Food Waste Drying Process

This study was conducted to derive operating conditions for biological wastewater treatment targeting highconcentration dry condensate generated in the drying process of food waste. In the biological treatment of dry condensate, lab. scale (40 L/d) bioreactor was manufactured and used in the study to evaluate the water quality of the treated water according to the change in operating conditions and to derive stable operating factors. Changes in the influencing factors inside the aeration tank according to the change of BOD load, hydraulic retention time (HRT) and F/M ratio were observed during the operation of the lab. scale bioreaction process. Thereafter, the treatment efficiency was evaluated by measuring the water quality concentration of the treated water. As a result of the study, the water quality of the treated water was BOD 71.14 ± 10.19 mg/L, TOC 49.54 ± 9.64 mg/L, T-N 33.78 ± 5.00 mg/L, T-P 3.35 ± 1.24 mg/L was evaluated as the highest treatment efficiency, under the HRT 5 day, BOD Load 0.30 ± 0.02 kg BOD/d, F/M ratio 0.40 ± 0.02 kg BOD/kg MLSS/d operating condition. It is concluded that the results of this study can be used as data for ensuring stable treated water quality and complying with the emission standards at real plant.

Experimental Study of a Gas-Liquid-Solid Three-Phase Flow in an Aeration Tank Driven by an Inverted Umbrella Aerator

The three-phase flow in a aeration tank driven by an inverted umbrella aerator is relatively complex, including the processes of the hydraulic jump, air entrainment, and sludge particle sedimentation. A three-phase flow test bench for an inverted umbrella aerator is established for studying its influence on aeration performance. The experiment mainly studies the changed law of aeration performance under different immersion depths or sludge concentrations and measures the flow rate and sludge concentrations in the aeration tank in different working conditions. The results are as follows. (1) The total oxygen transfer coefficient, standard oxygenation capacity, and standard power efficiency increase with the increase in rotational speed. The total oxygen transfer coefficient and standard-charge oxygen capacity first increase and then decrease with the decrease in immersion depth, reaching a maximum at −20 mm immersion depth. The standard dynamic efficiency has a similar trend and reaches a maximum at −8 mm immersion depth. (2) In the aeration tank, the flow velocity near the impeller is faster and has greater turbulence. The shallow water is more profoundly affected by the impeller compared with the deeper water. (3) The shallow-water sludge varies greatly, and the deep-water sludge is distributed uniformly when the inverted umbrella aerator works stably.

Microbiological aspects of the aeration tanks of an activated sludge treatment plant in dysfunction: Consequences on its treatment performance

The present study was conducted in a sewage treatment plant, called "El Kouwaer", located in the department of Mascara, North-West of Algeria. Mainly, the objective of this investigation is to evaluate the relevant settling and pollution parameters and to assess the proliferation level of filamentous microbial communities during the dysfunction period to further the effectiveness of the operative treatment. Sludge parameter values were estimated such us Settling Test, Diluted Sludge Volume Index (DSVI), and Total Suspended Solids (TSS) content to set up the sludge classification, the performance analysis of treatment was conducted by computing pollution indicators and removal efficiencies of organic pollution, as well as the Principal Component Analysis (PCA) of dysfunction parameters. The results showed that in aeration tanks 65% of samples represented a maximum Filament Index (FI) of 6. Diluted Sludge Volume Index (DSVI) was greater than 300 mg/L in 23% of samples. A high level of filamentous bacteria biodiversity was also noted during the assessment of the (FI) including Microthrix parvicella, Bogiotae, and Sphaerotilus natans. The effluent in the biological unit was characterized by BOD5/COD ratio of 0.17 and COD removal efficiency of 53.32%. Those results demonstrated that the sewage treatment plant is frequently affected by bulking problems. This study had confirmed the importance of continuous monitoring of different process parameters like Wastewater Biodegradability Index, Dissolved Oxygen, filamentous flora, and Dilute Sludge Volume Index (DSVI) to avoid irreversible damage at the level of a wastewater treatment plant.

Development of Single AI-MAS Process for Continuous Removal of Phosphorus, Nitrogen and Organic Compounds from Wastewater

The developed Anaerobic/Intermittent aerobic-Magnetic Activated Sludge (AI-MAS) process was found suitable for the continuous removal of phosphorus, nitrogen and organic compounds simultaneously from wastewater. This AI-MAS process reactor consisted of a small anaerobic compartment (first stage) placed at the corner of the intermittent aeration tank (second stage) with a magnetic separator in the middle. Better sludge separation was observed at 1-6 rpm of the magnetic drum. Using AI-MAS process, continuous removal of about 90% T-P, 96% T-N and 94% soluble CODCr were achieved with the loading rate of 3.5 mg/l T-P, 16 mg/l T-N and 250 mg/l CODCr, for the period of 160 d at the rate of 6 hrs hydraulic retention time (HRT). Simultaneous removal of phosphorus and nitrogen from the wastewater was possible due to coexistence of both phosphorus and nitrogen removal bacteria within the same sludge biomass. Phosphorus removal was performed through phosphate accumulation in aerobic condition and released again in anaerobic condition with the concomitant uptake of organic substances. Nitrification and denitrification occurred simultaneously in non-aeration/aeration (NA/A) cycle of the intermittent aeration. Plant Tissue Cult. &amp; Biotech. 32(1): 21-29, 2022 (June)

IMPROVEMENT OF THE MODE OF OPERATION OF BIOLOGICAL WASTEWATER TREATMENT FACILITIES

Despite the strict requirements for wastewater quality, intensive pollution and accumulation of industrial pollution, potentially hazardous substances, continues in the places of wastewater discharge. Therefore, the aim of the study is to improve the operation of biological wastewater treatment plants to ensure compliance with environmental requirements. To achieve this goal, the features of wastewater treatment are analyzed and it is found that the treatment process depends on the concentration of activated sludge, the amount of air and the properties of the wastewater entering the treatment. With this in mind, it is proposed to adjust the ratio of "sewage active sludge air" to ensure compliance with environmental requirements. Factors influencing the cleaning process are also identified. Such factors are the consumption of wastewater coming for treatment, oxygen saturation of the mixture of activated sludge and wastewater, the quantity and quality of activated sludge fed into the aeration tank. In addition, the peculiarities of the processes occurring in different parts of the buildings are taken into account, and it is proposed to divide the cleaning process into two stages. The first stage takes place in the first corridor of the aeration tank (regenerator), where the activated sludge enters for regeneration. The second stage covers the second or third corridors of the aeration tank and the secondary settling tank, where the wastewater is first mixed with activated sludge, then the mixture is discharged to the secondary settling tank. An experimental study of the cleaning process was carried out, as a result of which the necessary data for the mathematical description of the processes were obtained. After processing the experimental data, regression equations were obtained that describe the purification processes in the system "aeration tank-displacer - secondary settling tank", namely the change in the concentration of activated sludge at the outlet of the regenerator and the change in the concentration of contaminants in the purified water. The adequacy of the equations was checked according to Fisher's test. It was found that the equations are adequate to real processes within the accepted conditions and assumptions. Analytical solutions of the obtained equations allow to analyze the course of purification processes at different stages, to determine the influence of factors on the process. A procedure for the use of equations is proposed, which allows without additional experiments to choose the mode of operation of biological treatment facilities, which will ensure compliance with environmental requirements.

Possibilities of Real Time Monitoring of Micropollutants in Wastewater Using Laser-Induced Raman & Fluorescence Spectroscopy (LIRFS) and Artificial Intelligence (AI).

The entire water cycle is contaminated with largely undetected micropollutants, thus jeopardizing wastewater treatment. Currently, monitoring methods that are used by wastewater treatment plants (WWTP) are not able to detect these micropollutants, causing negative effects on aquatic ecosystems and human health. In our case study, we took collective samples around different treatment stages (aeration tank, membrane bioreactor, ozonation) of a WWTP and analyzed them via Deep-UV laser-induced Raman and fluorescence spectroscopy (LIRFS) in combination with a CNN-based AI support. This process allowed us to perform the spectra recognition of selected micropollutants and thus analyze their reliability. The results indicated that the combination of sensitive fluorescence measurements with very specific Raman measurements, supplemented with an artificial intelligence, lead to a high information gain for utilizing it as a monitoring purpose. Laser-induced Raman spectroscopy reaches detections limits of alert pharmaceuticals (carbamazepine, naproxen, tryptophan) in the range of a few µg/L; naproxen is detectable down to 1 × 10−4 mg/g. Furthermore, the monitoring of nitrate after biological treatment using Raman measurements and AI support showed a reliable assignment rate of over 95%. Applying the fluorescence technique seems to be a promising method in observing DOC changes in wastewater, leading to a correlation coefficient of R2 = 0.74 for all samples throughout the purification processes. The results also showed the influence of different extraction points in a cleaning stage; therefore, it would not be sensible to investigate them separately. Nevertheless, the interpretation suffers when many substances interact with one another and influence their optical behavior. In conclusion, the results that are presented in our paper elucidate the use of LIRFS in combination with AI support for online monitoring.

A probabilistic assessment of microbial infection risks due to occupational exposure to wastewater in a conventional activated sludge wastewater treatment plant

Exposure to pathogens during wastewater treatment could result in significant health risks. In this paper, a probabilistic approach for assessing the risks of microbial infection for workers in an activated sludge wastewater treatment plant is presented. A number of exposure routes were modelled, including hand-to-mouth and droplet ingestion of untreated wastewater, droplet ingestion and inhalation of aerosols after secondary treatment, and ingestion of sludge during drying. Almost all workers exposed to untreated wastewater could be infected with the three selected potential pathogens of pathogenic E. coli, Norovirus and Cryptosporidium spp. Hand-to-mouth ingestion is the single most significant route of exposure at the head of works. There is also a risk of infections resulting from ingestion of droplets or inhalation of aerosols at the aeration tanks or contaminated hands at the clarifiers during secondary wastewater treatment. For sludge, the risks of infection with Norovirus was found to be the highest due to accidental ingestion (median risks of 2.2 × 10−2(±3.3 × 10−3)). Regardless of the point and route of exposure, Norovirus and Cryptosporidium spp. presented the highest risks. The study finds that occupational exposure to wastewater at wastewater treatment plants can result in significant viral and protozoan infections. This risk assessment framework can be used to establish and measure the success of risk reduction measures in wastewater treatment plants. These measures could include the use of personal protective equipment and adherence to strict personal hygiene.

Expanding the activated sludge model no.1 to describe filamentous bulking: The filamentous model

Several wastewater treatment plants (WWTPs) worldwide have documented the occurrence of filamentous bulking in full-scale systems despite the efforts made for filamentous bulking control. The Activated Sludge Models (ASM) can neither describe nor predict filamentous bulking at WWTPs. This research aims to expand the ASM No. 1 to be able to describe filamentous bulking sludge and to model the effects of incorporating an aerobic selector on filamentous bulking. Four theories (hydrolysis of slowly biodegradable organics theory, kinetic selection theory, substrate diffusion limitation theory, and filamentous backbone theory) were combined to expand the ASM1. The results showed that this combination was successful to distinguish between the substrate uptake by filamentous organisms and by floc forming organisms. Moreover, the concentrations of filamentous and floc forming organisms inside the reactor were converted to a “filamentous score” that predicted the outcome of filamentous bulking. Filamentous bulking would occur if the filamentous score was higher than 3, in a range of 1–6. As a case study, the Fuhais WWTP in Jordan was modelled using the expanded-ASM1 “filamentous model” and the filamentous score of 4.2 was in accordance to the visually observed bulking. However, when an aerobic selector with 3 compartments would be added before the aeration tank, the filamentous score decreased to 1.5. The selector changed the hydraulic behaviour from a completely mixed mode to a plug flow mode, which created a substrate gradient in the model, making the floc forming organisms to outcompete the filamentous organisms. Additional experimental results are required to further calibrate and validate the filamentous model.

Direct Method to Design Solar Photovoltaics to Reduce Energy Consumption of Aeration Tanks in Wastewater Treatment Plants

Photovoltaic (PV) energy systems are considered good renewable energy technologies due to their high production of clean energy. This paper combines a PV system with wastewater treatment plants (WWTPs), which are usually designed separately. For this, a recent methodology was adopted, which provides direct steps to estimate the peak powers of PV plants (PVPs) by using the airflow of blowers. The goal was to reduce the energy consumption of aeration tanks in WWTPs. Analytical equations and parameters based on the air temperature, solar irradiation, biological kinetic, dissolved oxygen, and mechanical oxygenation are adopted. The key parameter in this methodology is the air temperature variation that represents an approximated temperature in the WWTP’s oxidation tanks. It is shown, through the analysis of small WWTPs, that since the temperature changes for each season, there is a peak in the function of the quantity of oxidation, which is high in the summer season. Further, the curve trends of temperature for WWRPs are similar to PVPs. Therefore, it could be possible to design the PV system with the WWTPs well. The results show that the air temperature curves increase in a directly proportional way with the consumption of energy from oxidation blowers; this could induce a more conservative PVP design. Furthermore, the results show that the mean trend of the energy consumption of the analyzed aeration systems reaches about 8.0% at a temperature of 20–25 °C, covering a good part of the oxidation tank consumption.

Biological treatment of slaughterhouse wastewater using Up Flow Anaerobic Sludge Blanket (UASB) - anoxic-aerobic system

Slaughterhouse wastewater (SWW) is heavily polluted wastewater. It contains high concentration of organic matters, suspended solids, nitrogen, phosphorus, oil and grease. Discharging of SWW without a proper treatment may cause many problems for the sewage network and municipal treatment plants. Thus, this study aims to investigate the treatability of SWW using a new treatment method consists of: Up-flow anaerobic sludge blanket (UASB) reactor, Anaerobic Anoxic and Oxic (A2/O), and Virginia Initiative Plant Method (VIP). The integrated process consists of UASB reactor, anoxic tank, aeration tank (UASBAA), and final settling tank, respectively.The value of the mixed liquor suspended solids (MLSS),and return activated sludge (RAS) flows from the final settling tank to the anoxic tank were 300% and 100% of the SWW inflow respectively. During the research the influence of HRT values in UASB, anoxic tank, and the aeration tank has been investigated on the efficiencies of pollutants removal that exist in SWW. The experiments proved that the suggested method achieved high removal efficiency of COD, BOD5, TS, TDS, TSS, NH4+, PO43−, and NO3−, respectively: 97.31%, 96.91%, 57.61%, 47.91%, 96.3%, 73.11%, 83.61%, 93.01%, at HRTs value of 24 h for UASB reactor; 12 h for anoxic tank: 24 h for aeration tank, and 3 h for final settling tank. The treated wastewater could be reused it in washing processes in the slaughterhouse or for the irrigation of industrial crops.