Slaughterhouse Wastewater Research Articles

Multi-characteristic optimization and modeling analysis of electrocoagulation treatment of abattoir wastewater using iron electrode pairs

Multi-characteristic optimization and modeling analysis of electrocoagulation (EC) treatment of abattoir wastewater (AWW) using iron‑iron electrodes are reported. Response Surface Methodology (RSM) and Artificial Intelligent (AI) modeling tools viz. Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) were used for the modeling while the numerical method of RSM and RSM-based Genetic Algorithm (RSM-GA) were used to optimize the response variable. The independent variables were pH, current intensity, electrolysis time, settling time, and temperature while the dependent variable was percentage turbidity removal. Based on high determination coefficient (R2) and low standard deviation (SD) values, the quadratic model was selected from the ANOVA of the RSM model. For the ANN model, the number of neurons were varied between 2 and 10 but based on low MSE and high R2 values, 10 was selected as the optimum number of neurons. The ANFIS network used the triangular input membership function (trimf) with 100 epochs. The three models depicted linear adequacy with respective R2 values of 0.9978, 0.9995, and 0.8285 for RSM, ANFIS, and ANN respectively. However, the performance error indices indicated that the prediction accuracy of the three models followed the order — ANFIS > ANN > RSM. Further, the validated optimization results produced 94.74 % and 97.42 % turbidity removal for the RSM and RSM-GA optimization methods respectively. This proved that RSM, ANN, and ANFIS can reliably be used to model the EC treatment of AWW using FeFe electrodes; while the response variable can successfully be optimized by RSM and RSM-GA methods.

Slaughterhouse Wastewater Treatment by Integrated Chemical Coagulation and Electro-Fenton Processes

The slaughterhouse industry produces large amounts of highly polluted wastewater which needs to be treated before being discharged water. Thus, this work was conducted to investigate the feasibility of treating slaughterhouse wastewater using combined chemical coagulation and electro-Fenton methods. We studied the effect of process parameters such as polyaluminum chloride (PAC) concentration (25, 50, 75, 100 mg/L) for chemical coagulation and hydrogen peroxide concentration (500, 1000, 1500, 2000, 2500, 3000, 4000 mg/L), the pH of the solution (3, 5, 7, 10), and the reaction time (5, 10, 15, 30, 45, 75, 120 min) and the voltage (10, 20, 30, 40 V) on the removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), total Kjeldahl nitrogen (TKN), and fecal coliforms (FC). The optimum removal efficiency for the electro-Fenton process was obtained at PAC = 75 mg/L, reaction time = 75 min, pH = 3, H2O2 = 2500 mg/L, and V = 20 V, which resulted in the removal efficiency of 89.55% for COD, 88.88% for BOD, 91.27% for TSS, 69.23% for TKN, and 100% for FC. The findings demonstrated that combined chemical coagulation and electro-Fenton processes effectively and efficiently treat slaughterhouse wastewater. The results of this research can be used by competent authorities to increase the efficiency of slaughterhouse wastewater treatment and to protect the environment.

Treatment of Slaughterhouse Wastewaters with Ti/IrO2/RuO2 Anode and Investigation of Energy Consumption

Treatment of Slaughterhouse Wastewaters with Ti/IrO2/RuO2 Anode and Investigation of Energy Consumption

Electrooxidation treatment of slaughterhouse wastewater: investigation of efficiency of Ti/Pt anode

In the present study, investigation of the applicability and efficiency of electrochemical oxidation (EO) processes for slaughterhouse wastewater (SWW) was targeted by evaluating the treatment efficiency and energy consumption values. The effects of operating parameters, such as the type of supporting electrolyte (SE) (Na2SO4, NaNO3, NaCl, and KCI), supporting electrolyte concentration (SE concentration) (0.1–0.4 M), initial wastewater pH (3–11), and current density (CD) (4.06–12.18 mA/cm2) on the removal of chemical oxygen demand (COD), suspended solids (SS), turbidity, and color were investigated. The most effective electrolyte type was observed to be NaCl. The experiment with 0.2 M SE type and 4.06 mA/cm2 current density, at a stirring speed of 400 rpm was accepted as optimum. For these conditions, it was observed that the COD, color, turbidity, and suspended solids (SS) removals were 80.05, 98.64, 99.18, and 98.47%, and energy consumption of 210.7 kWh/m3, respectively. It has been observed that the electro-oxidation process provides substantial efficiency in undesirable parameters in wastewater after 3 h of operation. Additional processes can be added to this process so that the SWW can be reused after treatment, and the recovery and further treatment of the wastewater can be achieved.

Application of synthesized Fish Scale Chito-Protein (FSC) for the treatment of abattoir wastewater: Coagulation-flocculation kinetics and equilibrium modeling

This work explores the use of chito-protein synthesized from fish scale as a bio-coagulant in Abattoir wastewater (AW) treatment. The effect of settling time, pH, adsorbent dosage, and temperature of coagulation on Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), turbidity, and Color from the AW sample were studied. The kinetic study was carried out using four process equilibrium models which are Langmuir, Freundlich, Frumkin, and Tempkin to investigate the mechanism of the reaction. SEM and FTIR spectral analyses were used to evaluate the surface morphology and chemical composition of the bio-coagulant. A low pH, 3 g of dosage in 250 mL vessel, settling period of 30 to 35 min, and temperatures of 323 K for all parameters resulted in the most efficient pollutant elimination. Turbidity, however, had an optimal temperature of 313 K. The result of the study shows that Langmuir model provided the best fit from the equilibrium models compared to Freundlich, Frumkin, and Temkin's models. The experimental data suited the Elovich, Pseudo-first, and Second order kinetic models’ analysis and the high values of the regression coefficient of 0.90 supported the idea of perikinetic as the governing mechanism of coag-flocculation in the study. It can be inferred from this study that fish scale as a bio-coagulant provides a significant resource for abattoir wastewater treatment.

Screening plant growth effects of sheep slaughterhouse waste-derived soil amendments in greenhouse trials.

Ameliorative effects of sheep slaughterhouse waste-derived soil amendments (struvite, blood meal, bone meal) were explored and quantified by a series of comparative greenhouse trials. A scoring matrix system was developed for 25 different test plants using 300 agricultural measurements obtained for three basic growth parameters (fresh-dry plant weights and plant heights) and four different fertilizer sources including solid vermicompost. More than 70% of NH4+-N recovery from sheep slaughterhouse wastewater was achieved using a chemical combination of MgCl2.6H2O+NaH2PO4.2H2O, a molar ratio of Mg2+:NH4+-N:PO43-P=1.2:1:1, a reaction pH of 9.0, an initial NH4+-N concentration of 240mg/L, and a reaction time of 15min. According to SEM micrographs, surface morphology of struvite exhibited a highly porous structure composed of irregularly shaped crystals of various sizes (11.34-79.38μm). FTIR spectroscopy verified the active functional groups on the proximity of all fertilizer sources within the spectral range of 500-3900cm-1. TGA-DTG-DSC thermograms of struvite revealed that the mass loss occurred in two temperature regions and reached a maximum mass loss rate of 1.63%/min at 317°C. The average percentages of increase (57.55-100.62%) and performance points (69-79) corroborated that the fertility value of struvite ranked first on average in cultivation of the analyzed plant species. Findings of this agro-valorization study confirmed that sheep slaughterhouse waste-derived fertilizers could be a beneficial way to promote bio-waste management and environmentally friendly agriculture.

Investigation on the Treatment of Slaughterhouse Wastewater in a Sequential Batch Reactor

In the present study, the treatment of slaughterhouse wastewater was carried out in a sequential batch reactor. A lab-scale column type reactor was fabricated with Perspex material having dimensions of 10 cm diameter, 100 cm height, and an effective volume of 7 liters provided with ports at different levels. The reactor performance was evaluated in terms of COD, BOD, TSS, TKN, and phosphorus removal. The reactor was operated for 432 days; the effectiveness of the reactor is the temperature of wastewater in the reactor. The removal efficiencies of COD and BOD were84% and 80% in the reactor. The maximum TSS removal was around 87% and TKN’s maximum removal efficiency was 61% in aerobic treatment. Phosphorus maximum removal efficiency was around 68%, in the meantime pH and alkalinity were also monitored, and no change in the pH was reported throughout the experiment. On the other hand, an aerobic SBR is also operated using wastewater after the DAF unit. In the same manner, the reactor was operated with initially diluted wastewater (05 times) and kept HRT 8 h. The reactor performance was studied in terms of COD, BOD, TSS, TKN, and phosphorus. The maximum removal efficiencies of COD and BOD were 80% and 81% respectively. The maximum removal efficiencies of TSS, TKN, and Phosphorus were 73%, 81%, and 69% respectively. It is concluded that the removal efficiency of COD was better in the anaerobic process as compared with the aerobic process in addition the generation of methane gas during the degradation of organic matter can be used for operating the aerobic unit by making some necessary arrangements. Besides this, it is also concluded that the removal efficiency of TKN was better in the aerobic process as compared with the anaerobic process. There was a buildup of VSS from 4500 mg.L-1 to 6500 mg.L-1 in the study.

Numerical Optimization of the Physico-chemical Process Used in the Treatment of Real Poultry Slaughterhouse Wastewater for Water Quality Improvement

Numerical Optimization of the Physico-chemical Process Used in the Treatment of Real Poultry Slaughterhouse Wastewater for Water Quality Improvement

AN INNOVATIVE SOLUTION FOR THE TREATMENT OF POULTRY INDUSTRY WASTEWATER WITH ADVANCED HYBRID TECHNOLOGY SONO-PHOTOCATALYSIS

<p>Poultry slaughterhouse wastewater (PSWW) is a crucial concern fundamentally due to extensive generation and related substantial amounts of recalcitrant organic content due to high COD and oil and grease (O&G) levels. Hybrid advanced oxidation processes are promising, green, and innovative options to treat various industrial wastewater; to date, this potential has not been implemented to high-strength wastewater from the poultry industry. This work aims to investigate the combination of ultrasound and photocatalysis processes in the treatment of poultry slaughterhouse wastewater for the removal of COD and O&G under different operating conditions such as catalyst type (TiO2 and ZnO), irradiation type (UVA365 and UVC254), catalyst dosage (0.5-2.5 g/L), pH (2–10), hydrogen peroxide concentration (0-10 mM) and operation time (30-180 min). Taguchi’s experimental design based on the L36 orthogonal array was adequately applied to optimize the process. The finding results presented that ZnO concentration of 2.5 g/L, pH 2, and operation time of 180 min under UVC254 were optimum parameters to achieve maximum COD removal while, ZnO concentration of 1.5 g/L, pH 6, H2O2 concentration of 5 mmol/L and operation time of 30 min under UVC254 were optimum parameters to achieve maximum oil and grease removal. With these optimum conditions, the best attained COD and O&G removal yields were 54% and 99%, respectively.</p>

Abattoir Wastewater Treatment in Anaerobic Co-Digestion with Sugar Press Mud in Batch Reactor for Improved Biogas Yield

Slaughterhouse wastewater (SHWW) has a great potential to generate biomethane energy when subjected to anaerobic digestion (AD). Nonetheless, the process is susceptible and prone to failure because of slow hydrolysis and the production of inhibitory compounds. Accordingly, to address this deficiency, anaerobic co-digestion (ACoD) is used to improve the treatment efficiency of the monodigestion of this high-strength waste and thereby increase methane production. The current investigation utilized the biochemical methane potential (BMP) test to assess the treatment performance of co-digested SHWW with sugar press mud (SPM) for improving biomethane energy recovery. It was established that the ACoD of SHWW with SPM increased methane (CH4) yield, enhanced organic matter removal efficiency and improved process stability, while also presenting synergistic effects. The anaerobic monodigestion (AMoD) of SHWW (100SHWW: 0SPM) showed a higher CH4 yield (348.40 CH4/g VS) compared with SPM (198.2 mL CH4/g VS). The 80% SPM: 20% SHWW mix ratio showed the optimum results with regard to organic matter removal efficiency (67%) and CH4 yield (478.40 mL CH4/g VS), with increments of 27% and 59% compared with AMoD of SHWW and SPM, respectively. However, it is also possible to achieve 5% and 46% CH4 yield increases under a 40% SPM: 60% SHWW mix proportion in comparison to the AMoD of SHWW and SPM, respectively. Furthermore, kinetic analysis of the study using a modified Gompertz model revealed that the CH4 production rate increased while the lag time decreased. The synergistic effects observed in this study demonstrate that incorporating SPM into the substrate ratios investigated can improve the AD of the SHWW. In fact, this represents the environmental and economic benefits of successfully implementing this alternative solution. Bioenergy recovery could also be used to supplement the country’s energy supply. This would help to increase the use of cleaner energy sources in electricity generation and heating applications, reducing the greenhouse gas effect.

Enhancement Effects of Water Magnetization and/or Disinfection by Sodium Hypochlorite on Secondary Slaughterhouse Wastewater Effluent Quality and Disinfection By-Products

Wastewater disinfection is one of the most critical issues in protecting human health against exposure to waterborne pathogenies. Chlorine is among the most commonly used disinfectants in many wastewaters’ treatment plants. Nevertheless, disquiets regarding chlorine’s disinfection by-products (DBPs) have grown recently. One of the most effective ways to reduce DBPs generation is to reduce chlorine dosage by increasing disinfectant efficiency. Using magnetic field (MF) in wastewater treatment is one of the promising research topics with significant progression. This study aimed to evaluate the efficiency of using a magnetic field and/or sodium hypochlorite (NaClO) disinfection on secondary slaughterhouse wastewater effluent quality and by-products. Three groups of secondary slaughterhouse wastewater effluents were used: G1 was treated with NaClO only at 0, 2, 4, and 6 mg/L; G2 was treated with exposure to MF at 14,500 gausses, and G3 was pretreated with MF, then NaClO at the exact chlorine dosages and MF strength. The results showed an augmented effect when using a magnetic field as a pre-treatment step before NaClO treatment in the remediation of slaughterhouse wastewater over the use of any of them solely. The removal rate of COD and BOD increased by up to 26 and 20%, respectively, when pre-treatment with MF was employed as a mean percentage at all chlorine dosages, while TSS, TDS, and EC increased by 23.5 and 5.5%, respectively. Over and above, the removal rate for each TN and TP increased by 12 and 6.5% as a mean percentage at all chlorine dosages when using a combination of the two. In addition, pre-treatment by MF reduced the required concentration of NaClO from 6 to 4 mg/L, resulting in an 11% increase in the reduction rate of total coliform count, 8% increase in the reduction rate of fecal coliforms, and 10% increase in the reduction rate of E. coli and 5% in Salmonella via increasing the disinfection efficiency of NaClO. Finally, it decreased the concentration of Chloroform produced by more than 77.2% by using the higher concentration of NaClO (6 mg/L). The issue that approved the promising approach of using MF as a pre-treatment step in the treatment of slaughterhouse wastewater provides the advantage of using smaller dosages of disinfection, lowering the cost of the procedure process, and reducing the harmful concentration of DBPs.

Advancements of sequencing batch biofilm reactor for slaughterhouse wastewater assisted with response surface methodology

Slaughterhouse wastewater (SWW) contains a significant volume of highly polluted organic wastes. These include blood, fat, soluble proteins, colloidal particles, suspended materials, meat particles, and intestinal undigested food that consists of higher concentrations of organics such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrogen and phosphorus hence an efficient treatment is required before discharging into the water bodies. The effluent concentrations and performance of simultaneous sequential batch biofilm reactor (SBBR) with recycled plastic carrier media support are better than the local single-stage sequential batch reactor (SBR), which is lacking in the literature in terms of COD, NH3, NO3, and PO4 treatment efficiency. The present study reports a novel strategy to remove the above mentioned contaminants using an intermittently aerated SBBR with recycled plastic carrier media support along with simultaneous nitrification and denitrification. The central composite design was evaluated to optimize the treatment performance of seven different process variables including; different alternating conditions (Oxic/anoxic) for aeration cycles (3/2 h in a 6 h cycle, 6/5 h in a 12 h cycle and 9/8 h in an 18 h cycle) and hydraulic retention time (6, 12 and 18 h). The average removal efficiencies are 94.5% for NH3, 93% for NO3 and 90.1% for PO4, and 99% for COD. The study reveals that the denitrification in the post-anoxic phase was more efficient than the pre-anoxic phase for pollutant removal and maintaining higher quality effluent. The effluent concentrations and performance of simultaneous SBBR with recycled polyethylene carrier support media were better than local SBR system in terms of COD, NH3, NO3 and PO4 treatment efficiency. Results stipulated the suitability of SBBR for wastewater treatment and reusability as a sustainable approach for wastewater management under optimum conditions.

Phytoremediation as a Sustainable Alternative for Organic Matter Removal From Slaughterhouse Wastewater Pretreated by Immediate One-Step Lime Precipitation

In this study, slaughterhouse wastewater previously treated by immediate one-step lime precipitation was treated using a vertical flow constructed wetland (VFCW). A VFCW pilot scale planted with Vetiveria zizanioides in light expanded clay aggregates was used to study the influence of the organic load applied (3 to 212 g m−2 d−1) and the bed depth of the VFCW (0.35 and 0.70 m) on the organic matter removal (COD). Two VFCWs operated in parallel under continuous flow, and a hydraulic load of around 80 L m−2 d−1 was used. The results indicated that an increase in the organic load decreased COD removal efficiency. The bed depth of the VFCW had a significant influence on the removal of organic matter, with greater removal at high bed depths. For organic loads applied up to 9.5 g m−2 d−1, COD removal efficiencies of 71.4 ± 4.0% and 85.2 ± 3.4% were observed for lower and higher VFCW bed depth, respectively, which met the requirements for water reuse for irrigation. Throughout the tests, Vetiveria zizanioides did not show signs of toxicity, and its growth was substantial.
 Keywords: slaughterhouse wastewater, vertical flow constructed wetlands, Vetiveria zizanioides, organic matter removal, immediate one-step lime precipitation

Poultry Slaughterhouse Wastewater Treatment Using an Integrated Biological and Electrocoagulation Treatment System: Process Optimisation Using Response Surface Methodology

The feasibility of a biological (EcoflushTM) and/or electrocoagulation (EC) treatment system in removing chemical oxygen demand (COD) and fats, oils, and grease (FOG) from poultry slaughterhouse wastewater (PSW) were studied. The response surface methodology (RSM) was used to identify the optimum operating condition for EC and its integration with EcoflushTM as a pre-treatment for the removal of lipids. The optimum operating conditions were obtained at a pH of 3.05, a current density of 66.9 A/m2, 74-min of treatment time, and without Ecoflush™. These conditions produced a high-quality clarified effluent after 92.4% COD reduction and 99% FOG reduction. The treatment with EcoflushTM only resulted in 85–99% FOG reduction, 20–50% COD reduction, and odourless effluent. However, the combination of both processes (EcoflushTM and EC) did not yield a significant difference (F test, p > 0.05) when compared to the performance of EC alone. Despite the low removal percentages of nitrogen and phosphorus, the present study proved that EC is an effective method for the removal of COD and FOG, rendering an effluent that meets the permissible discharge standards for the City of Cape Town. The novel Ecoflush™ also proved to be very efficient in the removal of FOG from PSW.

Physico-chemical and Microbiological Qualities of Abattoir Wastewater in Egbu, Imo State, Nigeria

Abbattoir waste water is of a complex composition. When discharged without being treated, poses a threat to human health and the environment. This is the practice common in Nigeria, and is worrisome.
 Objective: The aim of this study was to assess the physico-chemical and microbiological qualities of waste water from Egbu abattoir discharged into ‘Otamiri’ river in Owerri North local government area, Imo State, Nigeria.
 Methods: The microbial quality of abattoir wastewater was studied. The duration of the study was three months, from June to September, 2019. Sample collection was done in the morning (8-10am) and in the evening (4-6pm). A total of thirty samples (30) were collected from two sampling points, at the place of generation of the wastewater (Effluent source) and at the point of discharge into the river (POE). Standard methods were employed to assess the microbiological and physiochemical quality of the effluent. The microorganisms isolated from the samples included Escherichia coli, Salmonella, Staphylococcus, Aspergillus, Mucor, Listeria, Micrococcus and Candida species. The Total Heterotrophic Count (THC) of effluent samples, at source and POE were 8.51log10 cfu/ml and 6.15log10cfu/ml respectively, Total Coliform Count (TCC) for same samples were 6.77log10 cfu/ml and 4.56log10 cfu/ml respectively. The Total Fungal Count (TFC) of the effluent samples at source and at POE was 5.19log10 cfu/ml and 4.18log10 cfu/ml respectively. Results further revealed that the pH of the effluent at source was 6.58 while that at Point of Entry into the river was 7.30. The temperature of both samples was 25oC. The Total Dissolved Solid values of the effluent collected at source was higher, having a value of 1400mg/L against 1000mg/L at Point of Entry. Also the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values of the effluent at source were 5.10mg/L and 8.58mg/L respectively, while the BOD and COD of the water at the POE were 4.3mg/L and 7.9mg/L respectively.
 Conclusion: Abattoir wastes are becoming a major environmental health challenge and being discharged into the Otamiri River indiscriminately is of public health concern. The potential public health implications associated with discharging untreated abattoir wastewater into the environment and thus, the need for adequate treatment to ensure decontamination as well as providing wastewater treatment facility is imperative.

PENURUNAN COD, BOD, TSS, AMONIA DAN KOLIFORM AIR LIMBAH RUMAH POTONG HEWAN DENGAN BIOFILTER AEROBIC FIXED-BED REACTOR DAN KLORINASI

Slaughterhouses produce wastewater containing high organic matter, which has the effect of polluting water and the surrounding environment. Slaughterhouse wastewater treatment can be done biologically, namely biofiltration, by utilizing microorganisms and chlorination. Efforts in wastewater treatment continue to be developed. This study aimed to determine the effectiveness of biofiltration processing techniques with an Aerobic Fixed-Bed Reactor (AFBR) with pumice stone media combined with chlorination to reduce the levels of COD, BOD, TSS, ammonia, and coliform bacteria. The method applied was to use biofilms from the seedings on pumice with variations of with or without the addition of active suspension, aeration system treatment with time variations, and the addition of chlorine with variations of active chlorine doses. The results showed that the addition of active suspension in the process produced the best biofilm, and was effective in reducing the levels of COD, BOD, TSS, and ammonia. The best reduction of COD levels was at the 36th hour at 81.60 mg/L with an efficiency of 57.45%, BOD at the 36th hour was 24.67 mg/L with an efficiency of 65.74%, TSS at the 42nd hour was 54.0 mg/L with an efficiency of 85.66%, and ammonia at the 42nd hour of 1.5539 mg/L with an efficiency of 88.29%. Chlorination after the treatment with AFBR resulted in a decreased number of coliform bacteria from 1,100 MPN/100 mL to 0 MPN/100 mL with 100% efficiency. The chlorination process resulted in the optimum chlorine dose of 165 ppm with a chlorine residual of 28.80 mg/L. Thus, the treatment for 36-42 hours on AFBR followed by chlorination with a chlorine dose of 165 ppm was relatively effective in reducing COD, BOD, TSS, ammonia, and coliform levels of bacteria in slaughterhouses wastewater.
 Keywords: ammonia, biofiltration, chlorination, coliform.

Dissolved organic matter in bovine slaughterhouse wastewater using fluorescence spectroscopy associated with CP/PARAFAC and PCA methods.

In this work, we evaluated the potential application of fluorescence spectroscopy, associated with the canonical polyadic/parallel factor analysis and principal component analysis, to monitor the dissolved organic matter (DOM) generated from a slaughterhouse industry. During the monitoring process, we analyzed the residual water at the entrance and exit sites of the slaughterhouse effluent treatment as well as downstream and upstream the effluent receiving water body of a local river. The results revealed that the fluorescence analysis was able to identify proteins, chlorophylls, and humic substances at the entrance and exit sites of the slaughterhouse treatment plant and humic substances at the river water bodies. Our data also demonstrated that the industrial effluent discharged into the river did not impact the receiving water body quality as determined by the biological and humification indices obtained by fluorescence analysis, which was confirmed by conventional physicochemical analysis. In summary, the present findings indicate that fluorescence spectroscopy, in association with multivariate analysis, can be successfully applied as an analytical tool for evaluating the quality of DOM in slaughterhouse wastewater.

Biogas production and nutrients removal from slaughterhouse wastewater using integrated anaerobic and aerobic granular intermittent SBRs – Bioreactors stability and microbial dynamics

Slaughterhouse wastewater (SWW) was effectively treated in sequential anaerobic and aerobic granular intermittent sequencing batch reactors (ASBR+ISBR) for 665 days at different HRTs (48 h, 32 h, 24 h, and 12 h). The ASBR was stable at each HRT but performed relatively well at 12 h (OLR - 7.8–9.8 kg COD/m3-d) in terms of pollutants removal and biogas production than previously conducted research. The average biogas production was about 17.3 L/day having 70–76 % of CH4 which could subsidize around 52 % of electricity demand while saving 103 US dollars/day if installed at full scale. In the case of post aerobic granular ISBR, carbon and nutrients removal (N&P) was achieved by enriching granules (1.7–2.2 mm) at low DO (0.5–0.8 mg/L) via the nitrite pathway. The ISBR was also well stable at 12 h HRT (average OLR of 2.1 kg COD/m3-d) and met the effluent discharge guidelines recommended by the Central Pollution Control Board of India. During steady-state conditions (12 h HRT), the average removal efficiencies for COD, TSS, O&G, TN, and PO4-P were 98.8 %, 96.4 %, 98.7 %, 93.4 %, and 86.6 % respectively from combined ASBR and ISBR. The microbial analysis confirmed Euryarchaeota, Proteobacteria, Firmicutes, Chloroflexi, Bacteroidetes, Planctomycetes, and Synergistetes as the dominant phyla in ASBR. Methanosaeta (21.56 %) and Methanosarcina (6.48 %) were the prevailing methanogens for CH4 production. The leading phyla observed in ISBR were Bacteroidetes, Proteobacteria, Firmicutes, Armatimonadetes, Verrucomicrobia, Chloroflexi, and Planctomycetes. Heterotrophic AOB (Thauera, Xanthomonadaceae, Pseudomonas, Sphingomonadaceae, and Rhodococcus) were mainly detected in the system for ammonia oxidation besides common autotrophic AOB. Similarly, a known PAO (Accumulibacter) was not identified but other PAO (Rhodocyclaceae, Dechloromonas, Pseudomonas, Flavobacteriaceae, and Sphingobacteriaceae) were prevalent inside aerobic granular ISBR that contributed to both carbon and nutrients removal. The results obtained would help implement the investigated reactor configurations at the pilot and full scale for SWW treatment.

A comparative study of anodic oxidation and electrocoagulation for treating cattle slaughterhouse wastewater

In this study, industrial cattle slaughterhouse wastewater (ICSHWW) was treated by anodic oxidation (AO) and electrocoagulation (EC) processes using different electrode materials. Total organic carbon (TOC), chemical oxygen demand (COD), and total phosphorus (TP), among other parameters, were analyzed during the treatments. Electrochemical techniques were carried out in batch operation mode during five hours applying different current densities in sulfate and chloride media. The industrial cattle slaughterhouse wastewater contained TOC 1150 mg L–1, COD 4320 mg L–1, TP 25 mg L–1, TN 76 mg L–1, turbidity 516 NTU, color –absorbance 0.36 A.U. at 416 nm–, conductivity 2.79 mS cm–1, and pH 7.18. The highest TOC removal efficiencies were found at j = 20 mA cm–2 using the EC process (> 88%), with an energy consumption around 0.01 kW h m–3. Moreover, a complete discoloration and disinfection were achieved. Considering the high consumption of the freshwater destined to the livestock sector and global scarcity of water, electrochemical processes are an effective tool for decontaminating industrial waters produced from the meat industry.

Phycoremediation of slaughterhouse wastewater using microalgae for nutrient recovery and biodiesel production

Phycoremediation of slaughterhouse wastewater using microalgae for nutrient recovery and biodiesel production