Maximum COD Removal Efficiency Research Articles

Remediation of carcinogenic PAHs from landfill leachate by Electro-Fenton process – Optimization and modeling

PAHs is the group of emerging micro-pollutants present in most environmental matrices that has the tendency to bioaccumulate and cause carcinogenic effects to human health. The present research involved the quantification and treatment of leachate produced from secured landfill, to eliminate the PAHS. Electro-Fenton process, a class of advanced oxidation process, is adopted to degrade the PAHs using titanium electrodes as both anode and cathode. Artificial intelligence based statistical tool “Central Composite Design” a module of JMP -19 software was used to design the experiments and optimize the critical parameters involved in the research. It was observed that the value of P is significant (P < 0.05) for all the independent variables evidencing the significant correlation between experimental values and predicted values of the software. The value of R2 obtained was 0.96 and 0.97 for COD and PAHs respectively. The maximum removal efficiency of COD and PAH was found to be 84.24% and 90.78% respectively. The optimized conditions obtained from the central composite design were: pH = 5; Fe2+ = 0.1 g/L; H2O2 = 2 g/L; reaction time = 60 min; and electric intensity = 0.2 A. Additionally, optimized experimental conditions were used to study the removal efficiencies of individual 16 PAHs and are also reported. From the close proximity of experimental and predicted results of the software it can be proved that central composite design is efficient enough to be used as a statistical tool in design and analysis for treatment of landfill leachate.

Enhancing bioelectrochemical hydrogen production from industrial wastewater using Ni-foam cathodes in a microbial electrolysis cell pilot plant

Microbial electrolysis cells (MECs) have garnered significant attention as a promising solution for industrial wastewater treatment, enabling the simultaneous degradation of organic compounds and biohydrogen production. Developing efficient and cost-effective cathodes to drive the hydrogen evolution reaction is central to the success of MECs as a sustainable technology. While numerous lab-scale experiments have been conducted to investigate different cathode materials, the transition to pilot-scale applications remains limited, leaving the actual performance of these scaled-up cathodes largely unknown. In this study, nickel-foam and stainless-steel wool cathodes were employed as catalysts to critically assess hydrogen production in a 150 L MEC pilot plant treating sugar-based industrial wastewater. Continuous hydrogen production was achieved in the reactor for more than 80 days, with a maximum COD removal efficiency of 40 %. Nickel-foam cathodes significantly enhanced hydrogen production and energy efficiency at non-limiting substrate concentration, yielding the maximum hydrogen production ever reported at pilot-scale (19.07 ± 0.46 L H2 m−2 d−1 and 0.21 ± 0.01 m3 m−3 d−1). This is a 3.0-fold improve in hydrogen production compared to the previous stainless-steel wool cathode. On the other hand, the higher price of Ni-foam compared to stainless-steel should also be considered, which may constrain its use in real applications. By carefully analysing the energy balance of the system, this study demonstrates that MECs have the potential to be net energy producers, in addition to effectively oxidize organic matter in wastewater. While higher applied potentials led to increased energy requirements, they also resulted in enhanced hydrogen production. For our system, a conservative applied potential range from 0.9 to 1.0 V was found to be optimal. Finally, the microbial community established on the anode was found to be a syntrophic consortium of exoelectrogenic and fermentative bacteria, predominantly Geobacter and Bacteroides, which appeared to be well-suited to transform complex organic matter into hydrogen.

Promoting bioremediation of brewery wastewater, production of bioelectricity and microbial community shift by sludge microbial fuel cells using biochar as anode

Seeking low-cost and eco-friendly electrode catalyst of microbial fuel cell (MFC) reactor has received extensive attention in recent decades. In this study, a sludge MFC was coupled with biochar-modified-anode (BC-300, BC-400, and BC-500) for actual brewery wastewater treatment. The physicochemical properties of biochar largely depended on the pyrolysis temperature, further affecting the removal efficiency of wastewater indicators. BC-400 MFC proved to be efficient for TN and NH4+-N removal, while the maximum removal efficiencies of COD and TP were achieved by BC-500 MFC, reaching respectively 97.14 % and 89.67 %. Biochar could promote the degradation of dissolved organic matter (DOM) in wastewater by increasing the electrochemical performances of MFC. The maximum output voltage of BC-400 MFC reached 410.24 mV, and the maximum electricity generation of 108.05 mW/m2 was also obtained, surpassing the pristine MFC (BCC-MFC) by 4.67 times. High-throughput sequencing results illustrated that the enrichment of electrochemically active bacteria (EAB) and functional bacteria (Longilinea, Denitratisoma, and Pseudomonas) in BC-MFCs, contributed to pollutants degradation and electron transfer. Furthermore, biochar affected directly the electrical conductivity of wastewater, simultaneously changing microbial community composition of MFC anode. Considering both enhanced removal efficiency of pollutants and increased power generation, the results of this study would offer technical reference for the application of biochar as MFC catalyst for brewery wastewater treatment.

Eichhornia crassipes Leaves as a Waste-derived Bio-Sorbent to Remove Organics and Nutrients from Rice Mill Wastewater

The increased rate of population growth resulted in the increased number of rice mill industries to fulfill the demand for rice. The rice mill wastewater contains a high load of organics and nutrients. Therefore, the direct discharge of wastewater into the environment may degrade the quality of the environment as well as causes adverse effects on human health. Among various methods to treat waste effluent, bio-sorption is a cheap and environmentally sound approach. Eichhornia crassipes is a noxious weed that spreads rapidly. Most of the tanks in Vavuniya are polluted by E. crassipes and it needs a sustainable solution. This study uses the leaves of E. crassipes to produce waste-derived bio-sorbent to treat rice mill wastewater. The wastewater was collected from one of the rice mills in the Vavuniya town area. The adsorption isotherm and adsorption kinetics experiments were conducted to find out the removal efficiencies of COD, nitrate, and phosphate from wastewater. The effect of the dosage of bio-sorbent (1-6 g/L) and the contact time (30-180 min) with the wastewater was studied to determine the optimum dosage and optimum contact time. The bio-sorbent showed maximum removal efficiencies of COD (54.5%), nitrates (58.1%), and phosphates (29.5%) at the optimum dosage of 4 g/L at 120 min. Based on the t-test, E. crassipes leaves significantly reduce COD, nitrate, and phosphate (p-value&lt;0.05). However, COD and nitrate showed higher removal rates than phosphate. Further, long-term column studies should be conducted to apply the above technique in wastewater treatment plants in treating the rice mill wastewater in the real world. This study emphasizes that E. crassipes leaves have the potential to remove contaminants from wastewater as well as this would also help to minimize the spread of the weed to safeguard the environment. &#x0D; Keywords: Eichhornia crassipes, Bio-sorption, Vavuniya tank, Water quality

Biotreatment of swine wastewater by mixotrophic Galdieria sulphuraria

Biotreatment of swine wastewater via microalgae is an environmentally sustainable and economical efficient strategy capable to transform nitrogen, phosphorous, and organic/inorganic carbons into value added products as lipids, carbohydrates, and proteins, while high ammonium tolerant microalgal species with efficient COD and ammonium removal efficiency is lacking, limiting its practical application. Thermophilic and acidophilic Galdieria sulphuraria (G. sulphuraria) are reported to have high ammonium removal efficiency, while its application in ammonium rich swine wastewater treatment without dilution is rarely reported. Accordingly, mixotrophic cultivation of G. sulphuraria has been tested for biotreatment of swine wastewater. The results indicate that G. sulphuraria can grow well in swine wastewater with maximum growth rate of 0.72 g/(L.d) when 15 g/L of glucose is added. Simultaneously, a maximum COD removal efficiency of 94.8% and ammonium removal rate of 550.5 mg/(L.d) are observed. The addition of glucose leads to decreases of lipid, protein and ash contents, and simultaneous increase of carbohydrates owing to the varied C/N ratios. The final microalgal biomass has relatively lower carbon content of 48.5% with 20 g/L glucose than 49.3% of control, consequently leads to a relatively lower HHV value of 20.64 MJ.kg−1. Above all, mixotrophic cultivation of G. sulphuraria are promising strategy for swine wastewater treatment with high energy recovery, potentially providing an economical strategy for swine wastewater treatment.

Microporous nitrogen-rich biomass derived anode catalyst in clay membrane MFC for kitchen wastewater treatment

ABSTRACT Microbial fuel cells (MFC) have emerged as a sustainable wastewater treatment technique that offers simultaneous energy generation; however, the high cost of electrodes and their reduced catalytic activity have hindered their widespread adoption. To overcome this, an activated carbon synthesised from Areca nut husk was coated on different anodes viz. Carbon cloth and Stainless Steel (SS) mesh. Activated carbon was found to be highly porous with a carbon content of 85.39%, and a surface area of 767.98 m2/g, and was found to be amorphous with a high degree of graphitic structure. The electrical conductivities of the catalyst-coated SS mesh and carbon cloth were comparable, and the performance of the MFC was studied using both electrodes as anodes. A batch MFC with modified SS mesh as anode exhibited the highest power density of 155.35 mW/m3 in synthetic wastewater and 101.68 mW/m3 in kitchen wastewater, with COD removal efficiencies of 95.32% and 95.24%, respectively. In a continuous mode, the MFC delivered a maximum current density and power of 52.38 mA/m2 and 21.60 mW, respectively, with a maximum COD removal efficiency of 80.70% for an HRT of 20 hrs. These findings underscore the viability of using biomass-derived activated carbon as an anode catalyst in both batch and continuous modes of MFC.

Enhancing microbial desalination cell performance for water desalination and wastewater treatment: experimental study and modelling of electrical energy production in open and closed‐circuit modes

AbstractBACKGROUNDMicrobial desalination cell (MDC) is a new technology in the use of electrical energy for water desalination and wastewater treatment.RESULTSOpen circuit (OC) and closed circuit (CC) modes were successfully simulated with initial TDS concentrations of 10 g/L and 10–15 g/L, respectively (an external resistance of only 150 Ω was applied for CC). After 160 h of operation, the maximum OC voltage, desalination efficiency and COD removal efficiency were 809 mV, 32.2% and 79.2%, respectively. The maximum voltage was also obtained when the external resistances were 150 Ω (423.4 and 438 mV) for the initial NaCl concentrations (10 and 15 g/L) in the central chamber, respectively. Moreover, the maximal desalting and COD removal efficiencies after 24 h run‐time were (30% and 28%) and (24% and 25%) for initial NaCl concentrations (10 or 15 g/L) in the central chamber, respectively. Maintaining pH (8.61, 7.01) to (7.85, 7.8) in anode and cathode chambers was studied. This research accurately depicted microbial desalination's efficiency in generating OC voltages and CC electrical energy via Box–Behnken Design Distribution (BBD). Investigated factors’ interactions (initial salt/COD concentrations, time) on CC system's energy efficiency. Resulted in peak productivity at (1.85 mW), OC reaching (1100 mV).CONCLUSIONFinally, the research paper gave exciting results in improving the efficiency of the microbial desalination cell to increase the ability to produce electrical energy and desalinate water. © 2023 Society of Chemical Industry (SCI).

Anaerobic Fluidized Bed Reactor for the Treatment of Tannery Wastewater Using Crushed Tire Scraps as Support Material

Purpose: Due to tannery high pollution potential, is has become necessary to investigate in new treatment technologies that use recycled solid wastes as tires that are abundantly present in the environment. The application of anaerobic biological processes offers several advantages compared to aerobic processes, including lower energy consumption, reduced sludge production, and a smaller footprint, in addition to the potential utilization of methane as a fuel. Methods: A pilot scale anaerobic fluidized bed reactor was implemented, using crushed tire scraps with diameters ranging from 2.00 mm to 2.83 mm as support material. Results and conclusion: The maximum COD removal efficiency achieved in the system was 77.79% in the first stage and 92.9% in the second stage, while methane production reached 2,930.5 mL. The tire scraps demonstrated efficiency as a support material for biofilm development, with microbial biofilm growth observed through optical microscopy, showing morphologies similar to cocci. Research implications: The implications of this study are to verify the possibility of treatment of tannery wastewater along with the possibility of reuse of an environmental pollutant as tire residues. Originality/value: After the literature research, no study has focused in anaerobic fluidized bed reactors using tire scraps as a support media for the treatment of tannery wastewater.

Study on the performance of a new type of combined packing biofilm reactor treating wastewater

ABSTRACT The present work investigates the performance of a biofilm reactor filled with a new type of combined packing used to treat wastewater and explores a new technology approach for the application of coral sand and waste non-woven fabric. The combined packing was made of coral sand and waste non-woven fabric, which was used as a biofilm carrier to treat sewage. The experimental results showed that the removal efficiencies of COD, NH4 +-N and TN in the biofilm reactor containing the combined packing were 92.9%, 72.9% and 63.2%, respectively. The maximum removal efficiencies of COD, NH4 +-N and TN in the biofilm reactor containing single packing were 89.0%, 63.4% and 55.2%, respectively. The properties of the combined packing were characterized by Fourier Transform Infrared (FTIR), specific surface area, SEM and dehydrogenase activity. Infrared analysis showed that there were hydroxyl, carboxyl and carbonyl groups on the surface of coral sand and non-woven fabric which were beneficial for biofilm growth and wastewater treatment. The large pores in the interior of coral sand and non-woven fabric could provide a comfortable environment for microbes to grow and reproduce. The dehydrogenase activity of the biofilm on the surface of coral sand in the third biofilm reactor was 49.91 μgTF·g−1·h−1, which was significantly higher than that of the other two biofilm reactors. The new type of combined packing is suitable for biofilm carriers with low cost, which can be applied to actual sewage treatment projects. This study provides a reference for the practical application of the technique.

Statistical Analysis of COD and BOD Removal from Dairy Waste Water

One of most water polluted industry is Dairy industry. It produces various milk products like milk powder, butter milk, curd, cheese, pasteurized milk etc. More amount of fresh water is used for different purposes i.e., cooling/heating, sanitary, processing, utilities and service section during milk processing and production of different milk products. It is observed from a report that for processing 1L of milk, the Dairy industries produce 2.5 to 10L of waste water. Major pollutants found in dairy waste water are Organic components like dissolved sugars, carbohydrates, proteins and fat are found as the major pollutants in the Dairy waste water. Apart from organic compound some inorganic compounds like Sulfur, Phosphorous and Nitrogen are also found. Hence, the dairy wastewater is having large amount of organic matter that can be measured in term of BOD and COD. As it is having pungent odor and is responsible for fly generation, it should be treated properly before disposal. In this present work, the synthetic dairy waste water was prepared and was treated with activated carbon prepared from coconut shell collected from temple side. The activated carbon prepared from Coconut shell CGAC could be able to remove COD and BOD of the used water up to satisfactory level at different bed height and contact time. This paper shows the statistical analysis of COD and BOD using the activated carbon. In the experiment, the standard deviation of maximum removal efficiency of COD and BOD from the dairy wastewater was found as 0.59 and 0.49, respectively.

The regulating role of applied voltage on methanogenesis in an up-flow single-chamber microbial electrolysis assisted reactor

Applied voltage was introduced into the anaerobic system for improving the efficiency of sewage treatment and bioenergy production. For better energy efficient applications, it was necessary to have a good understanding of the effect of applied voltage, which is different from the conductive materials. In this study, the effects of applied voltage at different positions were investigated, considering the concentration gradients. Results showed that the maximum COD removal efficiency was 96.7% and the methane production rate was 0.434 ± 0.018 m3 CH4/m3/day in the reactor with two pairs of electrodes. The effect of the applied voltage on the organic matter conversion and methane production were dominant in the lower electrode. The increased energy output could content the required electric energy, and additional energy could be generated by CHP. The contribution of electrochemical direct action was lesser, and the increase of applied voltage led to the enrichment of functional microbes in this system, especially the hydrogenotrophic methanogens dominated by Methanocorpusculum.

Performance evaluation of hydrodynamic cavitation in combination with AOPs for degradation of tannery wastewater

Tannery wastewater effluent (TWE) consists of a variety of complex structured compounds having very low biodegradability. Few attempts have been made to treat real-time TWE consisting of complex compounds and find the intermediate compounds formed during the HC+PAA+ FeSO4.7 H2O treatment system. Therefore, a pilot scale study has been conducted on an orifice-embedded hydrodynamic cavitation reactor for treating real-time TWE. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) has been carried out to identify the specific compounds present in TWE before and after treatment. Response surface methodology (RSM) – Box-Behnken design (BBD) obtained maximum COD, TDS and turbidity removal efficiency of 72.36%, 94.54% and 98.89%, respectively, at cavitation time-97.5 min, inlet pressure-7.5 bar, pH-2, orifice diameter-0.5 mm, PAA dosage-17.5 g/L, and PAA /FeSO4.7 H2O-2:1 ratio. The reaction rate constant was increased from 2.455 × 10−3 to 12.75 × 10−3 min−1 when AOPs were combined with HC. The study concluded that the degradation using HC+PAA+ FeSO4.7 H2O successfully increased the biodegradability of the TWE without forming any toxic by-products.

The effect of aeration on treatment efficiency and bioenergy generation of septic-tank effluent in constructed wetland-microbial fuel cell

This study examines the effect of different rates and modes of supplementary aeration on the treatment of synthetic septic tank effluent in a lab-scale unplanted constructed wetland-microbial fuel cell (CW-MFC) along with bioenergy generation. The experiment was conducted in 4 sequential phases; 1) the cell was operated with no aeration (NA), 2&3) the cathode layer was continuously aerated under different aeration rates (CA-I and CA-II), and 4) the cathode layer was intermittently aerated (IA). Results showed that the dissolved oxygen gradient caused by IA formed aerobic and anoxic zones in CW-MFC and promoted total nitrogen removal. The best performance was observed with intermittent aeration where the maximum removal efficiencies of COD (96.8 ± 3.3 %), TN (62.3 ± 2.1 %), TKN (68.3 ± 2.0 %), and NH3 (64.8 ± 2.3 %) were achieved. Furthermore, this treatment efficiency corresponded with enhanced bioenergy generation under the IA regime, achieving maximum power output (7.5 mW/m2), highest average voltage output (0.399 ± 0.02 V), Coulombic efficiency (1.94 %), and normalized energy recovery (1.4 Wh/m3). Continuous aeration, however, induced an adverse effect on energy generation due to excessive oxygen penetration into the anode region. Nitrate accumulation was also observed as a sign of an incomplete denitrification process under the continuous aeration regime. Overall, it can be concluded that the intermittently aerated CW-MFC not only lowers operational costs but improves effectiveness in terms of the nitrogen removal process in the treatment of septic tank effluent.

Self-sustained semi-pilot scale Hybrid Eco-Electrogenic Engineered System for the wastewater treatment and bioenergy generation

Eutrophication in water bodies is a pervasive water quality issue that should be remediated to restore and recover natural resources. The systematic arrangement of aquatic macrophytes in the water bodies through ecological engineering principles will treat wastewater and rejuvenate the ecosystem. In this context, a novel semi-pilot scale Hybrid Eco-Electrogenic Engineered System (HEEES) was operated using aquatic macrophytes and a bioelectrogenic system to treat domestic wastewater and generate bioenergy. Three similar tanks were used with different functionally diverse biota, viz., floating macrophytes (water hyacinth) in tank A, submerged plants (water thymes) in tank B, and emergent plants (water lettuce) in tank C. Four different experimental setups (ES) were performed by placing specific parameters such as electrodes, aerators, and activated carbon viz., ES1 (plants), ES2 (Plants + Activated Carbon), ES3 (Plants + Activated Carbon + Aerators), and ES4 (Plants + Activated Carbon + Aerators + Electrodes). The results infer that tank A with water hyacinth showed maximum COD removal efficiency of 76.90 % (ES1), 77.24 % (ES2), 80.01 % (ES3), and 81.67 % (ES4), respectively. Maximum power and current density of 24.104 mW/m2 and 23.844 mA/m2 were attained, inferring that the ES4 condition showed the maximum pollutant removal efficiency and bioenergy generation. It is attained due to specific parameters in the system that increases the electrogenic activity by electrodes, adsorbing the property of activated carbon and increasing the oxygen concentration by aeration, enhancing effective treatment and bioenergy generation in the single-chambered hybrid system. The semi-pilot scale HEEES is a self-sustained system that mimics the natural cleansing function of aquatic bio-networks.

Catalytic Ozonation Combined with Conventional Treatment Technologies for the Recycling of Automobile Service Station Wastewater

The ample increase in water scarcity and depletion of natural resources due to their overconsumption and the contamination of water sources becomes more challenging day by day. This challenging situation has pushed the scientific community to cope with it by providing alternative solutions. Therefore, it is indeed important to conduct a sustainable study on recycling wastewater for a particular purpose. Taking this into account, an effort was made to develop a novel hybrid treatment system that applied both conventional and advanced oxidation treatment processes. In this sustainable study, an integrated system was designed for the effective treatment followed by the recycling of automobile service station wastewater (ASSWW) which comprised sedimentation (sed), catalytic ozonation, adsorption, and filtration. In the current investigation, two catalysts/adsorbents, the granular activated carbon (GAC) and rice husk (RH) were employed individually and in combination for the first time in the studied hybrid process and their performance was compared and evaluated. The obtained results revealed that the hybrid system combination-I (Sed–O3/GAC) was more efficient than combination-II (Sed–O3/RH); the maximum removal efficiency of COD was 100% and 80%, respectively. In addition, the hybrid system combination-III (Sed–O3/RH + GAC) was more economical and efficient than others by employing 35% of each absorbent in the adsorption column. Moreover, this efficient Sed–O3/RH + GAC system has a maximum removal efficiency 99%, 100%, 99%, 100%, (89%, 99%, 100%) and 100% for turbidity, COD, BOD5, fecal coliform, potentially toxic metals (Cd, Pb, As), oil and grease, respectively, at optimized conditions (O3 = 82.5 mg/L; contact time = 18 min and catalyst dose of GAC and RH = 200 g each). Furthermore, the treated water sample complied with the WWF-recommended Irrigation Water Quality Guidelines (IWQGs) for class D. The increase in biodegradability (BOD5/COD ratio) was observed from 0.41 to 0.83. Therefore, the proposed efficacious hybrid system may be employed for the recycling of ASSWW for irrigation purposes.

Chemical characterization and anaerobic treatment of bitumen fume condensate using a membrane bioreactor

Bitumen fume condensate (BFC) is a hazardous wastewater generated at asphalt reclamation and production sites. BFC contains a wide variety of potentially toxic organic pollutants that negatively affect anaerobic processes. In this study, we chemically characterized BFC produced at an industrial site and evaluated its degradation under anaerobic conditions. Analyses identified about 900 compounds including acetate, polycyclic aromatic hydrocarbons, phenolic compounds, and metal ions. We estimated the half maximal inhibitory concentrations (IC50) of methanogenesis of 120, 224, and 990 mgCOD·L−1 for three types of anaerobic biomass, which indicated the enrichment and adaptation potentials of methanogenic biomass to the wastewater constituents. We operated an AnMBR (7.0 L, 35 °C) for 188 days with a mixture of BFC, phenol, acetate, and nutrients. The reactor showed a maximum average COD removal efficiency of 87.7 ± 7.0 %, that corresponded to an organic conversion rate of 286 ± 71 mgCOD−1·L−1d−1. The microbial characterization of the reactor’s biomass showed the acetoclastic methanogen Methanosaeta as the most abundant microorganism (43 %), whereas the aromatic and phenol degrader Syntrophorhabdus was continuously present with abundances up to 11.5 %. The obtained results offer the possibility for the application of AnMBRs for the treatment of BFC or other petrochemical wastewater.

Assessment of Sago Wastewater Treatment Process in an Aerobic Bio-Reactor with the Support of Chemisorbent

The Performance of an Aerobic Bio-Reactor (ABR) for the behavior of synthetic sago processing wastewater was investigated. The system with 13.3 liters of working volume was accomplished by attached as well as suspended growth process. The experimental analysis was carried out with the influent Chemical Oxygen Demand of 3920 mg/l, 4360 mg/l and 4640 mg/l at Hydraulic Retention Times (HRT) of 11, 14, 17, 21, 28, 42, 84 and 141 hours. During the experiment, pH plays an important role and the Dissolved Oxygen was maintained within the permissible limit continuously. In an ABR, the maximum COD removal efficiency was attained 91.20% with an Organic Loading Rate (OLR) of 1.518 kg COD/m3. To achieve the goal of reusing the wastewater, again the treated effluent was analyzed by the technology of adsorption process using zinc oxide nano powder as a Chemisorbent and the maximum COD removal efficiency of 100% was observed with 0.75 g of dosage content at the pH of 6 at the contact time of 180 minutes.

Treatment of Dairy Waste Water using Adsorbents from Solid Waste

Abstract: Dairy industry is a major food processing industry. The waste water from dairy industries are mainly produced in the receiving station, starting, stopping and washing any of the processing units, using the processes pasteurization, homogenization of fluid milk and the production of dairy products. It is estimated that dairy industries generate 2.5 to 10L of wastewater per L of milk processed. Major pollutants found in dairy waste water are organic components like dissolved sugars, carbohydrates, proteins and fat, Suspended Solid, Total Dissolved Solid, Sulfur, Phosphorous and Nitrogen. So the dairy wastewater is considered as high concentration of organic matter and high BOD. Disposal of the waste water is a major challenge for dairy industries. As it produced pungent odor it should be treated before disposal to keep environment free from various problems. In this work, the synthetic dairy waste water was prepared and was treated with activated carbon prepared from waste dried coconut shell. The activated carbon prepared from Coconut shell CGAC could be able to remove COD and BOD of the used water up to satisfactory level at different bed height and contact time. This paper shows the removal efficiency of COD and BOD using the activated carbon. In the experiment, the maximum removal efficiency of COD and BOD from the dairy wastewater was found in bed height 10cm with contact time 2hours

Application of copper and aluminium electrode in electro coagulation process for municipal wastewater treatment: A case study at Karachi

The reuse of treated domestic wastewater is an imperative source of water for numerous purposes. The treatment of municipal wastewater can be process by utilizing the technique for electrocoagulation. Electrocoagulation (EC) is an eco-friendly technique that combines the functions and advantages of conventional coagulation, flotation, and electrochemistry in water and wastewater treatment. The aim of present study was to assess the potential of electrocoagulation process in removing COD, BOD, TSS, turbidity, sulphate, nitrate, chloride and TDS from municipal wastewater. This experimental study was carried out at a batch system by using copper and aluminium electrodes aiming to treat the municipal wastewater at (0, 7, 14, and 21 volts, 50mamp for 60minutes) from Sample Baloch Colony (SBC), Sample Rind Goth (SRG), Sample Cattle Colony (SCC), Sample Pakistan Machine Tool Factory (SPMTF) and Sample Mehran Highway (SMH). The results revealed that the maximum removal efficiency of COD 96% for SPMTF, BOD 38.5% for SPMTF, TSS 98.14% for SMH, Turbidity 95.7% for SPMTF, Sulphate 95.9% for SRG, Nitrate 95.23% for SMH, Chloride 97.92% for SMH and TDS 96.9% for SRG at 21 volt. The present study suggested that the treated wastewater could be safely reuse for lawns, parks, tree plantation and recreation purpose.

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.