scholarly journals Continuous flow electrocoagulation system for the treatment of coir industry wastewater

2021 ◽  
Author(s):  
Ayyappan U ◽  
Indu M.S ◽  
Adithya G Murickan ◽  
Balagopal J ◽  
Arun S Kumar ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Continuous Flow ◽  
Electrolyte Concentration ◽  
Oxygen Demand ◽  
Synthetic Dyes ◽  
Operational Parameters ◽  
Colour Removal ◽  
Chemical Reagents ◽  
Secondary Pollutants ◽  
Industry Wastewater

Coir industry, a prominent industry in Kerala, uses huge amount of water and chemical reagents for its functioning. The effluent from these industries has high BOD, COD, toxic chemicals, oils and grease etc. Of the various pollutants, synthetic dyes are the most concerning. Electrocoagulation has advantages over other systems, as it doesn’t produce any secondary pollutants. In this study, a continuous flow electrocoagulation reactor is designed and operational parameters like flow rate, voltage, pH, electrolyte concentration, dye concentration and electrode orientation are optimized. The influence of these parameters are assessed by measuring colour removal efficiency (CRE) and chemical oxygen demand (COD). The optimum flow, voltage, electrolyte concentration, pH and electrode orientation were 1000 mL/hr., 8V, 1000 mg/L, 7 and parallel respectively. The optimized parameters were used for performance evaluation of the system in treating coir industry wastewater. Under these optimized conditions, colour removal efficiency, turbidity, pH, COD removal efficiency and BOD removal efficiency for the treated coir industry wastewater was found as 92.17%, 25 NTU, 8.7, 95.49%, and 92.20% respectively.

scholarly journals Treatment of vinegar industry wastewater by electrocoagulation with monopolar aluminum and iron electrodes and toxicity evaluation

2018 ◽  
Vol 78 (12) ◽  
pp. 2542-2552 ◽  
Author(s):  
Seval Yılmaz ◽  
Emine Esra Gerek ◽  
Yusuf Yavuz ◽  
Ali Savaş Koparal
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Oxygen Demand ◽  
Electrical Current ◽  
Cod Removal ◽  
Toxicity Tests ◽  
Polyaluminum Chloride ◽  
Chemical Complexity ◽  
Iron Electrodes ◽  
Industry Wastewater

Abstract We present electrocoagulation (EC) treatment results of vinegar industry wastewater (VIW) using parallel plate aluminum and iron electrodes, and analyze the toxicity of the treatment processes. Due to the chemical complexity of vinegar production wastewater, several parameters are expected to alter the treatment efficiency. Particularly, current density, initial pH, Na2SO4 as support electrolyte, polyaluminum chloride (PAC) and kerafloc are investigated for their effects on chemical oxygen demand (COD) removal. Following several treatment experiments with real wastewater samples, aluminum-plate electrodes were able to reach to a removal efficiency of 90.91% at pH 4, 10 mg/L PAC and an electrical current density of 20.00 mA/cm2, whereas iron-plate electrodes reached to a removal efficiency of 93.60% at pH 9, 22.50 mA/cm2 current density. Although EC processes reduce COD, the usefulness of the system may not be assessed without considering the resultant toxicity. For this purpose, microtox toxicity tests were carried out for the highest COD removal case. It was observed that the process reduces toxicity, as well as the COD. Consequently, it is concluded that EC with aluminum and iron electrodes is COD removal-wise and toxicity reduction-wise a plausible method for treatment of VIW, which has high organic pollutants.

scholarly journals Industrial Wastewater Treatment in North Gas Company By Using Coagulation – Flocculation Process

2020 ◽  
Vol 10 (4) ◽  
pp. 252-269
Author(s):  
Sanarya K. Kamal ◽  
Awad E. Mohammed ◽  
Waleed M. Alabdraba ◽  
Hussein H. Hamed ◽  
Kamaran A. Waly
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Industrial Wastewater ◽  
Oxygen Demand ◽  
Oil Refinery ◽  
Toxic Substances ◽  
Operational Parameters ◽  
Industrial Oil ◽  
Jar Test ◽  
Coagulation Process

Recently, water pollution considered a major problem that faced the human. Large quantities of water consume in various industrial oil refinery processes, where the wastewater discharged from these processes contains high organic, phosphate, ammonia, nitrite compounds, and toxic substances. Regarding that, making this resource a fresh is a major concern.  Furthermore, a great attention has been given for the removal of these contaminants discharged by Fenton process combined with coagulation process. Combined Fenton/Coagulation process was used and applied in this study as a novel wastewater treatment to remove Chemical Oxygen Demand (COD), Phosphate (PO4), Ammonia (NH3), Nitrite (NO3) compounds, and turbidity (NTU) from industrial wastewater in North Gas Company (NGC), Iraq. The industrial wastewater used in this study was characterized with 114 mg/L COD ,10.28 mg/L PO4, 4.123 mg/L NH3, 95.6 mg/L NO3, 98 NTU Turbidity. The main goal from this work was to evaluate the performance removal efficiency of combined Fenton/Coagulation process and examine the effect of various operational parameters such as Fenton’s dosages (H2O2, Fe2+), the concentration of coagulant (Alum) on the removal efficiency. The results obtained in this work revealed that maximum removal efficiency of COD, PO4, NH3, NO3, turbidity was 89.43%, 72.94 %, 91.065%, 90.96%, 89.85%, respectively was achieved using Fenton combined with coagulation process at 60 mg/L of Alum and 2.5 Fenton’s mole ratio. Overall it can be established that Combined Fenton/Coagulation process plays an important role in obtaining good results and had better removal efficiency. All the experiments were carried out using jar test apparatus at constant temperature (room temperature).

scholarly journals Treatment of leachate by combining PAC and UV/O3 processes

2012 ◽  
Vol 3 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Huu Tap Van ◽  
Van Tuyen Trinh ◽  
Xuan Hien Dang
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Ph Value ◽  
Oxygen Demand ◽  
Experimental Investigations ◽  
Colour Removal ◽  
Treatment Stage ◽  
Pre Treatment ◽  
Optimal Reaction

The landfill leachate is commonly treated for non-biodegradable organic matters, ammonia and colour. Experimental investigations using polyaluminium chlorite (PAC) and UV/O3 have been conducted for the determination of optimal pH value, reaction time and PAC concentration for the removal of chemical oxygen demand (COD) and colour. In pre-treatment coagulation stages, the highest COD and colour removal efficiencies were observed at the concentration of PAC ≥ 3,000 mglG1 and pH values between 7 and 8. However, these experiments also indicated significant removal efficiency for PAC starting with concentrations of 1,500 mglG1. The efficiency of COD and colour removal were approximately 30% and 70%, respectively. Similar efficiencies have been observed also during the second treatment stage where UV/O3 processes were used to treat coagulated leachate. After UV/O3 application, the pH of leachate reached the optimum value of 7.5 whereas the highest COD and colour removal efficiency was 55% and 72%, respectively, and the optimal reaction time was achieved after 80 min. Nước rỉ rác sinh ra từ bãi chôn lấp chất thải rắn cần được xử lý các thành phần chất hữu cơ khó phân hủy sinh học, xử lí amoni và độ màu. Một số kết quả thử nghiệm về xử lý COD và màu của nước rỉ rác bằng việc sử dụng phương pháp keo tụ vớiPAC và quá trình UV/O3 đã được thực hiện cùng với việc xác định các giá trị pH tối ưu, thời gian phản ứng và nồng độ PAC tối ưu. Hiệu suất xử lý cao nhất đạt được khi nồng độ của PAC ≥ 3.000 mg/l, pH trong khoảng từ 7 đển 8 trong giai đoạn tiền xửlý. Tuy nhiên, hiệu quả loại bỏ COD và màu bắt đầu tăng rõ khi nồng độ PAC từ 1.500 mg/l trở lên. Hiệu quả loại bỏ COD và màu tương ứng là khoảng 30% và 70%. Các giá trị pH này phù hợp cho quá trình phản ứng UV/O3 được sử dụng sau giai đoạn keo tụ. Sau quá trình xử lý bằng hệ UV/O3, pH của nước rỉ rác tối ưu được xác định là 7,5 (hiệu suất xử lý COD và màu cao nhất tương ứng là 55% và 72%), thời gian phản ứng tối ưu là 80 phút.

Electrochemical Degradation of Phenol Using the Oxygen Diffusion Cathode in an Undivided Cell

2011 ◽  
Vol 183-185 ◽  
pp. 575-579
Author(s):  
Hui Wang ◽  
Zhao Yong Bian ◽  
Guang Lu ◽  
Xiang Jia Wei ◽  
Xiu Juan Yu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Supporting Electrolyte ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Degradation Pathway ◽  
Phenol Removal ◽  
Electrochemical Degradation ◽  
Undivided Cell

Electrochemical degradation of phenol was studied in an undivided cell with a Ti/IrO2/RuO2 anode and a carbon/polytetrafluoroethylene (C/PTFE) O2-fed cathode which produced hydrogen peroxide (H2O2) by the electro-reduction of dissolved oxygen. The effect of current density, supporting electrolyte concentration and initial pH on the removal efficiency of phenol were investigated systematically. Results indicated that the optimal removal efficiency of phenol was achieved under the conditions of current density of 39 mA/cm2 and supporting electrolyte concentration of 0.02 mol/L. The phenol removal efficiency in the neutral condition was higher than that of acidic and basic conditions. The chemical oxygen demand (COD) and total organic carbon (TOC) removal achieved 71.6% and 63.6% for 100 min’s electrolysis, respectively. Benzoquinone, maleic acid, oxalic acid, acetic acid and formic acid were identified as intermediates by HPLC. A general phenol degradation pathway involving all these intermediates was proposed.

scholarly journals Electrochemical treatment of spent tan bath solution for reuse

2016 ◽  
Vol 8 (1) ◽  
pp. 123-134
Author(s):  
Amel Benhadji ◽  
Mourad Taleb Ahmed ◽  
Hayet Djelal ◽  
Rachida Maachi
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Optimum Operating ◽  
Operational Parameters ◽  
High Concentration ◽  
Leather Processing ◽  
Chromium Salt

Abstract A spent tanning bath contains high concentration of salts, chromium and protein. The treatment system for removal of chlorides or chromium from this effluent is expensive. In this context this waste has to be reused. Our study focuses on the application of advanced oxidation processes for protein removal present in a tanning bath. To improve the quality of the chromium tanning bath, two electrochemical processes (electrooxidation and peroxi-electrocoagulation process, PEP) are investigated in a batch reactor. The effects of operational parameters such as reactor configuration, current density and electrolysis time on chemical oxygen demand (COD) and protein removal efficiency are examined. Results indicated that under the optimum operating range for process, the COD and protein removal efficiency reached 53 and 100%, respectively. The optimum values are determined for the hybrid process (PEP) under 0.13 A·cm−2 over 2 h. The treated tanning bath is used as a tanning solution in leather processing. The influence of chromium salt dose, pH solution, stirring time and contact time on the leather characteristic is evaluated. The hides tanned after the addition of 0.25% of commercial chromium salt, at pH solution, leaving them stirring for 4 h with a contact time of 2 days, and showed good hydrothermal stability and physical characteristics of leather.

scholarly journals Photoelectrocatalytic Oxidation of Textile Industry Wastewater by RuO2/IrO2/TaO2 Coated Titanium Electrodes

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
R. Rathinam ◽  
M. Govindaraj
Keyword(s):  
Current Density ◽  
Textile Industry ◽  
Electrolyte Concentration ◽  
Treatment Time ◽  
Photoelectrocatalytic Oxidation ◽  
Decolorization Efficiency ◽  
Secondary Pollutants ◽  
Visible Spectra ◽  
True Color ◽  
Industry Wastewater

Photoelectrocatalytic Oxidation (PECO) system prominently increases the migration of photoexcited charges, hinders the fast recombination of electron-hole, and increases the period of photogenerated holes. In this article, we constructed a novel PECO system to degrade textile industry wastewater by RuO2/IrO2/TaO2 coated titanium electrodes. The result shows that PECO treatment can effectively reduce the color and true color of the secondary pollutants present in the wastewater. It is confirmed that a synergistic effect exists between photocatalysis (PC) and electrocatalysis (EC). Moreover, we discussed the influence of pH, current density, electrolyte concentration, and stirring speed. The maximum decolorization efficiency of textile industry wastewater with a pH of 8.2 was found to be 96% under the optimum condition stirrer speed of 200 rpm, an electrolyte concentration of 0.05M, a current density of 15 mA.cm-2, and at a treatment time of 30 mins. The UV-Visible spectra confirm the degradation of textile industry wastewater.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

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