Treatment of Tannery Wastewater by Electrochemical Oxidation Process

2013 ◽  
Vol 361-363 ◽  
pp. 697-700
Author(s):  
Lin Lin Huang ◽  
Jun Feng Liu ◽  
Nan Zhang ◽  
Bin Sun ◽  
Yu Jie Feng
Keyword(s):  
Electrochemical Oxidation ◽  
Oxidation Process ◽  
Treatment Time ◽  
Chloride Concentration ◽  
Oxygen Demand ◽  
Electrochemical Reactor ◽  
Tannery Wastewater ◽  
Processing Unit ◽  
Applied Current ◽  
Toc Removal

Electrochemical oxidation process was adopted to treat the tannery wastewater effluent from a biological processing unit. The experiments were carried out in an electrochemical reactor using RuO2\SnO2coated on titanium as anode and stainless steel as cathode. The changes of Chemical Oxygen Demand (COD) reduction, Total Organic Carbon (TOC) removal and other relative parameters have been determined as a function of treatment time, applied current density and chloride concentration. Results indicate that electrochemical oxidation can treat tannery wastewater effectively. The results obtained at 7.5mA/cm2demonstrated that 48.7% of TOC and 58.9% of COD were degraded in 150min of processing. In addition, the addition of chloride showed no significant to the removal of COD and TOC.

Experimental Study on Papermaking Wastewater by Advanced Electrochemical Oxidation Method

2013 ◽  
Vol 726-731 ◽  
pp. 1699-1703
Author(s):  
Lin Lin Huang ◽  
Jun Feng Liu ◽  
Bin Sun ◽  
Nan Zhang ◽  
Yong Qing Tang ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Treatment Time ◽  
Oxygen Demand ◽  
Treatment Method ◽  
Electrochemical Reactor ◽  
Advanced Treatment ◽  
Processing Unit ◽  
Optimum Reaction ◽  
Papermaking Wastewater

Papermaking wastewater effluent from a biological processing unit was treated by an advanced treatment method-electrochemical oxidation process. The experiments were carried out in an electrochemical reactor using RuO2\SnO2 coated on titanium as anode and stainless steel as cathode. The changes of Chemical Oxygen Demand (COD) reduction and other relative parameters have been determined as a function of treatment time and applied current density. The optimum reaction time and current density was 60min and 5mA/cm2, respectively. Results indicate that as an advanced treatment method, electrochemical oxidation can treat papermaking wastewater to achieve the standard of effluents effectively.

scholarly journals Synthesis, characterization and application of a bio-derived ZnO nano-powder from spinacia oleracea leaf extract for the removal of BOD and COD from tannery wastewater

2021 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
Danauta Feka ◽  
Amaya Habila ◽  
Kyauta Francis ◽  
James Habila ◽  
Moses Bammai
Keyword(s):  
Leaf Extract ◽  
Treatment Time ◽  
Spinacia Oleracea ◽  
Oxygen Demand ◽  
Mesoporous Structure ◽  
Tannery Wastewater ◽  
Zno Nps ◽  
Adsorbent Dosage ◽  
Zno Nanopowder ◽  
Bet Analysis

Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) as biological and chemical pollutants of wastewater are renowned environmental problems. A study of the performance of BOD and COD degradation via adsorption was undertaken using Bio-derived ZnO nanopowder (ZnO-NP), synthesized using leaf extract of Spinacia oleracea, and Zn (NO3)2 at 500 0C, following a simple and green approach. XRD, SEM, FTIR, EDS and BET analysis were used to characterize the nano-adsorbent. EDS spectrum recorded elemental weight compositions of 67.33% and 32.67% for Zn and O, while the FTIR absorption peaks revealed the presence of Zn-O–H and Zn-O. Surface area analysis revealed the mesoporous structure of the ZnO-NPs. The reduction efficiency of the ZnO-NPs was evaluated in the presence of raw tannery wastewater by application of treatment time and adsorbent dosage as parametric factors; results obtained were compared to environmental regulatory limits (WHO and NESREA). Contact times reported removal efficiencies of 81.5-90.8 % and 12.8-50 % for BOD and COD, while adsorbent dosage-influenced BOD and COD removal at an optimum contact time of 30 minutes was found to be 79.2 - 97.5 % and 27.8 to 55.6 % respectively. This study reveals that ZnO nanopowder is better applied as BOD reductants over COD for spent tan liquor.

Destruction of refractory humic acid by electromechanical oxidation process

2000 ◽  
Vol 42 (3-4) ◽  
pp. 225-232 ◽  
Author(s):  
L.-C. Chaing ◽  
J.-E. Chang ◽  
T.-Cn. Wen
Keyword(s):  
Humic Acid ◽  
Electrochemical Oxidation ◽  
Humic Substance ◽  
Current Density ◽  
High Efficiency ◽  
Oxidation Process ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Gel Permeation Chromatography ◽  
Indirect Oxidation

Electrochemical oxidation of humic acid has been conducted to evaluate the efficacy of the process for the destruction of high-molecular-weight (HMW) compounds. Experimental results show that the destruction of humic acid obtained by the electrolysis supported by chloride ion is much better than that obtained by sulfate ion. Accordingly, HMW compound such as humic substance is suggested to be resistant to directly anodic oxidation, but to be readily destroyed by an indirect oxidation of chlorine/hypochlorite during an electrochemical treatment process. The effects of operating parameters, including anode material, current density, electrolyte concentration, have been investigated in this study. A tertiary-oxide of Sn, Pd, Ru coated titanium (SPR) anode with high electrocatalytic activity was found to have high efficiency for humic acid destruction, and the destruction efficacy of humic substance increased with increasing current density and chloride concentration. In this study, gel permeation chromatography (GPC) and adsorptive organic halide (AOX) had been performed to examine the variation of organic characteristics during the electrochemical oxidation of humic acid. The results from GPC and AOX show that HMW organic compounds could be effectively destroyed by electrochemical oxidation process, and the process also produced less undesirable chlorinated byproducts than the chlorination process. From the above results, the electrochemical oxidation conducted by indirect oxidation effect of chlorine/hypochlorite could be concluded to be a feasible method for the destruction of HMW compounds.

scholarly journals A 2.5D Electrode System Constructed of Magnetic Sb–SnO2 Particles and a PbO2 Electrode and Its Electrocatalysis Application on Acid Red G Degradation

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 875 ◽  
Author(s):  
Yuan ◽  
Salman ◽  
Guo ◽  
Xu ◽  
Xu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Electrochemical Oxidation ◽  
High Performance ◽  
Oxygen Demand ◽  
Electrode System ◽  
Toc Removal ◽  
Pbo2 Electrode ◽  
Higher Temperature ◽  
Acid Red G

A novel electrode consisting of a Ti/PbO2 shell and Fe3O4/Sb–SnO2 particles was developed for electrochemical oxidation treatment of wastewater. Scanning electron microscope (SEM), X-ray diffraction (XRD), the current limiting method, toxicity experiments, and high-performance liquid chromatography were adopted to characterize its morphology, crystal structure, electrochemical properties, the toxicity of the wastewater, and hydroxyl radicals. Acid Red G (ARG), a typical azo dye, was additionally used to test the oxidation ability of the electrode. Results indicated that the 2.5D electrode could significantly improve the mass transfer coefficient and •OH content of the 2D electrode, thereby enhancing the decolorization, degradation, and mineralization effect of ARG, and reducing the toxicity of the wastewater. The experiments revealed that, at higher current density, lower dye concentration and higher temperature, the electrochemical oxidation of ARG favored. Under the condition of 50 mA/cm2, 25 °C, and 100 ppm, the ARG, Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiency reached 100%, 65.89%, and 52.52%, respectively, and the energy consumption and the current efficiency were 1.06 kWh/g COD, 8.29%, and energy consumption for TOC and mineralization current efficiency were 3.81 kWh/g COD, 9.01%. Besides, the Fe3O4/Sb–SnO2 particles after electrolysis for 50 h still had remarkable stability. These results indicated that the ARG solution could be adequately removed on the 2.5D electrode, providing an effective method for wastewater treatment.

Coupled photochemical-biological system to treat biorecalcitrant wastewater

2007 ◽  
Vol 55 (12) ◽  
pp. 95-100 ◽  
Author(s):  
J. Bacardit ◽  
V. García-Molina ◽  
B. Bayarri ◽  
J. Giménez ◽  
E. Chamarro ◽  
...  
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Oxygen Demand ◽  
Coupled System ◽  
Synthetic Wastewater ◽  
Second Step ◽  
Photochemical Process ◽  
Whole Process ◽  
Toc Removal ◽  
Start Up

The aim of the present work is to study a coupled system to treat biorecalcitrant wastewaters. The combination consists of an advanced oxidation process (AOP) named photo-Fenton (Ph-F), which is a photochemical treatment and a sequencing batch biofilter reactor (SBBR). The synthetic wastewater used to optimise this process is a solution of 200 ppm of 4-chlorophenol (4-CP). The first part of the work is the study of the biodegradability enhancement achieved by the photochemical process, measured as the ratio between the biochemical oxygen demand (BOD5) and the chemical oxygen demand (COD). The second step is the start-up and optimisation of the biological process. The results showed that it is necessary to severely treat the toxic solution (with 500 ppm of [H2O2]0) in order to achieve more than 90% of TOC removal in the whole process. The photochemical and biological treatments lasted 50 minutes and 24 hours, respectively.

scholarly journals Treatment of petroleum refinery wastewater by electrochemical oxidation using graphite anodes

2019 ◽  
Vol 12 (3) ◽  
pp. 144-150
Author(s):  
Sajjad Sarhan Jawad ◽  
Ali H. Abbar
Keyword(s):  
Electrochemical Oxidation ◽  
Removal Efficiency ◽  
Current Density ◽  
Treatment Time ◽  
Petroleum Refinery ◽  
Electrochemical Reactor ◽  
Phenol Removal ◽  
Nacl Concentration ◽  
Graphite Anodes ◽  
Petroleum Refinery Effluent

An electrochemical oxidation method was performed in a batch electrochemical reactor using graphite anodes for treating an effluent obtained from Al-Diwaniyah petroleum refinery plant. The effective f process parameters like current density (4-20m Acm-2), pH (3-9), and NaCl concentration (0-3 g/l) on the COD and phenol removal efficiency have been investigated. The results reveal that the best conditions were current density 12 mA cm-2, pH 7, NaCl concentration 2 gl-1 at a treatment time of 60 minutes. Under  best conditions of COD removal efficiency 100% and phenol removal efficiency 99.12% were obtained at current efficiency 33.5% and power consumption 59.9 kWh/kg COD. The anodic oxidation was proven to be efficient for treatment Al-Diwaniyah petroleum refinery effluent to get effluent with features in agreement with the standard limits for discharge to the environment at a lower cost.

scholarly journals Extended Fenton's process: toward improving biodegradability of drilling wastewater

2019 ◽  
Vol 79 (9) ◽  
pp. 1790-1797
Author(s):  
Ran Ding ◽  
Yanming Wang ◽  
Xing Chen ◽  
Yingxin Gao ◽  
Min Yang
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Oxidation Process ◽  
Oxygen Demand ◽  
Fenton Oxidation ◽  
Oxidation Time ◽  
Drilling Mud ◽  
Molecular Weights ◽  
Toc Removal ◽  
Fenton Oxidation Process

Abstract In this study, an extended Fenton process was used to improve biodegradability of the waste drilling mud containing bio-refractory polymers. Variation of biodegradability and organics with different molecular weights with the oxidation time were investigated during the Fenton oxidation process. Although the residual total organic carbon (TOC) arrived at a stable level soon after oxidation reaction, organics with the lower molecular weight increased and its biodegradability was improved significantly in the extended oxidation process, which originated from decomposition of residual H2O2 catalyzed by transformation of the Fe3+/Fe2+ and organoradicals. Under the conditions that follow: pH 3.0, H2O2 500 mg L−1, Fe2+ 250 mg L−1, oxidation time 120 min, further TOC removal of 35.9% and biochemical oxygen demand and total organic carbon (BOD/TOC) ratio of 0.83 was achieved. At the biological test, a substantial increase in TOC degradation by biological treatment with extension of Fenton oxidation time was observed. Finally, more than 90% biological removal of the TOC was achieved for the 120 min oxidation treatment. The experimental results highlight that an extended process can be adopted to improve the biodegradability of wastewater by utilization of the slow reaction of hydrogen peroxide with Fe3+ and organoradicals.

scholarly journals Application of Taguchi’s experimental design method for optimization of Acid Red 18 removal by electrochemical oxidation process

2018 ◽  
Vol 5 (4) ◽  
pp. 241-248 ◽  
Author(s):  
Zabihollah Yousefi ◽  
Ali Zafarzadeh ◽  
Abdolaziz Ghezel
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Oxidation Process ◽  
Design Method ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Fractional Factorial ◽  
Synthetic Wastewater ◽  
Electro Oxidation ◽  
Electro Coagulation

Background: Electro-oxidation is developed as an electrochemical method to overcome the problems of the conventional decolorization technologies and is an appropriate alternative for the treatment of colored wastewater from various industries. The purpose of this study was to evaluate the efficiency of the electrochemical oxidation process in removal of chemical oxygen demand (COD) and Acid Red 18 (AR18) dye from aqueous solutions. Methods: In this research, a laboratory scale of electro-coagulation reactor for the treatment of synthetic wastewater was made and studied. The effects of different variables including pH, current density, dye concentration, and electrolysis time were investigated. The experiment steps were designed by DesignExpert 10 software using the selected variables. Finally, the dye and COD analysis was performed by spectrophotometer. The optimization was performed using Taguchi fractional factorial design during the removal of dye and COD. Results: Maximum removal of dye (89%) and COD (72.2%) were obtained at pH=3, current density=20 mA/cm2 , initial dye concentration=100 mg/L, and reaction time=45 min. ANOVA test showed a significant relationship between statistical model and test data. Also, the results indicate that the distribution of the residues of the model was normal. Conclusion: By designing experiments through Taguchi method, the removal process will be optimized and by decreasing the number of experiments, the optimal conditions for pollutant removal will be prepared. The results suggest that the Electro-oxidation system is a very suitable technique for the enhancement of wastewater treatment.

Electrochemical oxidation process in application to raw and biologically pre-treated tannery wastewater

2019 ◽  
Vol 162 ◽  
pp. 166-175 ◽  
Author(s):  
Jeremi Hubert Naumczyk ◽  
Małgorzata Anna Kucharska ◽  
Joanna Agnieszka Ładyńska ◽  
Dominik Wojewódka
Keyword(s):  
Electrochemical Oxidation ◽  
Oxidation Process ◽  
Tannery Wastewater

scholarly journals Combined homogeneous and heterogeneous advanced oxidation process for the treatment of tannery wastewaters

2015 ◽  
Vol 6 (1) ◽  
pp. 59-71 ◽  
Author(s):  
G. Selvabharathi ◽  
S. Adishkumar ◽  
S. Jenefa ◽  
G. Ginni ◽  
J. Rajesh Banu ◽  
...  
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Treatment Time ◽  
Initial Level ◽  
Degradation Kinetics ◽  
Oxygen Demand ◽  
Advanced Oxidation ◽  
Experimental Conditions ◽  
Optimization Study ◽  
Effective Removal

This study investigated the practical application of combined advanced oxidation processes (AOPs), such as homogeneous TiO2 photocatalysis and heterogeneous photo-Fenton, for the treatment of tannery wastewaters. An optimization study was conducted on the photocatalytic degradation of tannery wastewaters, in order to understand the effects of different operating parameters on the degradation kinetics. The chemical oxygen demand of tannery wastewater decreased from an initial level of 3,400 mg/L in raw wastewater to 140 mg/L (96% removal) in wastewater treated by the combined advanced oxidation process at optimum pH 7, TiO2 dosage of 0.2 g/L, Fe2+ dosage of 0.5 g/L, H2O2 dosage of 1.8 g/L and a treatment time of 4 hours. The biodegradability of wastewater increased from an initial level of 0.4 to 0.7 after treatment under optimum experimental conditions at a treatment time of 60 min. An annual treatment cost of US$21.34/m3 of treated water was obtained. The combined advanced oxidation process proved to be an efficient and appropriate technique for the effective removal of complex organic compounds in industrial wastewater.

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