Electrochemical Treatment of organic and oily wastewaters (original) (raw)
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Wastewater containing oil is becoming a growing problem worldwide due to increasing quantities and existing pollution. The pollutants contained in these effluents, when released into the environment, affect surface and groundwater pollution, endanger human life and health, and pollute the atmosphere. Their sustainable treatment should be cost-effective and meet all requirements to prevent the pollutants from being transferred to the environment or to humans. This study gives a brief overview of some conventional and modern technologies that have been proven in practice for the treatment of oily wastewater. Due to the high concentrations of chemical oxygen demand (COD) and total hydrocarbons (mineral oils) in oily wastewater its treatment is complex, and to achieve optimum treatment conditions and efficiency a combination of different technologies is required. This paper focuses on hybrid electrochemical process combining the electro-Fenton process (EF) using stainless steel (SS), an...
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The successful application of electrochemical technology, employing a dimensionally stable anode (DSA((R))), for the remediation of wastewater from the oil extraction industry has been demonstrated. Samples from the oil-water separation box of an effluent treatment plant were submitted to voltammetry, chronoamperometry and electrolysis studies using a DSA anode of nominal composition Ti/Ru(0.34)Ti(0.66)O(2). Electrolysis of the oily wastewater lead to a time-dependent reduction in chemical oxygen demand (COD) in the sample that could be attributed to: (i) the direct oxidation of oil components at the electrode, by the metal oxide itself or by OH() radicals available at the electrode surface, (ii) the indirect oxidation of oil components by intermediate oxidising agents formed in parallel reactions (ex. ClO(-)), and (iii) the aggregation of suspended oil droplets by electroflotation. The largest reduction (57%) in COD was obtained following electrolysis of an oily sample for 70 h at ...
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Textile wastewater containing toxic dyes needs efficient treatment before being released into the environment. Certain dyes are known or presumed to have carcinogenic potential for humans. In this work, hybrid electrochemical processes including electrocoagulation (EC) alone and combined with electro Fenton (EF), anodic oxidation (AO) and peroxi-coagulation (PC) were tested to treat real textile wastewater using a batch reactor. A sequential EC and EF (EC-EF) process was found to be more effective. The experimental results indicated that the effectiveness of the treatment decreases in the following order: EC-EF > EC-AO > EC-PC > EC. EC-EF results showed a decrease in chemical oxygen demand (COD, 97%), total organic carbon (98%), total suspended solids (98%), and the concentration of metal species; showing that the treatment of such wastewater type can be achieved by combined EC-EF process in a one-pot bench-scale reactor. The electrical energy consumption, the iron dissolut...