The Journal of

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  Background: Olive oil extraction in the world is considered an important economic activity . Environmental impacts of olive oil wastewater is related to the chemical contents and organic materials load that are resistant to biodegradation. Olive wastewater due to phenolic compounds, inhibitors, toxicity to microorganisms in municipal wastewater treatment units, unpleasant odor, high COD, high BOD, high suspended solids, high resistant compounds to biodegradation, the threat potential to surface and underground water resources is to be considered and paid attention to. So far, several studies in olive oil mill wastewater treatment are carried out. This study aimed to determine efficiency of coagulation process in olive oil wastewater treatment to reduce pollution load and improve the biological degradability.

  Methods: This study was conducted in laboratory scale and Batch reactor on the real wastewater. Coagulation process using alum and polyaluminum chloride (PAC) coagulants was done and the removal value of COD, TSS and total phenolic compounds was investigated.

  Results: The results demonstrated that the highest removal efficiency of pollutants in the optimum pH and dose of PAC achieved turned out to be 7 and 1 000 mg/L respectively. In these conditions , the removal values of COD, TSS and total phenolic compounds by PAC achieved were 88 .3, 90.2 and 9 9 . 2 %, respectively. Also analysis of the ratio of BOD/COD showed that after coagulation process, the value could increase from 0.14 up to 0. 5 8.

  Conclusion: This process can be regarded an effective and economical method in the reduction of pollution of this type of wastewater.

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Introduction: Color is one of the indices of water pollution. Discharge of colored effluent can damage to receiving water resources. One of the proposed methods for treating dyeing wastewater is electrocoagulation process. In this study, decolorization of the real textile effluent by electrocoagulation process using monopolar iron electrodes was studied. Methods: This study was run experimentally in the electrochemical batch reactor with a useful volume of 0.5 L. Reactor was equipped with 4 iron plate electrodes that were connected to direct current (DC) power in monopolar mode. The 400mL of wastewater into the reactor in each stage of test and effects of operation parameters such as current density (5.02-26.04 mA), reaction time (20-60 min) and the pH of wastewater (pH=4-9) were studied in color and COD removal efficiency. Results:The results showed that the color and COD removal efficiency increases with increasing of the current density, reaction time and pH. Optimum operation conditions were observed in current density (15.62 mA/cm2), retention time (60 minutes) and pH=9. In this condition, color & COD removals and the electrical energy consumption were 92%, 89% and 26.25kWhm-3 respectively. Conclusion:This study showed that electrocoagulation process with iron electrodes in decolorization of textile wastewater is an effective and efficient method.