Studies on treatment of automotive industry wastewater using ozonation, electro-Fenton and chitosan based coagulation process

A wide range of toxic derivatives in automotive industry wastewater (AIW) is a serious environmental issue due to its prospective human toxicity. Hence, automotive industry must use the technologies, which reduces the toxic matters found in AIW. Three types of process were used include ozonation (ON), Electro-Fenton process (EFP) and chitosan based coagulation (CBC) for the removal of turbidity from AIW. Central Composite Design (CCD) based response surface method (RSM) was studied to analyze the turbidity removal from AIW. The analysis of variance (ANOVA) indicated that quadratic model was significant to predict the removal of turbidity with R2 value of 0.95. According to the model, >55% of removal of turbidity was obtained in the optimal conditions of each process. The order of effieicny was found to be: OZ ​> ​EFP ​> ​CBC and operating cost of 7.4$/m3, 6.5$/m3, 2.1$/m3, respectively. UV/Vis spectrophometer confirms the efficiency of each process for the turbidity removal. The turbidity removal from the laboratory experiment agrees well with the predicted response value of model. 95% of organic matters was found in sediment of CBC process, which used as outstanding organic fertilizer.