The characteristics of wastewater produced by automotive services, including its biodegradability, have not been studied extensively. However, without a firm base, this wastewater is usually treated by conventional biological treatment systems like that used to treat the wastewater generated from Hamdan Industrial Zone (HIZ) in Basrah governorate, south of Iraq. Thus, to justify a conventional treatment system application for reducing the environmental impact of automotive services wastewater, it is essential to characterize such wastewater. The study objective is to investigate the characteristics of the raw wastewater generated in the HIZ and identify its biodegradability measured in terms of biodegradability index which is the ratio of BOD5 to COD. The study involved the analysis of different physiochemical parameters present in the wastewater. The study results revealed that the wastewater generated from the automotive services in HIZ can be characterized as oily, saline, organically polluted, slightly alkaline, and of strong strength. The automotive services wastewater was found to be not readily biodegradable since its biodegradability index values during the study period were below 0.5. The results showed that the major part of the non-biodegradable organics is particulate. Based on the detected wastewater characteristics, it was concluded that conventional treatment of automotive services wastewater needs to be upgraded by adding advanced oxidation and/or chemical precipitation processes for removing the non-biodegradable organics.
Gatea et al. (Mon,) studied this question.