Investigation of in-line coagulation-MF hybrid process for oily wastewater treatment by using novel ceramic membranes

Oily wastewater is one of the great threats for environment, animals and plants due to high hazardous organic content. In this paper, oily wastewater was treated with in-line coagulation-MF hybrid process using novel and high performance Mullite-Alumina-Zeolite (MAZ) and Mullite-Zeolite (MZ) ceramic microfiltration (MF) membranes. The MF membranes were fabricated by extrusion method using cheap and convenient accessible raw materials such as kaolin clay, natural zeolite and a-alumina powder. Aluminum and iron salts (Al-2(SO4)(3), FeCl3, Fe-2(SO4)(3) and FeSO4) were used for in-line coagulation in the hybrid process with 50, 100, 150 and 200 mg L-1 concentrations. Experiments were carried out in order to determine the effects of coagulation agent dose on the Permeation Flux (PF) and the Oil Rejection Percent (ORP) during oily wastewater treatment. Results showed that FeSO4 with 200 mg L-1 concentration is the best coagulation agent for enhancement of PF of two types of membranes significantly. Also, Al-2(SO4)(3) was the best coagulation agent that enhanced ORP of MAZ from 96.2% to 99% and 96.6%-98.8% for MZ membranes. (C) 2017 Elsevier Ltd. All rights reserved.