1. aDepartment of Petroleum and Chemical Engineering, College of Engineering, Sultan Qaboos University, Muscat, Oman
2. bDepartment of Chemical Engineering, COMSATS University Islamabad (C.U.I.), Lahore, Pakistan
3. cSchool of Chemistry and Chemical Engineering, Queens University Belfast, Belfast, Northern Ireland, UK
4. dEnvironmental Technology Management Department, College of Life Sciences, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait