Abstract

Electro-Coagulation Treatment and De-oiling of Wastewaters Arising from Petroleum Industries

Sellami MH*, Loudiyi K, Bellemharbet K and Djabbour N

Petroleum region of Haoud Berkaoui (HBK) is one of the first areas to provide great efforts in the field of environmental protection; this region has a resort of de-oiling, a recovery unit flaring gas, a potable water station and will soon have a wastewater treatment plant. Generally, wastewaters discharged by petroleum industries may contain hydrocarbons and suspended solids. The charge of wastewaters derived from petroleum industry exists in various forms: solutions, colloids and particles. It is important to treat this wastewater at low cost by electrocoagulation compared with traditional chemical treatments as conventional coagulation-flocculation process instead of reusing or re-injecting it directly into oil wells. The treatment by electro-coagulation was applied. This treatment provides two separate phases by settling or flotation. The electro-coagulation produces a similar separation as coagulation -flocculation using reagents such as FeCl3 or Al2(SO4)3 but in this case, the coagulant is derived from the anodic dissolution of Aluminum. In this experiment we have studied the effect of several parameters, namely: the solution pH, current intensity and clarification time on the process efficiency. The results showed that the Oil and Wastes Removal Efficiency (OWRE) was 79.61% for both current intensities of 0.3 and 0.65 A in a medium basic solution pH (9-11) and respectively after 100 and 80 min of clarification time. To see the impact of the treated water on vegetations, some irrigation tests have been conducted regarding two types of plants (date palm and shaft apocalyptic) for 13 months. The tests showed that the thick layer of 5 cm and fine particles diameter of dune sand removes most of the remaining oil. The layer that fills the basin surrounding the shaft is removed and replaced every 03 months. So, fine dune sand plays the role of biological filter. The little garden plants appear and grow normally.