Electrocoagulation technique for refinery wastewater treatment in an internal loop split-plate airlift reactor

In the present work, an internal loop split-plate airlift reactor was used as an electrocoagulation cell. The performance of this airlift/electrocoagulation reactor has been assessed by treating petroleum refinery wastewater for COD/TSS removal. Experimental parameters include current density, initial pH, air input (between the two split-plate of airlift reactor), electrocoagulation time and implicitly, and internal liquid circulation velocity were investigated. The results revealed that the COD removal increased with increasing current density and electrocoagulation time. The minimum electrocoagulation time required to reach 90% of COD is reduced from 80 to 16 min when the current density increased from 1.8 to 18.5 mA/cm(2). Furthermore, the highest COD/TSS removal was accomplished when using initial pH between 7.0 and 9.0. Considerably, the results have shown the technical feasibility of this airlift/electrocoagulation design as a potential method for refinery wastewater treatment by electrocoagulation/flotation without the need of a mechanical stirrer and thereby, low operational costs.