treatment of wastewater by a combined technique of adsorption, electrocoagulation followed by membrane separation

In this study, a combined lab-scale purification system was set up to treat wastewater from the national iranian oil company. the combined system was composed of three main sections: pre-filtration using activated carbon filter (acf), electrocoagulation (ec) system, and a filtration section (mf followed by ro). the performance of the treatment system was evaluated by measuring heavy metals, bod, cod, tds, tss, and o&g. the results showed that pre-filtration using acf could lead to the removal of the bod, cod, tds, tss, and o&g by 24.6%, 21.12%, 31.07%, 36.9% and 8.49%, respectively; the heavy metals were removed significantly. in the ec section, heavy metals were rejected by more than 98% using both the al and fe electrode, except for the cr ions that were mostly removed with fe electrodes. the removal of bod, cod, tds, tss, and o&g using the al and fe electrode was 95.6%, 96%, 91%, 76.6%, and 98.6% and 93.2%, 92.1%, 76%, 83% and 99%, respectively. ec followed by mf/ro filtration led to a remarkable purification performance, and the rejection rate of all pollutants was obtained over 99% after this section. the experimental results indicated that the optimum time for acf and ec processes were 20 and 50 minutes.