Comparison study of produced water treatment using electrocoagulation and adsorption

Abstract

In the present work, electrocoagulation and adsorption were applied as environmentally friendly methods to treat produced water (PW) obtained from East Baghdad oil field. Electrocoagulation was applied using iron-iron and aluminum-aluminum electrodes while modified silica was used as adsorbent material to remove total dissolved solids (TDS) and reduce electrical conductivity (EC) of produced water. XRD, SEM and AFM were used to characterize the modified silica. The experiments were achieved using different adsorbent doses (0.2 and 0.4 mg/L) and contact times (30-180 min) at room temperature. The results showed that the electrocoagulation failed to treat the produced water. The surface roughness of modified silica had a significant role in adsorbing TDS. The lowest values of TDS and EC were 513 mg/L and 781 μS/cm, respectively, obtained using adsorbent dose of 0.4 mg/L modified silica at a contact time of 180 min. These results were within the permissible limit according to the specifications of the WHO to provide the possibility of reuse of produced water when re-injected into oil wells.