Combined solar electrocoagulation and adsorption processes for Pb(II) removal from aqueous solution

A combination of electrocoagulation with other methods seems to have garnered much attention in the research area for the past decade to eliminate heavy metal ions from the synthetic and real wastewater effluents. Combining two various methods into a single system appears to be an efficient and promising approach for heavy metal removal, mainly due to their cost-effectiveness, simple operation and suitability for industrial applications. Solar photovoltaic systems have gained much attention because they make use of clean, renewable energy and make the treatment method cost-effective. In this regard, it is imperative to explore the potential of solar photovoltaic systems to remove heavy metals. A response surface methodology based on the central composite design (CCD) was employed to examine the effects of three independent variables such as pH, initial Pb(II) concentration and adsorbent dosage. The results indicated that the highest Pb(II) removal efficiency up to 99.88% can be achieved using the CCD model with the following optimum conditions: (1) pH: 6.01, (2) initial Pb(II) concentration: 15.00 mg/L and (3) adsorbent dosage: 2.50 g/L. Based on the results, the combined system offered an attractive alternative over the single electrocoagulation and adsorption treatment systems as it can produce high Pb(II) removal efficiency.