Comparison of Various Adsorbents such as Algae, Bi-raw Algae and Bi- H3PO4 Algae towards Achieving High Removal Efficiency of Hexavalent Chromium Removal

Abstract: Hexavalent chromium is the most toxic form of chromium compounds and it is applied in various textile, tanning and paints industries. Contamination of water with hexavalent chromium destroys the ecosystem in addition to its carcinogenic effect on human health. Therefore, hexavalent chromium removal from contaminated wastewater is an important matter that was investigated by many researchers. Efforts were recently directed towards adsorption using low-cost eco-friendly adsorbents such as biomasses. Through the current work, algal biomasses were applied in the raw form, H3PO4 activated carbon, and algal materials loaded by bimetallic nano-zerovalent to select the potent form that achieves high hexavalent chromium removal efficiency. Materials were prepared and characterized using different characterization techniques such as IR, XRD, and SEM. After that, a screening experiment was performed to select the potent materials that could achieve high hexavalent chromium removal efficiency.

The selected potent materials were further optimized using Response Surface Methodology and analyzed by Artificial Neural Network in addition to isotherm and kinetics analysis. Results stated that raw algae achieved the highest hexavalent chromium removal efficiency of nearly 90 % for 100 ppm Cr (VI) Combined material bi-metallic raw algae achieved the highest removal efficiency of nearly 99.5 % for 25 ppm hexavalent chromium concentration, and 1.3 g/l dose, after 178 min. Contact time with shaking rate 120 rpm