ADSORPTION OF HEAVY METALS FROM CONTAMINATED WATER ON FE2 O3 / SIO2 NANOCOMPOSITE AND NATURAL SILICA RICE HULL-BASED AND INVESTIGATE THEIR EFFECTS ON BLOOD BIOMARKERS AND RENAL TOXICITY IN RATSSOHEIR N. ABD EL-RAHMAN1 *, SAAD A. MAHGOUB1, AMAL M. H. ABDEL-HALEEM1* AND AFAF A. SHAABAN2Abstract The detection of heavy metals in industrial effluent and some sectors of the global drinking water supply stands in direct opposition to the limits set by the regulatory authorities and the recommended Guidelines by the World Health Organization. Rice husk, as underutilized agricultural biomass, could be transferred into a promising low-cost adsorbent for removing heavy metals as it is abundant in nature, from a biogenic source, and requires little processing. In the present study, silica and Fe2 O3 silica nanocomposite were prepared from rice husk and used to clean contaminated water with a heavy metal mixture. Silica 0.5 and 1% exhibited up to 97.05 and 100% removal for Zn2+, Fe2+, and Ni2+, respectively, as they were affected by the cristobalite amorphous microstructures and the non-uniform pore sizes. Silica 0.5% adsorbed more Mn2+ (29.45 mg) and Fe2+ (54.02 mg) than 1% silica. Fe2O3 / silica nanocomposite 1% showed a specific selectivity to bind Hg2+ with a maximum adsorption removal of 40.42% and adsorption capacity of 0.02 mg/ g. Serum urea, creatinine, and uric acid in rats exposed to drinking water cleaned with 0.5, 1% silica exhibited close p ï£ 0.05 results to the normal values, and kidney histopathological examinations do not exhibit any sign of nephrotoxicity. |