Utilization of a low cost agro-residue for production of coagulant aids and their applications.

Different samples of rice husk ash (RHA) and sodium silicate were prepared and characterized using FTIR, NFTIR and XRD. The selected sample of RHA was obtained by calcination of untreated rice husk (RH) in a semi-closed system at 650°C. Four novel polyinorganic coagulants were also prepared, namely, poly aluminum chloride silicate, poly hydroxy aluminum sulphate silicate, poly ferric chloride silicate and poly ferric aluminum chloride silicate. Applications were carried out for the removal of some pollutants from ground, sewage and industrial waste waters. It was found that the maximum percentages removal of Fe(2+) and Mn(2+) ions in ground water reached 99 and 97%, respectively, the maximum percentage removal of, Pb(2+) ion in industrial waste water reached 97%. In addition, the maximum percentages removal of COD, BOD and TSS in sewage waste water reached 90, 92, and 93%, respectively.

Removal of some heavy metals ions from wastewater by copolymer of iron and aluminum impregnated with active silica derived from rice husk ash.

Recently because of increasing of the environmental awareness and demands, several attempts were carried out for the conversion of by-products of natural materials, especially agricultural wastes, to highly sorption capacity materials. In recent years, attention has been focused on the utilization of unmodified or modified agro-residues as sorbents for removal of pollutants. Various modifications have been reported to enhance sorption capacities for heavy metals. The present study deals with the adsorption equilibrium of iron, manganese, lead and arsenic ions from aqueous solutions on copolymer of Al(+3), Si(+4) and Fe(+3) using batch techniques. The influence of various parameters, such as agitation time, sorbent mass and pH of sorbate solution were investigated. Under this study the maximum adsorption capacity of iron and aluminum copolymer impregnated with silica (PAlFeClSi) for lead, iron, manganese and arsenic are found to be 416, 222, 158, 146 mg/g, respectively.

Incorporation of simulated waste raffinates containing 134Cs into cement-clay matrices.

Simulated waste solutions containing 134Cs were incorporated into cement matrices at varying compositions and in the presence and absence of various additive materials. Montmorillonite and kaolinite clay minerals, in addition to sand, were added for improving the properties of the cement composites. The leachability of 134Cs was measured for different cement-clay mixtures. The effect of the presence of ions, such as borates, sulphate, and nitrates commonly found in waste raffinates, was also investigated. The results for compressive strength and leachability were explained in light of the effect of the presence of clay additives on cement matrices.