Rice husk templated water treatment sludge as low cost dye and metal adsorbent

The preparation of adsorbents at low cost as alternatives to the expensive ones in the treatment processes of water and wastewater is the interest of the researchers worldwide. Here, a novel cheap mesoporous adsorbent was prepared via the recycling of wastes namely water treatment sludge and rice husk (RH) as textural modifier. Surface area and pore dimensions were optimized against RH ratio. The mesoporous sludge was employed in adsorption of rosaniline dye, Pb2+, Ni2+ and chlorine from aqueous solutions under dynamic experimental conditions. It was found that the initial dye concentration and textural structure of the adsorbent played important roles in adsorption capacity. The reusability test shows the ease desorption of dye with slightly alkaline water (pH = 8) indicating the stability and reusability of the ceramic adsorbent for several times. For metallic cations, the characteristics (ionic radius and ΔHhyd) of ions affect the adsorption affinity. Chlorine adsorption is controlled by the cation exchange capacity(CEC).