Activated carbons and low cost adsorbents for remediation of tri- and hexavalent chromium from water.

Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions - a review.

Heavy metal remediation of aqueous streams is of special concern due to recalcitrant and persistency of heavy metals in environment. Conventional treatment technologies for the removal of these toxic heavy metals are not economical and further generate huge quantity of toxic chemical sludge. Biosorption is emerging as a potential alternative to the existing conventional technologies for the removal and/or recovery of metal ions from aqueous solutions. The major advantages of biosorption over conventional treatment methods include: low cost, high efficiency, minimization of chemical or biological sludge, regeneration of biosorbents and possibility of metal recovery. Cellulosic agricultural waste materials are an abundant source for significant metal biosorption. The functional groups present in agricultural waste biomass viz. acetamido, alcoholic, carbonyl, phenolic, amido, amino, sulphydryl groups etc. have affinity for heavy metal ions to form metal complexes or chelates. The mechanism of biosorption process includes chemisorption, complexation, adsorption on surface, diffusion through pores and ion exchange etc. The purpose of this review article is to provide the scattered available information on various aspects of utilization of the agricultural waste materials for heavy metal removal. Agricultural waste material being highly efficient, low cost and renewable source of biomass can be exploited for heavy metal remediation. Further these biosorbents can be modified for better efficiency and multiple reuses to enhance their applicability at industrial scale.

Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions

T. Karthikeyan

Papers

Chromium(VI) adsorption from aqueous solution by Hevea Brasilinesis sawdust activated carbon.

Kinetic and isotherm studies of Cu(II) adsorption onto H3PO4-activated rubber wood sawdust

Utilization of fluidized bed reactor for the production of adsorbents in removal of malachite green