Chromium Fluid Analysis

bedrock and soil. Chromium weathered from the rocks is deposited on the soil and groundwater. Chromium is also generated anthropogenically from various industrial processes which includes electroplating, leather tanning, wood preservations, manufacturing of dye, paint, paper, petroleum refining processes, metal finishing, alloysteel manufacturing, and lasers(Owlad et al., 2010). According to BIS (Bureau of Indian Standards) and USEPA the maximum acceptable limit for Cr(VI) in drinking water is 0.05 mg/L and total chromium (Cr(VI) and Cr(III)) is 2 mg/L(Jain et al., 2010). Various conventional techniques have been employed for the removal of chromium from water which includes Reverse osmosis, Chemical precipitation, Filtration, Ion exchange,

Adsorption is one of the major process used for the removal of Cr(VI) worldwide because it is inexpensive, widely applicable, efficient and creates little amount of sludge(Kannan and Rengasamy, 2005). Chromium can be removed using adsorbents of natural as well as chemical origin. However, these bio-adsorbents have various disadvantages like waste may itself contain various toxicants and subsequently increase the organic content of water. Studies have showed adsorption capacities and applicability for some low-cost materials, among others like alluminium oxide, chitosan, bentonite, saw dust and waste slurry (Dubey and Gopal, 2007). Activated carbon is an effective inexpensive adsorbent which has use in various industries to purify water (D Mohan and Chander, 2001; Yoshihara et al.,2007; Yin et al., 2007). Activated charcoal possesses large surface area and number of micropores that make it a suitable for application as adsorbent for environmental pollutants. In commercial scale they are considered as good absorber for the removal of the

nZVI possesses a large removal capacity, fast kinetics and high reactivity for the degradation/removal of many environmental pollutants (Chen et al., 2012; Chen et al., 2013). It has also been confirmed in previous studies that nZVI has higher absorption and enhanced reactivity for Cr(VI) removal (Zhang et al., 2013) compared to other materials (Montesinos et al., 2014). However, bare nZVI are prone to rapid agglomeration leading to the formation of micro-sized aggregates which lead to loss in reactivity and reduced in the environmental mobility (Grieger et al., 2010). This is attributed to their rapid oxidation, magnetization and high reactivity (Zhang et al., 2013; Zhou et al., 2015). One of the proposed method to overcome this drawback is to coat the nZVI particle surface with surfactants, upon rapid desorption of surfactants into the waste water the particle stability would markedly reduce. Alternate method introduces support to immobilize nZVI on surface, thus reducing agglomeration of nZVI. The immobilizer studies for such purpose includes, MWCNTs (Lv et al., 2011), cellulose, biochar, montmorillonite(Zhang et al., 2013), fullers earth and bentonite(Shi et al., 2011) etc. In an earlier study by (Sharma et al., 2015) we found the optimum loading with lower