Removal of contaminants from waste water and groundwater

Removal of contaminants from waste water and groundwater 

Malathion, even in a low dose, would produce a very harmful effect on environmental safety. The possible applications of a-CD in remediation of malathion contamination was assessed and the results showed that a-CD had a remarkable effect on the hydrolysis of malathion in natural groundwater. The facihtative effects increase with increasing the concentration of a-CD [87]. Several crosshnked CD gels were prepared and proposed for removal of various aromatic derivatives, such as chloro and nitro phenols, benzoic acid derivatives, dyes et al, from aqueous solutions. Results of adsorption experiments showed that these crosslinked polymers exhibited high sorption capacities, and usually 

Low bioavailability of hydrocarbon pollutants can limit the biodegradation by indigenous micro-communities in soils. CDs enhance desorption of the nonpolar contaminants from the solid surface and transfer them to the water-phase biofilms, where the hydrocarbon-degrading microbes work. Therefore, this special character of CDs and their derivatives can be used for enhanced removal of hydrocarbon contaminants from soil [92]. This is so-called CD-enhanced pump and treat technology for the removal of dense, non-aqueous phase liquid from the saturated soil. For example, HP- -CD solution was added into the source zone 

Soil wettability is another important factor besides contamination, which governs water retention and transport processes [97]. Strong interaction of mineral phases with CDs suggests that the properties of the soils may also be seriously affected by CDs, which may have an influence on soil remediation processes. The effect of RM-/9-CD on surface and pore properties of common clay minerals such as bentonite, illite and kaohnite had been studied and it was found that the wettability of the soil decreased at low CD concentration and increased again at the highest load. The increased concentration of CDs reduced the effective radius of the soil bed which improved the average force of interaction among soil particles via water layer, despite the simultaneous decrease of adhesion forces of water to the soil. 

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