The removal of arsenic from water and wastewater is obligatory. Resin is one of the most effective adsorbents for the removal of arsenic. In order to improve the adsorption capacity of resin, a new cerium-loaded cation exchange resin arsenic adsorbent was prepared by impregnating cerium into the cation exchange resin. Batch adsorption experiments under various conditions, such as time, temperature, pH and with coexisting ions were carried out to evaluate the adsorption characteristics of cerium-loaded resin in the removal of As（V） and As（III） from aqueous solutions. The results showed that the adsorption kinetics of As（V） and As（III） obeyed a pseudo second-order kinetic model and the adsorption rate constants were 0.3159 and 0.5215 g.mg-1-min-1, respectively. The adsorption of As（V） followed the Freundlich adsorption isotherm model and the adsorption isotherm data for As（III） fitted well to the Langmuir equation model. The adsorption capacities were 1.0278 mg/g for As（V） and 2.5297 mg/g for As（Ill）. Both the adsorption of As（V） and As（Ill） were found to be pH sensitive and the optimum pH was found to be 5-6. Except for the phosphate ion, the coexisting anionics, such as nitrate, chlorate, sulphate and carbonate, showed no remarkable effect on As（V） and As（ill） adsorption. The desorption and regeneration study showed that the adsorption capacity of Ce-loaded resin for As（V） and As（Ill） could be restored to 97.80% and 69.61%, respectively, using 0.5 moFL sodium hydroxide solution.
Surfactant-enhanced remediation （SER） is an effective method for the removal of volatile organic compounds （VOCs） from contaminated soils and groundwater.To reuse the surfactant the VOCs must be separated from the surfactant solutions.The water solubility of VOCs can be enhanced using reversible surfactants with a redox-acive group,（ferrocenylmethyl）dodecyldimethylammonium bromide （Fc12） and （ferrocenylmethyl）tetradecanedimethylammonium bromide （Fc14）,above and below their critical micelle concentrations （CMC） under reducing （I ＋ ） and oxidative （I 2＋ ） conditions.The CMC values of Fc12 and Fc14 in I ＋ are 0.94 and 0.56 mmol/L and the solubilization of toluene by Fc12 and Fc14 in I ＋ for toluene is higher than the solubilization achieved with sodium dodecyl sulfate,cetyltrimethylammonium bromide and Trition X-114.The solubilization capacity of the ferrocenyl surfactants for each tested VOCs ranked as follows： ethylbenzene toluene benzene.The solubilities of VOCs by reversible surfactant in I ＋ were 30% higher than those in I 2＋ at comparable surfactant concentrations.The effects of Fc14 concentrations on VOCs removal efficiency were as follows： benzene toluene ethylbenzene.However,an improved removal efficiency was achieved at low ferrocenyl surfactant concentrations.Furthermore,the reversible surfactant could be recycled through chemical approaches to remove organic pollutants,which could significantly reduce the operating costs of SER technology.
