Adsorption kinetics of Cd2+ on amphoteric-nonionic surface active agent co-modified Lou soil.

【Objective】 Investigation on the characteristic of adsorption kinetics of Cd2+ on amphoteric-nonionic surface active agent co-modified Lou soil could provide a theoretical foundation for the characteristic and mechanism of adsorption kinetics of Cd2+ on amphoteric-nonionic surface active agent co-modified Lou soil.【Method】 The original soil,unmodified soil(CK),was used as the control,Dodecane-Betaine(BS) as amphoteric surface active agent and Octylphenol polyoxyethylene ether(OP) as nonionic surface active agent,to study the kinetics characteristics of Cd2+ adsorption by BS single modified and BS-OP co-modified Lou soil by the batch techniques at 20 and 40 ℃.【Result】 These outcomes indicated that,at 20 and 40 ℃,the fast-adsorption-velocity(Vf) order was 100% BS50% BS≈50% BS+50% OP100% BS+100% OP≈100% BS+50% OPCK50% BS+100% OP and 100% BS100% BS+50% OP100% BS+100% OP50% BS50% BS +50% OP≈50% BS+100% OPCK respectively on all modified Lou soil in general.The Vf of Cd2+ on co-modified Lou soil with the same BS proportion modified decreased with the rise of OP modified ratio,meanwhile,the Vf of Cd2+ on co-modified Lou soil with the same OP proportion modified increased with the rise of OP modified ratio.【Conclusion】 BS modification can promote the adsorption-velocity of Cd2+ on co-modified Lou soil,however,OP co-modification can inhibit the absorption of Cd2+ on BS modified soil.The double constant model is better than other models to describe the absorption kinetic curves of Cd2+ on modified soil.