Studies On The Adsorption Of Complex Pollutants Of Cd²⁺ And Phenol On Amphoteric-Nonionic Co-Modified Soil

The hazard of the organic matter and heavy metal are the most severe hazards in soil pollution. However, organic matter and heavy metal pollution ofen coexist at the same time. The amphoteric surfactant has the capability of adsorpting and fixing organic matter and heavy metal simultaneously. The nonionic surfactant also has certain effect to heavy metal and organic. Nonionic surfactant and amphoteric surfactant compound modify Lou soil and form amphoteric-nonionic co-modified soil. And the adsorption effect of co-modified soil to heavy metal and organic has not yet been reported at present. This article using batch treatment method, firt studied the adsorption kinetic and equilibrium adsorption of Cd²⁺ and phenol in single and complex treatment on Dodecane- Betaine (BS) single modified Lou soil and on different proportion of Dodecane-Betaine (BS)+ Octylphenol polyoxyethylene ether(OP) co-modified(BP) Lou soil at different temperatures. And all the experiments are to privide theory basis to the heavy metal and organic pollutant adsorption. The mainly obtained result are following:1. Cd²⁺ adsorption kinetic shows: in Cd²⁺ single treatment and Cd²⁺ and phenol complex treatment, all the adsorption processes of Cd²⁺ on BP Lou soil can be devided into two stages, the fast reactionVf and the slow reactionVs. The Vf order of Cd²⁺ on modified siols is 100BS>100+100BP>100+50BP>50+50BP>50+100BP>50BS>CK at 20℃and 100BS> 100+100BP>50BS>50+50BP>100+50BP>50+100BP>CK at 40℃in Cd²⁺ single treatment. The Vf order of Cd²⁺ on modified soils is 100BS>100+50BP>100+100BP>50BS>50+50BP> 50+100BP>CK at 20℃and 40℃in Cd²⁺ and phenol complex treatment. BS modified as a critical role to Vf of Cd²⁺on co-modified Lou soil, howere, OP modified as a hindrance effect. The double constant model is the best model to describe the adsorption kinetic curves of the all the soils. The fitting parameter A and fitting parameter B can become characteristic parameter to describe the adsorption velocity of Cd²⁺ on amphoteric-nonionic co-modified Lou soil.2. Cd²⁺ equilibrium adsorption shows: the capacity of Cd²⁺adsorption on all the modified soils is higher than that on unmodified soil. Amphoteric- non-ionic compound modified soils on the adsorption of Cd²⁺ is the interaction of two surface modifier results. With the increasing proportion of BS modification, the Cd²⁺adsorptive capacitity increased on compound soils; and OP co-modified has different influence on soil adsorption of Cd²⁺with the ratio of OP modified and the proportion of different BS modification in general. The Langmuir model is the best model to describe the equilibrium adsorption of Cd²⁺ on all the soils in Cd²⁺single treatment and Cd²⁺ and phenol complex treatment. The soils are spontaneity responded to the Cd²⁺ adsorption reaction. And the heat adsorption entopy increases. The jioning of phenol can hamper the adsorption of Cd²⁺.3. Phenol adsorption kinetic shows: in phenol single treatment and phenol and Cd²⁺ complex treatment, all the adsorption processes of phenol in BP co-modified Lou soil can be devided into two stages, the fast reaction(hydrophobic physisorption) and the slow reaction(chemical adsorption). The BP co-modified play a the promote role to the Vt, Vf of phenol adsorption on BP co-modified soils. The increasing of BS or OP modified proportion can promote the soils to adsorb phenol. From 20℃to 40℃, the Vt, Vf of all the siols adsorb phenol assume the declining trend and present warming negative effect. And it's the result of BS and OP synergy. The coexistent of Cd²⁺ play anti-function to the co-modified soil to adsorb phenol The order of phenol adsorption speed is 100+100BP>100+50BP> 100BS>50+100BP>50+50BP>50BS>CK at 20℃and 40℃. The double constant model is the best model to describe the adsorption kinetic curves of the all the soils. The fitting parameter A and fitting parameter B can become characteristic parameter to describe the adsorption velocity of phenol.4. Phenol equilibrium adsorption shows: the phenol adsorptive capacity on BS and OP co-modified soils obvious enhanced. The order of phenol adsorption capacity is 100+100BP>100+50BP>100BS>50+100BP>50+50BP>50BS>CK at 20℃and 40℃in all treatments. The soils are spontaneity responded to the phenol adsorption reaction in BP co-modified soil. And the apparent free energy–ΔG and the model fitting's distribution coefficient K of Henry has the same change order. The results confirmed that the adsorption spontaneity is bigger, the adsorptive capacity is more bigger. All soils adsorp phenol show warming negative effect. The coexistence of Cd²⁺ has certain anti-function to the phenol adsorption on modified soils. Henry model is the best model to describe soils adsorp phenol model.