Compounding Effect Of Coexistent Metal Ion And Surfactant On Adsorption Of Organic Compounds By Sediment

Different mechanisms and model of the sorption of organic compounds by soli/sediment in combined polluted environment were reviewed, including many factors which influence the sorption. Interaction between two coexistent organic compounds, and interaction between organic pollutants and coexistent metal, were expatiated. The characters and the sorption properties to soil or sediment of surfactants were summarized. Based on the influence of surfactants on the characters of soil and solution, the environmental behavior of organic pollutants including transport and transform in soil and water medium were described.Based on the combined polluted environment, the compounding effect of coexistent surfactant and metal ion on adsorption of polar organic compounds by sediment, using orthogonal test method. At first,rules of interaction between two factors were investigated. And then,in presence of metal ion, the coadsorption of organic compounds and surfactant was studied principally. The main conclusions of this dissertation are:(1) It was observed that a competition between Pb²⁺ and PNP for occupying the adsorption sites on sediment. And the capacity of competitive adsorption was dependent on concentration of Pb²⁺ and pH of system. Positive correlation was observed between the capacity of competitive adsorption and the concentration of Pb²⁺. When pH was below 4, the competitive adsorption was strengthened by the increased pH. while the capacity of competitive adsorption decreased with increased pH above 4. (2 )The presence of Pb(NO₃)₂ decreased the critical micelle concentration(CMC) of cationic surfactant Cetylpyridinium Chloride(CPC), and enhanced adsorption of surfactant. It was attributed to the counterion effect of NO₃^-. while competition between Pb2+ and CPC for occupying the adsorption sites was not observed.( 3 ) In the complex system containded Pb(NO₃)₂-CPC-PNP. interactions between two factors were exsisted simultaneously, such as the competitive adsorptionbetween Pb2+ and PNP, the adsorption-enhancement of PNP induced by CPC and the adsorption-enhancement of CPC induced by the counterion effect of NO3".And the competitive adsorption between Pb2+ and PNP weakened the enhancement of adsorption induced by CPC.So compounding effect of coexistent Pb2+ and PNP on adsorption of PNP existed. | A lg/*ad| and | Alg?mjc|, which represented the degree of compounding effect of Pb2+ and CPC below and above CMC respectively, increased with increasing initial concentration of Pb2+,but decreased with increasing concentration of CPC. And with continuing increase of CPC's concentration, the compounding effect went to be an independent effect just induced by CPC.(4) In complex system with different metal ion, the compounding effect of coexistent metal and CPC was different, which was dependent on the capacity of competitive adsorption between metal ion and PNP. Values of | A lgPad| and | A lgPmid in different system with Pb(NO3)2,Cd(NO3)2 and Zn(NO3)2 were 8.83x 10'2,6.56x 10"2 3.3Ox 10"2 and 6.90x 10"2, 6.13 x l(T2and 2.70x 10"2.(5) Effect of different pH on adsorption of PNP in Pb(NO3)2-CPC-PNP system was studied. The partition coefficient Kad|PNP>| A lg/'ad|0NP>| A lgPad|MNP...