Studies On Combined Sorption Behaviors Of Cationic Surfactant And Heavy Oil On Marine Sediments

Combined pollution has become one of the important directions of environmental chemistry at present. With the development of agriculture and industry, there have been more and more organic contaminants in combined polluted environment and interaction between two coexistent organic compounds has become increasingly apparent.The sorption of an organic contaminants on sediments(soils) depends on the physico-chemical properties of the chemical,the sediment characteristics (composition, surface area,pore size, and surface functional groups).Some studies show the effects of the environmental factors (temperature, salinity, coexistent organic compounds,etc).Oil and surfactants are toxic organic pollutants,which are ubiquitous in the marine environment.They have done great harm to the human being and marine organisms.Chemists and environmental researchers have paid much attention to them. The sorption of is a main factor in controlling the fate and transport of oil and surfactants in the environment,and investigation on sorption behaviors of oil /surfactants on marine sendiments in combined polluted environment is very important from the practical points of view of the oceanic and environmental science.In this thesis the parameters of sorption kinetics and thermodynamics of heavy oil and cationic surfactants cetyltrimethylammonium bromide(CTAB) on JiaozhouBay sediment are studied in artificial seawater. Furthermore, the effects of other environmental factors such as salinity.temperature are also investigated in combined polluted environment. The probable sorption mechanisms were discussed on the basis of the investigated data. The main results are as follows:(1)The results showed that the sorption kinetic process of heavy oil and CTAB on sediment can be described by the Pesudo-second-order kinetic rate equation in combined polluted environment. (2) The sorption isotherms of heavy oil and CTAB on sediments presented nonlinear and were well described by the Freundlich equation in combined polluted environment.(3) In combined polluted environment,the sorption of heavy oil was favorably influenced by increasing initial CTAB concentration,salinity and decreasing temperatures;the sorption capability of CTAB on sediment increased with decreasing initial heavy oil concentration and temperatures and increasing salinity.(4) The thermodynamic parameters(ΔG0<0,ΔH0<0,ΔS0<0) for heavy oil on sediments were calculated.which, indicated that the sorptions were physical processes and were spontaneous and exothermic with a decrease randomness.The thermodynamic parameters(ΔG0<0,ΔH0<0,ΔS0>0) for CTAB on sediments in presence of heavy oil were also calculated,,which,indicated that the sorption was spontaneous and exothermic.the randomness at the solid-liquid interface was increased during the process.