Study On Cu～(2+), Pb～(2+) Adsorption And AVS In Coastal Sediments Of The Bohai Sea

The surface sediments of Huanghe estuary and the north of the Bohai Bay are selected as the research objects to study the adsorption characteristics of Cu, Pb in coastal sediments of the Bohai Sea in this thesis. The sediments are screened out to four gradational granularities: <75μm, 75~125μm, 125~250μm and 250~500μm. The effects of granularity, pH value, adsorption time and initial concentration of sorbent have been discussed, and the acid volatile sulfide (AVS) of surface sediments collected from Huanghe estuary has been studied simultaneously. The results indicate that:The adsorption equilibrium time of Cu, Pb in sediments of Huanghe estuary and north of the Bohai Bay is different, but all can achieve adsorption equilibrium in 1.5h. In the preliminary stage of the reaction, the adsorption capacitiy increases rapidly along with time, and then changes on the small side after equilibrium. The adsorption capacity increases gradually along with pH value, that of Cu in sediments increases rapidly, but of Pb it increases slowly. The adsorption capacity of Cu assumes a linear relation with initial concentration of absorbent basically; that of Pb increases rapidly under lower initial concentration of absorbent, but then becomes lower along with initial concentration adding. The adsorption capacity of Cu, Pb increases along with the equilibrium concentration elevating, that of Huanghe estuary increases slowly, but that of Cu in the north of Bohai Bay increases rapidly, of Pb it increases rapidly when the equilibrium concentration is relatively lower, then it become slower along with the concentration adding.The adsorption isotherms of Cu, Pb in sediments of Huanghe estuary and the north of the Bohai Bay are calculated using Langmuir and Freundlich adsorption equations, the correlation coefficients are relatively high, there not only physisorption but also chemical adsorption. The adsorption isotherms of Cu in Huanghe estuary conform to Langmuir type; the saturated adsorption capacities of gradational...