title: The effects of red soil in removing phosphorus from water column and reducing phosphorus release from sediment in Lake Taihu.
abstract: A natural red soil and a lanthanum-modified soil (LMS) were tested to compare their phosphorus (P) adsorption capacities and their effectiveness in removing P from the water column and reducing P release from sediment. The equilibrium of P adsorption demonstrated that the maximum P adsorption for the soil was 1.29 and 2.22 mg g(-1) at pH 8.5 and 5.5, respectively, and for the LMS these were increased by 45.6 and 77.6% at pH 8.5 and 5.5, respectively, indicating that the soil was effective in P adsorption and the doping of lanthanum could substantially increase P adsorption. The sediment-water column incubation showed that, due to the P adsorption of the soil and LMS, the total P in the water column decreased by 58.5, 60.6, 68.2 and 77.2% for 180 g m(-2) soil, 900 g m(-2) soil, 180 g m(-2) LMS and 900 g m(-2) LMS treated systems, respectively, in a short time (6 h), and the capping layer substantially reduced the P release from sediment during column incubation, indicating that the soils were effective in reducing internal P load. However, considering the cost of LMS, the natural soil was suggested to be a cost-effective material to control internal P load.
authors.affiliation: Biomass Energy Technology Research Center, Biogas Institute of Ministry of Agriculture, Chengdu 610041, China E-mail: dailichun@caas.cn.
authors.forename: Lichun
authors.initials: L
authors.lastname: Dai
authors.affiliation: Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Pan
mesh_terms: D000327:Adsorption; D002681:China; D019015:Geologic Sediments / Q000737:chemistry; D060106:Lakes; D007811:Lanthanum / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry / Q000302:isolation & purification*; D012987:Soil / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D012987:Soil; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D007811:Lanthanum