选用9种人工湿地基质(包括3种人工土基质)进行了等温吸附试验。结果表明,在溶液浓度为100~500mgP·L^-1条件下,试验所得结果均符合Langmuir和Freundlich等温吸附方程,并且用Langmuir方程的拟合效果要好于Freundlich方程。在9种基质中,最大吸附量以草炭最大,达到4242.48mg·kg^-1土;中粗砂最小,仅为404.11mg·kg^-1土,其余基质从大到小的排列顺序依次是高炉渣人工土、高炉渣、煤灰渣、耕层土、煤灰渣人工土、中粗砂人工土和砾石。在溶液初始磷浓度为5mgP·L^-1条件下,草炭对磷的吸附去除率最高,达到92.0%,砾石仅为3.1%,其余基质从大到小的排列顺序依次为煤灰渣人工土(57.3%)、煤灰渣(55.7%)、耕层土(40.7%)、高炉渣人工土(24.1%)、高炉渣(20.6%)、中粗砂(18.9%)和中粗砂人工土(11.8%)。
Nine substrates (three substrates of artificial soil)used as media in the vertical-flow constructed wetland were measured under isothermal adsorption experiment, and the data obtained in this study was fitted to both Freundlich and Langmuir isothermal adsorption equations. To simulate the equilibrium P adsorption data, the Langmuir equation was better than the Freundlich equation. When phosphorous concentration in solution was 100-500 mg·L^-1, the maximum phosphate adsorption of substrates predicted by Langmuir equation was in the fol lowing order:, tuff (4 242.48 mg·kg^-1soil)〉 artificial soil of blast furnace slag (BFAS, 2 115.65 mg·kg^-1soil)〉 blast furnace slag (BFS, 1 597.92 mg·kg^-1soil)〉 artificial soil of coal burn slag (CBAS)〉 top soil〉 coal burn slag (CBS)〉 artificial soil of mid-sized sand (MSAS)〉 gravel (494.42 mg·kg^-1soil)〉 and mid-sized sand (MSS, 403.11 mg·kg^-1soil). When phosphorous concentration in solution was 5 mg·L^-1, the order of phosphorus removal rate by these nine substrates was: turf (92.0%) 〉 CBAS (57.3%) 〉 CBS (55.7%)〉top soil (40.7%) 〉 BFAS (24.1%) 〉 BFS (20.6%) 〉 MSS (18.9%) 〉 MSAS (11.8%)〉gravel (3.06%).