3种基质对污水中总磷的吸附性能

以粒径为2~5 mm的无烟煤、活性炭和草炭3种基质为实验材料进行吸附等温线和吸附动力学实验,探讨和对比3种基质对污水中总磷的吸附性能,选用吸附效果最好的无烟煤作为玻璃柱的填料模拟土壤渗滤系统。结果表明,3种填料基质对总磷的吸附均符合Freundlich和Langmuir吸附等温线方程,通过拟合方程得出无烟煤、活性炭和草炭的最大静态吸附量分别为1.249、0.254和0.716 mg/g;用一级动力学方程拟合3种填料基质对总磷的吸附反应过程较好,相关系数都在0.900以上,无烟煤、活性炭和草炭吸附速率分别为0.025、0.023和0.014 mg/(g·h),其中经无烟煤处理过的污水,出水最清澈;在模拟土壤渗滤系统实验中,当进水浓度为3.43~8.43 mg/L,水力负荷为0.08 m3/(m2·d)时,出水中总磷平均浓度为0.08 mg/L,满足《城镇污水处理厂污染物排放标准》中的一级A标准,对总磷的去除率高达96.48%~99.19%。

Performances of three substrates in adsorbing total phosphorus in polluted water

Anthracite, activated carbon and grass carbon with their grain sizes of 2~5 mm were used as the substrates to carry out adsorption isotherm and adsorption kinetics experiments and to comparatively discuss the performance of the three substrates in adsorbing the total phosphorus in the polluted water. On this basis, the anthracite which delivered the best adsorption performance was selected as the filler of the glass beads in order to simulate the percolation system of the soil. The experimental results showed that the performances of the three substrates in adsorbing total phosphorus followed the Freundlich and Langmuir equations of adsorption isotherm. By using the fitting equation, we obtained the static adsorption quantities of the three substrates which were 1.249, 0.254 and 0.716 mg/g, respectively. The first order kinetics equation was used to fit the reaction process of the three substrates' adsorption of total phosphorus. The correlation coefficients were all desirably above 0.900. Furthermore, the adsorption rates of the three substrates were 0.025, 0.023 and 0.014 mg/(g·h), respectively. The polluted water that was treated with the anthracite was clearest. In the simulation of the soil's percolation system, the concentration of the total phosphorus in the treated water averaged at 0.08 mg/L when the concentration of the polluted water was 3.43~8.43 mg/L and the hydraulic loading was 0.08 m3/(m2·d). The removal rate of the total phosphorus reached 96.48%~99.19%, satisfying Level A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant.