台风强降雨输入水源水库悬浮泥沙的氮磷吸附特性

为研究台风强降雨后输入水源水库的悬浮泥沙对水体氮磷的吸附特性,本文于2015年10月强台风"彩虹"登陆粤西期间,采集高州水库原水和表层沉积物泥沙样品,模拟悬浮泥沙对氮磷的吸附动力学过程,对比分析不同粒径和不同含量悬浮泥沙对磷的吸附等温线.结果表明,高州水库悬浮泥沙不具有明显的氮吸附动力学特性,对磷的吸附动力学平衡时间为10 h;泥沙粒径小于0.25 mm时,对磷的平衡吸附量随着泥沙粒径的减小而增大;泥沙含量在0.2~2.0 kg·m-3时,对磷的平衡吸附量随着泥沙含量的增大而增大;悬浮泥沙对磷的吸附等温线符合Langmuir及Freundlich模型,最大吸附量随泥沙粒径的减小而增大,随泥沙含量的增大而增大,悬浮泥沙对磷的最大吸附量为0.073~1.776 mg·g~(-1).台风强降雨作用导致高州水库水体悬浮泥沙含量增大,促进对磷营养盐的吸附作用,对高州水库富营养化有一定的改善作用.

Nitrogen and Phosphorous Adsorption Characteristics of Suspended Solids Input into a Drinking Water Reservoir via Typhoon Heavy Rainfall

During typhoon "Mujigae" in October 2015, water samples and surface sediments were collected from Gaozhou Reservoir, a drinking water reservoir, for simulation and analysis of the kinetics of suspended solids adsorption to nitrogen and phosphorus and the adsorption isotherms of suspended solids with different particle sizes and different concentrations. The results showed no obvious nitrogen adsorption of suspended solids of Gaozhou Reservoir. However, the adsorption effect to phosphorus by suspended solids was significant and the equilibrium time of phosphorus adsorption was 10 hours. The adsorption capacity of phosphorus increased with the decrease of sediment particle size when particle sizes were less than 0.25 mm, whereas it increased with the increase of suspended solids concentration when the concentration was in the range of 0.2-2.0 kg·m^-3. The adsorption isotherm of suspended solids to phosphorus conformed to the Langmuir and Freundlich models, and the maximum adsorption capacity increased with the decrease of suspended solids particle sizes, which increased with the increase of suspended solids concentrations. The maximum adsorption capacity of suspended solids to phosphorus was 0.073-1.776 mg·g^-1. These results indicated that the increase of suspended solids concentration due to the heavy rainfall of the typhoon promoted the adsorption of suspended solids to phosphorus, which reduced eutrophication in Gaozhou Reservoir.