煅烧改性净水厂污泥对底泥内源磷释放的控制效果

以自主研发的煅烧改性净水厂污泥（C-WTPS）作为污染底泥活性覆盖材料，室内静态模拟实验研究C-WTPS覆盖强度对控制底泥磷释放效果的影响，分析C-WTPS和底泥中不同形态磷含量变化，探讨C-WTPS薄层覆盖对上覆水体中pH、DO和ORP的影响.结果表明，实验历时40天，在底泥TP释放强度为6.25~10.87 mg/（m²·d）时，覆盖强度为0.25、0.50、1.00、1.50和2.00 kg/m²的C-WTPS对TP平均削减率分别为59.68%、75.71%、88.75%、92.42%和96.28%，可见覆盖强度为1.00 kg/m²以上的C-WTPS能控制底泥中90%以上TP释放.C-WTPS吸附的磷主要以无机磷（IP）中的铁铝结合态磷（NAIP）形式存在，有机磷（OP）和钙磷（AP）形式较少.C-WTPS促进了底泥中易释放形态磷迁移到C-WTPS中，并转化较为稳定的形态磷，可见C-WTP覆盖不仅控制了底泥磷释放，而且也削减了底泥磷释放风险.C-WTPS覆盖后，上覆水体中pH开始呈现下降趋势，最终维持在pH=7范围波动；C-WTPS覆盖强度越大，上覆水体pH下降也明显；C-WTPS覆盖改善上覆水体中DO和ORP环境的效果不明显.

The efficiency of controlling the phosphorus release from the sediment using calcined modified water purification plant sludge (C-WTPS)

In this paper, the self-developed calcined water treatment plant sludge (C-WTPS) was used as an active sediment capping material for contaminated sediments. The static simulation experiment was conducted to study the effect of C-WTPS capping intensity on controlling phosphorus release from the sediment. Changes of phosphorus contents with different forms in the C-WTPS and sediment were analyzed, and the effect of thin-layer capping of C-WTPS on the pH, dissolved oxygen (DO) and oxidation-reduction potential (ORP) in overlying water was also discussed. The results showed that during a 40-day experiment, when the total phosphorus (TP) release intensity of the sediment was 6.25-10.87 mg/(m²·d), the TP average reduction rate of C-WTPS with the capping intensity of 0.25, 0.50, 1.00, 1.50 and 2.00 kg/m² were 59.68%, 75.71%, 88.75%, 92.42% and 96.28%, respectively. It means that C-WTPS with a capping intensity over 1.00 kg/m² could restrain over 90% TP from releasing. The phosphorus adsorbed by C-WTPS mainly exist in the form of iron-aluminum bounded phosphorus (NAIP)which were included in the inorganic phosphorus (IP), but the forms of organic phosphorus (OP) and calcium phosphate (AP) were less. C-WTPS promoted the migration of phosphorus which were easily released into the C-WTPS and turn it into the relatively stable phosphorus. It showed that the using capping material C-WTPS could not only control the release of phosphorus from the sediment but also reduce the potential risk of phosphorus release. During the process of C-WTPS capping, the pH of the overlying water began to decline at first, and maintained to be around 7 in the end. The higher intensity of capping was used, the lower pH in the overlying water was discovered. Although, the effect of improving the overlying water by using covering material C-WTPS in the DO and ORP were not obvious.