【摘要】 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/(m~2·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/m~2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p H开始呈现下降趋势,最终维持在p H=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.更多还原

【Abstract】 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 p H,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/m~2 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/m~2 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 p H 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.更多还原