循环速率及低温环境对复合生态床修复北方景观水体的影响

Effect of Recycling Rate and Low Temperature on Remedying Northern Landscaping Water by Ecological Filter

以天然矿物质沸石及煤渣为基质构建新型复合生态滤床,分层布设并采用下向流-上向流联合运行方式,修复北方微污染景观水体.通过出水循环方式下的动态实验,考察循环速率、低温环境对污染物去除过程的影响,深入分析水体氮、磷在系统内的转换过程及修复机理.结果表明,加快循环速率提高了NH_4^+-N及TN的去除率,且使得硝化作用进行得更加迅速和彻底,补充了氮从系统中去除的好氧反硝化途径.温度下降过程中,动态运行24 h及48 h的去除率无明显变化,TP去除率明显降低,分别由15～25℃时的72%、77.4%降低到0～5℃的42.4%及60.2%;温度是TP去除的主要影响因索,对NH_4^+-N影响不大.

Natural zeolite and coal cinder were chosen as main compound of the substrate layered ecological bed instead of traditional filling to bio-remedy the static lake water in Northern China, and its running mode was upward combining with downwards flow. Dynamic experiments were carried to study the effect of main factors on contamination removal rate by zeolite ecological filter. It showed that Removal ratios of NH4^＋ -N and TN were promoted with recycling rate increase. The increase of recycling rate made the nitrification more rapidly and completely, and the transition approach of nitrogen was shortened. And the aerobic denitrification was added in the nitrogen removal process, when the temperature declined, the instant removal rate of NH4^＋- N fell, but the removal rate of remained when it operated for 24 housr and 48 hours respectively. It means that rest time played an important role in NH4^＋ -N removal; removal rates of TP after 24 h and 48 h decreased when temperature declined evidently, and it was from 72% and 77.4% in 15-25 ℃ to 42.4% and 60.2% in 0--5 ℃respectively. Environment temperature was the important factor for TP removal.