碳源种类及其添加量对生物滞留性能的影响研究

Effects of carbon sources and their amounts on bioretention

以生物滞留模拟装置为研究对象,探讨了不同碳源(发酵木屑、腐熟落叶、泥炭土)、不同添加量(3%、8%)对系统水力性能和水质净化的影响。结果表明,添加3种碳源均可提升生物滞留系统的渗透系数,且相同添加量下腐熟落叶对渗透系数的提升效果最显著,而泥炭土最弱。外加碳源并不影响NO^(-)_(3)-N的最终去除程度,但可使得系统NO^(-)_(3)-N去除提前发生,也可降低系统NO^(-)_(3)-N的淋失风险。在进水12 h左右,LH(8%发酵木屑)、LL(3%发酵木屑)和SH(8%腐熟落叶)组NO^(-)_(3)-N去除率即可达到79.28%~85.48%,在进水18 h碳源添加组(SH、SL、LH、LL、PH和PL组)NO^(-)_(3)-N去除率为74.51%~94.38%,明显高于BK组(对照组)的46.62%。BK组在进水12 h发生NO^(-)_(3)-N淋失,碳源添加组在实验阶段均未发生NO^(-)_(3)-N淋失,所有组在实验阶段内未发生COD、TP淋失。

The biological retention simulation device is used as the research object to study the influence of different carbon sources(fermented wood chips,decomposed leaves,peat soil)and different addition amounts(3%,8%)on the hydraulic performance of the system and water purification.The results show that the addition of three carbon sources can increase the permeability coefficient of the biological retention system,and the decomposed fallen leaves have the most significant effect on the increase of permeability coefficient under the same addition amount,while peat soil is the weakest.The addition of carbon source does not affect the final removal degree of NO^(-)_(3)-N,but it can make the system NO^(-)_(3)-N removal occur in advance,and can also reduce the risk of system NO^(-)_(3)-N leaching.At about 12 h of water intake,the NO^(-)_(3)-N removal rate of LH(8%fermented wood chips),LL(3%fermented wood chips)and SH(8%decomposed fallen leaves)groups can reach 79.28%~85.48%.After 18 h of water intake,the carbon source the NO^(-)_(3)-N removal rate of the addition group(SH,SL,LH,LL,PH and PL group)was 74.51%~94.38%,which was significantly higher than the 46.62%of the BK group(control group).NO^(-)_(3)-N Leaching occurred in the BK group 12 h after water intake,and no NO^(-)_(3)-N leaching occurred in the carbon source addition group during the experimental stage,and no COD and TP leaching occurred in all groups during the experimental stage.