研究报告
闫诚,马汤鸣,杨顺清,杨柳燕,高燕.曝气-电解生态浮床的净化效果与机理分析[J].环境科学学报,2020,40(11):3885-3894
曝气-电解生态浮床的净化效果与机理分析
- Purification effects and mechanisms of aeration-electrolysis ecological floating bed
- 基金项目:国家自然科学基金青年科学基金(No.51908277);江苏省自然科学基金青年基金(No.BK20190320);国家水体污染控制与治理科技重大专项(No.2017ZX07204002);苏州市科技局民生项目(No.SS201817)
- 闫诚
- 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023
- 马汤鸣
- 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023
- 杨顺清
- 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023
- 杨柳燕
- 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023
- 高燕
- 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023
- 摘要:为强化生态浮床对重污染河道水体的净化能力,采用曝气-电解生态浮床联合技术增强生态浮床的净化功能.试验考察了电流密度、曝气量和处理时间对模拟的高氮磷重污染水体的净化潜力,分析了电解反应对填料细菌群落结构组成和浮床水生植物黄菖蒲(Iris pseudacorus)生长的影响.结果表明:在进水NH3-N浓度为10 mg·L-1,PO43--P浓度为0.8 mg·L-1,电流密度为0.74 mA·cm-2,水力停留时间为3 d的条件下,相比于电解生态浮床和传统的生态浮床,曝气-电解生态浮床有利于水体中NH3-N的去除(p<0.001),其NH3-N浓度下降至(0.92±0.24)mg·L-1,而电解生态浮床处理的水体NH3-N浓度为(6.85±0.17)mg·L-1,传统生态浮床处理水体中NH3-N浓度高达(8.09±0.40)mg·L-1,曝气促进了水体中NH3-N向NO2--N和NO3--N的转化.电解有利于水体中PO43--P的去除,电解生态浮床处理水体中的PO43--P浓度下降至(0.43±0.02)mg·L-1,曝气-电解生态浮床处理的水体中PO43--P下降至(0.46±0.02)mg·L-1,可见,电解促进了PO43--P的去除.从对I.pseudacorus生理生化指标变化分析可知,曝气有利于减弱电解反应对I.pseudacorus的损伤;对基质生物膜的16S rDNA分析可知,电解反应增加了浮床基质中自养反硝化微生物数量.因此,曝气-电解生态浮床是一种有效的净化重污染水体的方法.
- Abstract:The combined aeration-electrolysis ecological floating bed (A-EEFB) was established to enhance the purification ability of ecological floating bed (EFB) for heavily polluted river water. For this purpose, we investigated the effects of current density, aeration amount, and processing time on the purification ability of A-EEFB to the water with high concentrations of nitrogen and phosphorus, and the influence of electrolysis reaction on the bacterial community structure of the substrate and floating bed plants. During the experiment, the influent concentration of NH3-N was 10 mg·L-1, PO43--P was 0.8 mg·L-1, hydraulic retention time (HRT) was 3 days and the current density was 0.74 mA·cm-2. The results showed that comparing with EEFB and the traditional EFB, the A-EEFB was beneficial to the removal of NH3-N from the water (p<0.001), as the concentration of NH3-N decreased from 10 mg·L-1 to (0.92±0.24) mg·L-1 in A-EEFB, but to (6.85±0.17) mg·L-1 and (8.09±0.40) mg·L-1 in EEFB and EFB, respectively. Aeration promoted the transformation of NH3-N into NO2--N and NO3--N. The electrolysis reaction was beneficial to the removal of PO43--P as its concentration was reduced to (0.46±0.02) mg·L-1 and (0.43±0.02) mg·L-1 in A-EEFB and EEFB, respectively. The insignificant difference (p=0.265) between A-EEFB and EEFB further suggests that aeration didn't increase the removal of PO43--P. When evaluating the effect of electrolysis on the aquatic plant Iris pseudacorus, we found that aeration reduced the damage of electrolysis on I. pseudacorus, while electrolysis reaction increased the number of autotrophic denitrifying microorganisms in the substrate of EEFB.