Does rice straw application reduce N2O emissions from surface flow constructed wetlands for swine wastewater treatment?
Does rice straw application reduce N2O emissions from surface flow constructed wetlands for swine wastewater treatment?
复制标题
稻草的应用是否可以减少用于养猪废水处理的地表流人工湿地的 N2O 排放？
DOI：
10.1016/j.chemosphere.2019.03.084
复制
发表时间：
2019
期刊：
影响因子：
8.8
通讯作者：
Wu Jinshui
中科院分区：
文献类型：
--
作者：
Zhang Shunan;Liu Feng;Luo Pei;Xiao Runlin;Chen Junli;Chen Liang;Wu Jinshui
稻草作为碳源常被用于提高人工湿地脱氮效果，但很少有研究考虑稻草对人工湿地脱氮过程中氧化亚氮（N2 O）排放的影响。本研究构建了18个由稻草塘和表面流处理器组成的组合系统，研究了稻草施用对3种不同处理强度猪场废水N2 O排放的影响。结果表明，与不施稻草处理相比，施用稻草处理使低强度水煤浆的N2 O排放因子增加了131.5%，但使中、高强度水煤浆的N2 O排放因子降低了37.2-43.7%。RS的应用导致平均10.7%的潜在反硝化率的增加，同时增强基因丰度的总细菌（16 S rRNA），氨氧化古菌，氨氧化细菌，硝酸还原酶，和N2 O还原酶（nosZ）的所有强度的CW。多元回归模型显示N2 O排放量与水温、硝酸盐、化学需氧量和反硝化基因密切相关。在中、高浓度下，RS（0.7-1.3%）的16 SrRNA中nosZ基因丰度比例高于NRS（0.4-0.9%），而在低浓度下则相反。这种差异是不同施用强度RS增加或减少N2 O排放的主要原因。这些结果表明，RS应用于控制表面流CW的N2 O排放的有效性与废水的污染程度有关。
Rice straw was applied often as a carbon source to improve nitrogen removal; however, few studies have considered the effect of rice straw on nitrous oxide (N2O) emission during nitrogen removal in constructed wetlands (CWs). We constructed eighteen combined systems, consisting of rice straw ponds and surface flow CWs to investigate the effect of rice straw application on N2O emission in three strengths of swine wastewater treatments. The results showed rice straw (RS) treatment increased 131.5% of N2O emission factor from low strength CWs, but decreased 37.2–43.7% of N2O emission factors for medium and high strengths compared with no rice straw (NRS) treatment. The RS application led to an average 10.7% increase in the potential denitrification rate, and simultaneously enhanced gene abundances of the total bacteria (16S rRNA), ammonia-oxidising archaea, ammonia-oxidising bacteria, nitrate reductase, and N2O reductase (nosZ) for all strengths CWs. The multiple regression model revealed N2O emissions were strongly related to water temperature, nitrate, chemical oxygen demand, and denitrification genes. The proportion ofnosZgene abundance in 16S rRNA was higher in RS (0.7–1.3%) than NRS (0.4–0.9%) for medium and high strengths, while an opposite trend was observed for low strength. The discrepancy was responsible for increasing or decreasing N2O emission by RS application among different strengths. These findings indicated the effectiveness of RS application to control N2O emissions from the surface flow CWs was related to the pollution level of wastewater.