Large-scale multi-stage constructed wetlands for secondary effluents treatment in northern China: Carbon dynamics
Large-scale multi-stage constructed wetlands for secondary effluents treatment in northern China: Carbon dynamics
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中国北方用于二级污水处理的大规模多阶段人工湿地：碳动力学。
DOI：
10.1016/j.envpol.2017.09.048
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发表时间：
2018
影响因子：
8.9
通讯作者：
Guo Wenshan
中科院分区：
文献类型：
--
作者：
Wu Haiming;Fan Jinlin;Zhang Jian;Ngo Huu Hao;Guo Wenshan
与传统的单级人工湿地相比，多级人工湿地在处理各种废水方面具有良好的经济效益。然而，很少有长期的全面的多级CW已被执行和评价抛光废水从生活污水处理厂（WWTP）。研究了北方大规模七级乌江生活污水处理厂出水中碳的季节和空间动态以及关键因子（输入负荷和温度）的影响。结果表明，水质有了显著改善。结果表明，乌江湿地对有机物的去除具有明显的季节和空间差异，夏季和秋季COD去除率较高，为64-66%. CH 4和CO2排放具有明显的季节和空间变化特征，平均排放速率分别为3.78-35.54 mg m−2d− 1和610.78-8992.71 mg m−2d−1，春季和夏季的排放通量较高.季节性气温和进水COD负荷率显著影响有机物去除率和CH 4排放量，但对CO2排放量影响较弱。总体而言，本研究表明，大规模的乌江CW可能是一个潜在的温室气体源，但考虑到多级CW的可持续性，进水COD负荷率为1.8-2.0 g m−2d− 1和温度为15-20 °C可能是实现生活污水处理厂出水精处理中较高的有机物去除效率和较低的温室气体（GHG）排放的合适条件。对大规模乌江污水处理厂碳动力学的认识将有助于理解碳循环，也可以为多级污水处理厂的设计、运行和管理提供有益的现场经验。
Multi-stage constructed wetlands (CWs) have been proved to be a cost-effective alternative in the treatment of various wastewaters for improving the treatment performance as compared with the conventional single-stage CWs. However, few long-term full-scale multi-stage CWs have been performed and evaluated for polishing effluents from domestic wastewater treatment plants (WWTP). This study investigated the seasonal and spatial dynamics of carbon and the effects of the key factors (input loading and temperature) in the large-scale seven-stage Wu River CW polishing domestic WWTP effluents in northern China. The results indicated a significant improvement in water quality. Significant seasonal and spatial variations of organics removal were observed in the Wu River CW with a higher COD removal efficiency of 64–66% in summer and fall. Obvious seasonal and spatial variations of CH4and CO2emissions were also found with the average CH4and CO2emission rates of 3.78–35.54 mg m−2d−1and 610.78–8992.71 mg m−2d−1, respectively, while the higher CH4and CO2emission flux was obtained in spring and summer. Seasonal air temperatures and inflow COD loading rates significantly affected organics removal and CH4emission, but they appeared to have a weak influence on CO2emission. Overall, this study suggested that large-scale Wu River CW might be a potential source of GHG, but considering the sustainability of the multi-stage CW, the inflow COD loading rate of 1.8–2.0 g m−2d−1and temperature of 15–20 °C may be the suitable condition for achieving the higher organics removal efficiency and lower greenhouse gases (GHG) emission in polishing the domestic WWTP effluent. The obtained knowledge of the carbon dynamics in large-scale Wu River CW will be helpful for understanding the carbon cycles, but also can provide useful field experience for the design, operation and management of multi-stage CW treatments.