Zhao Zhong-Jing, Hao Qing-Ju, Tu Ting-Ting, Hu Man-Li, Zhang Yao-Yu, Jiang Chang-Sheng
State Cultivation Base of Eco-agriculture for Southwest Mountainous Land, College of Resources and Environment, Southwest University, Chongqing 400716, China.
Key Laboratory of Eco-environment in Three Gorges Reservoir Region, Ministry, Education, Chongqing 400715, China.
Huan Jing Ke Xue. 2021 Jul 8;42(7):3482-3493. doi: 10.13227/j.hjkx.202011248.
As the problem of global warming becomes increasingly serious, the greenhouse gas (GHG) emission reduction measures of constructed wetlands (CWs) have drawn significant attention. Ferric-carbon micro-electrolysis exhibits an excellent effect on wastewater purification as well as the potential to reduce GHG emissions. Therefore, to explore the impact of ferric-carbon micro-electrolysis on GHG emissions from intermittent aeration constructed wetlands, four kinds of different wetlands with different fillers were constructed. The four fillers were ferric-carbon micro-electrolysis filler+gravel (CW-Ⅰ), ferric-carbon micro-electrolysis filler+zeolite (CW-Ⅱ), zeolite (CW-Ⅲ), and gravel (CW-Ⅳ). Intermittent aeration technology was used to aerate the wetland systems. The results show that ferric-carbon micro-electrolysis significantly improved the nitrogen removal efficiency of the intermittent aeration constructed wetlands and reduced GHG emissions. Compared with CW-Ⅳ, the CH fluxes of CW-Ⅰ, CW-Ⅱ, and CW-Ⅲ decreased by 32.81% (<0.05), 52.66% (<0.05), and 54.50% (<0.05), respectively. Among them, zeolite exhibited a stronger reduction effect on CH emissions in both the aeration and non-aeration sections. The ferric-carbon micro-electrolysis substantially reduced NO emissions. In comparison with CW-Ⅳ, CW-, and CW-Ⅱ achieved NO emission reduction by 30.29%-60.63% (<0.05) and 43.10%-73.87% (<0.05), respectively. During a typical hydraulic retention period, the comprehensive GWP caused by CH and NO emitted by each group of wetland system are (85.21±6.48), (49.24±3.52), (127.97±11.44), and (137.13±11.45) g·m, respectively. The combined use of ferric-carbon micro-electrolysis and zeolite effectively reduces GHG emissions in constructed wetlands. Overall, ferric-carbon micro-electrolysis combined with zeolite (CW-Ⅱ) can be regarded as one of the valuable filler combination methods for constructed wetlands, which can ensure high removal efficiency of pollutants and effective GHG emission reduction in constructed wetlands.
随着全球变暖问题日益严重，人工湿地的温室气体减排措施备受关注。铁碳微电解对废水净化效果良好，且具有减少温室气体排放的潜力。因此，为探究铁碳微电解对间歇曝气人工湿地温室气体排放的影响，构建了四种填充不同填料的不同湿地。这四种填料分别是铁碳微电解填料+砾石（CW-Ⅰ）、铁碳微电解填料+沸石（CW-Ⅱ）、沸石（CW-Ⅲ）和砾石（CW-Ⅳ）。采用间歇曝气技术对湿地系统进行曝气。结果表明，铁碳微电解显著提高了间歇曝气人工湿地的脱氮效率并减少了温室气体排放。与CW-Ⅳ相比，CW-Ⅰ、CW-Ⅱ和CW-Ⅲ的CH通量分别降低了32.81%（<0.05）、52.66%（<0.05）和54.50%（<0.05）。其中，沸石在曝气段和非曝气段对CH排放均表现出较强的减排效果。铁碳微电解大幅降低了NO排放。与CW-Ⅳ相比，CW-Ⅰ和CW-Ⅱ的NO减排率分别为30.29%-60.63%（<0.05）和43.10%-73.87%（<0.05）。在典型水力停留时间内，每组湿地系统CH和NO排放导致的综合全球变暖潜势分别为（85.21±6.48）、（49.24±3.52）、（127.97±11.44）和（137.13±11.45）g·m。铁碳微电解与沸石联合使用可有效降低人工湿地的温室气体排放。总体而言，铁碳微电解与沸石联合（CW-Ⅱ）可被视为人工湿地有价值的填料组合方式之一，可确保人工湿地对污染物的高去除效率和有效的温室气体减排。
