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2019年中国生态环境状况公报显示,全国地表水中Ⅰ~Ⅲ、Ⅳ~Ⅴ、劣Ⅴ类水质断面分别占71.0%、22.3%和6.7%,水环境污染依然是现阶段我国环境污染治理的重大难题[1]。人工湿地(constructed wetlands, CWs)作为一种新型污水生态处理技术,具有成本低、绿色持续和稳定有效等优点,近年来被广泛运用于各类水处理中[2]。CWs由物理、化学和生物三重机制协同净化,其中,起主导作用的为生物机制[3],其由微生物和植物协同完成[4]。湿地植物作为CWs核心成分之一,对CWs高效净化污水起到关键作用。植物特有的景观功能可以营造优美空间,提升湿地生态美学价值。因此,合理选用湿地植物对CWs净化、景观等功能的发挥至关重要。
传统CWs植物的选用多偏向单一种,造价便宜、施工简单和易于管理,但湿地植物单一,植物-微生物稳定性差,协同作用未充分发挥,植物景观功能未得到有效利用。国外学者研究了欧洲植物物种丰富度对生态系统的影响,结果表明,植物物种丰富度的减少会改变群落组成及功能特性,降低群落结构复杂性,导致维持生态系统服务功能的系统稳定性和弹性降低;而增加植物物种丰富度能大幅度提升景观多样性及生态系统服务功能(生产、气候调节、侵蚀控制等),因此,增加人工湿地的植物多样性对系统稳定性的维持具有重要作用[5-7]。
当人工湿地植物群落布局不同时,植物生物量、根系分布特征、生长期、营养吸收能力、抗逆性等方面均存在显著差异,使用多种植物组合,不同植物互相协同,可以提高综合性污水净化率,保持较为稳定的水质净化效果[8]。现有研究报道多集中在植物组合对不同浓度污水净化效果及不同植物群落对水体氮磷净化差异上[9-10],在景观化湿地植物群落的构建以及植物生理响应对人工湿地水质净化改善的原因等方面尚缺乏深入研究。因此,本文从植物净化效果、株高、花期、季相、生长期等角度,筛选4种大型华东地区常用湿地植物,结合景观生态理念,合理配置2种中型、1种小型湿地植物,构建不同湿地植物群落,分析了不同群落污水净化效果,探究了植物群落构建效果,阐述植物生理响应、植物-微生物协同净化机理,得到适宜人工湿地的最佳植物群落配置。预期成果将为提升CWs净化与景观美学功能,提高CWs系统生物多样性及稳定性,并为CWs工程建设、植物筛选与配置提供科技支撑。
植物群落对湿地净化生活污水的影响
Influence of plant community on the purification of domestic sewage by constructed wetland
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摘要: 为解决植物配置对水质净化影响问题,研究了不同植物群落对生活污水的净化效果及其响应机理,并探索了人工湿地植物的最佳组合。结合景观生态学,运用7种湿地植物构建4种植物群落的人工湿地CW-G1、CW-G2、CW-G3、CW-G4,HRT为4 d,水力负荷为0.125 m3·(m2·d)−1,分析了各人工湿地对污染物的去除率,通过对植物酶活性变化、渗透调节能力和根际微生物演替情况探究了其净化机理。结果表明:CW-G1装置内群落对污染物去除效果最佳;CW-G1装置内植物的SOD、POD、CAT酶活性较单种显著提高,MDA含量显著降低;CW-G1装置内植物群落根际微生物Alpha多样性最高,门水平上各类菌丰度较为均匀。CW-G1装置内植物相互协作,提高抗氧化酶含量,增强了植物群落抗干扰能力,增加了根际微生物群落多样性、丰度和均匀度,植物-微生物协同高效净化污水。以上结果可为湿地植物的配置与运用提供参考。Abstract: To solve the problem of influence of plant configuration on water purification, the purification rate and response mechanisms of different plant communities in domestic sewage treatment were studied to obtain the optimal plant assemblage of constructed wetlands(CWs). Combined with landscape ecology, 7 kinds of aquatic plants were used to construct 4 types of CWs (CW-G1, CW-G2, CW-G3 and CW-G4) with different assemblages, the removal rate of pollutants from domestic sewage by each constructed wetland was analyzed at HRT of 4 d and HLR of 0.125 m3·(m2·d)−1. Furthermore, the purification mechanisms were discussed on the basis of enzyme activity change, osmotic regulation of plants and rhizosphere microbial succession. The results showed that the plant community in CW-G1 had the highest pollutant removal rate. SOD, POD and CAT enzyme activities of plants in CW-G1 significantly increased, while MDA content significantly decreased. Alpha diversity of the rhizosphere microbial was the highest in CW-G1, and the bacteria distributed equally at phylum level. The cooperation with each other for plants in CW-G1 led to the increase of antioxidant enzyme activity of plants, the enhancement of the anti-interference ability of plant community, and the increase of the diversity, abundance and evenness of rhizosphere microbial community, plant-microbial cooperated well to decontaminate sewage efficiently. This study provides theoretical and technical support for the allocation and application of wetland plants.
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表 1 人工湿地实验装置
Table 1. Constructed wetlands devices
装置 黄花美人蕉 红花美人蕉 千屈菜 黄菖蒲 西伯利亚鸢尾 灯芯草 铜钱草 CW-CK-C.f √ CW-CK-C.i √ CW-CK-L.s √ CW-CK-I.p √ CW-CK-I.s √ CW-CK-J.e √ CW-CK-H.v √ CW-G1 √ √ √ √ CW-G2 √ √ √ √ CW-G3 √ √ √ √ CW-G4 √ √ √ √ CK -
[1] 中华人民共和国生态环境部. 2018中国生态环境状况公报[EB/OL]. [2020-02-01]. http://www.mee.gov.cn/hjzl/zghjzkgb/lnzghjzkgb/201905/P020190619587632630618, 2019. [2] ZHAO Z M, ZHANG X, WANG Z F, et al. Enhancing the pollutant removal performance and biological mechanisms by adding ferrous ions into aquaculture wastewater in constructed wetland[J]. Bioresource Technology, 2019, 293: 122003. doi: 10.1016/j.biortech.2019.122003 [3] 沈莹, 郑于聪, 王晓昌, 等. 不同尺度潜流人工湿地对污染河水的净化机制[J]. 环境工程学报, 2018, 12(6): 1667-1675. doi: 10.12030/j.cjee.201711009 [4] 卢少勇, 金相灿, 余刚. 人工湿地的氮去除机理[J]. 生态学报, 2006, 26(8): 255-262. [5] TILMAN D, ISBELL F, COWLES J M. Biodiversity and ecosystem functioning[J]. Annual Review of Ecology Evolution and Systematics, 2014, 45: 471-473. doi: 10.1146/annurev-ecolsys-120213-091917 [6] REA M, NICOLE P, MONIKA K, et al. Vegetation management intensity and landscape diversity alter plant species richness, functional traits and community composition across European vineyards[J]. Agricultural Systems, 2020, 177: 102706. doi: 10.1016/j.agsy.2019.102706 [7] BALVANERA P, PFIFISTERER A B, BUCHMANN N, et al. Quantifying the evidence for biodiversity effec ts on ecosystem functioning and services[J]. Ecological Letters, 2006, 9(10): 1146-1156. doi: 10.1111/j.1461-0248.2006.00963.x [8] 陈永华, 吴晓芙, 郝君, 等. 4种木本植物在潜流人工湿地环境下的适应性与去污效果[J]. 生态学报, 2013, 34(4): 916-924. [9] GU B, DRESCHEL T. Effects of plant community and phosphorus loading rate on constructed wetland performance in Florida, USA[J]. Wetlands, 2008, 28(1): 81-91. doi: 10.1672/07-24.1 [10] HENNY C, MEUTIA A A. Urban lakes in megacity Jakarta: Risk and management plan for future sustainability[J]. Procedia Environmental Science, 2014, 20: 737-746. doi: 10.1016/j.proenv.2014.03.088 [11] ZHAO H J, WANG Y, YANG L L, et al. Relationship between phytoplankton and environmental factors in landscape water supplemented with reclaimed water[J]. Ecological Indicators, 2015, 58: 113-121. doi: 10.1016/j.ecolind.2015.03.033 [12] CHANG N N, ZHANG Q H, WANG Q, et al. Current status and characteristics of urban landscape lakes in China[J]. Science of the Total Environment, 2020, 712: 135669. doi: 10.1016/j.scitotenv.2019.135669 [13] 崔卫华, 卢少勇, 陈亮, 等. 人工湿地中植物的作用与选择原则[J]. 化工之友, 2006(6): 51-52. [14] 王圣瑞, 年跃刚, 侯文华, 等. 人工湿地植物的选择[J]. 湖泊科学, 2004, 16(1): 93-98. [15] 李海燕, 陈章和. 三种湿地植物的生长及根系溶解性有机碳分泌物研究[J]. 热带亚热带植物学报, 2011, 19(6): 536-542. doi: 10.3969/j.issn.1005-3395.2011.06.008 [16] 魏成, 刘平, 秦晶. 不同基质和不同植物对人工湿地净化效率的影响[J]. 生态学报, 2008, 28(8): 211-217. [17] 郝桂枝, 张银龙, 祝浩翔. 3种人工植物群落对污水净化模拟试验[J]. 安徽农业科学, 2019, 47(11): 81-85. doi: 10.3969/j.issn.0517-6611.2019.11.023 [18] 李莎莎, 田昆, 刘云根, 等. 不同空间配置的湿地植物群落对生活污水的净化作用研究[J]. 生态环境学报, 2010, 19(8): 1951-1955. doi: 10.3969/j.issn.1674-5906.2010.08.032 [19] XU D, WU Y, LI Y, et al. Influence of UV radiation on chlorophyll, and antioxidant enzymes of wetland plants in different types of constructed wetland[J]. Environmental Science and Pollution Research, 2014, 21(17): 10108-10119. doi: 10.1007/s11356-014-2909-5 [20] 薛鑫, 张芊, 吴金霞. 植物体内活性氧的研究及其在植物抗逆方面的应用[J]. 生物技术通报, 2013, 33(10): 6-11. [21] 鲁敏, 裴翡翡, 宁静, 等. 4种湿地植物受污水胁迫生理生化特性影响的相关性研究[J]. 山东建筑大学学报, 2011, 26(5): 416-419. doi: 10.3969/j.issn.1673-7644.2011.05.002 [22] YIN X L, ZHANG J, GUO Y Y, et al. Physiological responses of potamogeton crispus to different levels of ammonia nitrogen in constructed wetland[J]. Water, Air and Soil Pollution, 2016, 227: 65. doi: 10.1007/s11270-016-2763-9 [23] HUA D, MA M Z, GE G F, et al. The role of cyanide-resistant respiration in Solanum tuberosum L. against high light stress[J]. Plant Biology, 2020, 22(3): 425-432. [24] 孙瑞莲, 刘健. 3种挺水植物对污水的净化效果及生理响应[J]. 生态环境学报, 2018, 27(5): 138-144. [25] 孟昱, 路斌, 张钢. 涝渍胁迫下白桦叶和茎中可溶性糖和淀粉含量相关性研究[J]. 河北林果研究, 2018, 33(1): 50-55. [26] 贾琼. 水分胁迫对马铃薯生长与生理特性的影响[D]. 呼和浩特: 内蒙古农业大学, 2009. [27] 梁丽娜, 刘雪, 唐勋, 等. 干旱胁迫对马铃薯叶片生理生化指标的影响[J]. 基因组学与应用生物学, 2018, 37(3): 1343-1348. [28] 李玫, 陈志力, 廖宝文. 5种华南沿海湿地植物对人工含盐污水的生理响应[J]. 安徽农业科学, 2012, 40(27): 13441-13443. doi: 10.3969/j.issn.0517-6611.2012.27.081 [29] KIM Y, LOGAN B E. Simultaneous removal of organic matter and salt ions from saline wastewater in bioelectrochemical systems[J]. Desalination, 2013, 308: 115-121. doi: 10.1016/j.desal.2012.07.031 [30] 陈重军, 朱为静, 黄孝肖, 等. 有机碳源下废水厌氧氨氧化同步脱氮除碳[J]. 生物工程学报, 2014, 30(12): 45-54.