-
黑臭水体是城市化进程中水生系统面临的一个重要的环境问题. 2015年国务院发布的《水污染防治行动计划》(简称“水十条”)中明确要求,采取控源截污、垃圾清理、清淤疏浚、生态修复等措施,加大黑臭水体治理力度[1]. 其中生态修复主要利用微生物、水生动植物等生物的生命活动,对水中污染物进行转移、转化及降解,恢复水体在一定污染负荷下的自净化能力[2]. 在水生态修复工作中,恢复水生植物尤其是恢复沉水植物被广泛认为是水体治理的有效途径[3]. 目前用于恢复河湖生态的沉水植物种植常通过排干上覆水、清淤后将沉水植物种植于水体土壤中,再蓄水使沉水植物生长达到净化水质、防治污染的目的. 但该种植方式耗时长、成本高,且河湖清淤后的底质较硬,植物生长必需的营养物质也随清淤过程被移除,导致沉水植物成活率较低. 另外,部分城市硬化沟渠因其“三面光”的特点,在发生黑臭后的生态修复主要依靠生态浮岛种植浮水植物,而沉水植物需要沉没于水中完成生活史,其通过光合作用产生的氧气都释放到水中,可以显著增加水体中的溶解氧含量[4]. 因此,开发新型种植技术提高沉水植物的河湖生态修复效果具有重要意义.
针对沉水植物种植困难的问题,目前有基于砾石和滤料构成的生物循环床[5]、网床或网箱[6],以及基于苯乙烯和树脂构成的生态浮岛[7]. 而这些基质都存在经济和环境效益问题,例如维护成本高、微塑料释放等. 污泥陶粒是污泥稳定化、轻量化及无害化处置的产物,具有比表面积大和多孔结构等特性. 据统计,至2021年全国已建成
2827 座城市污水处理厂,每年产生的污泥量约3000 —6000 万t[8]. 我国污水处理产业因处理能力、技术和投入仍存在不足,行业内“重水轻泥”的现状依然没有得到有效改善,导致大量污泥未能得到有效处置[9]. 目前研究报道的污泥陶粒基于其多孔结构的特性已被广泛用作建筑材料[10]、人工湿地基质[11 − 13]、滤池填料[14 − 16]和各种水处理设备的滤材[17]. 已报道的污泥陶粒中,吸水率大多在50% 以下,导致其应用于人工湿地时需补充土壤或砂砾才能满足湿地植物的种植[12]. 而亲水性污泥陶粒保水保墒更利于植物的定植和生根,在提供固着基质的同时,还能避免植物烧根[17]. 同时亲水性污泥陶粒的吸附性能使得其可为植物根系提供营养物质,更利于植物的生长发育. 通过污泥陶粒构建的人工湿地用于污水处理后,能值产出和可持续性指数相较其他污泥处置方式更高[11]. 因此,开发利用亲水性污泥陶粒种植水生植物不仅能解决沉水植物种植困难的问题,还能进一步实现污泥资源化利用,具有可观的经济效益,符合可持续性发展的需求.基于此,本研究提出亲水性污泥陶粒可作为水生植物的栽培基质(“新型土壤”),提高水生植物存活率. 开发一套运用亲水性污泥陶粒种植沉水植物构建“水下森林”生态系统的新策略,以恢复淡水生态系统的结构和功能并改善水质. 该策略的实施将为城市淡水生态系统实现固碳增汇,为“双碳”目标的实现提供新思路.
基于亲水性污泥陶粒开展城市黑臭水体生态修复的应用示范
Remediation of urban black-odorous water based on hydrophilic sludge ceramsite
-
摘要: 重建水生植物尤其是沉水植物群落结构,被广泛认为是水体修复治理的有效途径. 目前城市河、湖、渠的黑臭水体治理主要采用截污、清淤等方式,生态功能恢复大多围绕生态浮岛开展浮水、挺水植物的种植,加之城市硬化沟渠等封闭的水系统由于硬化的底质无法种植沉水植物,造成了城市黑臭水体生态修复收效甚微. 本文以江汉大学清源河作为城市硬化沟渠黑臭水体的典型代表,利用亲水性污泥陶粒作“新型土壤”种植苦草(Vallisneria natans (Lour.) H. Hara),构建“水下森林”生态系统,实现城市黑臭水体的生态原位修复. 种植沉水植物后,沉水植物生物量从241.20 g显著增长至
1566.13 g,清源河中水生微型生物的生物多样性显著提升,蓝藻(Cyanobacteria)相对丰度显著降低,总体水质从劣V类提升至近III类,且平稳运行两年未返黑臭. 该应用示范体系中,亲水性污泥陶粒一方面为苦草提供固着基质,实现了无底泥硬化沟渠中沉水植物的种植和生长,另一方面可为水生微型生物提供栖息地. 清源河示范治理工程应用亲水性污泥陶粒开展城市黑臭水体生态修复,不仅将城市生态系统中的污泥烧制成陶粒后回用到淡水生态系统的修复,同时实现污泥的无害化和资源化的循环利用,为城市黑臭水体的修复及生态重构和国家达成“碳中和”目标提供了新思路.Abstract: The reconstruction of aquatic plant communities, particularly submerged plant communities, is widely acknowledged as an effective approach for the remediation of water bodies. Recently, the treatment of urban black-odorous water bodies has primarily focused on pollution interception and dredging. Efforts to restore ecological functions have predominantly centered on cultivating floating and emergent plants on ecological floating islands. Moreover, closed water systems such as urban hardened ditches are incapable of supporting submerged plant life due to their hardened bottom material, resulting in minimal ecological restoration effect on in urban black-odorous water bodies. The present study takes the Qingyuan River at Jianghan University as a typical representation of urban hardened ditches with black-odorous water bodies. It employs hydrophilic sludge ceramsite as “new soil” for planting Vallisneria natans (Lour.) H. Hara, thereby establishing an “underwater forest” ecosystem to achieve in-situ ecological restoration of urban black-odorous water bodies. After planting submerged plants, the biomass of submerged plants significantly increased from 241.20 g to1566.13 g. The biodiversity of aquatic microorganisms in the Qingyuan River significantly improved, with a notable decrease in the relative abundance of Cyanobacteria. The overall water quality improved from below Class V to nearly Class III, and the system operated stably for two years without returning to a state of black and odorous water. In this system, the sludge ceramsite serves a dual purpose: firstly, it provided a stable rooting medium, enabling submerged plants to thrive in hardened ditches without natural sediment; secondly, it created habitats for plankton and microorganisms. The application in Qingyuan River utilizes hydrophilic sludge ceramsite for the ecological restoration of urban black-odorous water bodies. This approach not only repurposes sludge from the urban ecosystem by converting it into ceramsite for freshwater ecosystem restoration but also achieves the harmless and resourceful recycling of sludge. This innovative approach provides a new direction for the restoration and ecological reconstruction of urban black-odorous water bodies, as well as contributes to the national goal of achieving carbon neutrality. -
图 4 亲水性污泥陶粒种植沉水植物构建“水下森林”淡水生态系统种植点和对照点示意图(a),种植前(b)后(c)水质情况,2022—2023年对照点(d,f)和种植点(e,g)的水质变化
Figure 4. Construction of ‘underwater forest’ freshwater ecosystem by planting submerged plants with hydrophilic sludge ceramsite schematic diagram of planting sites and control sites (a), water quality before (b) and after (c) planting, water quality changes at control sites (d, f) and planting sites (e, g) from 2022 to 2023
表 1 清源河采样点主要污染指标与地表水环境质量的比较
Table 1. Comparison of main pollution index and surface water environmental quality in Qingyuan River sampling sites
点位
Sites时间
TimeDO/
(mg·L−1)TP/
(mg·L−1)TN/
(mg·L−1)NH4+-N/
(mg·L−1)NO3−-N/
(mg·L−1)CODMn/
(mg·L−1)1#(对照点)
Control site2022.11 8.10 0.39 6.92 2.51 1.58 5.60 2023.02 8.37 0.08 1.93 0.71 0.84 3.28 2023.05 5.88 0.14 1.80 1.38 0.53 5.30 2#(对照点)
Control site2022.11 5.37 0.56 8.87 5.30 1.34 5.80 2023.02 10.69 0.05 1.17 0.39 0.55 4.12 2023.05 7.49 0.12 0.97 0.36 0.33 3.50 3#(种植点)
Planting site2022.11 6.33 0.16 2.91 1.02 1.12 4.30 2023.02 10.06 0.08 1.28 0.43 0.44 2.96 2023.05 11.36 0.03 1.09 0.13 0.76 3.50 4#(种植点)
Planting site2022.11 5.59 0.12 1.33 0.43 0.83 3.30 2023.02 10.36 0.06 1.19 0.22 0.13 3.20 2023.05 11.47 0.03 0.69 0.12 0.46 2.40 5#(对照点)
Control site2022.11 2.74 0.50 6.79 4.45 0.22 8.00 2023.02 6.02 0.43 6.94 4.92 1.13 4.08 2023.05 6.93 0.23 1.80 1.43 0.53 4.10 I类[19] — ≥ 7.5 ≤ 0.01 ≤ 0.2 ≤ 0.15 — ≤ 2.0 II类[19] — ≥ 6 ≤ 0.025 ≤ 0.5 ≤ 0.5 — ≤ 4.0 III类[19] — ≥ 5 ≤ 0.05 ≤ 1.0 ≤ 1.0 — ≤ 6.0 IV类[19] — ≥ 3 ≤ 0.1 ≤ 1.5 ≤ 1.5 — ≤ 10 V类[19] — ≥ 2 ≤ 0.2 ≤ 2.0 ≤ 2.0 — ≤ 15 -
[1] 中华人民共和国国务院. 国务院关于印发水污染防治行动计划的通知[EB/OL]. [2015-04-16]. [2] 王胜利, 张宏耀, 杨青, 等. 本土微生物引导的原位生态修复技术在白洋淀水域污染治理中的应用[J]. 环境工程, 2023, 41(增刊2): 62-64. WANG S L, ZHANG H Y, YANG Q, et al. Application of in situ ecological restoration technology guided by indigenous microorganisms in Baiyangdian water pollution control project[J]. Environmental Engineering, 2023, 41(Sup 2): 62-64 (in Chinese).
[3] 邢书语, 原璐彬, 刘鑫, 等. 沉水植物体表附着物重量及碳氮磷元素含量特征分析[J]. 环境化学, 2021, 40(7): 2092-2104. doi: 10.7524/j.issn.0254-6108.2021011103 XING S Y, YUAN L B, LIU X, et al. Characterization of dry weight and elements contents of biofilms attached on aquatic macrophytes and non-living substrates surface[J]. Environmental Chemistry, 2021, 40(7): 2092-2104 (in Chinese). doi: 10.7524/j.issn.0254-6108.2021011103
[4] 龚深, 巢传鑫, 邹冬生, 等. 人工湿地中植物对污染物去除机理研究进展[J]. 湿地科学, 2023, 21(6): 927-935. GONG S, CHAO C X, ZOU D S, et al. Research progress on pollutant removal mechanism of plants in constructed wetland[J]. Wetland Science, 2023, 21(6): 927-935 (in Chinese).
[5] 商放泽, 贾娟华, 李兵, 等. 基于FBR生物循环床的小微黑臭水体治理研究[J]. 环境科学与技术, 2021, 44(增刊2): 259-265. SHANG F Z, JIA J H, LI B, et al. Study on treatment of small black and odorous water body based on FBR biological circulating bed[J]. Environmental Science & Technology, 2021, 44(Sup 2): 259-265 (in Chinese).
[6] 吴建勇, 温文科, 吴海龙, 等. 种植方式对沉水植物生态修复效果的影响[J]. 湿地科学, 2015, 13(5): 602-608. WU J Y, WEN W K, WU H L, et al. Effects of different planting patterns on the ecological restoration of the submerged plant nets[J]. Wetland Science, 2015, 13(5): 602-608 (in Chinese).
[7] CHANG Y Y, CUI H, HUANG M S, et al. Artificial floating islands for water quality improvement[J]. Environmental Reviews, 2017, 25(3): 350-357. [8] 从“重水轻泥”到“泥水并重”污泥处置产业面临新的使命和机遇[J]. 中国环保产业, 2023 (1): 16-17. From “emphasizing water over mud” to “paying equal attention to mud and water” , the sludge disposal industry is facing new missions and opportunities [J]. China Environmental Protection Industry, 2023 (1): 16-17 (in Chinese).
[9] FENG L Y, LUO J Y, CHEN Y G. Dilemma of sewage sludge treatment and disposal in China[J]. Environmental Science & Technology, 2015, 49(8): 4781-4782. [10] 王珂乐. 城市污泥处理处置与建材化利用研究[J]. 河南科技, 2023, 42(4): 59-62. WANG K L. Research on urban sludge treatment and disposal and utilization of building materials[J]. Henan Science and Technology, 2023, 42(4): 59-62 (in Chinese).
[11] SHAO Q, ZHANG Y, LIU Z, et al. Phosphorus and nitrogen recovery from wastewater by ceramsite: Adsorption mechanism, plant cultivation and sustainability analysis[J]. The Science of the Total Environment, 2022, 805: 150288. [12] WU H M, FAN J L, ZHANG J, et al. Intensified organics and nitrogen removal in the intermittent-aerated constructed wetland using a novel sludge-ceramsite as substrate[J]. Bioresource Technology, 2016, 210: 101-107. [13] CHENG G, LI Q H, SU Z, et al. Preparation, optimization, and application of sustainable ceramsite substrate from coal fly ash/waterworks sludge/oyster shell for phosphorus immobilization in constructed wetlands[J]. Journal of Cleaner Production, 2018, 175: 572-581. [14] LIU Y S, DU F, YUAN L, et al. Production of lightweight ceramisite from iron ore tailings and its performance investigation in a biological aerated filter (BAF) reactor[J]. Journal of Hazardous materials, 2010, 178(1/2/3): 999-1006. [15] 孙康康, 张凌燕, 刘理根, 等. 赤泥强磁尾矿制备水处理陶粒滤料的研究[J]. 硅酸盐通报, 2016, 35(7): 2270-2275. SUN K K, ZHANG L Y, LIU L G, et al. Preparation of ceramsite filter materials for water treatment by tailings with high-intensity magnetic separation from red mud[J]. Bulletin of the Chinese Ceramic Society, 2016, 35(7): 2270-2275 (in Chinese).
[16] 李倩炜, 周笑绿, 李环, 等. 粉煤灰陶粒填料制备及用作曝气生物滤池填料的性能考察[J]. 化工进展, 2015, 34(9): 3379-3382. LI Q W, ZHOU X L, LI H, et al. Research on the preparation of fly ash ceramisite as filler of BAF and its performance in wastewater treatment[J]. Chemical Industry and Engineering Progress, 2015, 34(9): 3379-3382 (in Chinese).
[17] 叶晶, 怀志文, 黄咏文, 等. 底泥陶粒在水生态修复中的应用[J]. 中南农业科技, 2023, 44(5): 242-245. YE J, HUAI Z W, HUANG Y W, et al. Application of sediment ceramsite in water ecological restoration[J]. South-Central Agricultural Science and Technology, 2023, 44(5): 242-245 (in Chinese).
[18] 郭鹤方, 甄志磊, 赵林婷, 等. 潮汐流-潜流人工湿地对城市污染水体中氮的去除[J]. 环境化学, 2021, 40(12): 3887-3897. doi: 10.7524/j.issn.0254-6108.2021053002 GUO H F, ZHEN Z L, ZHAO L T, et al. Research on the removal effect of tidal flow–subsurface flow constructed wetland on nitrogen in urban polluted water[J]. Environmental Chemistry, 2021, 40(12): 3887-3897 (in Chinese). doi: 10.7524/j.issn.0254-6108.2021053002
[19] GB 3838, 地表水环境质量标准 [S]. 2002 [20] 王英哲, 胡海燕, 朱琳, 等. 富营养化对靖海湾浮游植物群落的影响[J]. 环境化学, 2024, 43(3): 1010-1024. WANG Y Z, HU H Y, ZHU L, et al. Effects of eutrophication on phytoplankton community in Jinghai Bay[J]. Environmental Chemistry, 2024, 43(3): 1010-1024(in Chinese).
[21] CAO J X, SUN Q, ZHAO D H, et al. A critical review of the appearance of black-odorous waterbodies in China and treatment methods[J]. Journal of Hazardous Materials, 2020, 385: 121511. [22] 代威, 纠敏, 王文辉, 等. 人工微宇宙下粘细菌捕食对微生物群落结构的影响[J]. 微生物学报, 2020, 60(3): 452-463. DAI W, JIU M, WANG W H, et al. Effects of myxobacteria predation on microbial community structure of artificial microcosm[J]. Acta Microbiologica Sinica, 2020, 60(3): 452-463 (in Chinese).
[23] BURIAN A, PINN D, PERALTA-Maraver I, et al. Predation increases multiple components of microbial diversity in activated sludge communities[J]. Multidisciplinary Journal of Microbial Ecology, 2022, 16(4): 1086-1094. [24] 焦岗伟, 赵倩名, 何培民, 等. 基于化感原理的复合抑藻剂研究进展[J]. 环境污染与防治, 2023, 45(9): 1287-1293. JIAO G W, ZHAO Q M, HE P M, et al. Progress on the study of compound algaecide based on allelopathy[J]. Environmental Pollution & Control, 2023, 45(9): 1287-1293 (in Chinese).
[25] 任庆莲, 徐超, 郑瑞文, 等. 多水源水库蓝藻水华风险防范措施成效研究: 以玉清湖水库为例[J]. 湿地科学, 2023, 21(6): 820-829. REN Q L, XU C, ZHENG R W, et al. Study on effectiveness of prevention and control measures for cyanobacteria bloom risk in the multi-source reservoir: Take the yuqinghu reservoir as an example[J]. Wetland Science, 2023, 21(6): 820-829 (in Chinese).
[26] 文刚, 白愿楠, 王茹, 等. 淡水硅藻水华成因与控制技术研究进展[J]. 环境科学研究, 2024, 37(2): 316-325. WEN G, BAI Y N, WANG R, et al. Review of causes and control technologies of freshwater diatom blooms[J]. Research of Environmental Sciences, 2024, 37(2): 316-325 (in Chinese).
[27] WANG T T, LIU H C. Aquatic plant allelochemicals inhibit the growth of microalgae and cyanobacteria in aquatic environments[J]. Environmental Science and Pollution Research, 2023, 30(48): 105084-105098.