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

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.

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 to 1566.13 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.