武汉北湖硬质底板湖泊治理技术研究

Treatment Technology for Hard-Bottom North Lake in Wuhan

随着城市化的不断发展,硬质底板景观湖泊的水质问题越来越受到关注。武汉北湖属于硬质底板景观湖泊,存在藻类暴发严重、水生态差、水体透明度低等问题。基于此,采用去除底板、水生态、水循环等措施进行北湖水体修复中试。结果表明,在3个实验区中去除底板、水循环和水生态3种措施联用的效果最佳,与湖泊原水相比,总氮、总磷、浊度和藻密度分别降低19.6%、30.0%、26.5%和68.7%。其原因在于微生物、植物吸收与循环过滤的共同作用。在藻类易暴发时期,仍能使水体水质达到Ⅳ类水标准。去除底板后底质中有机质、总磷、总氮等都有所降低,实验区的优势菌门为变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi),最大相对丰度分别为60.86%和71.33%,同时微生物的α多样性有所提升,有利于湖泊底质的稳定性和生态完整性。该方法的成本为0.13~0.14元/m^(3),具有较高的经济性,可为其他硬质底板景观湖泊治理所借鉴和推广。

As urbanization continues to advance,the water quality of hard bottom landscape lakes has garnered increasing attention.The North Lake in Wuhan exemplifies a hard bottom landscape lake that is experiencing significant algal blooms,deteriorating aquatic ecology,and reduced water transparency.Based on this,a comprehensive approach involving the removal of hard bottom,enhancement of aquatic ecology,and implementation of water circulation measures was employed to conduct a pilot test for the remediation of the water body in North Lake.In the three experimental areas,the synergistic effects of hard bottom removal,water circulation enhancement,and ecological remediation yielded optimal results.When compared to untreated lake water,reductions in total nitrogen,total phosphorus,turbidity,and algal density were observed at percentages of 19.6%,30.0%,26.5%,and 68.7%,respectively.The underlying cause was attributed to the synergistic effects of microorganisms,plant uptake,and cyclic filtration.During periods of algal blooms,the water quality could still meet the classⅣsurface water standard.The removal of hard bottom resulted in a reduction of organic matter,total phosphorus,and total nitrogen in the substrate.The dominant bacterial phyla identified in the experimental areas were Proteobacteria and Chloroflexi,exhibiting maximum relative abundances of 60.86%and 71.33%,respectively.Concurrently,there was an increase in microbialα-diversity within the experimental areas,which contributed positively to the stability and ecological integrity of the lake bottom.The cost ranged from 0.13 yuan/m^(3) to 0.14 yuan/m^(3),demonstrating a high level of economic efficiency and serving as a valuable reference for potential application and promotion in other hard bottom landscape lakes.