大型城市污水处理厂全地下式改建思路与方案

Ideas and Schemes for Fully Underground Reconstruction of Large-Scale Urban WWTP

早期建成的城市污水处理厂离主城区较远,但随着城市发展,一方面使得公众接触市政污水设施,导致“邻避”等环境问题,另一方面促使污水处理厂向地下发展,并逐渐展示出优异的环境相容性和土地综合开发潜力。以某大型污水处理厂原址下地改建为案例,一是最大化土地利用并释放城市紧缺的土地资源,二是极大提升了片区的城市面貌,并通过综合开发提供了可供市民休闲的城市公共空间及新型产业拓展空间。改建后的生化方案拟采用多段缺氧-好氧(AO)工艺,并通过深度处理提升出水TN和SS指标。由于规模大且改建期间要求不减量、不降标,研究采用了“建一拆一、先建后拆”的分阶段实施方案,通过合理分期确保水量平衡和下地改建的可行性。改建完成后该污水处理厂吨水用地指标从现状约0.478 m^(2)/(m^(3)·d^(-1))降至0.236 m^(2)/(m^(3)·d^(-1)),其思路可为大型城市大规模污水处理厂下地改建提供一定借鉴。

Early built urban wastewater treatment plants(WWTPs)are far away from the main city area.With development of city,on one hand,the public is exposed to municipal wastewater facilities,leading to environmental problems such as"neighborhood",on the other hand,it promotes the development of WWTPs underground,and gradually demonstrates excellent environmental compatibility and land comprehensive development potential.Taking the underground reconstruction in original site for a WWTP as a case,firstly,it maximizes the land use and releases the scarce land resources of the city,and secondly,it greatly enhances the urban landscape of the area and provides urban public space for public recreation and new industrial expansion space through comprehensive development.The biochemical program of the wastewater plant reconstruction plans to adopt multi-stage anoxic-oxic(AO)process,and through advanced treatment to improve the effluent TN and SS indices,due to the large scale and requirement not to reduce the quantity and lower standards during the reconstruction period,the study adopted a phased implementation plan of"build one,demolish one,build first,then demolish",and ensure the water balance and the feasibility of the underground reconstruction through reasonable stages.After all reconstructions are completed,water usage per unit area is reduced from about 0.478 m^(2)/(m^(3)·d^(-1))to 0.236 m^(2)/(m^(3)·d^(-1)).Its ideas can provide certain reference for the large-scale WWTPs to reconstruction underground in large cities.