【作者】 马宁；

【导师】 高健磊；

【作者基本信息】 郑州大学 ， 工程硕士（专业学位）， 2017， 硕士

【摘要】 污水处理厂作为城市市政基础设施的重要组成部分,在节约淡水资源、控制水污染、改善人居生态环境等方面起着非常巨大的作用。就目前世界范围内的污水处理厂来看,大部分污水处理厂都是露天式的地上建设。可随着城市化的不断扩张,主城区面积的不断扩大,城市的土地资源变得越来越昂贵。地下式污水处理厂因污染少、占地面积小、对地上景观无显著影响等因素,在土地资源紧张、环境污染问题日益严重的大城市,越来越成为新建污水处理厂发展的趋势,为环保工作者所重视。郑州市南三环污水处理厂是我国中原地区第一座半地下式污水处理厂,设计规模10万m3/d,主体工艺采用前置缺氧A2/O工艺,出水水质执行《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准。本文以南三环污水处理厂为研究对象,并选取相同处理规模相近设计进出水水质的郑州市某地上式污水处理厂作为对照,分别从工程设计、设备安装、工艺运行、建设运行成本等方面分析了半地下式污水处理的设计和运行特点。本文的主要结论如下:在工程设计上,由于半地下式污水处理厂对土地利用的集约化程度更高,出于节约用地的考虑,在二沉池池型的选择上,更适合选用结构紧凑、易于共壁合建的平流式沉淀池。在对深度处理工艺的选择上,高效沉淀池集絮凝、混凝、沉淀、排泥、回流等若干功能于一体,较传统混凝沉淀工艺更具优势。在除臭系统的设计上,地上式污水处理厂只需收集处理格栅井、曝气沉砂池以及贮泥池的臭气,而半地下式污水处理厂需要对箱体内所有构筑物以及箱体外污泥脱水段构筑物内的臭气实现全收集、全处理,生物除臭投入的费用是地上式污水处理厂的10倍多;由于半地下式污水处理厂大部分构筑物都布置在箱体内,大型设备的安装往往需要通过箱体顶部的吊装孔完成,因此其设备安装程序更加复杂,设备的检修难度也加大。另外,由于设备常年处于地下,其材质要求也更高;从运行实践来看,南三环半地下污水处理厂的全年出水保证率除TP(92%)外,均达到97%以上,处理水质良好;冬季低温条件下出水保证率虽然较全年有所下降,但是仍可保持95%以上的达标率,运行效果良好;另外,与对照地上污水处理厂相比,冬季低温条件下,地下污水处理厂的TN达标率仍可达到95%以上,较地上污水处理厂(冬季TN达标率80%)具有更加稳定的脱氮效果;从投资和成本来说,虽然半地下污水处理厂的厂区工程投资和年平均运行成本分别较对照地上污水处理厂增加了100%和24%,但是其占地面积节约了46%左右,具有良好的环境效益和社会效益。更多还原

【Abstract】 As an important part of urban municipal infrastructure,wastewater treatment plants(WWTP)play a very important role in conserving fresh water resources,controlling water pollution and improving living environment.Most of the WWTPs in the world now are constructed in the open air.However,urban land becomes increasingly expensive with the continuous expansion of urbanization.Thus,the underground WWTP would be the developing trend in super cities whose land sources are increasingly in shortage for its less pollution,less area occupied and insignificant influence on landscape.As the first semi-underground WWTP in the central plains of China,Zhengzhou Nansanhuan WWTP adopts pre-anoxic A2/O process with design scale of100,000m3/d,and its effluent quality can meet first class of A of < Discharge standard of pollutants for municipal wastewater treatmentplant >(GB18918-2002).By comparing with a similar aboveground WWTP in Zhengzhou,the engineering design,equipments installation,operation practice and construction cost of Nansanhuan semi-underground WWTP was analyzed to study the design and operation characteristics of the semi-underground WWTPs.The main conclusions are as follows:In the engineering design,due to the high degree of intensiveness of land use of semi-underground WWTP,horizontal flow sedimentation tank is preferred as secondary sedimentation tank for its compact structure.Besides,the high-efficient sedimentation tank that integrates flocculation,coagulation,precipitation,sludge discharge and reflux,etc is more suitable for the advanced treatment processes.In the design of the odor control system,while the above-ground WWTP collects only the odor of the grid,aeration grit chamber and the sludge storage tank,the semi-underground WWTP is required to implement full collection and treatment of all the odor in the structures located in the box and sludge dewatering section outside the box,which induces more than 10 times cost for biological deodorant input thanthe above-ground WWTP.In addition,the equipments installation and inspection are more complicated for most of the structures are arranged in the box,and the large scale equipments have to be installed through the holes for hoist.In addition,the high requirement of equipments material are necessary to avoid corrosion in underground.In operation practice aspect,more than 97% of assurance rate could be achieved in Nansanhuan WWTP except for TP whose assurance rate was 92% in the whole2016.It’s worth noting that the 95% of assurance rate was remained during the winter.Contrastively,the assurance rate of TN dropped to 80% in the above-ground WWTP.Thus,the semi-underground WWTP possesses more stable nitrogen removal effect.In investment and costs,although the investment within-site and annual average cost is increased 100% and 24%,respectively than the contrastive above ground WWTP,it has 46% saving in occupied area.Thus,the semi-underground WWTP has a good environmental and social benefits.更多还原