城市轨道交通车辆段生产废水处理工艺改造

通过调研运营多年的城市轨道交通车辆段生产废水处理厂,发现实际生产废水量远小于设计规模,运行中存在隔油沉淀调节池人工刮油困难、重力排泥管道堵塞、气浮设备中的释放器经常堵塞等问题。由此建议:废水处理厂设计规模宜为50～100 m3/d;在轴箱清洗和转向架清洗处就地设隔油沉淀池;将调节和隔油沉淀功能分离,废水泵站兼具水量调节功能,平流式隔油沉淀池承担隔油沉淀功能;采用压力溶气气浮设备并使用压缩空气冲洗TV-Ⅱ型溶气释放器。北京地铁某车辆段生产废水处理厂改造采用了以上措施,出水水质优于《污水综合排放标准》(GB8978—1996)的二级标准。

Reconstruction of Treatment Process of Production Wastewater from Urban Rail Transit Vehicle Depot

Through investigation on WWTPs of urban rail transit vehicle depots which have been operated for many years,it is found that the actual production wastewater quantity is much lower than the design capacity,and problems exist,such as difficulty in manual oil removal in oil separation,sedimentation and equalization tank,blockage in gravity sludge discharge pipeline,and blockage in release gear of dissolved air floatation equipment.Therefore,the following suggestions are proposed: ① The design capacity of production wastewater treatment plant of urban rail transit vehicle depot should be controlled at 50 to 100 m3/d;② Oil separation and sedimentation tank is used to treat the production wastewater at the washing place of the bearing box and turning frame;③ The functions of equalization,oil separation and sedimentation are separated by pump station for wastewater volume equalization and horizontal-flow oil separation and sedimentation tank for oil separation and sedimentation;④ The pressure dissolved air floatation equipment is adopted,and the compressed air is used for washing the release gear of TV-Ⅱ type.After the reconstruction of a WWTP of Beijing urban rail transit vehicle depot by taking the above-mentioned measures,the quality of the treated effluent is superior to the second class criteria specified in the Integrated Wastewater Discharge Standard(GB 8978-1996).