Study On The Treatment Technology Of Tunnel Construction Wastewater

This thesis, by taking tunnel construction waste water as the research subject, experimentally investigated the wastewater quality and flux, and further draw a set of technological process of wastewater treatment to keep the effect on the environment in the permissible range under environmental quality standards, provided theoretical support for the treatment of similar wastewater and technical support for similar engineering construction,also provided technical instruction and data reserve for further theoretical research.The paper presented coagulative treatment of tunnel construction wastewater firstly in china. By analyzing coagulation treatment result of different coagulant,7# Al-polymerization-cationic organic polymer flocculant and non-ionic polypropylene acyle amine are chosen as the operating coagulant. The Taper Whirling Flow Clarifier is characterized by simple, easy operation and good hydraulic conditions in the treatment process of tunnel construction wastewater. So the mechanism of using taper whirling flow clarifier to treat tunnel wastewater.Experiment content includes chosing coagulant and.clarification experiment. Experimental research shows that the 7# flocculant has advantages of rapid destability and good treating effect. As the flocculant is acidic, it is suitable to the meta-alkalescence tunnel wastewater. Besides, the flocculant with polypropylene acyle amine strengthen the flocculation speed of colloid particles, which increasing the density and intensity and reducing the moisture content of flocs. When Q=0.3m3/hr, the average concentration of Suspended Solids(SS), Oil and chemical Oxygen Demands(COD) of the outlet waters are estimated to 41.40mg/L,3.863mg/L, 84.4mg/L, and these removal ratio are 66.10%,49.73% and 19.54%, respectively; when Q=0.375m3/hr, the average concentration of SS, Oil and COD are estimated to 52.10mg/L,3.733mg/L,78.10mg/L, and these removal ratio are 65.62%,60.15%和24.10% respectively. The two outlet water quality can meet the first class requirement of sewage discharge standards. The mechanism of using taper whirling flow clarifier to treat tunnel wastewater and hydraulic loss in the clarifier are analyzed.The result shows that taper whirling flow clarifier has certainly actual application feasibility.Found the appropriate and efficient technological process by technology operation experiment in lab.The process is that adopt Taper Whirling Flow Clarifier as main treatment equipment,7# Al-polymerization-cationic organic polymer flocculant and non-ionic polypropylene acyle amine are chosen to treat tunnel construction wastewater.Using coagulation-settlement experiment, the suspended substances,oils, and other pollutants was reduced,,so as to reach the emission standards..