A Study on Analyzing the Pollutants of Construction Wastewater in Northern Section of Qinling Tunnel of the YinHanJiWei Project and Its Treatment Processes

The Qinling tunnel is an important part of hanjiang-to-weihe river water transfers project.In the construction period of northern section of Qinling tunnel, large amount of wastewater was produced and after direct discharged into water, the adverse effects to the environment will become a serious issue. According to the analysis by drilling and blasting method of construction and the prediction of construction wastewater by TBM in the later stage, it can be found that tunnel construction wastewater hashigh SS, low COD as well as relatively small amount of nitrogen and phosphorus nutrients. Therefore, it can be regarded as inorganic polluted wastewater. Meanwhile, by continuous monitoring on wastewater, it proves the accuracy of the formal analysis and prediction. According to the constitution of wastewater, the treatment combined with coagulation, filtration, manganese sand filter, adsorption is proposed. The related researches show thate the mentioned treatmente removal rate for suspended solids, COD and ammonia nitrogen can be more than 90%, 85% and 60% respectively. The treated water quality can meet "The Surface Water Environment Quality Standard"（GB3838-2002）of the Ⅱwater index. Consideration of tunnel construction characteristic and analysis of variation pattern of pollutants in wastewater provide basis and reference for construction wastewater treatment.