The Influence Of PTA Project On The Groundwater Environment In Xinjiang

Groundwater as an important water resource in the production and life, has been threatened by a variety of pollution. In order to reduce the negative impact of the construction project on groundwater environment, ensure the safety of groundwater resources, must be on the construction project of groundwater environment impact was analyzed and forecast, to early prevention, early control, make the construction project really promote the healthy development of society, environment and economy. This article selects 1.2 million tons/year PTA project in Xinjiang as the research object, by means of field investigation, field and indoor test analysis, etc. Finally through the establishment of the numerical model of solute transport in the study area to assess project on surrounding the possible impact of groundwater environment, for projects where the industrial zone will provide a scientific basis for the rational planning and protection of water resources.Xinjiang 1.2 million tons/year PTA project is a high-risk chemical projects, In the process of production and operation, may affect groundwater quality. In this paper, on the basis of understanding and identifying the geological background a, the regional hydrogeological conditions, the stratum structure characteristics, the dynamic characteristics of groundwater, the present situation of groundwater environment of the study area, Through the study of the risk factors of project identification, environmental risk source analysis, three kinds of prediction scenarios with high risk were selected. Hydrogeological parameters determined by field water penetration test, pumping test, dispersion test, indoor soil column leaching test, leaching test. Through theoretical research and empirical analysis, the three-dimensional flow model of the study area is established. On this basis, coupled solute transport equation, the model of groundwater solute transport was obtained. Setting and forecasting different groundwater pollution scenarios, demonstrating potential impacts and risks of the project on the groundwater environment, and put forward the prevention and control measures to protect the groundwater environment, which provides the basis for engineering design and construction. The main results of this paper are as follows:(1) Sampling and analysis of groundwater quality in project area, it is concluded that the groundwater chloride ion is generally exceeding standard, and the sodium ion, iron ion, sulfate ion and ammonia nitrogen showed varying degrees of excessive phenomenon.(2) In the research project, the risk of material, the risk of the production process, the risk of the storage process, the risk of transport process and other environmental risks are identified, determine the mixed wastewater leakage, xylene tank bottom leakage and p-xylene oil tank explosion as the source of environmental risk items.(3) Combined with the identification results of environmental risk sources in the project area and the analysis of indoor and outdoor test, coupled with solute transport equation, the model of groundwater solute transport in the study area is obtained based on the three-dimensional flow model in the simulation area, predict the influence of different scenarios on the groundwater environment of the project. The results obtained from the model prediction are as follows, the prediction results of the tank area under the condition of damage and long-term leakage are in the greatest impact range, 50 years later, the influence range of groundwater was 131400m2, and the maximum migration distance was 314m, not directly affect surrounding civil water wells, but a potential threat to the region of water supply; Project is whether can take seepage control measures or whether can timely monitoring both work to prevent the groundwater contamination has very important significance. If appropriate preventive measures and emergency treatment measures can be taken, the influence of non-normal working conditions on the groundwater environment can be controlled to the extent that the groundwater environmental capacity can be accepted.