Research On Evaluation And Utilization Configuration Of Heavy Metals Over Standard Construction Land

Urban construction land is the most disturbing area of human activities to the land system;in recent years,the problem of soil environmental pollution in urban construction land is becoming more and more serious in recent years.The problem of soil safety in new construction land has attracted the attention of scholars both at home and abroad.At the same time,the content of heavy metals is closely related to people's living aspects.In order to realize the evaluation and allocation of heavy metals in the construction land,this paper takes the A city as an example to carry out an empirical study,aiming at a more comprehensive understanding of the situation of excessive heavy metals in the construction land,realizing the optimal allocation of new construction land,and thus promoting the construction of urban and rural areas.The environment of land use is safe,efficient and sustainable.The results show that:(1)According to the guiding principle of integrated application,relying on the "soil environmental quality standard"(GB15618-1995)and the “guiding value of soil pollution risk screening for construction land”(the three solicitation draft),o determine the standard values of heavy metal in the soil of commercial land,science and education land and other land.The standard values of soil heavy metals in various kinds of soil are determined by the“guidelines on risk assessment of contaminated sites”(Draft for consultation)and the “technical guide for risk assessment of Zhejiang pollution sites”(DB33/T 892-2013).The safety utilization of heavy metals in construction land was evaluated,and the evaluation results were characterized by exceeding standard rate,safety utilization grade and evaluation grade map.(2)The evaluation results of heavy metals in soil showed that the most serious soil pollution in the study area was Cr,followed by As,while all the soil samples in Cd,Hg,Zn and Cu had no problem of exceeding the standard.The pollution regularity of different heavy metals in various utilization types is different,and the order of various types of utilization of heavy metal concentration capacity is in turn: industrial land > commercial land > science and education land > residential land.(3)According to the evaluation result of heavy metals in the construction land,the construction land to be occupied in the permitted construction area is optimized.The result shows that,for the land without pollution,the priority is to be allocated to the residential land and the land of science and education,followed by industrial land and commercial land,and the land for pollution can be converted into a science and education land.For industrial land and commercial land,for contaminated land for science and education,consideration of conversion into industrial land and commercial land;for contaminated commercial land to be converted into industrial land;and for contaminated industrial land,new values can be created by reorganizing industrial elements,strengthening high technology content and so on,as far as possible to reduce pollution.