The Research Of Soil-Environmental Capacity Of Heavy Metals And Critical Load Of Acid Deposition Of Mount Lao

The prevention and control of soil pollution have been arranged one of the most important works of ecological protection in the 11th five-year plans of our country. Launching a preparatory research of soil-environmental capacity in a region has been arranged in national environmental protection plans. Now the present condition investigation of soil pollution in all our country has started, the purpose is to get to know the present condition of the soil in our country and lay a foundation for soil environmental protection. This fully shows that the government thinks much highly of the soil pollution. This thesis started with the zone of Mount Lao to study soil-environmental capacity of heavy metals and critical load of acid deposition.This thesis firstly investigated the form and distribution, types and characteristics of the soil of Mount Lao from five aspects. It described chemical component ,pH and exchange property, physical component, and so on.This provided basic data for the research of soil-environmental capacity of heavy metals and critical load of acid deposition of Mount Lao.This thesis established the concept of soil-environmental capacity. Based on the static capacity and considered the purified capacity of soil, it is the whole capacity of soil, or soil-environmental dynamic capacity. So the mathematical model of soil-environmental capacity was selected and established on the basis of the concept and the theory of soil-environmental capacity. According to the basic data of Mount Lao and the established model, we calculated the soil-environmental capacity of Cu, Pb, Zn, Cd, Cr, As in several kinds of soil of Mount Lao. The outcome has been compared and analysed. The annual soil -environmental dynamic capacity is bigger than static capacity, it proves that soil has some capacity because of its self-purification and pollutant's output. Soil has capacity for pollutant and soil can regulate pollutant. The annual static capacity and dynamic capacity have something to do with soil -environmental quality standard and time. With the rising of the numbers of years, the total dynamic capacity Cs and the amount Cs-Cso rise also.According to the concept of critical load of acid deposition and the different methods of calculation, this thesis collected the model of simple-mass-balance(SMB) to calculate critical load of acid deposition, based on plants respond, soil stability, the density of Al, pH and alkalinity standard . We collected soil stability standard, density of Al standard and alkalinity standard to determine the critical load of acid deposition of Mount Lao, the smallest number of all the numbers was the critical load of acid deposition. The critical load of acidity is 1.53keq/(hm~2·a), the critical load of potential acidity is 0.32keq/(hm~2·a), the critical load of N is 0.47keq/(hm~2·a), the critical load of S is 2.84keq/(hm~2·a). On the basis of the critical load of S deposition and the S deposition amount of Mount Lao over the years, the S deposition amount of Mount Lao over the years surpasses the critical load of S deposition, it should be decreased 3.7-66.8%.