摘要
本文简要地介绍了土壤环境容量研究的现状和展望,对当前以“黑箱”理论为基础或以“总量”与“有效态”关系为起点的容量值作了评论。认为这是一个表观值,提出容量值应为“范围值”并给出了以实验为基础的经验修正式。
Current situation and prospect of the studies on the loading capacity of soil for pollutants (LCSP) are briefly introduced in this paper. The values of LCSP which are based at present on the 'black box' theoretics or take the 'total amount' and 'availability' as starting points are reviewed. The main problems existing in the present studies are described as follows. (1) there is a lack of long-term experimental results. Tests with wetland rice as an index for four years in succession showed that the significant difference of the LCSP value among the years appeared in the same soil. The coefficient of variability reached 51—66% and the highest value was 3.2—4.6 times as much as the lowest one. Therefore the reliable values of LCSP should be acquired from the long-term experiment in a fixed region, and the lowest value is the appropriate one. (2) There is certain limitation in the choosing of chemical compounds. For instance, the marked differences were found in the yield decrement and the amount of As absorbed by rice plant at the same concentration of As added with various compounds. So, the choice of appropriate chemical compounds, or the amendment of difference among the compounds used, remains to be further studied. (3) The experiments of combination pollution of heavy metals are scarce. For example, the experiments of combination pollution of Pb, Cd, Cu, Zn and Ni showed that the value calculated from single element was only an 'apparent value' or 'apparent LCSP (ALCSP)' and should be amended to the 'practical LCSP (PLCSP)' with the following empirical amendment equation:PLCSP=ALCSP×C^(1/n)_s/∑C^(1/n)_iwere C. , n and C_j are the 'apparent critical level' calculated with the test of single element, the oxidation number of the element and the concentration of Cu, Pb, Zn, Cd, Co and Ni in soil, respectively. The choice of the heavy metal concentration in the equation is well worth studying although a method is recommened in the present paper. The LCSP is not considered as a 'fixed value' but a 'range val
出处
《土壤学报》
CAS
CSCD
北大核心
1992年第2期219-225,共7页
Acta Pedologica Sinica
