LAS对土壤环境理化性状和生物活性的影响

以太湖地区黄泥土为例 ,通过土壤物理性质测定、毒性物质吸附实验以及实验室微生物培养 ,研究了不同浓度LAS对土壤环境理化性质和微生物活性的影响 .表明LAS显著影响土壤溶液性质 ,降低土壤环境对苯酚的吸附量 ,但对重金属离子的吸附无明显效应 ;土壤硝化作用和氨化作用对LAS十分敏感 ,反硝化作用受到一定程度的促进 ;土壤中细菌受到LAS的刺激 ,而真菌受到抑制 ;土壤呼吸活性在培养前期随LAS浓度表现增强 ,但在 >5mg/L浓度下 ,一周后均表现出抑制 .本研究表明 ,土壤中存在对LAS耐受的微生物群落 .土壤对LAS污染的环境效应与土壤类型和性质有关 ,尚需进一步研究 .

Effect of LAS on Physico-chemical Properties and Microorganism Activity in Soil Environment

Using a well drained paddy soil and the derived soil under vegetables in the Taihu Lake region,China,experiments of soil capillary rise,colloid dispersion and adsorption of toxic organics and heavy metals by soil under various degrees of LAS addition were conducted.Also incubation experiments of microorganism activity in soil with added LAS in different concentrations were carried out in laboratory.LAS addition resulted in lower capillary rise of soil solution,higher dispersion of soil colloids and lower capacity of soil for organic pollutants but no significant influence on adsorption of heavy metal cations.The nitrification and amonification in soil were very sensitive to LAS stress while denitrification turned to be stimulated.LAS addition gave stronger growth of soil bacteria while decreased growth of fungus.Meanwhile,soil respiration was stimulated in the first week of incubation and compressed afterwards by LAS at concentration over 5mg/kg.It seemed that some species of microorganisms were tolerant of LAS in the studied soils.