土壤对病毒的吸附行为及其在环境净化中的作用

VIRUS-ADSORBING BEHAVIOR OF SOIL AND ITS SIGNIFICANCE IN NATURAL DISINFECTION

病毒在土壤上的吸附行为在很大程度上决定着其对饮用水的污染威胁。通过一次平衡法实验,比较研究噬菌体MS2和X174在6种不同性质土壤上的吸附行为的差别,同时阐述土壤中本身存在的微生物对土壤吸附行为的影响。总体趋势为土壤对X174的吸附能力高于对MS2的吸附能力;红黏土对病毒的吸附能力最强,而沙质潮土最弱;土壤中本身存在的微生物对土壤吸附病毒的影响依不同类型的土壤和病毒而异,除了红黏土外,灭菌土壤显著增加其对MS2的吸附;但对X174来说,灭菌后显著降低其在红黏土上的吸附,其他5种土壤的灭菌处理对X174的吸附行为没有显著影响。说明红黏土或与红黏土类似性质的材料在净化被病毒污染的水域时可能是一比较理想的病毒吸附剂;而在沙质潮土地区,病毒通过被土壤吸附而达到过滤净化的可能性则比较小。土壤中可能存在某一种或一类特殊微生物,它们可能可以控制病毒在土壤中的吸附行为,因而进一步研究其机理十分必要。

Virus-adsorbing behavior of soil, to a large extent, determines the risk of viruses polluting drinking water. Batch sorption experiments were carried out with bacteriophages MS2 and φX174 to compare 6 different soils with contrast properties in virus-adsorbing behavior, and to expound effect of the presence of indigenous microorganisms on the behavior. In general, soils were more adsorptive to φX174 than to MS2. Among the studied 6 soils, clayed red soil showed the greatest adsorption capacity, while sandy Chao soil the lowest. Effect of the presence of indigenous microorganisms on soil virus-adsorbing behavior varied with soil and bacteriophage. Sterilization increased soil adsorption of MS2 in all the soil samples, except in clayed red soil, whereas it did not affected their adsorption of φX174 except in clayed red soil, where adsorption of φX174 decreased significantly, which suggests that clayed red soil or materials with similar properties may be used as an ideal virus sorbent to purify virus-contaminated water. In areas dominated with sandy Chao soil, the possibility of ＂natural disinfection＂ through soil adsorption is rather limited. In soils may exit some microorganisms and some special groups of microorganisms that may control the process of virus adsorption by soils. It is, therefore, essential to further study mechanisms involved in this process.