饱和硫化钠对土壤HgS提取的专性质疑

Quest About Extraction Specificity of ss-Na_2S for Soil HgS

通过饱和硫化钠（ｓｓ－Ｎａ＿２Ｓ）对Ｆｅ＿２Ｏ＿３－Ｈｇ，ＭｎＯ＿２－Ｈｇ，高岭土─Ｈｇ和膨润土一Ｈｇ的提取试验，对ＨｇＳ形成条件的理论探讨，以及ｓｓ一Ｎａ＿２Ｓ提取态汞能为ＣａＣＯ＿３、腐殖酸、膨润土等所抑制的试验结果，证明了Ｎａｔｂａｎｉｅｌ（１９８９）提出的土壤ＨｇＳ的专性提取剂──ｓｓ－Ｎａ＿２Ｓ并不具备专性，它能强烈提取各种土壤矿物结合态汞。采用ｓｓ－Ｎａ＿２Ｓ作为土壤ＨｇＳ的提取剂将会过高估计ＨｇＳ在环境中的存在。

In order to prove the specificity of ss-Na_2S(saturated solution ofNa_2S)for soil HgS suggested by Nathaniel(1989),several experiments weredone. All results show that: ss-Na_2S is not a special extractant for soilHgS, while it can strongly extract Hg bound by soil minerals. The exper-ments include: extraction experiments for Hg bound to four types of soilmineral: effects of soil factors(CaCO_3,humus,bentonite)on the forma-tion of Hg extracted by ss-Na_2S. Theoretical discussion on the formationconditions of HgS in upland soil is also presented.