土壤砷复合污染及其防治研究

The Combined Pollution of Arsenic with Other Metals and Its Prevention

通过盆栽试验，研究了旱作（大豆、苜蓿）、水作（水稻）二种环境条件下，砷与镉、铅、铜、锌共存时的复合生态效应，砷处理浓度为２０、４０ｍｇ／ｋｇ；对砷复合污染防治措施研究，包括土壤改性（施酸、喷酸、施加石灰等）、施用腐殖酸以及水旱田对比试验等。结果表明：砷复合污染下毒性＞Ｃａ－Ａｓ＞Ｆｅ－Ａｓ＞Ｎａ－Ａｓ，Ｃａ－Ａｓ复合污染对苜蓿试验的生态效应既与污染物绝对浓度有关，也与Ａｓ／Ｃａ比值有关，Ｃｄ－Ａｓ复合污染诱使苜蓿吸收更多的Ｃｕ和Ｐｂ，产生次生生态效应，旱田上，改性措施或许有一定的抑制砷吸收作用，在水田上效果不明显，水改旱，砷吸收量可减少２．５－７．８倍，但这将增加大大豆对镉的吸收量达１．９－４．７倍。因此认为在砷复合污染情况下，在生产实践上应用改良措施十分困难。

AbstractBased on pot experiment, this paper reports the combined ecological effects of As with Cb, pb, Cu, Zn in dry (soybean and alfalfa )and paddy fields rice).The concentrations of As treatment were 20 and 40 mg/kg. Modifying soil property(adding acid; spraying acid; adding lime ) and adding humic acid were conducted to study the control measures for As combined pollution with other four metals.The results indicated that measures for modifyingsoil property could inhibit As absorbtion in the dry land to some degrees.But in paddy field,the most efficient method was to chang paddy field todry land,which could reduce the absorbtion of As 2.5-7.8 times less,butincreased the absorbtion of Cd 1.9-4.7 times more in the meantime. Ther-efore,measures are very difficuIt take to reducc multi-heavy metal pollu-tion in practice.