改性膨潤土修復(fù)銅污染的土壤

原文麗　馮磊　劉永紅等

摘 要 在實(shí)驗(yàn)室內(nèi)，以礦區(qū)Cu污染的紅壤R1，人工污染的紅壤R2和黃棕壤R3為供試土壤，選用己二胺二硫代氨基甲酸鹽（DTC）改性的膨潤土為修復(fù)材料，以歐共體標(biāo)準(zhǔn)物資局（European Communities Bureau of Reference）改進(jìn)的三步連續(xù)提取法（BCR）分析污染土壤中Cu的形態(tài)，并研究礦物材料用量、土壤類型、pH和土壤含水量等因素對(duì)土壤中Cu形態(tài)轉(zhuǎn)化的影響.研究結(jié)果表明：改性膨潤土對(duì)Cu污染的土壤具有一定的修復(fù)效果，可使酸溶態(tài)和還原態(tài)含量大大降低，氧化態(tài)和殘?jiān)鼞B(tài)含量大大升高；且其修復(fù)效果隨礦物用量、pH值的增加而升高，隨電解質(zhì)濃度的增加而降低，淹水時(shí)不利于土壤修復(fù).

關(guān)鍵詞 膨潤土；改性；土壤；銅；修復(fù)

中圖分類號(hào) X53文獻(xiàn)標(biāo)識(shí)碼 A文章編號(hào) 10002537（2016）02004305

Remediation of Soils Contaminated with Cu Using Modified Bentonite

YUAN Wenlia， FENG Leia， LIU Yonghonga，b*， ZHENG Xinshenga， HU Hongqingb

（a.College of Science， b.College of Resources and Environment，

Huazhong Agricultural University， Wuhan 430070， China）

Abstract In the laboratory， three kinds of soil samples， the copper contaminated soil （R1） collected from mining areas of Daye city， Hubei Province， artificiallypolluted red soil （R2）， and yellow brown soil （R3） with exogenous copper， were selected to be remediated by modified bentonite with diethyidithiocarbamate （DTC）. Four kinds of copper forms were analyzed with the modified BCR sequential extraction procedures. Additionally， impacts of the mineral material dosage， soil type， pH， soil moisture and other factors on Cu transformation in soil were systematically investigated. Results from this study show that the modified benotinite has the ability to repair the soils contaminated by copper， with the content of soluble and reduced copper states markedly reduced， and that of the oxidation and residual states significantly increased. The reparation effect on the soil samples contaminated by copper was enhanced with an increased bentonite dosage and pH values. Conversely， the reparation effect was reduced with an increased electrolyte concentration. However， we found that the flooding condition was disadvantageous to soil remediation.

Key words bentonite； modification； soils； copper； remediation

當(dāng)前，由于工農(nóng)業(yè)、采礦業(yè)的快速發(fā)展，土壤重金屬污染問題日益突出.銅是常見土壤污染重金屬之一，部分地區(qū)的土壤銅污染遠(yuǎn)超出了土壤的承載能力[13]，對(duì)人類的生存和安全造成嚴(yán)重的威脅[4].因此，土壤環(huán)境中的Cu污染亟待治理.化學(xué)修復(fù)技術(shù)是廣泛采用的土壤修復(fù)方式之一，其主要是通過采用土壤改良劑來降低土壤中重金屬的活性及生物有效性，達(dá)到降低污染的效果[5].劉秀珍等利用天然膨潤土和沸石處理鎘污染土壤，修復(fù)效果較好[6]；羅成玉等采用陰、陽離子表面活性劑混合物改性制備的膨潤土，對(duì)廢水中Cu2+的去除效果很好[7]；蘇玉紅等研究了膨潤土原土、表面活性劑改性膨潤土處理廢水中的Pb2+，研究結(jié)果顯示，改性膨……