韩宝红,宋蕾,李浩,宋虹苇.不同温度条件下稳定剂对沉积物中镉稳定化的影响[J].环境科学学报,2019,39(8):2610-2616
不同温度条件下稳定剂对沉积物中镉稳定化的影响
- Effect of stabilizers on cadmium immobilization in sediments under various temperature conditions
- 基金项目：国家自然科学基金（No.21107041）；内蒙古自治区自然科学基金（No.2017MS0216）；内蒙古工业大学中青年学术骨干计划项目
- 韩宝红
- 内蒙古工业大学土木工程学院, 呼和浩特 010051
- 宋蕾
- 内蒙古工业大学土木工程学院, 呼和浩特 010051
- 李浩
- 内蒙古工业大学土木工程学院, 呼和浩特 010051
- 宋虹苇
- 内蒙古工业大学土木工程学院, 呼和浩特 010051
- 摘要：为阐明不同温度条件下，生物炭（BC）、纳米零价铁（nZVI）和生物炭负载纳米零价铁（BC-nZVI）稳定剂对沉积物中镉（Cd）固定的影响，并探究固定过程中稳定剂与pH值、氧化还原电位（ORP）和有效磷之间的关系.本文以中国北方典型寒旱区湖泊乌梁素海表层沉积物中的Cd为研究对象，研究了空白对照（CK）及加入BC、nZVI和BC-nZVI 3种稳定剂并分别在0、10、20和30℃下老化35 d后沉积物pH值、ORP值、有效磷含量及Cd形态的变化情况.结果表明，随着温度的升高，pH值整体呈下降趋势，但BC和BC-nZVI的加入均可使沉积物的pH值较对照组增加；沉积物的ORP值随温度的升高先增加后减小；有效磷含量随温度的升高而增加，加入不同稳定剂后有效磷含量高低次序为：BC>CK>BC-nZVI>nZVI.同时发现，在不同温度条件下BC-nZVI对Cd的稳定效果最好，特别是在0℃和30℃时，残渣态含量分别达到77.26%和71.67%，显著降低了Cd的流动性.由此得出，温度对沉积物的理化性质与稳定剂固化Cd的效果影响较大；在0℃和30℃时，更有利于稳定剂固化Cd.
- Abstract：This study aims to elucidate the effects of stabilizers, such as biochar (BC), nanoscale zero-valent iron (nZVI), and biochar-supported nanoscale zero-valent iron (BC-nZVI), on immobilization of cadmium (Cd) in sediments under various temperature conditions. This study also explores the relationship between the stabilizers and pH, oxidation reduction potential (ORP), and available phosphorus in the immobilization process. Taking the Cd in the surface sediments of Ulansuhai in the typical cold and dry regions of northern China as research object, this study examines the pH value, ORP value, effective phosphorus content, and Cd morphology of sediments after 35 days of incubation at temperatures of 0, 10, 20, and 30℃ through blank control(CK) and addition of three stabilizers (BC, nZVI, and BC-nZVI). Results show that pH decreased with the increase of temperature, but adding BC and BC-nZVI could increase pH of the sediments compared with that of the control group. The ORP of the sediments increased first and then decreased with the increase of temperature; the available phosphorus content also rose with the increase of temperature. The order of available phosphorus content after addition of different stabilizers was BC> CK> BC-nZVI> nZVI. At the same time, BC-nZVI had the best stablization to Cd under various temperature conditions, especially at 0℃ and 30℃; the residual fraction reached 77.26% and 71.67%, respectively, thereby significantly reduced the fluidity of Cd. It is concluded that temperature greatly influences the physicochemical properties of the sediments and the effect of stabilizers on immobilization of Cd; temperatures of 0℃ and 30℃ are conducive to immobilization of Cd by stabilizers.
