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| 壳聚糖改性钠基膨润土稳定剂对重金属污染底泥的处理 | |
| 引用本文： | 刘丁玮, 王春荣, 赵明川, 韩璐瑞, 韩善萌, 柯述, 韩港胜, 董滨, 李攀. 壳聚糖改性钠基膨润土稳定剂对重金属污染底泥的处理[J]. 环境工程学报, 2022, 16(12): 3906-3915. doi: 10.12030/j.cjee.202208068 |
| 作者姓名： | 刘丁玮 王春荣 赵明川 韩璐瑞 韩善萌 柯述 韩港胜 董滨 李攀 |
| 作者单位： | 1.中国矿业大学 (北京) 化学与环境工程学院，北京 100083; 2.同济大学环境科学与工程学院，上海 200082 |
| 基金项目： | 国家重点研发计划项目(2020YFC1908703-02)； |
| 摘 要： |  为有效处理重金属污染的疏浚底泥并验证重金属稳定剂的稳定性，采用重金属稳定化的方法，以Cu2+、Zn2+、Cd2+单一和复合重金属污染的疏浚底泥为研究对象，以壳聚糖改性后的钠基膨润土为稳定剂，在不同稳定剂投加量、pH和液固比的条件下，对污染底泥进行稳定化处理，并采用毒性特征沥滤方法 (TCLP) 和BCR连续提取法对稳定化效果进行分析与评价。结果表明：经过壳聚糖改性后的钠基膨润土稳定重金属的能力显著提高，在投加量为5%时，对Cu2+、Zn2+、Cd2+单一重金属污染底泥便可达到较高的稳定化率；聚糖改性钠基膨润土稳定剂 (NaBent-CTS) 处理Cu2+、Zn2+、Cd2+单一重金属污染底泥的最佳投加量为5%~7%，pH为6~7，液固比为1.3:1~1.7:1；NaBent-CTS处理Cu2+、Zn2+、Cd2+复合重金属污染底泥的最佳投加量为5%、pH为7、液固比为1.5:1，稳定化率分别达到75.95%、73.71%和59.00%；NaBent-CTS处理复合重金属污染底泥时重金属存在竞争吸附，由强到弱排列顺序为Cu2+>Zn2+>Cd2+；经NaBent-CTS稳定化处理14 d后，可氧化态和残渣态占比显著提高，稳定性能佳。NaBent-CTS对Cu2+、Zn2+、Cd2+单一和复合重金属污染底泥具有较好的稳定效果。该研究结果可为重金属污染疏浚底泥的稳定化处理提供相关参考。 |
| 关 键 词： | 壳聚糖 钠基膨润土 稳定剂 重金属 底泥 |
| 收稿时间： | 2022-08-10 |
Treatment of heavy metal polluted sediment with chitosan modified Na-bentonite stabilizer |
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| LIU Dingwei, WANG Chunrong, ZHAO Mingchuan, HAN Lurui, HAN Shanmeng, KE Shu, HAN Gangsheng, DONG Bin, LI Pan. Treatment of heavy metal polluted sediment with chitosan modified Na-bentonite stabilizer[J]. Chinese Journal of Environmental Engineering, 2022, 16(12): 3906-3915. doi: 10.12030/j.cjee.202208068 | |
| Authors: | LIU Dingwei WANG Chunrong ZHAO Mingchuan HAN Lurui HAN Shanmeng KE Shu HAN Gangsheng DONG Bin LI Pan |
| Affiliation: | 1.School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; 2.College of Environmental Science and Engineering, Tongji University, Shanghai 200082, China |
| Abstract: | In order to effectively treat the dredged sediment polluted by heavy metals and verify the stability of heavy metal stabilizer, a type of heavy metal stabilization method with the stabilizer of the Na-bentonite modified by chitosan was adopted, the dredged sediment polluted by single and complex heavy metals Cu2+, Zn2+ and Cd2+ was taken as the research object to perform the stabilizing treatment under the conditions of different stabilizer dosage, pH and liquid-solid ratio. Toxicity characteristic leaching method (TCLP) and BCR continuous extraction method were used to analyze and evaluate the stabilization effect. The results showed that the ability of Na-bentonite modified by chitosan to stabilize heavy metals increased significantly. When the dosage of sodium bentonite modified by chitosan was 5%, the sediment contaminated by single heavy metal of Cu2+, Zn2+ or Cd2+ could reach a high stabilization rate. The optimal dosage of Na-bentonite stabilizer (NaBent-CTS) treating contaminated sediments by Cu2+, Zn2+ and Cd2+ alone was 5%~7%, pH was 6~7 and the liquid-to-solid ratio was 1.3:1~1.7:1. The optimal dosage of NaBent-CTS treating contaminated sediment by Cu2+, Zn2+ and Cd2+ composite heavy metals was 5%, pH was 7 and liquid-to-solid ratio was 1.5:1, and the stabilization rates were 75.95%, 73.71% and 59.00%, respectively. The competitive adsorption of heavy metals occurred in NaBent-CTS treatment process, and the corresponding competitive order from strong to weak was Cu2+>Zn2+>Cd2+. After 14 days of NaBent-CTS stabilization treatment, the proportions of oxidizable state and residue state for heavy metals increased significantly, and heavy metal stability was good. NaBent-CTS has good stabilization effects on sediment polluted by single and complex heavy metals of Cu2+, Zn2+ and Cd2+. The results can provide a relevant reference for the stabilization treatment of dredged sediment polluted by heavy metals. |
| Keywords: | chitosan Na-bentonite stabilizer heavy metals sediment |
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