SYNERGISTIC REMOVAL OF Cu, Co, Ni AND Cr FROM CONTAMINATED SOIL BY BIOCHAR-SUPPORTED NANOSCALE ZERO-VALENT IRON
-
摘要: 合成了一种低成本、高效生物炭负载纳米零价铁的复合材料(ZVI-SM)并应用于铜、钴、镍、铬污染土壤的修复。采用X射线衍射(XRD)、X射线光电子能谱(XPS)和金属吸附实验等方法,考察了不同碳化温度下制备的生物炭前驱体和生物炭复合材料对复合重金属污染修复的影响及去除作用机制。其中,吸附-还原后形成的FeCr2O4极大地降低了铬的毒性,同时提高了铜、钴、镍的去除率。Fe0的引入既提高了生物炭对重金属的吸附量,又解决了Cr(Ⅵ)毒性的问题;XPS的结果进一步阐明了生物炭可以作为电子传递介质,通过表面官能团得失电子与Fe0间形成强相互作用,增强了复合材料对多重金属离子的去除效果。除ZVI-SM500外,ZVI-SM100、300、400、700 4种材料对于铜、钴、镍、铬的去除率要远高于商用纳米Fe0和单纯的生物炭材料,表现为对铬和铜有较强的亲和力和反应性,均能在5 min内完全去除铜和铬,钴和镍也能在180 min内达到80%以上的去除率。在反应过程中存在显著的离子竞争效应:铬≥铜>钴>镍,这与金属离子的标准还原电位大小的趋势一致。土壤修复实验表明:ZNI-SM300用于污染土壤的修复,15 d后,Cr(Ⅵ)含量从480 mg/kg降至0.52 mg/kg,水溶态Cr总量从500 mg/kg降至1.2 mg/kg,两者的固定化效率均达到99%以上,并能达到完全去除水溶态的铜、钴、镍、Cr(Ⅵ)的效果。因此,以SM300为载体的纳米零价铁可作为复合重金属污染土壤修复的理想材料。Abstract: In this study, a low-cost and highly efficient composite material (ZVI-SM) with nanoscale zero-valent iron loaded by biochar was synthesized and applied to the remediation of copper, cobalt, nickel and chromium contaminated soil. The effects of biochar precursors and biochar composites prepared at different carbonation temperatures on the remediation of heavy metal contamination, and their removal mechanisms were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and metal adsorption experiment. FeCr2O4 formed by adsorption and reduction greatly reduced the toxicity of chromium and improved the removal efficiency of copper, cobalt and nickel. The introduction of Fe0 not only increased the adsorption capacity of heavy metals to biochar, but also solved the problem of toxicity of Cr(Ⅵ). XPS further clarified that biochar could be used as the electron transfer medium; the strong interaction between the gain and loss electrons of the surface functional groups; Fe0 could enhance the removal effect of the composite material on multi-heavy metal ions; besides ZVI-SM500, the removal rates of rest of the four materials, ZVI-SM100, 300, 400, 700 for copper, cobalt, nickel, chromium were much higher than the commercial nanoscale Fe0 and single application of biological carbon materials; this kind of composite material (ZVI-SM) showed a strong affinity and reactivity to chromium and copper, and completely removed copper and chromium in 5 minutes. Cobalt and nickel could also achieve more than 80% removal rate in 180 minutes. There was a significant ion competition effect in the reaction process in the order of Cr≥Cu>Co>Ni, consistent with the trend of the standard reduction potential of metal ions. Soil remediation experiments showed that ZNI-SM300 for remediation of contaminated soil, after 15 days, the content of Cr(Ⅵ) decreased from 480 mg/kg to 0.52 mg/kg, and the total amount of water-soluble Cr decreased from 500 mg/kg to 1.2 mg/kg. The immobilization efficiency of both was more than 99%, while the total removal effect of water-soluble copper, cobalt, nickel and Cr(Ⅵ) was achieved. Therefore, the nanoscale zero-valent iron with SM300 as the carrier could be used as the ideal material for the remediation of soil contaminated by composite heavy metals.
-
Key words:
- biochar /
- Fe0 /
- hexavalent chromium /
- reduction /
- heavy metal /
- collaborative removal
-
DIACONU M, PAVEL L V, HLIHOR R M, et al. Characterization of heavy metal toxicity in some plants and microorganisms: a preliminary approach for environmental bioremediation[J]. New Biotechnology, 2020, 56: 130-139. WEN Q X, WANG Q, LI X Q, et al. Enhanced organics and Cu2+ removal in electroplating wastewater by bioaugmentation[J]. Chemosphere, 2018, 212: 476-485. LI X, WU Y E, ZHANG C, et al. Immobilizing of heavy metals in sediments contaminated by nonferrous metals smelting plant sewage with sulfate reducing bacteria and micro zero valent iron[J]. Chemical Engineering Journal, 2016, 306: 393-400. CHEN X, CUI J, XU X R, et al. Bacterial cellulose/attapulgite magnetic composites as an efficient adsorbent for heavy metal ions and dye treatment[J]. Carbohydrate Polymers, 2020, 229:115512. PAP S, J RADONIC', S TRIFUNOVIC', et al. Evaluation of the adsorption potential of eco-friendly activated carbon prepared from cherry kernels for the removal of Pb2+, Cd2+ and Ni2+ from aqueous wastes[J]. Journal of Environmental Management, 2016, 184: 297-306. FERRI M, CAMPISI S, SCAVINI M, et al. In-depth study of the mechanism of heavy metal trapping on the surface of hydroxyapatite[J]. Applied Surface Science, 2019, 475: 397-409. 李明, 程寒飞, 安忠义, 等. 化学淋洗与生物质炭稳定化联合修复镉污染土壤[J]. 环境工程学报, 2018, 12(3):904-913. 张志红, 陈家煜, 郭观林, 等. 稳定剂协同水泥固化/稳定化重金属污染土壤的工程特性[J]. 环境工程学报, 2017, 11(5):3172-3178. 陈亚奎, 卢滇楠. 重金属污染土壤生物修复技术研究进展与现状[C]//2019中国环境科学学会科学技术年会论文集(第三卷), 2019: 564-568. 朱玉斌. 土壤重金属污染现状及修复技术比较[J]. 中国资源综合利用, 2017, 35(5):56-58. YU H W, ZOU W X, CHEN J J, et al. Biochar amendment improves crop production in problem soils: a review[J]. Journal of Environmental Management, 2019, 232: 8-21. NIE C, YANG X, NIAZI N K, et al. Impact of sugarcane bagasse-derived biochar on heavy metal availability and microbial activity: a field study[J]. Chemosphere, 2018, 200: 274-282. 张杏锋, 冯健飞, 姚航, 等. 美洲商陆生物炭对Zn、Pb、Cd和Cu的吸附特性分析[J].环境工程, 2019, 37(8):88-94. LU X Q, LIU X W, ZHANG W Q, et al. The residue from the acidic concentrated lithium bromide treated crop residue as biochar to remove Cr (Ⅵ)[J]. Bioresource Technology, 2020, 296: 122348. 熊静, 王蓓丽, 刘渊文, 等. 生物炭去除土壤重金属的研究进展[J].环境工程, 2019, 37(9):182-187. SHEN Z T, HOU D Y, JIN F, et al. Effect of production temperature on lead removal mechanisms by rice straw biochars[J]. Science of the Total Environment, 2019, 655: 751-758. LI S L, WANG W, LIANG F P, et al. Heavy metal removal using nanoscale zero-valent iron (nZVI): theory and application[J]. Journal of Hazardous Materials, 2017,322:163-171. 薛嵩, 钱林波, 晏井春, 等. 生物炭携载纳米零价铁对溶液中Cr (Ⅵ)的去除[J]. 环境工程学报, 2016, 10(6): 2895-2901. 孟繁健, 朱宇恩, 李华, 等. 改性生物炭负载nZVI对土壤Cr(Ⅵ)的修复差异研究[J]. 环境科学学报, 2017, 37(12):4715-4723. MANDAL S, PU S Y WANG X K, et al. Hierarchical porous structured polysulfide supported nZVI/biochar and efficient immobilization of selenium in the soil[J]. Science of the Total Environment, 2020, 708: 134831. 王维大, 林薇, 李玉梅, 等. 黑炭负载零价铁对复合污染土壤中铜和铬的稳定化效果及生物有效性影响[J]. 环境工程学报, 2019, 13(4):944-954. 孟李群, 张云鹏, 苏漳文, 等. 不同炭化温度下杉木生物炭产率及特性比较[J].福建林业科技,2014,41(2):38-41. LV D, ZHOU J S, CAO Z, et al. Mechanism and influence factors of chromium(Ⅵ) removal by sulfide-modified nanoscale zerovalent iron[J]. Chemosphere, 2019, 224: 306-315. QIAN L B, SHANG X, ZHANG B, et al. Enhanced removal of Cr(Ⅵ) by silicon rich biochar-supported nanoscale zero-valent iron[J]. Chemosphere, 2019, 215: 739-745. LI Z, SUN Y Q, YANG Y, et al. Biochar-supported nanoscale zero-valent iron as an efficient catalyst for organic degradation in groundwater[J]. Journal of Hazardpus Materials, 2020, 383: 121240. WU H H, WEI W X, XU C B, et al. Polyethylene glycol-stabilized nano zero-valent iron supported by biochar for highly efficient removal of Cr(Ⅵ)[J]. Ecotoxicology and Environmental Safety, 2020, 188: 109902. LI J X, ZHANG X Y, LIU M C, et al. Enhanced reactivity and electron selectivity of sulfidated zerovalent iron toward chromate under aerobic conditions[J]. Environmental Science & Technology, 2018, 52(5): 2988-2997. LING L, HUANG X Y, LI M R, et al. Mapping the reactions in a single zero-valent iron nanoparticle[J]. Environmental Science & Technology, 2017, 51(24): 14293-14300.
点击查看大图
计量
- 文章访问数: 323
- HTML全文浏览量: 66
- PDF下载量: 2
- 被引次数: 0