CAJ | 학술논문

重金属污染的地下水治理不断面临着挑战，尤其是在一些发展中国家。纳米铁颗粒代表新一代环境治理技术，面对最具挑战的环境治理问题能够提供有效的解决办法。在实验室制得纳米铁颗粒，粒径为20~40 nm，比表面积（BET）为49.16 m2·g-1。通过考察纳米铁对多种重金属共存水体的去除情况，包括As(III)、As(V)、Cd(II)、Pb(II)、Cr(VI)、Cu(II)和Mn(II)，实验结果表明，重金属的去除效果与重金属类型，纳米铁投加量和反应时间有关。通常当纳米铁投加量为1.25 g·L-1时，反应时间在30 min内，纳米铁对水体中质量浓度范围为0.1~1.0 mg·L-1的重金属离子As(III)、As(V)、Cd(II)、Pb(II)、Cr(VI)、Cu(II)和Mn(II)去除率达90%以上，还可获得以下结论：1）纳米铁能同时对As(III)和As(V)去除，而不需要将As(III)预先氧化成As(V)；2）纳米铁对重金属去除速率快慢为Cu(Ⅱ)> Pb(Ⅱ)>Cr(Ⅵ)>Cd(Ⅱ)；3）纳米铁对重金属去除由刚开始快速消失，到后期缓慢去除的2个步骤组成；4）纳米铁对实际水样中重金属都有很好的去除效果，尤其是对高浓度Mn去除效果更明显，可通过延长处理时间或增加纳米铁的投加量方式，去除率能达99%以上。纳米铁对重金属的去除机理取决于重金属的标准电势，纳米铁对As和Cd(Ⅱ)的去除主要是通过吸附沉淀作用，而对Cu(Ⅱ)、Pb(Ⅱ)和Cr(Ⅵ)去除以还原为主。纳米铁因具有高的比表面积和高的反应活性，更重要的是，它在现场应用时具有很好的灵活性，故可通过高压喷射方式直接注入到地下水中用于多种污染物治理。
중금속오염적지하수치리불단면림착도전，우기시재일사발전중국가。납미철과립대표신일대배경치리기술，면대최구도전적배경치리문제능구제공유효적해결판법。재실험실제득납미철과립，립경위20~40 nm，비표면적（BET）위49.16 m2·g-1。통과고찰납미철대다충중금속공존수체적거제정황，포괄As(III)、As(V)、Cd(II)、Pb(II)、Cr(VI)、Cu(II)화Mn(II)，실험결과표명，중금속적거제효과여중금속류형，납미철투가량화반응시간유관。통상당납미철투가량위1.25 g·L-1시，반응시간재30 min내，납미철대수체중질량농도범위위0.1~1.0 mg·L-1적중금속리자As(III)、As(V)、Cd(II)、Pb(II)、Cr(VI)、Cu(II)화Mn(II)거제솔체90%이상，환가획득이하결론：1）납미철능동시대As(III)화As(V)거제，이불수요장As(III)예선양화성As(V)；2）납미철대중금속거제속솔쾌만위Cu(Ⅱ)> Pb(Ⅱ)>Cr(Ⅵ)>Cd(Ⅱ)；3）납미철대중금속거제유강개시쾌속소실，도후기완만거제적2개보취조성；4）납미철대실제수양중중금속도유흔호적거제효과，우기시대고농도Mn거제효과경명현，가통과연장처리시간혹증가납미철적투가량방식，거제솔능체99%이상。납미철대중금속적거제궤리취결우중금속적표준전세，납미철대As화Cd(Ⅱ)적거제주요시통과흡부침정작용，이대Cu(Ⅱ)、Pb(Ⅱ)화Cr(Ⅵ)거제이환원위주。납미철인구유고적비표면적화고적반응활성，경중요적시，타재현장응용시구유흔호적령활성，고가통과고압분사방식직접주입도지하수중용우다충오염물치리。
Remediation of groundwater contaminated by heavy metal is a recurring challenge, especially in developing countries. Nanoscale iron particles represent a new generation of environmental remediation technologies that could provide cost-effective solutions to some of the most challenging environmental cleanup problems. This study investigated the use of nZVI particles with the particle size of 20-40 nm and specific surface area (BET) of 49.16 m2·g-1 in removing mixed heavy metal contaminants including As(III), As(V), Cd(II), Pb(II), Cr(VI), Cu(II) and Mn(II) from groundwater. Results showed that the removal efficiencies of heavy metals varied with the metal species, nZVI loading, and reaction time. In most cases, use of 1.25 g·L-1 nZVI resulted in removal efficiencies of more than 90% for Cr(VI), Cu(II), Cd(II), Pb(II), Mn(II), As(III), and As(V) with different concentration levels (0.1-1.0 mg·L-1) in 30 min. The following points may be concluded: 1) Both As(III) and As(V) from aqueous solution were removed effectively using NZVI without additional oxidant for oxidizing As(III) to As(V). 2) The removal rate of the heavy metals by nZVI particles followed the sequence Cu(Ⅱ)> Pb(Ⅱ) >Cr(Ⅵ) >Cd(Ⅱ). 3) Batch studies indicate that the removal of heavy metals is a two-step reaction with a fast initial reaction which remove heavy metals to a near-disappearance (or very low) level followed by a slow subsequent removal process. 4) This study demonstrated the efficacy of nZVI particles for the rapid removal of mixed heavy metals, especially for high level Mn(II) from groundwater. 99% for Mn(II) can be removed by prolonging reaction time or increasing the nZVI loading. Depending on the standard potential E0of the heavy metals, the removal mechanisms of Cd(Ⅱ) and As(III) by nZVI is due to sorption or coprecipitation while that of Cu(Ⅱ), Pb(Ⅱ) or Cr(Ⅵ) is mainly redox processes. Due to their small particle size and reactivity, the nanosacle particles may be useful in wide array of environmental applications including subsurface injection for groundwater treatment.