人民黄河
人民黃河
인민황하
Yellow River
2015年
4期
85-89,93
,共6页
白雪梅%董军%王美丽%袁震%何连生
白雪梅%董軍%王美麗%袁震%何連生
백설매%동군%왕미려%원진%하련생
纳米零价铁%重金属%地下水%分散性%抗氧化性
納米零價鐵%重金屬%地下水%分散性%抗氧化性
납미령개철%중금속%지하수%분산성%항양화성
nanoscale zero-valent iron%heavy metal%groundwater%dispersibility%inoxidizability
纳米零价铁(nZVI)粒径小、比表面积大、反应活性高,可降解多种污染物,但nZVI分散性差、抗氧化性弱的特点使其在地下水修复中的应用受到限制。改性nZVI可以提高nZVI的分散性及稳定性,研究了现有改性nZVI的特点:多孔材料负载改性nZVI成本较低,但可选择的材料相对较少;有机物包覆分散改性nZVI的改性材料较多,可以促进非水相液体污染物与nZVI的接触反应,但选择不当容易引起二次污染;双金属改性纳米材料的反应速度较快,不易形成腐蚀产物,但成本较高,且过渡金属可能对环境有害。nZVI可以处理多种地下水重金属污染物,根据Fe2+和目标重金属离子污染物的标准电极电位的相对大小,降解方式分为表面吸附—配合作用、表面吸附—还原作用和表面还原作用,但是改性nZVI存在价格高、有环境毒性等问题。
納米零價鐵(nZVI)粒徑小、比錶麵積大、反應活性高,可降解多種汙染物,但nZVI分散性差、抗氧化性弱的特點使其在地下水脩複中的應用受到限製。改性nZVI可以提高nZVI的分散性及穩定性,研究瞭現有改性nZVI的特點:多孔材料負載改性nZVI成本較低,但可選擇的材料相對較少;有機物包覆分散改性nZVI的改性材料較多,可以促進非水相液體汙染物與nZVI的接觸反應,但選擇不噹容易引起二次汙染;雙金屬改性納米材料的反應速度較快,不易形成腐蝕產物,但成本較高,且過渡金屬可能對環境有害。nZVI可以處理多種地下水重金屬汙染物,根據Fe2+和目標重金屬離子汙染物的標準電極電位的相對大小,降解方式分為錶麵吸附—配閤作用、錶麵吸附—還原作用和錶麵還原作用,但是改性nZVI存在價格高、有環境毒性等問題。
납미령개철(nZVI)립경소、비표면적대、반응활성고,가강해다충오염물,단nZVI분산성차、항양화성약적특점사기재지하수수복중적응용수도한제。개성nZVI가이제고nZVI적분산성급은정성,연구료현유개성nZVI적특점:다공재료부재개성nZVI성본교저,단가선택적재료상대교소;유궤물포복분산개성nZVI적개성재료교다,가이촉진비수상액체오염물여nZVI적접촉반응,단선택불당용역인기이차오염;쌍금속개성납미재료적반응속도교쾌,불역형성부식산물,단성본교고,차과도금속가능대배경유해。nZVI가이처리다충지하수중금속오염물,근거Fe2+화목표중금속리자오염물적표준전겁전위적상대대소,강해방식분위표면흡부—배합작용、표면흡부—환원작용화표면환원작용,단시개성nZVI존재개격고、유배경독성등문제。
Nanoscale zero-valent iron (nZVI)has the characteristics of small size,large specific surface,high reactivity and degradation with various contaminations,whereas it is limited in remediation of contaminated groundwater because of the lack of dispersibility and inoxi-dizability. Modified nZVI can improve the dispersibility and stability. The following characteristics of modified nZVI had be studied:nZVI modified in porous media needed lower cost,but fewer materials could be used;nZVI modified with various polymers could promote the reac-tivity towards NAPL,but it might cause secondary pollution without appropriate choice;Bimetallic nano-particles had the character of faster response speed and lower possibility to corrode,however,it would need high cost,and transition metal might be harmful to the environment. nZVI could degrade different heavy metal contaminates in groundwater,there different reaction mechanisms based the relative size between Fe2+ and standard electrode potential of heavy metal contaminates:adsorption/surface complexing,dual adsorption and reduction and redu-ation. However,modified nZVI had several disadvantages such as high cost and environmental toxicity.