CAJ | 학술논문

采用振荡浸提方法，研究了有机酸（柠檬酸、酒石酸）与FeCl3复合浸提对Cd、Pb污染农田土壤重金属的去除效果和影响因素，测定了浸提前后土壤中重金属形态和浸提液中常量元素含量。结果表明，柠檬酸（100 mmol·L-1）和FeCl3（20 mmol·L-1）复合浸提，对土壤中Cd、Pb的去除效率分别达到了40.7％和20.9％，酒石酸（100 mmol·L-1）和FeCl3（20 mmol·L-1）复合浸提，对Cd、Pb的去除效率分别达到了42.6％和16.5％，均高于相同浓度有机酸、FeCl3单独浸提的去除效率。有机酸- FeCl3对重金属的去除率随pH值升高而减少。液固质量比为5∶1、浸提时间为24 h、浸提3次比较适宜；有机酸-FeCl3对Cd的去除主要是交换态（77.3％~79.8％）和铁锰氧化态（86.7％~87.0％），有机结合态几乎没有变化；对Pb的去除主要是铁锰氧化态（70.0％~70.8％）和有机结合态（58.8％~66.0％），交换态显著增加至24.2％~24.5％，Cd、Pb碳酸盐结合态几乎消失，残渣态无变化。污染土壤中的Pb经过多次浸提，去除率可显著提高，连续3次浸提达到47.0％~48.2％。
채용진탕침제방법，연구료유궤산（저몽산、주석산）여FeCl3복합침제대Cd、Pb오염농전토양중금속적거제효과화영향인소，측정료침제전후토양중중금속형태화침제액중상량원소함량。결과표명，저몽산（100 mmol·L-1）화FeCl3（20 mmol·L-1）복합침제，대토양중Cd、Pb적거제효솔분별체도료40.7％화20.9％，주석산（100 mmol·L-1）화FeCl3（20 mmol·L-1）복합침제，대Cd、Pb적거제효솔분별체도료42.6％화16.5％，균고우상동농도유궤산、FeCl3단독침제적거제효솔。유궤산- FeCl3대중금속적거제솔수pH치승고이감소。액고질량비위5∶1、침제시간위24 h、침제3차비교괄의；유궤산-FeCl3대Cd적거제주요시교환태（77.3％~79.8％）화철맹양화태（86.7％~87.0％），유궤결합태궤호몰유변화；대Pb적거제주요시철맹양화태（70.0％~70.8％）화유궤결합태（58.8％~66.0％），교환태현저증가지24.2％~24.5％，Cd、Pb탄산염결합태궤호소실，잔사태무변화。오염토양중적Pb경과다차침제，거제솔가현저제고，련속3차침제체도47.0％~48.2％。
Soil washing is one option to remediate heavy metal contaminated soils. The present study examined the removal efficiency of cad-mium(Cd)and lead(Pb)from a farmland soil by batch extraction with mixture of organic acid(citric acid or tartaric acid)and FeCl3. Metal fractions before and after soil washing were also determined. The Cd and Pb removal efficiency from the soil was up to 40.7%and 20.9%for mixture of citric acid(100 mmol·L-1)and FeCl3(20 mmol·L-1), and up to 42.6%and 16.5%for mixture of tartaric acid(100 mmol·L-1) and FeCl3(20 mmol·L-1), respectively. The metal removal efficiency was higher for mixed reagents than single reagent. Increasing pH of washing solution decreased the removal efficiency of heavy metals. The optimum washing conditions were liquid to solid ratio of 5∶1, washing time of 24 h and washing cycles of 3. Metal fractionation showed that the removed Cd by organic acids combined with FeCl3 was mainly from exchangeable(77.3%~79.8%decline)and Fe-Mn oxides forms(86.7%~87.0%reduction), while the organic matter bound metals were al-most unchanged. The removed Pb came from Fe-Mn oxides(70.0%~70.8%decrease)and organic matter form(58.8%~66.0%drop). After soil washing, however, the exchangeable Pb significantly increased to 24.2%~24.5%, but Cd and Pb in carbonates almost disappeared with residual metal form unchanged. The removal efficiency of Pb in soil could be significantly increased by repeated washing, and up to 47.0%~48.2%of Pb could be extracted after 3 washing cycles.