CAJ | 학술논문

[目的]研究紫花苜蓿（Medicago sativa L.）对河道底泥中重金属的修复作用,为利用植物修复技术解决受污染河道沉积物的重金属污染问题提供可靠依据。[方法]将过筛的底泥（以风干土计）混和均匀后装入长方形PVC箱（0.6m×0.5m×0.4m）,底部设有渗流通气孔;将箱中底泥用去离子水调至30%～60%持水率（WHC）。2010年4月播入紫花苜蓿种子,生长7d后间苗,每隔30d采集植物根际土壤样品,监测底泥重金属含量、细菌及酶的活性。10月收获植物并测定植物根、茎、叶部分的重金属吸收情况。[结果]紫花苜蓿的同一部位对不同的重金属积累量不同,且同一重金属在植株的不同部位积累量也不同。紫花苜蓿对Zn的总积累量最大,且主要积累在根部;Ni、Cr、Cu和Pb也主要积累在根部;Mn在紫花苜蓿叶片中的积累最多,占植物中总积累量的42.47%;各种重金属在茎内的积累量均较低。紫花苜蓿对Ni、Cu、Pb和Cr的降解效果比较好,延长种植作物的种植时间或增加作物的播种次数有利于重金属的降解;紫花苜蓿对Mn的降解效果不明显。种植紫花苜蓿后,底泥中微生物数量显著增加,脱氢酶活性也有所提高。[结论]紫花苜蓿对Zn、Ni、Cr、Cu和Pb均有一定的修复作用,可以用于解决受污染河道底泥的重金属污染问题。
[목적]연구자화목숙（Medicago sativa L.）대하도저니중중금속적수복작용,위이용식물수복기술해결수오염하도침적물적중금속오염문제제공가고의거。[방법]장과사적저니（이풍간토계）혼화균균후장입장방형PVC상（0.6m×0.5m×0.4m）,저부설유삼류통기공;장상중저니용거리자수조지30%～60%지수솔（WHC）。2010년4월파입자화목숙충자,생장7d후간묘,매격30d채집식물근제토양양품,감측저니중금속함량、세균급매적활성。10월수획식물병측정식물근、경、협부분적중금속흡수정황。[결과]자화목숙적동일부위대불동적중금속적루량불동,차동일중금속재식주적불동부위적루량야불동。자화목숙대Zn적총적루량최대,차주요적루재근부;Ni、Cr、Cu화Pb야주요적루재근부;Mn재자화목숙협편중적적루최다,점식물중총적루량적42.47%;각충중금속재경내적적루량균교저。자화목숙대Ni、Cu、Pb화Cr적강해효과비교호,연장충식작물적충식시간혹증가작물적파충차수유리우중금속적강해;자화목숙대Mn적강해효과불명현。충식자화목숙후,저니중미생물수량현저증가,탈경매활성야유소제고。[결론]자화목숙대Zn、Ni、Cr、Cu화Pb균유일정적수복작용,가이용우해결수오염하도저니적중금속오염문제。
[Objective] The aim was to study the phytoremediation of heavy metal pollution in river sediment by Medicago sativa L.,so as to provide reliable references for the phytoremediation of heavy metal pollution in river sediment.[Method] The air-dried,screened and mixed sediment was put in rectangular PVC box（0.6 m×0.5 m×0.4 m） with seepage vent at the bottom,and the water holding capacity（WHC） of sediment was kept at 30%-60% by deionized water.The seeds of Medicago sativa L.were sown in April 2010,and seedlings were thinned after 7 d.Samples were collected from rhizosphere soil every 30 d,and were used to determine the content of heavy metals,bacteria quantity and enzyme activity in sediment.In addition,the accumulation of heavy metals in the roots,stems and leaves of plant was measured after harvest in October.[Result] Different parts of Medicago sativa L.varied in accumulation capacity to different heavy metals.The accumulation amount of Zn in Medicago sativa L.was the highest,especially in roots.Meanwhile,the accumulation amount of heavy metals like Ni,Cr,Cu and Pb in roots was higher than that of stems and leaves.In contrast,Mn was mainly accumulated in leaves and its amount accounted for 42.47% of the total amount in plant.Besides,the accumulation amount of all heavy metals was the lowest in stems.Ni,Cr,Cu and Pb could be degraded more effectively than Mn,and increasing the planting time and sowing times of crop was beneficial to the degradation of heavy metals.After planted Medicago sativa L.,the quantity of microorganisms in sediment went up obviously,and dehydrogenase activity also showed an increaseing trend.[Conclusion] Medicago sativa L.has certain restoring effect on Zn,Ni,Cr,Cu and Pb,and could be used to restore heavy metal pollution in river sediment.