CAJ | 학술논문

采用改进后的BCR四步连续提取法,分析了甘肃省白银市黄灌农业区农田土壤5个土层重金属Cd, Cu, Pb, Zn的4种赋存形态,并依其污染指数和潜在生态危害指数,评价了白银黄灌农业区各层土壤中重金属的污染程度及其潜在生态危害.结果表明：白银黄灌农业区土壤重金属各形态质量分数(包括重金属总量)均在表层中达到最大值,而在中层最低.各层土壤中Cu以残渣态为主,占比为72.83%～91.80%.除表层外, Pb, Zn也以残渣态为主,占比分别为57.14%～70.19%,69.56%～80.95%,而Cd各形态在不同土层中没有呈现规律性分布.根据污染水平,各层土壤中4种重金属的污染程度顺序均为Cd>Pb>Zn>Cu.根据潜在生态危害,各层土壤中4种重金属的潜在生态危害顺序均为Cd>Pb>Cu>Zn,其中Cd的污染程度最高,潜在生态危害最强,表层尤其突出.综合本研究结果,白银市黄灌农业区土壤Cd污染严重,亟需整治以减小其对当地农作物及居民的潜在危害.
채용개진후적BCR사보련속제취법,분석료감숙성백은시황관농업구농전토양5개토층중금속Cd, Cu, Pb, Zn적4충부존형태,병의기오염지수화잠재생태위해지수,평개료백은황관농업구각층토양중중금속적오염정도급기잠재생태위해.결과표명：백은황관농업구토양중금속각형태질량분수(포괄중금속총량)균재표층중체도최대치,이재중층최저.각층토양중Cu이잔사태위주,점비위72.83%～91.80%.제표층외, Pb, Zn야이잔사태위주,점비분별위57.14%～70.19%,69.56%～80.95%,이Cd각형태재불동토층중몰유정현규률성분포.근거오염수평,각층토양중4충중금속적오염정도순서균위Cd>Pb>Zn>Cu.근거잠재생태위해,각층토양중4충중금속적잠재생태위해순서균위Cd>Pb>Cu>Zn,기중Cd적오염정도최고,잠재생태위해최강,표층우기돌출.종합본연구결과,백은시황관농업구토양Cd오염엄중,극수정치이감소기대당지농작물급거민적잠재위해.
The chemical speciations of heavy metals (Cd, Cu, Pb and Zn) in five layers of irrigated lands of the Yellow River in Baiyin were analyzed by means of the modified BCR-sequential extraction procedure. Elemental contamination index and integrate ecological risk index were employed to assess the contamination degree and potential ecological risks of heavy metals. The results showed that the mass fractions of heavy metals’ specia-tions in the surface layer of the studied area reached the highest level, while those in the middle layer hit the lowest point. Besides, Cu in different layers mainly existed in residual form, accounting for 72.83%～91.80%. Pb and Zn were also chiefly presented in residual form in different layers, except for the surface layer, representing 57.14%～70.19% and 69.56%～80.95% respectively. Moreover, speciations of Cd did not regularly distribute in different layers. According to elemental contamination index and integrate ecological risk index, the contamina-tion degree and the potential ecological risk of detected heavy metals was Cd>Pb>Zn>Cu and Cd>Pb>Cu>Zn respectively, of which Cd in the surface layer was the highest. In conclusion, Cd pollution in Baiyin farmland soil is rather severe. Therefore, it is suggested that strict measures must been taken to diminish the potential hazard of Cd to local crops and inhabitants.