CAJ | 학술논문

为揭示粤西3座供水水库（高州水库、鹤地水库、大水桥水库）沉积物营养盐负荷及重金属污染特征，于2008年6月在各水库大坝前湖泊区采集柱状沉积物，运用SMT法、碱性过硫酸钾消解法、烧失法和ICP-MS法分别测定其柱状沉积物中氮磷营养盐、有机质和7种重金属（Cu、Pb、Zn、Cd、Ni、Cr与Hg）的含量，并采用潜在生态风险指数法对表层重金属污染的潜在生态风险进行评价，同时通过相关性分析重金属的可能来源。结果表明：3座水库沉积物总氮质量分数为1.13~3.37 mg·g-1，有机质为11.83~20.37 mg·g-1，其表层总氮、有机质的质量分数大小顺序为高州水库>大水桥水库>鹤地水库，总磷的质量浓度在0.22~0.77 mg·g-1之间，其表层总磷质量分数大小顺序为高州水库>鹤地水库>大水桥水库，在垂直剖面上，总氮、总磷与有机质的质量分数在16 cm至表层沉积物垂直断面显著高于其他断面，表明近些年来水库内源营养盐负荷逐渐加重。重金属质量分数平均值均高于广东省土壤环境背景值，总体呈现随深度增加而降低的趋势，但3座水库间重金属质量分数差异较大，其中鹤地和高州水库的Zn和Pb污染相对严重（质量分数分别为Zn：353.15、693.35 mg·kg-1；Pb：74.51、127.91 mg·kg-1），大水桥水库的Cr和Ni污染相对严重（质量分数分别为Cr：238.69 mg·kg-1；Ni：251.06 mg·kg-1）。潜在生态风险评价表明，3座水库Cd和Hg具有高的生态危害，应引起重视，其他重金属则处于轻微的生态危害等级。同时沉积物高有机质的质量浓度经矿化分解可能加剧水体重金属生态危害。根据相关性分析和其他相关资料可知，粤西农业区大量化肥农药面源污染汇入造成水库初级生产力提高并最终沉降可能是沉积物营养盐、有机质与重金属的主要来源。
위게시월서3좌공수수고（고주수고、학지수고、대수교수고）침적물영양염부하급중금속오염특정，우2008년6월재각수고대패전호박구채집주상침적물，운용SMT법、감성과류산갑소해법、소실법화ICP-MS법분별측정기주상침적물중담린영양염、유궤질화7충중금속（Cu、Pb、Zn、Cd、Ni、Cr여Hg）적함량，병채용잠재생태풍험지수법대표층중금속오염적잠재생태풍험진행평개，동시통과상관성분석중금속적가능래원。결과표명：3좌수고침적물총담질량분수위1.13~3.37 mg·g-1，유궤질위11.83~20.37 mg·g-1，기표층총담、유궤질적질량분수대소순서위고주수고>대수교수고>학지수고，총린적질량농도재0.22~0.77 mg·g-1지간，기표층총린질량분수대소순서위고주수고>학지수고>대수교수고，재수직부면상，총담、총린여유궤질적질량분수재16 cm지표층침적물수직단면현저고우기타단면，표명근사년래수고내원영양염부하축점가중。중금속질량분수평균치균고우광동성토양배경배경치，총체정현수심도증가이강저적추세，단3좌수고간중금속질량분수차이교대，기중학지화고주수고적Zn화Pb오염상대엄중（질량분수분별위Zn：353.15、693.35 mg·kg-1；Pb：74.51、127.91 mg·kg-1），대수교수고적Cr화Ni오염상대엄중（질량분수분별위Cr：238.69 mg·kg-1；Ni：251.06 mg·kg-1）。잠재생태풍험평개표명，3좌수고Cd화Hg구유고적생태위해，응인기중시，기타중금속칙처우경미적생태위해등급。동시침적물고유궤질적질량농도경광화분해가능가극수체중금속생태위해。근거상관성분석화기타상관자료가지，월서농업구대양화비농약면원오염회입조성수고초급생산력제고병최종침강가능시침적물영양염、유궤질여중금속적주요래원。
Sediment cores were sampled from the three reservoirs of west area of Guangdong province in June, 2008. Total nitrogen (TN), total phosphorus (TP), organic matter (OM) and the main heavy metals including Cu, Pb, Zn, Cd, Ni, Cr and Hg in sedimentcolumns were determined by SMT, Alkaline Persulfate Digestion, loss on ignition Method, ICP-MS, respectively. Pollution of heavy meteals was evaluated by potential ecological risk index, and the possible sources of heavy metals were estimated with correlation analysis. The results showed that contents of total nitrogen TN and OM ranged from 1.13-3.37, 11.83-20.37 mg·g-1, respectively. TP ranged from 0.22-0.77 mg·g-1, the total nitrogen (TN) and the organic matter (OM) content in the surface sediments followed the order: Gaozhou Reservoir > Dashuiqiao Reservoir > Hedi Reservoir, whereas, total phosphorus (TP) is: Gaozhou Reservoir > Hedi Reservoir > Dashuiqiao Reservoir. From the depth of 16 cm to the surface in sediment columns, TN, TP and OM were significantly higher than others, and implied that internal loading getting heavier in recent years. The content of heavy metals was higher than the background values of soils in Guangdong province, and decreased with increasing depth, but there were great variations among the reservoirs. Zn and Pb polluted seriously in Hedi Reservoir and Gaozhou Reservoir (Zn: 353.15, 693.35 mg·kg-1; Pb: 74.51, 127.91 mg·kg-1), where as Cr and Ni showed serious pollution in Dashuiqiao Reservoir (Cr: 238.69 mg·kg-1; Ni: 251.06 mg·kg-1). We introduced risk index (RI) to evaluate the potential ecological risk of heavy metals, and results showed that there was low ecological risk except for Cd and Hg in the three reservoirs. However, mineralization of OM would result in heavy metals release into waterbody and increase ecological risk of heavy metals. Based on the correlation analysis, over input of fertilizer and pesticide would be the main source for the primary productivity and heavy metals, and settling to sediment in west area of Guangdong province.