子牙新河下游湿地土壤重金属垂直分布及形态特征
Vertical distribution and speciation characteristics of heavy metals in wetlands soils of Ziyaxin River downstream
-
摘要: 2014年秋季在子牙新河下游湿地采集柱状土壤样品,分析了Cd、Zn、Cu、Pb的垂向分布特征,利用Tessier连续浸提法,分析了典型湿地N1、N3、B3的重金属形态.研究结果表明,Cd、Zn、Cu、Pb含量垂向分布差异性比较大,波动幅度比较大,多数点位Cd、Cu、Zn在11-19 cm深度处出现峰值,可能与过去金属的输入和周期性淹水有关.Zn、Cu、Pb形态分布为残渣态 > 铁锰氧化物结合态 > 有机物结合态 > 可交换态 > 碳酸盐结合态,Cd形态分布为铁锰氧化物结合态 > 可交换态 > 残渣态 > 有机物结合态 > 碳酸盐结合态,Cd的生物有效性较高.湿地淹水条件影响到湿地重金属Cd的交换态和铁锰氧化物结合态的垂直分布.Cd主要以铁锰氧化物结合态的形式存在于湿地土壤中,其百分含量占53.2%,而重金属Zn、Cu、Pb主要以残渣态的形式存在于湿地土壤中,其百分含量均高于60%.根据风险评价编码法(RAC)对重金属的化学形态进行风险评价,风险顺序为:Cd>Zn>Cu>Pb,因此重金属Cd应引起足够的重视.Abstract: Soil samples were collected from wetlands of Ziyaxin River downstream in the fall of 2014. The vertical distribution characteristics of heavy metals (Cd, Zn, Cu, Pb) were analyzed. Speciation of Cd, Zn, Cu and Pb of typical wetland were analyzed using the method of Tessier sequential extraction. Wave variances of heavy metal concentration were observed in vertical direction, which implied the difference of metals input in different periods. Peak values of Cu, Cd and Zn in depth 11-19 cm showed that the concentration was affected by historical input of metals to wetlands and vertical transport caused by water level. The order of form distribution of Zn, Cu and Pb was residual fraction > Fe-Mn oxide-bound fraction > organio-bound fraction > exchangeable fraction > carbonate-bound fraction. However, the order of form distribution of Cd was Fe-Mn oxide-bound fraction > exchangeable fraction > residual fraction > organio-bound fraction > carbonate-bound fraction. Therefore, the bioavailability of Cd was high. The vertical distributions of exchangeable and Fe-Mn oxide-bound fraction Cd were affected by the waterflooding environment. Fe-Mn oxide-bound Cd accounted for 53.2%, and residual Zn, Cu and Pb accounted for more than 60% in wetland soil. According to risk assessment of coding method (RAC), the risk order of heavy metal, speciation was Cd > Zn > Cu > Pb. Therefore more attention should be paid to the risk of Cd in this area.
-
Key words:
- wetlands /
- heavy metals /
- vertical distribution /
- speciation characteristics
-
-
[1] 李瑞利, 柴民伟, 邱国玉, 等. 三江平原典型沼泽湿地养分累积与沉积特征[J]. 环境科学, 2014, 35(8): 2928-2936. LI R L, CHAI M W, QIU G Y, et al. Profile nutrient distribution and sedimentary characteristics in typical marshes of Sanjiang plain[J]. Environmental Science, 2014, 35(8): 2928-2936(in Chinese).
[2] TAM N F, WONG Y S. Spatial variation of heavy metals in surface sediments of Hong Kong mangrove swamps[J]. Environmental Pollution, 2000, 110(2): 195-205. [3] YUAN C G, SHI J B, HE B, et al. Speciation of heavy metals in marine sediments from the East China Sea by ICP-MS with sequential extraction.[J]. Environment International, 2004, 30(6): 769-783. [4] FENG Y, HUANG X, ZHANG D, et al. Distribution of heavy metals in sediments of the Pearl River Estuary,Southern China:Implications for sources and historical changes[J]. Journal of Environmental Sciences, 2012, 24(4): 579-588. [5] HU B, CUI R, LI J, et al. Occurrence and distribution of heavy metals in surface sediments of the Changhua River Estuary and adjacent shelf (Hainan Island)[J]. Marine Pollution Bulletin, 2013, 76(1-2): 400-405. [6] AKCAY H, OGUZ A, KARAPIRE C. Study of heavy metal pollution and speciation in Buyak Menderes and Gediz river sediments[J]. Water Research, 2003, 37(4): 813-822. [7] 王菊英, 张曼平. 重金属的存在形态与生态毒性[J]. 海洋湖沼通报, 1992(2): 83-89. WANG J Y, ZHANG M P. Existing forms and ecotoxicity of heavy metals[J]. Transactions of Oceanology and Limnology, 1992 (2): 83-89(in Chinese).
[8] FORSTNER U. Metal speciation-general concepts and applications[J]. International Journal of Environmental Analytical Chemistry, 1993, 51(1-4): 5-23. [9] Williams T P, Bubb J M, Lester J N. Metal accumulation within salt marsh environments: A review[J]. Marine Pollution Bulletin, 1994, 28(5): 277-290. [10] 王艳, 刘汝海, 于萍, 等. 锦州湾沉积物重金属污染特征及基于三角模糊数的生态风险评价[J]. 海洋与湖沼, 2013, 44(4): 860-865. WANG Y, LIU R H, YU P, et al. Heavy metal pollution in surface sediment of Jinzhou Bay and ecological risk assessment based on triangular fuzzy number[J]. Oceanologia et Limnologia Sinica, 2013, 44(4): 860-865(in Chinese).
[11] Tessier A, Campbell P G C, Bisson M. Sequential extraction procedure for the speciation of particulate trace metals[J]. Analytical Chemistry, 1979, 51(7): 844-851. [12] 李永霞, 黄莹, 高甫威, 等. 娄山河表层沉积物重金属赋存形态及风险评价[J]. 环境化学, 2016, 35(2): 393-402. LI Y X, HUANG Y, GAO F W, et al. Speciation and risk assessment of heavy metals in surface sediments of the Loushan River[J]. Environmental Chemistry, 2016, 35(2): 393-402(in Chinese).
[13] 许柏宁, 王鹏, 王建壹, 等. 北京某环路两侧土壤重金属污染风险评价[J]. 环境化学, 2014, 33(12): 2152-2161. XU B N, WANG P, WANG J Y, et al. Evaluation of heavy metal pollution in the soil sampled from a ring road in Beijing[J]. Environmental Chemistry, 2014, 33(12): 2152-2161(in Chinese).
[14] 陈同斌, 陈志军. 土壤中溶解性有机质及其对污染物吸附和解吸行为的影响[J]. 植物营养与肥料学报, 1998, 4(3): 201-210. CHEN T B, CHEN Z J. Dissolved organic matter and its effects on adsorption and desorption of pollutants in soils[J]. Plant Nutrition and Fertilizer Science, 1998, 4(3): 201-210(in Chinese).
[15] 高智群, 张美剑, 赵科理, 等. 土壤-水稻系统重金属空间异质性研究——以浙江省嵊州市为例[J]. 中国环境科学, 2016, 36(1): 215-224. . GAO Z Q, ZHANG M J, ZHAO K L, et al. Heavy metal contamination in soil-rice system and its spatial variation in Shengzhou City[J]. China Environmental Science, 2016, 36(1): 215-224(in Chinese).
[16] 方盛荣, 徐颖, 魏晓云, 等. 典型城市污染水体底泥中重金属形态分布和相关性[J]. 生态环境学报, 2009, 18(6): 2066-2070. FANG S R, XU Y, Wei X Y, et al.Morphological distribution and correlation of heavy metals in sediment of typical urban polloted water bodies[J]. Ecology & Environmental Sciences, 2009, 18(6): 2066-2070(in Chinese).
[17] 姚新颖. 黄河三角洲湿地土壤重金属形态特征及风险评价[D]. 北京:北京林业大学, 2015. YAO X Y. Fraction characteristics and risk assessment of heavy metals in wetland soil of the Yellow River Delta[D]. Beijing: Beijing Forestry University, 2015(in Chinese). [18] 王爽, 李畅游, 史小红, 等. 乌梁素海沉积物中重金属形态分布特征及污染状况评价[J]. 环境化学, 2012, 31(10): 1555-1561. WANG S, LI C Y, SHI X H, et al. Heavy metal speciation and pollution evaluation in the sediments of Wuliangsuhai Lake[J]. Environmental Chemistry, 2012, 31(10): 1555-1561(in Chinese).
[19] 许友泽, 刘锦军, 成应向, 等. 湘江底泥重金属污染特征与生态风险评价[J]. 环境化学, 2016, 35(1): 189-198. XU Y Z, LIU J J, CHENG Y X, et al. Characteristics and ecological risk assessment of heavy metals contamination in sediments of the Xiangjiang River[J]. Environmental Chemistry, 2016, 35(1): 189-198(in Chinese).
[20] WANG Y, LIU R H, ZHANG Y Q, et al. Transport of heavy metals in the Huanghe River estuary, China[J]. Environmental Earth Sciences, 2016, 75(4): 1-11. -

计量
- 文章访问数: 1292
- HTML全文浏览数: 1236
- PDF下载数: 475
- 施引文献: 0