茶园土壤中铅的生物有效性直接影响茶叶中铅的积累。为了解外加天然矿物对土壤中铅的固定作用,本文比较研究了4种矿物（高岭石、膨润土、沸石和磷灰石）在不同加入量和不同磨细程度条件下对土壤交换态铅和水溶性铅的影响。结果表明,加入矿物改良剂对土壤有效态铅（交换态铅和水溶性铅）有明显的降低作用,其效果与矿物类型、矿物加入量及加入矿物的磨细程度等有关。矿物对土壤有效铅的降低作用是：磷灰石>沸石>膨润土>高岭石。过100目处理矿物对土壤中铅的固定效果高于过18目处理的矿物。加入矿物对土壤水溶性铅的降低作用明显高于对交换态Pb的作用。结果认为,用天然矿物来改良铅污染茶园土壤、降低土壤有效铅是可行的。当土壤铅污染水平较低时,加入矿物量为20 g/kg已能达到改良效果。
The soluble and exchangeable fractions of Pb in the tea garden soils are the most important pools regarding toxicity and bioavailability of Pb to tea plants. Thus, it is very important to reduce Pb solubility and bioavailability in Pb-contaminated tea garden soils. Reducing Pb solubility and bioavailability in contaminated area without removing it from the soil is one of the common practices in decreasing the negative impacts on the crops and improving the soil quality. Therefore, the aim of this work was to study the effect of natural minerals: kaolinite, bentonite, zeolite,and apatite applied to Pb-contaminated tea garden soil on water extractable and exchangeable forms of Pb. A soil derived from Pb contaminated tea garden was incubated with clay minerals of either kaolinite, bentonite, zeolite,or apatite, for 100 d. During the incubation experiment, concentrations of exchangeable and water soluble Pb in the soils were measured. Water extractable and exchangeable forms of Pb were changed by incubation and addition of minerals. The addition of clay minerals led to a significant decrease in water soluble and exchangeable forms of soil Pb during the incubation experiment, resulting in low Pb extractability. The reduction in Pb extractability decreased in the order of apatite > zeolite > bentonite> kaolinite, and increased with increasing applied amount of the minerals and decreasing size of the minerals. The reduction in water soluble Pb due to the addition of the minerals was greater than that of exchangeable Pb in the soils. Our results clearly show that the use of natural minerals, especially of apatite and zeolite, is promising tool for reduction the availability and possible toxicity of Pb in Pb-contaminated tea garden soils. Therefore, the soils polluted with Pb may be ameliorated by addition of clay minerals, especially apatite and zeolite. Recommended amount of minerals for ameliorating Pb-contaminated soil is 20 g/kg.
[1] 姜红艳, 龚淑英. 茶叶中铅含量现状及研究动态[J]. 茶叶, 2004, 30(4): 210~212.
[2] 石元值, 韩文炎, 马立峰, 等. 龙井茶中重金属元素铅含量的影响因子探究[J]. 农业环境科学学报, 2004, 23(5): 899~903.
[3] Han W Y, Zhao F J, Shi Y Z, et al. Scale and causes of lead contamination in chinese tea[J]. Environmental Pollution, 2006, 139(1): 125~132.
[4] 张寿宝. 汽车尾气中的铅对茶园污染的研究[J]. 江苏环境科技, 2000, 13(3): 1~2.
[5] 王林云. 土壤对茶叶含铅量影响研究[J]. 中国公共卫生管理, 2001, 17(4): 318~319.
[6] 石元值, 马立峰, 韩文炎, 等. 铅在茶树中的吸收累积特性[J]. 中国农业科学, 2003, 36(11): 1272~1278.
[7] 石元值, 马立峰, 韩文炎, 等. 浙江省茶园中铅元素含量现状研究[J]. 茶叶科学, 2003, 23(2): 163~166.
[8] 章明奎, 黄昌勇. 公路附近茶园土壤中铅和镉的化学形态[J]. 茶叶科学, 2004, 24(2): 109~114.
[9] 金崇伟, 郑绍建. 茶叶的铅污染问题及铅污染的来源[J]. 广东微量元素科学, 2004, 11(3): 12~16.
[10] Jin CW, Zheng SJ, He YF, et al. Lead contamination in tea garden soils and factors affecting its bioavailability[J]. Chemosphere, 2005, 59(8): 1151~1159.
[11] 章明奎, 方利平, 张履勤. 酸化和有机质积累对茶园土壤铅生物有效性的影响[J]. 茶叶科学, 2005, 25(3): 159~164.
[12] Zhang MK, Fang LP.Tea plantation-induced activation of soil heavy metals[J]. Communication in Soil Science and Plant Analysis, 2007, 38(11~12): 1467~1478.
[13] 龙新宪, 杨肖娥, 倪吾钟.重金属污染土壤修复技术研究的现状与进展[J]. 应用生态学报, 2002, 13(6): 757~762.
[14] 鲁春霞, 于云江, 吴俊平. 粘土矿物对环境的防治作用[J]. 中国沙漠, 1999, 19(3): 265~267.
[15] 王焰新. 去除废水中重金属的低成本吸附剂:生物质和地质材料的环境利用[J]. 地学前缘, 2001, 8(2): 302~306.
[16] 莫慧明, 王光火, 朱祖祥. 天然沸石作为离子交换肥料的研究[J]. 浙江农业大学学报, 1990, 16(3): 229~223.
[17] Viaraghavan T, Rao G A K. Adsorption of mercury from wastewaters by bentonite[J]. Applied Clay Science, 1993, 9(1): 31~49.
[18] Pansini M.Natural zeolites as cation exchangers for environment protection[J]. Mineral Deposit, 1996, 31(4): 563-575.
[19] Leppert D.Heavy metal sorption with clinoptilolite zeolite:alternatives for treating contaminated soil and water[J]. Mining Engineering, 1990, 42(4): 604~608.
[20] Sparks D L.Methods of soil analysis, Part 3: Chemical methods[M]. SSSA Book Series No 5, Wisconsin: Madison, WI: SSSA and ASA, 1996, 703~722.
[21] Cao RX, Ma LQ, Chen M, et al. Phosphate-induced metal immobilization in a contaminated site. Environmental Pollution, 2003, 122(1):19-28.
[22] Yoon JK, Cao XD, Ma LQ.Application methods affect phosphorus-induced lead immobilization from a contaminated soil[J]. Journal of Environmental Quality, 2007, 36(2): 373~378.
浙公网安备 33019902000101号