Influence Mechanism of Dissolved Organic Matter (DOM) from Straw Humification on Chemical Speciation of Lead in Loess Region
FAN Chun-hui1, ZHANG Ying-chao2, WANG Jia-hong1
1. College of Resource & Environment, Shaanxi University of Science & Technology, Xi’an 710021, China 2. College of Environment, Tsinghua University, Beijing 100084, China
Abstract：Heavy metal is regarded as one of the most representative contaminants in soil, and the chemical speciation is greatly related to the toxicity and transformation behavior, which attracts the attention of researchers for years. The environmental factors could change the speciation of heavy metals, plus to the complexity of soil system, and the transformation variation of speciation might occasional existed under similar conditions. At present, the different viewpoints of related issues are urgent to be investigated. The characteristics of DOM from straw humification were revealed with UV spectra, 3D-EEMs spectra and FTIR spectra, and the Tessier Sequential Extraction Procedure was used to study the speciation transformation behavior of lead affected by DOM. The linear relationship of the contents between DOC and lead bound to organic matter was indicated to further discuss the influence mechanism of lead speciation using FTIR. The results showed: the absorbance peak of DOM located in 229 nm in UV spectra, and the fluorescence peaks appeared around the regions of λex/em=250/350 nm, λex/em=250/450 nm and λex/em=330/450 nm, referred as UV fulvic-like fluorescence, and visible humic-like fluorescence, respectively. The dominant functional groups of DOM included —OH, CO and N—H. The three fractions contents of lead (exchangeable, bound to iron and manganese oxides, residual) decreased, while that of lead bound to carbonates varied little. The contents of DOC and lead bound to organic matter appeared positive correlation (r=0.691 8), indicating the effective complexation between DOM and lead ions. The functional groups of —OH, CO and —COOH played an important role for the speciation transformation of lead, suggested from the FTIR spectra.
Key words：Straw humification;Chemical speciation of heavy metals;Dissolved organic matter (DOM);Fourier transform infrared spectrometry (FTIR)
范春辉1，张颖超2，王家宏1 . 黄土区秸秆腐殖化溶解性有机质对土壤铅赋存形态的影响机制 [J]. 光谱学与光谱分析, 2015, 35(11): 3146-3150.
FAN Chun-hui1, ZHANG Ying-chao2, WANG Jia-hong1 . Influence Mechanism of Dissolved Organic Matter (DOM) from Straw Humification on Chemical Speciation of Lead in Loess Region . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2015, 35(11): 3146-3150.
[1] Nahmani J, Lavelle P. European Journal of Soil Biology, 2002, 38(3/4): 297. [2] Tessier A, Campbell P G C, Blsson M. Analytical Chemistry, 1979, 51(7): 844. [3] Claret F, Tournassat C, Crouzet C, et al. Waste Management, 2011, 31(9/10): 2036. [4] Sundaray S K, Nayak B B, Lin S, et al. Journal of Hazardous Materials, 2011, 186(2/3): 1837. [5] Murakami M, Fujita M, Furumai H, et al. Journal of Hazardous Materials, 2009, 164(2/3): 707. [6] Jansen B, Nierop K G J, Verstraten J M. Geoderma, 2003, 113(3/4): 323. [7] FAN Chun-hui, ZHANG Ying-chao, MA Hong-rui, et al(范春辉, 张颖超, 马宏瑞, 等). Journal of Analytical Science(分析科学学报), 2014, 30(1): 5. [8] FAN Chun-hui, ZHANG Ying-chao, CAI Shao-yuan, et al(范春辉, 张颖超, 蔡少渊, 等). Journal of Arid Land Resources & Environment(干旱区资源与环境), 2013, 27(9): 171. [9] XI Dan-li, SUN Yu-sheng, LIU Xiu-ying(奚旦立, 孙裕生, 刘秀英). Environmental Monitoring(环境监测). Beijing: Higher Education Press(北京: 高等教育出版社), 1996. [10] HAO Rui-xia, CAO Ke-xin, ZHAO Gang, et al (郝瑞霞, 曹可心, 赵 钢, 等). Journal of Beijing University of Technology(北京工业大学学报), 2006, 32(12): 1062. [11] Komada T, Schofield O M E, Reimers C E. Marine Chemistry, 2002, 79(2): 81. [12] Filgueiras A V, Lavilla I, Bendicho C. Science of the Total Environment, 2004, 330(1/2/3): 115. [13] FANG Sheng-rong, XU Ying, WEI Xiao-yun, et al(方盛荣, 徐 颖, 魏晓云, 等). Ecology & Environmental Sciences(生态环境学报), 2009, 18(6): 2066. [14] Merckx R, Brans K, Smolders E. Soil Biology & Biochemistry, 2001, 33(2): 235. [15] WU Jin-guang(吴瑾光). Modern Fourier Transform Infrared Spectroscopy & Applications, Vol. 2(近代傅利叶变换红外光谱技术及应用，下卷). Beijing: Scientific & Technical Documentation Press(北京: 科学技术文献出版社), 1994.
