Spectral and photodegradation properties of dissolved organic matter in brines

被引：0
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作者：
Yang K. [1 ,2 ]
Dong Y. [1 ,2 ]
Li W. [1 ,3 ]
Peng J. [1 ,2 ]
Liu H. [1 ,3 ]
机构：
[1] CAS Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining
[2] Qinghai Technology Research and Development Center of Comprehensive Utilization of Salt Lakes Resources, Xining
[3] Qinghai Provincial Key Laboratory of Resources and Chemistry of Salt Lakes, Xining
来源：
Earth Science Frontiers | 2021年 / 28卷 / 06期
关键词：
Dissolved organic matter; Oilfield produced brine; Photodegradation; Salt lake brine; Spectral;
D O I：
10.13745/j.esf.sf.2021.1.56
中图分类号：
学科分类号：
摘要：
Dissolved organic matter (DOM) in brines has adverse effects on solar pond performance and evaporite product quality, such as slowing down evaporation rate, reducing evaporation level, and causing pungent smell and heavy coloration in evaporate products. Therefore, characterization of DOM in brines in terms of utilization values is essential to guide DOM removal and new technologies development for better mineral extraction. Here, DOM from salt lake (SLDOM) and oilfield (OFDOM) were size-fractionated into high (MW>1 kDa) and low (MW≤1 kDa) molecular weight fractions and analyzed through dissolved organic carbon (DOC) analysis, absorption spectroscopy, fluorescence parallel factor (PARAFAC) analysis to determine their spectral and photodegradation properties. DOC analysis and fluorescence indexes indicated that SLDOM and OFSDOM had comparable organic carbon contents and BIX (biological index), and they both had higher FIX (fermentation index) than DOM from natural water. Compared to OFDOM, SLDOM had higher HIX and HMW DOM. SUVA254 and carbohydrates measurements revealed that aromatic compounds and carbohydrates were mainly in the HMW fraction regardless of sample types. Fluorescence spectra showed that SLDOM mainly consisted of humic-substance, while OFDOM mainly protein-like substances. As for MW fractionation, for SLDDOM, fulvic acids were mainly in HMW DOM while humic acids in LMW DOM; for OFDOM, aromatic amino acids were abundant in HMW DOM. Photodegradation experiment indicated that DOC content in SLDOM and OFDOM decreased by 29.32% and 15.11%, respectively, with increasing light radiation. Further analysis showed that decreasing carbohydrate content and preferential degradation of LMW DOM occurred for both sample types. Moreover, during light irradiation, aromatic content increased and humification status remained stable in SLDOM, whereas in OFDOM aromatics decreased and humification increased. PARAFAC analysis showed that fluorescence intensities of PARAFAC components were enhanced for SLDOM, but reduced for OFDOM. © 2021, Editorial Office of Earth Science Frontiers. All right reserved.
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页码：187 / 195
页数：8
相关论文
共 24 条
  • [1] ZHENG M., Resources and eco-environmental protection of salt lakes in China, Environmental Earth Sciences, 64, 6, pp. 1537-1546, (2010)
  • [2] (2012)
  • [3] SHALEV N, LAZAR B, KOBBERICH M, Et al., The chemical evolution of brine and Mg-K-salts along the course of extreme evaporation of seawater: an experimental study, Geochimica et Cosmochimica Acta, 241, 15, pp. 164-179, (2018)
  • [4] 40, 11, (2008)
  • [5] 39, 2, (2010)
  • [6] WU J, ZHANG H, YAO Q S, Et al., Toward understanding the role of individual fluorescent components in DOM-metal binding, Journal of Hazardous Materials, 215, pp. 294-301, (2012)
  • [7] WANG X, GOUAL L, COLBERG P J., Characterization and treatment of dissolved organic matter from oilfield produced waters, Journal of Hazardous Materials, 217, 218, pp. 164-170, (2012)
  • [8] XU H, ZOU L, GUAN D, Et al., Molecular weight-dependent spectral and metal binding properties of sediment dissolved organic matter from different origins, Science of the Total Environment, 665, pp. 828-835, (2019)
  • [9] 27, 6, (2011)
  • [10] 23, (2015)
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