title: Predicting potential release of dissolved organic matter from biochars derived from agricultural residues using fluorescence and ultraviolet absorbance.
abstract: A combination of fluorescence excitation-emission (EEM) spectrophotometry with parallel factor analysis (PARAFAC) and UV-vis spectroscopy was used to assess dissolved organic matter (DOM) release by the wheat straw-derived biochar in various environmental conditions. The results showed that the concentration of dissolved organic carbon (DOC) extracted from the biochar ranged from 435 to 5000mgkg-1, and the high DOM release would occur under the high temperature and alkaline environmental conditions. Four humic acid-like substances (C1, C2, C4 and C5), one fulvic acid-like substance (C3) and one tryptophan-like substance (C6) were identified by PARAFAC model. The distribution of the PARAFAC components in DOM was distinctively different among various extracts, and mainly composed of humic acid-like and fulvic acid-like material (accounting 55-78% and 10-37%). The high temperature enhanced the high release of humic acid-like DOM from the biochar. Humification index (HIX) of DOM released from the biochar in various extracts at the temperature of 20°C (0.99-1.09) was lower than that at the temperature of 60°C (1.31-1.92). The results obtained in the present study would be beneficial to understand biochar's effects and processes in the possible environmental applications.
authors.affiliation: College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Afeng
authors.initials: A
authors.lastname: Zhang
authors.affiliation: College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: haimingwu14@nwsuaf.edu.cn.
authors.forename: Haiming
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, United States.
authors.forename: Hai
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Jialong
authors.initials: J
authors.lastname: Lv
mesh_terms: D000383:Agriculture; D000468:Alkalies / Q000737:chemistry; D002606:Charcoal; D006358:Hot Temperature; D006812:Humic Substances / Q000032:analysis*; D012995:Solubility; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D000468:Alkalies; D006812:Humic Substances; C540010:biochar; D002606:Charcoal
keywords: Agricultural residues; Biochar; Dissolved organic matter; Fluorescence; Parallel factor analysis