Effect of leaching time on phytotoxicity of dissolved organic matter derived from black carbon based on spectroscopy. (15th August 2022)

• Record Type: Journal Article
• Authors: Zhang, Ruju; Deng, Ze; Li, Jiulong; Zhang, Yunxian; Wei, Zimin; Cao, Huan
• Is Part Of: Environmental pollution. Volume 307(2022)
• Publication Date: 2022-08-15
• Subjects: Black carbon -- Dissolved organic matter -- Excitation-emission matrix-parallel factor -- Fourier transform infrared spectrometry -- Phytotoxicity; BC black carbon -- DOM dissolved organic matter -- HT heating temperature -- TOC total organic carbon -- GI germination index -- EEM-PARAFAC excitation-emission matrix-parallel factor -- 2DCOS two-dimensional correlation spectroscopy -- SEMs structural equation models -- FTIR Fourier transform infrared spectroscopy; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.119595
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Black carbon (BC) exports huge amounts of its derived DOM from terrestrial ecosystems annually through a variety of ways (i.e., erosion or runoff migration). The pyrolytic feedstock type and temperature resulted in DOM derived from highly condensed aromatic and non-aromatic BC. However, the behaviors of low aromatic BC-derived DOM at diverse leaching time are poorly understood. In this work, low aromatic BCs were prepared by pyrolysis corn straws at 250 °C, 350 °C and 450 °C. Extraction experiments for four leaching time (6 h, 10 h, 15 h and 21 h) were set up to simulate BC-derived DOM generative process in nature. The phytotoxicity of BC-derived DOM was evaluated via germination index (GI). Spectral characteristics were discussed to analyze the phytotoxicity variations of fluorescence components composition at different time, including the excitation-emission matrix-parallel factor, two-dimensional correlation spectra and Fourier transform infrared spectroscopy. The results suggested that low aromatic BC-derived DOM might contain aromatic phenolic compounds. A longer time contributed to accumulate the complex, hard-to-use organic matters, leading to lower GI. These results would supplement the dynamic spectral characteristics of low aromatic BC-derived DOM and its environmental risks during the leaching process. Graphical abstract: Image 1 Highlights: The dissolved organic matter of black carbon (BC) degraded with the leaching time. BC derived dissolved organic matter (DOM) contained 0.95–5.87 mg/L phenols. Leaching time promoted the dissolution of phenolic compounds from low-aromatic BC. The accumulation of phenolic compounds in BC-derived DOM inhibited root growth.