摘要
为探究水热炭中具有高反应活性的溶解性有机质(DOM)在不同条件下的释放行为及化学特性,本研究采用三维荧光光谱-平行因子分析(PARAFAC)和紫外-可见光谱,分析了水热温度(180、200℃及220℃)和浸提环境(去离子水、盐溶液、酸溶液及碱溶液)对番茄废弃物水热炭(分别记为H-180、H-200及H-220)DOM的释放行为及光谱特征的影响。结果表明:H-220释放的DOM含量最高(52.1~70.5 mg·g^(−1)),且所有水热炭均在碱性环境中释放的DOM最多(66.6~77.0 mg·g^(−1))。3种水热炭DOM的释放行为遵循二级动力学模型(R 2>0.95),且均在短时间内(0.25 h)释放大量DOM(65.7%~85.8%)。通过PARAFAC分析可知,水热炭DOM共解析出3种荧光组分,包括2种类腐殖质组分(C1和C2)和1种类蛋白与可溶性微生物降解产物的混合组分(C3)。水热炭DOM的荧光强度随水热温度升高而逐渐升高。水热温度和浸提环境均会影响水热炭DOM中3种荧光组分的相对分布,且对所有DOM而言,C1的相对占比均最高(40.4%~53.6%)。提高水热温度(180~220℃)增强了水热炭DOM的腐殖化程度(6.1%~42.5%),降低了DOM的生物可利用性(5.5%~22.2%)。此外,碱性环境促进了水热炭DOM中高芳香性及疏水性组分的释放。主成分分析结果表明,水热温度和浸提环境尤其是碱性环境对水热炭DOM的光谱特征有较大影响。
This study examined the release behavior and chemical properties of highly reactive dissolved organic matter(DOM)in hydrochar under different conditions.To do so,three-dimensional fluorescence spectroscopy with parallel factor analysis(PARAFAC)and UV-Vis spectroscopy were employed to analyze the effects of hydrothermal carbonization(HTC)temperatures(180,200℃and 220℃)and extraction conditions(deionized water,salt solution,acidic solution,and alkaline solution)on the release kinetics and spectral characteristics of DOM in tomato waste hydrochar(H-180,H-200,and H-220).The results show that H-220 released the highest levels of DOM content(52.1~70.5 mg·g^(−1)),and each hydrochar released the maximum amount of DOM in alkaline solutions(66.6~77.0 mg·g^(−1)).The release kinetics of DOM from the hydrochars followed a second-order model(R 2>0.95),and the hydrochars released a large amount of DOM(65.7%~85.8%)in a short time(0.25 h).Three fluorescent components were identified in the hydrochar DOM by PARAFAC:two humic-like components(C1 and C2)and a mixed component(C3)of protein-like and soluble microbial by-product-like substances.The fluorescence intensity of hydrochar DOM gradually increased with increasing HTC temperature.The HTC temperature and extraction conditions both influenced the relative distribution of the three fluorescent components in the hydrochar DOM,and C1 had the highest relative fractional distribution(40.4%~53.6%)of all the hydrochar DOMs.Elevated HTC temperatures(180~220℃)increased the humification degree(6.1%~42.5%)and decreased the bioavailability(5.5%~22.2%)of the hydrochar DOM.Moreover,alkaline conditions promoted the release of substances with high aromaticity and hydrophobicity in the hydrochar DOM.Principal component analysis showed that the HTC temperature and extraction conditions(especially alkaline conditions)both exerted significant effects on the spectral characteristics of the hydrochar DOM.
作者
李凌瑶
郭旋
李钰飞
李吉进
孙钦平
王平
郎乾乾
LI Lingyao;GUO Xuan;LI Yufei;LI Jijin;SUN Qinping;WANG Ping;LANG Qianqian(College of Resources and Environmental Sciences,Gansu Agricultural University,Lanzhou 730070,China;Institute of Plant Nutrition,Resources and Environment,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2022年第8期1816-1824,共9页
Journal of Agro-Environment Science
基金
北京市农林科学院青年基金项目(QNJJ202125)
北京市农林科学院植物营养与资源环境研究所所长基金项目(YZS202101)
国家重点研发计划项目(2017YFD0801400)
财政部和农业农村部:国家现代农业产业技术体系
北京市奶牛创新团队项目(BAIC06-2021)。
