生态环境学报 ›› 2023, Vol. 32 ›› Issue (8): 1496-1506.DOI: 10.16258/j.cnki.1674-5906.2023.08.015

• 研究论文【环境科学】 • 上一篇    下一篇

生物质废弃物类型和水热pH对人工腐殖酸性能影响

张睿含1(), 智燕彩1, 贾明昊1, 李晓娜1,2,*(), 王震宇1,2   

  1. 1.江南大学环境与土木工程学院/绿色低碳技术与可持续发展研究中心，江苏 无锡 214122
    2.江南大学/生物质能源与减排技术江苏省工程实验室，江苏 无锡 214122
  • 收稿日期:2023-05-04 出版日期:2023-08-18 发布日期:2023-11-08
  • 通讯作者: *李晓娜。E-mail: xiaonali@jiangnan.edu.cn
  • 作者简介:张睿含（2002年生），女，研究方向为可再生资源利用。E-mail: 1103200214@stu.jiangnan.edu.cn
  • 基金资助:
    国家自然科学基金青年基金项目(42107244);江苏省自然科学基金青年基金项目(BK20210486);中央高校基本科研计划青年基金项目(1122050205222380)

Effects of Feedstock Types and Hydrothermal Solution pH on the Properties of Artificial Humic Acids

ZHANG Ruihan1(), ZHI Yancai1, JIA Minghao1, LI Xiaona1,2,*(), WANG Zhenyu1,2   

  1. 1. Research Center of Low-carbon Technology and Sustainable Development/School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, P. R. China
    2. Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology/Jiangnan University, Wuxi 214122, P. R. China
  • Received:2023-05-04 Online:2023-08-18 Published:2023-11-08

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摘要：

腐殖酸是土壤有机质中最活跃的部分，能改善土壤理化性质、提高土壤保肥性，是土壤的重要组成，也是植物营养的主要来源之一。为提高土壤中腐殖酸的含量，解决天然腐殖酸形成困难且周期长的问题，水热合成人工腐殖酸技术逐渐被关注。然而，水热条件和原料对人工腐殖酸性质的影响还鲜有报道。以乔木树枝——香樟树（Cinnamomum camphora）、灌木树枝——黄杨树（Buxus sinica）和香樟树叶为原料，在水热溶液pH分别为2、5、9和12的条件下制备人工腐殖酸并对其性质表征。结果表明，1）在水热过程中，纤维素相对含量高的树叶，其降解率随溶液pH升高而降低，在pH为2时，降解率为59.3%，而在pH为12时，降解率仅为41.0%，所得人工腐殖酸具有较好的导电性、营养价值和荧光特性；而木质素相对含量较高的乔木，其降解率随溶液pH升高而升高，在pH为12时，降解率可达到59.0%，所得人工腐殖酸具有较丰富的含氧官能团。2）强酸强碱条件下制备的人工腐殖酸具有较强导电性和较高的营养元素总量。强酸条件（pH=2）下提高人工腐殖酸中钠、钙和硫等元素的含量，强碱条件（pH=12）下提高人工腐殖酸中钠、硫和钾的含量。3）强碱条件（pH=12）更有利于人工腐殖酸的制备，所得人工腐殖酸自中和程度最佳，有机碳产量最高，导电性最强，营养价值和表面官能团能等性能方面均最佳；其中，由树叶生物质制备的人工腐殖酸，总有机碳含量最高且导电性最强，分别为2.60 g?L-1和3.10 mS?cm-1。研究结果为改良人工腐殖酸的制备工艺、指导人工腐殖酸的农业和环境应用提供了数据支撑，对环境的可持续发展具有积极意义。

关键词: 可再生资源利用, 人工腐殖酸, 水热合成, pH

Abstract:

Humic acid is the most active part of soil organic matter, improving soil physical and chemical properties and enhancing soil fertility. Therefore, humic acid is one of the most important components in soil and the main nutrition source for plant growth. To increase the content of humic acid in soils and solve the difficulty in the formation of humic acid in natural soils, a green chemical hydrothermal humification technology has been proposed to produce artificial humic acids. Hydrothermal humification is a top-down chemical technology for efficiently converting waste biomasses into high-value artificial humic acids. However, how the feedstock types and the pH of hydrothermal solution affects the properties of artificial humic acids were unsure. In this study, artificial humic acids were prepared from three common green waste biomasses including trees (Cinnamomum camphora), shrubs (Buxus sinica) and leaves (Cinnamomum camphora). Under the hydrothermal solution with pH 2, 5, 9 and 12, and the structure, nutrient and component properties of artificial humic acids were characterized to explore the effects of feedstock types and pH conditions on them. The results indicated that 1) the degradation rate of leaves with relatively high cellulose content decreases with the increase in solution pH. The degradation rate was 59.3% at pH 2 and only 41.0% at pH 12, and the resultant artificial humic acids had good conductivity, high nutrition, and rich fluorescence characteristics; while the degradation rate of trees with relatively high lignin content increases with the increase in solution pH, the degradation rate could reach 59.0% at pH 12, and the resultant artificial humic acids contain abundant functional groups. 2) Artificial humic acids prepared under strong acid and alkaline solutions have strong conductivity and nutritional contents. Specifically, the strong acid condition (pH=2) benefits the retention of sodium, calcium and sulfur in artificial humic acids, and the strong alkaline condition (pH=12) benefits the retention of sodium, sulfur and potassium in artificial humic acids. 3) Solution with strongly alkaline condition (pH=12) are conducive to a thorough self-neutralization, leading to the highest organic carbon contents, the strongest conductivity, the most nutritional contents and the most abundant surface functional group in artificial humic acids. In particular, the artificial humic acids derived from leaf biomass had the highest organic carbon contents and the highest conductivity, which were 2.60 g?L-1 and 3.10 mS?cm-1, respectively. This study provides a theoretical foundation for improving the preparation process of artificial humic acids and guiding the agricultural and environmental applications of artificial humic acids in the future, which shows great significance for the environmental sustainability.

Key words: renewable resource utilization, artificial humic acids, hydrothermal synthesis, solution pH

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