Dissolved carbon in biochar:Exploring its chemistry,iron complexing capability,toxicity in natural redox environment  

作　　者：Chaochao Lai Juhong Zhan Qiuyun Chai Changlu Wang Xiaoxia Yang Huan He Bin Huang Xuejun Pan 

机构地区：[1]Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650500,China [2]Research Institute for Environmental Innovation(Suzhou)Tsinghua,Suzhou 215163,China

出　　处：《Journal of Environmental Sciences》2025年第1期217-229,共13页环境科学学报(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.42207450,42067056,and 21866017);the Yunnan Fundamental Research Projects(No.202101BE070001-013);the Foundation for Distinguished Young Talents of Yunnan Province(No.202101AV070006).

摘　　要：Dissolved black carbon(DBC)plays a crucial role in the migration and bioavailability of iron in water.However,the properties of DBC releasing under diverse pyrolysis conditions and dissolving processes have not been systematically studied.Here,the compositions of DBC released from biochar through redox processes dominated by bacteria and light were thoroughly studied.It was found that the DBC released from straw biochar possess more oxygen-containing functional groups and aromatic substances.The content of phenolic and carboxylic groups in DBC was increased under influence of microorganisms and light,respectively.The concentration of phenolic hydroxyl groups increased from 10.0~57.5 mmol/gC to 6.6~65.2 mmol/gC,and the concentration of carboxyl groups increased from49.7~97.5 mmol/gC to 62.1~113.3 mmol/gC.Then the impacts of DBC on pyrite dissolution andmicroalgae growth were also investigated.The complexing Fe^(3+)was proved to play a predominant role in the dissolution of ferrous mineral in DBC solution.Due to complexing between iron ion and DBC,the amount of dissolved Fe in aquatic water may rise as a result of elevated number of aromatic components with oxygen containing groups and low molecular weight generated under light conditions.Fe-DBC complexations in solution significantly promoted microalga growth,which might be attributed to the stimulating effect of dissolved Fe on the chlorophyll synthesis.The results of study will deepen our understanding of the behavior and ultimate destiny of DBC released into an iron-rich environment under redox conditions.

关 键 词：Dissolved black carbon BACTERIA Light Iron complexes TOXICITY 

分 类 号：X132[环境科学与工程—环境科学]