Insight into the co-hydrothermal humification of corn stalk and sewage sludge for enhanced nitrogen-rich humic acid production  

作　　者：Zhihua Li Yuchao Shao Wenjing He Zhangrui Luo Weizhong Huo Rong Ye Wenjing Lu 

机构地区：[1]School of Materials,Beijing Institute of Technology,Beijing 100081,China [2]School of Environment,Tsinghua University,Beijing 100084,China [3]Nanjing Institute of Environment Sciences,Ministry of Ecology&Environment,Nanjing 210042,China

出　　处：《Frontiers of Environmental Science & Engineering》2024年第12期127-137,共11页环境科学与工程前沿(英文)

基　　金：financially supported by the Major Program of National Natural Science Foundation of China(No.52091543).

摘　　要：The high organic carbon content in corn stalks(CS)and the rich nitrogen resources in sewage sludge(SS)render them ideal for the hydrothermal production of nitrogen-enriched hydrothermal humic acid(HHA).This study conducted co-hydrothermal humification experiments using varying ratios of CS to SS under two distinct mixing modes:1)co-hydrothermal carbonization of CS and SS,followed by alkaline hydrothermal humification to yield HHA,and 2)mixing CS-derived hydrochar with SS,followed by alkaline hydrothermal humification to yield HHA.The results indicated no significant difference in HHA yield between the modes when using equivalent raw material ratios.Importantly,the HHA produced did not pose a heavy metal risk.However,HHA from mode(1)had nearly double the nitrogen content compared to mode(2)and contained more valuable metal elements.The study confirmed that while co-hydrothermal humification of CS and SS did not significantly enhance HHA yield,it did markedly increase nitrogen content.Furthermore,HHA yield decreased with increasing SS content in the raw materials,likely due to SS's high ash content(52.4 wt%).In contrast,the nitrogen content in HHA increased with higher SS content,rising from 2.0 wt% to 3.8 wt% in mode(1)and from 1.1 wt%to 2.3 wt%in mode(2).Upon comprehensive analysis of both modes,the study suggests that mode(1)is more promising for engineering applications,as it facilitates the efficient disposal of a larger amount of SS.

关 键 词：Corn stalk Sewage sludge Hydrothermal humification Hydrochar Humic acid Nitrogen content 

分 类 号：F42[经济管理—产业经济]