EDTA强化污泥水热碳化释磷及磷的迁移转化规律  

The release,migration and transformation of phosphorus from sludge during hydrothermal carbonization enhanced by EDTA

作　　者：刘文肖 张彦平 李一兵 贾小赛 王庆元 LIU Wenxiao;ZHANG Yanping;LI Yibing;JIA Xiaosai;WANG Qingyuan(School of Civil Engineering and Transportation,Hebei University of Technology,Tianjin 300401,China;Tianjin Chuangye Environmental Protection Group Co.,Ltd.,Tianjin 300000,China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]天津创业环保集团股份有限公司,天津300000

出　　处：《环境工程学报》2025年第2期384-392,共9页Chinese Journal of Environmental Engineering

基　　金：河北省研究生创新资助项目(CXZZSS2023022)。

摘　　要：磷资源短缺使得磷回收成为我国可持续发展的战略需求。剩余污泥具有高磷含量和大排放特性,可以作为2次磷资源循环利用。本研究采用EDTA强化污泥水热碳化提升释磷效果,考察了反应温度、反应时间、EDTA投加量和污泥浓度对污泥释磷效果的影响,并分析了EDTA对水热固相产物中磷的赋存形态及液相中金属离子(Ca、Mg、Fe、Al)释放量的影响。结果表明,反应温度为210℃,反应4 h,EDTA投加量10 mmol·L^(-1)条件下,污泥释磷效果最佳,液相中TP和PO43-浓度分别达339.1和325.6 mg·L^(-1),释放率为96.2%,同时有大量金属离子被释放到液相。EDTA促进了水热炭中OP向IP转化,NAIP向AP转化。经EDTA强化污泥水热碳化后,水热炭保留了污泥原有的官能团,芳香性增强、极性减弱,燃烧性和热值提高。该结果为从污泥中同步回收碳磷,实现污泥高值化利用提供了一种新方法。Phosphorus recovery has become a strategic requirement for sustainable development in China due to the shortage of phosphorus resources.The waste activated sludge with high phosphorus content and large discharge can be used as a secondary phosphorus resource for recycling.In this study,EDTA was used to enhance phosphorus release from sludge during hydrothermal carbonization(HTC).The effects of reaction temperature,reaction time,EDTA dosage,and sludge concentration on the release efficiency of phosphorus from sludge were investigated.The forms of phosphorus in the hydrothermal solid products and the contents of metal ions(Ca,Mg,Fe,Al)released into the liquid phase were also analyzed.The results showed that under the optimal conditions of reaction temperature of 210℃,reaction time of 4 hours,and EDTA dosage of 10 mmol·L^(-1),the rate of phosphorus released from sludge reached 96.2%.The concentrations of total phosphorus and PO43-in the process water(PW)reached 339.1 and 325.6 mg·L^(-1),respectively.At the same time,a large amount of metals ions(Ca,Mg,Fe,Al)were released into the PW.EDTA enhanced the conversion of organophosphorus to inorganic phosphorus in the hydrochar,as well as the conversion of non-apatite inorganic phosphorus to apatite inorganic phosphorus.After the HTC enhanced with EDTA,the hydrochar retained the functional groups of the original sludge.The aromaticity of the hydrochar was enhanced,and it’s polarity was weakened.The combustibility and calorific value were both improved.This study provides a new method for synchronous recovering of carbon and phosphorus from sludge and achieving high-value utilization of sludge.

关 键 词：污泥 磷 水热碳化 EDTA 

分 类 号：X705[环境科学与工程—环境工程]