Phosphorus recovery from biogas fermentation liquid by Ca-Mg loaded biochar

作     者：Ci Fang Tao Zhang Ping Li Rongfeng Jiang Shubiao Wu Haiyu Nie Yingcai Wang 

作者机构：Key Laboratory of Plant–Soil Interactions of Ministry of Education College of Resources and Environmental SciencesChina Agricultural University College of Engineering China Agricultural University College of Science China Agricultural University 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2015年第27卷第3期

页      面：106-114页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 

基　　金：supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20120008120013) the National Natural Science Foundation of China (No. 31401944) the Beijing Natural Science Foundation (No. 6144026) the China Scholarship Council (No. 201206355006) the Chinese Universities Scientific Fund of China Agricultural University (No. 2011JS169) 

主　　题：Phosphorus Ca Mg loaded biochar Biogas fermentation liquid Recovery 

摘      要：Shortage in phosphorus （P） resources and P wastewater pollution is considered as a serious problem worldwide. The application of modified biochar for P recovery from wastewater and reuse of recovered P as agricultural fertilizer is a preferred process. This work aims to develop a calcium and magnesium loaded biochar （Ca-Mg/biochar） application for P recovery from biogas fermentation liquid. The physico-chemical characterization, adsorption efficiency, adsorption selectivity, and postsorption availability of Ca-Mg/biochar were investigated. The synthesized Ca-Mg/biochar was rich in organic functional groups and in CaO and MgO nanoparticles. With the increase in synthesis temperature, the yield decreased, C content increased, H content decreased, N content remained the same basically, and BET surface area increased. The P adsorption of Ca-Mg/biochar could be accelerated by nano-CaO and nano-MgO particles and reached equilibrium after 360min. The process was endothermic, spontaneous, and showed an increase in the disorder of the solid-liquid interface. Moreover, it could be fitted by the Freundlich model. The maximum P adsorption amounts were 294.22, 315.33, and 326.63 mg/g. The P adsorption selectivity of Ca-Mg/biochar could not be significantly influenced by the typical pH level of biogas fermentation liquid. The nano-CaO and nano-MgO particles of Ca-Mg/biochar could reduce the negative interaction effects of coexisting ions. The P releasing amounts of postsorption Ca-Mg/biochar were in the order of Ca-Mg/B600 〉 Ca-Mg/B4S0 〉 Ca-Mg/B300. Results revealed that postsorption Ca-Mg/biochar can continually release P and is more suitable for an acid environment.