Bioelectrochemical acidolysis of magnesia to induce struvite crystallization for recovering phosphorus from aqueous solution  

作　　者：Zuobin Wang Jiao Zhang Xiao Guan Lu She Pengyu Xiang Siqing Xia Zhiqiang Zhang 

机构地区：[1]Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse,College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China [2]Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China [3]School of Civil and Transportation Engineering, Shanghai Urban Construction Vocational College, Shanghai 200432, China [4]Zhejiang Weiming Environment Protection Co., Ltd., Wenzhou 325000, China

出　　处：《Journal of Environmental Sciences》2019年第11期119-128,共10页环境科学学报（英文版）

基　　金：supported by the National Key R&D Program of China(No.2017YFC0403400);the Fundamental Research Funds for the Central Universities;the Foundation of Key Laboratory of Yangtze River Water Environment,Ministry of Education(Tongji University),China(No.YRWEF201805)

摘　　要：A novel struvite crystallization method induced by bioelectrochemical acidolysis of magnesia (MgO) was investigated to recover phosphorus (P) from aqueous solution using a dual-chamber microbial electrolysis cell (DMEC).Magnesium ion (Mg2+) in the anolyte was firstly confirmed to automatically migrate from the anode chamber to the cathode chamber,and then react with ammonium (NH4+) and phosphate (PO34-) in the catholyte to form struvite.Recovery efficiency of 17.8%-60.2% was obtained with the various N/P ratios in the catholyte.When MgO (low solubility under alkali conditions) was added into the anolyte,the bioelectrochemical acidolysis of MgO naturally took place and the released Mg2+ induced struvite crystallization in the cathode chamber for P recovery likewise.Besides,there was a strong linear positive correlation between the recovery efficiency and the MgO dosage (R2 =0.935),applied voltage (R2 =0.969) and N/P ratio (R2 =0.905).Increasing the applied voltage was found to enhance the P recovery via promoting the MgO acidolysis and the released Mg2+ migration,while increasing the N/P ratio in the catholyte enhanced the P recovery via promoting the struvite crystallization.Moreover,the electrochemical performance of the system was promoted due to more stable anolyte pH and lower pH gradient between the two chambers.Current density was promoted by 10%,while the COD removal efficiency was improved from 78.2% to 91.8% in the anode chamber.A novel struvite crystallization method induced by bioelectrochemical acidolysis of magnesia（MgO） was investigated to recover phosphorus（P） from aqueous solution using a dual-chamber microbial electrolysis cell（DMEC）. Magnesium ion(Mg2+) in the anolyte was firstly confirmed to automatically migrate from the anode chamber to the cathode chamber, and then react with ammonium（NH+4） and phosphate(PO43-) in the catholyte to form struvite. Recovery efficiency of 17.8%–60.2% was obtained with the various N/P ratios in the catholyte. When MgO（low solubility under alkali conditions） was added into the anolyte, the bioelectrochemical acidolysis of MgO naturally took place and the released Mg2+induced struvite crystallization in the cathode chamber for P recovery likewise.Besides, there was a strong linear positive correlation between the recovery efficiency and the MgO dosage（R2= 0.935）, applied voltage（R2= 0.969） and N/P ratio（R2= 0.905）. Increasing the applied voltage was found to enhance the P recovery via promoting the MgO acidolysis and the released Mg2+migration, while increasing the N/P ratio in the catholyte enhanced the P recovery via promoting the struvite crystallization. Moreover, the electrochemical performance of the system was promoted due to more stable anolyte pH and lower pH gradient between the two chambers. Current density was promoted by 10%, while the COD removal efficiency was improved from 78.2% to 91.8% in the anode chamber.

关 键 词：PHOSPHORUS STRUVITE Microbial ELECTROLYSIS cell MAGNESIA ACIDOLYSIS Migration 

分 类 号：X[环境科学与工程]