文献类型：期刊文献

英文题名：Recovery of phosphate from the supernatant of activated sludge pretreated by microwave irradiation through chemical precipitation

作者：Xiao, Dean Huang, Haiming Jiang, Yang Ding, Li

第一作者：Xiao, Dean

通信作者：Huang, HM[1]

机构：[1]Guizhou Inst Technol, Coll Resource & Environm Engn, Guiyang 550003, Guizhou, Peoples R China;[2]Yanshan Univ, Hebei Key Lab Appl Chem, Sch Environm & Chem Engn, Qinhuangdao 066004, Peoples R China

第一机构：贵州理工学院资源与环境工程学院

通信机构：corresponding author), Yanshan Univ, Hebei Key Lab Appl Chem, Sch Environm & Chem Engn, Qinhuangdao 066004, Peoples R China.

年份：2017

卷号：24

期号：35

起止页码：26901-26909

外文期刊名：ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

收录：;EI(收录号：20242616446070);Scopus(收录号：2-s2.0-85049192645);WOS:【SCI-EXPANDED(收录号:WOS:000417545800003)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Grant No. 51408529), the Natural Science Foundation of Hebei Province (Grant No. E2014203080), the Free Research Foundation for Young Teachers of Yanshan University (13LGB023), and the Development Program and Research of Science and Technology of Qinghuangdao (201401A004).

语种：英文

外文关键词：Chemical precipitation; Activated sludge; Phosphate recovery; Microwave irradiation; Anaerobic stirring

摘要：This paper presents a technology of releasing phosphate from activated sludge by using a combined process of microwave irradiation and anaerobic stirring, followed by phosphate recovery from the resulting supernatant via chemical precipitation without addition of chemicals, except for a pH regulator. A series of experiments was conducted to examine the effects of microwave irradiation time, sludge solution pH, sludge concentration, and anaerobic stirring time on the release of phosphate. The results revealed that all of these parameters had a significant effect on the release of phosphate via the proposed combined process, and the combination of 180 s of microwave irradiation and 1 h of anaerobic stirring was found to give optimal phosphate release. When the sludge solution was acidized before pretreatment, the phosphate concentration of the supernatant increased rapidly. A 25 g/L sludge concentration was found to be optimal for the release of phosphate, beyond this concentration, there was no increase in the phosphate release. Under the optimal conditions of phosphate release (irradiation time, 180 s; solution pH, 2; sludge concentration, 25 g/L; anaerobic stirring time, 1 h), the total orthophosphate (P-T) concentration in the supernatant reached 396 mg/L, accompanied by high concentrations of metal cations such as Ca, Mg, K, Al, and Fe. When the pH of the supernatant was adjusted to 9-10, the recovery efficiency of phosphate reached approximately 95 %. The analysis results indicated that the main components of the collected precipitates were amorphous calcium phosphate and struvite, which can be used as alternate phosphate minerals.