title: Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.
abstract: The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; College of Environment, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China.
authors.forename: Jinte
authors.initials: J
authors.lastname: Zou
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. Electronic address: liyongmei@tongji.edu.cn.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Li
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000693:Anaerobiosis; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism; D004492:Edetic Acid / Q000737:chemistry*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D005290:Ferric Compounds / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D017607:Aluminum Compounds; D005232:Fatty Acids, Volatile; D005290:Ferric Compounds; D010710:Phosphates; D012722:Sewage; D010758:Phosphorus; D002244:Carbon; D004492:Edetic Acid; C012714:aluminum phosphate; C035885:ferric phosphate
keywords: Aluminum phosphate; Anaerobic fermentation; Ethylene diamine tetraacetic acid (EDTA); Ferric phosphate; Phosphorus release; Waste activated sludge