title: Effects of three kinds of organic acids on phosphorus recovery by magnesium ammonium phosphate (MAP) crystallization from synthetic swine wastewater.
abstract: P recovery from swine wastewater has become a great concern as a result of the high demand for P resources and its potential eutrophication effects on water ecosystems. The method of magnesium ammonium phosphate (MAP) crystallization was used to recover P from simulated swine wastewater, and the effects of three organic acids (citric acid, succinic acid and acetic acid) on P removal efficiency and rate at different pH values were investigated. The results indicated that the P removal efficiency was worst affected by citric acid in the optimal pH range of 9.0-10.5, followed by succinic acid and acetic acid, and the influencing extent of organic acids decreased with the increasing pH value. Due to the complexation between organic acid and Mg(2+)/NH4(+), all of three organic acids could inhibit the P removal rate at the beginning of the reaction, which showed positive correlation between the inhibition effects and the concentration of organic acids. The high concentration of citric acid could completely suppress the MAP crystallization reaction. Moreover, citric acid and succinic acid brought obvious effects on the morphology of the crystallized products. The experimental results also demonstrated that MAP crystals could be obtained in the presence of different kinds and concentrations of organic acids.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China; Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China. Electronic address: songyh@craes.org.cn.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China; Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China.
authors.forename: Yunrong
authors.initials: Y
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China; Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China; School of Civil Engineering, Beijing Jiaotong University, 100044 Beijing, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Hu
authors.affiliation: School of Civil Engineering, Beijing Jiaotong University, 100044 Beijing, China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China; Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qian
mesh_terms: D000144:Acids, Acyclic / Q000737:chemistry*; D000818:Animals; D003460:Crystallization; D008274:Magnesium / Q000737:chemistry; D017616:Magnesium Compounds / Q000138:chemical synthesis*; D010710:Phosphates / Q000138:chemical synthesis*; D010758:Phosphorus / Q000302:isolation & purification*; D000069877:Struvite; D013552:Swine; D062065:Wastewater / Q000737:chemistry*
chemical_list: D000144:Acids, Acyclic; D008274:Magnesium; D017616:Magnesium Compounds; D010710:Phosphates; D010758:Phosphorus; D000069877:Struvite; D062065:Wastewater
keywords: Crystallization reaction; Magnesium ammonium phosphate; Organic acid; Phosphorus removal; Swine wastewater