title: Ammonia nitrogen removal from acetylene purification wastewater from a PVC plant by struvite precipitation.
abstract: Acetylene purification wastewater (APW) usually contains high concentrations of ammonia nitrogen (NH4-N), which is generated during the production of acetylene in a polyvinylchloride manufacturing plant. In this study, a struvite precipitation method was selected to remove NH4-N from the APW. Laboratory-scale batch experiments were performed to investigate the effects of the initial APW pH, phosphate (PO4(3-)) concentration, magnesium (Mg(2+)) concentration, and sources of PO4(3-) and Mg(2+) on NH4-N removal. The results indicated that the initial APW pH had a significant effect on the removal of NH4-N, while the other factors had relatively minor effect. The NH4-N could be effectively removed at an optimum initial APW pH of 9.5, when Na2HPO4·12H2O and MgSO4·7H2O were both applied to NH4-N at a ratio of 1.2. Under these conditions, the efficiency of removal of NH4-N, total nitrogen and chemical oxygen demand were 85%, 84% and 18%, respectively. The X-ray diffraction analysis indicated that the precipitates were dominated by struvite. The scanning electron microscopy analysis of the precipitates showed a typical morphology of stick-like and prismatic crystals with coarse surface. The energy dispersive spectroscopy analysis indicated that the precipitates contained P, O, Mg and Ca.
authors.affiliation: Key Laboratory of Groundwater Resources and Environment of Ministry of Education, Key Laboratory of Water Resources and Aquatic Environment of Jilin Province, College of Environment and Resources, Jilin University, Changchun 130012, China E-mail: huaxy@jlu.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Groundwater Resources and Environment of Ministry of Education, Key Laboratory of Water Resources and Aquatic Environment of Jilin Province, College of Environment and Resources, Jilin University, Changchun 130012, China E-mail: huaxy@jlu.edu.cn.
authors.forename: DeMing
authors.initials: D
authors.lastname: Dong
authors.affiliation: Key Laboratory of Groundwater Resources and Environment of Ministry of Education, Key Laboratory of Water Resources and Aquatic Environment of Jilin Province, College of Environment and Resources, Jilin University, Changchun 130012, China E-mail: huaxy@jlu.edu.cn.
authors.forename: XiuYi
authors.initials: X
authors.lastname: Hua
authors.affiliation: Key Laboratory of Groundwater Resources and Environment of Ministry of Education, Key Laboratory of Water Resources and Aquatic Environment of Jilin Province, College of Environment and Resources, Jilin University, Changchun 130012, China E-mail: huaxy@jlu.edu.cn.
authors.forename: ZhiYong
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Key Laboratory of Groundwater Resources and Environment of Ministry of Education, Key Laboratory of Water Resources and Aquatic Environment of Jilin Province, College of Environment and Resources, Jilin University, Changchun 130012, China E-mail: huaxy@jlu.edu.cn.
authors.forename: DaPeng
authors.initials: D
authors.lastname: Liang
mesh_terms: D000114:Acetylene; D000641:Ammonia / Q000378:metabolism*; D011232:Chemical Precipitation; D058440:Denitrification; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis; D008274:Magnesium / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D011143:Polyvinyl Chloride; D000069877:Struvite / Q000737:chemistry*; D062065:Wastewater / Q000032:analysis*
chemical_list: D000114:Acetylene; D000641:Ammonia; D007220:Industrial Waste; D008274:Magnesium; D010710:Phosphates; D011143:Polyvinyl Chloride; D000069877:Struvite; D062065:Wastewater