title: Removal of ammonium from rare-earth wastewater using natural brucite as a magnesium source of struvite precipitation.
abstract: This paper presents a study regarding ammonium removal from rare-earth wastewater by struvite precipitation with natural brucite mineral as a source of magnesium. Experimental results indicated that a pH ranging from 8.5 to 9.5 was the optimum for the removal of ammonium using the soluble form of brucite as a magnesium source. Additionally, when solid brucite was used as a magnesium source as well as an alkali reagent, the initial ammonium concentration of 4,535 mg/L decreased to 239-317 mg/L after an reaction time of 12 h in wastewater treated with the S/L (solid brucite/liquid wastewater) ratios ranging from 31.2 to 63.2 g/L. Furthermore, as some non-reacted brucite still remained in the precipitates obtained at the end of reaction, the precipitates were subjected to reuse. The reuse results demonstrated that the reuse of the precipitates obtained with 63.2 g/L was feasible, and almost half of the brucite dose could be saved.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. huanghaiming52hu@163.com
authors.forename: H M
authors.initials: HM
authors.lastname: Huang
authors.forename: X M
authors.initials: XM
authors.lastname: Xiao
authors.forename: L P
authors.initials: LP
authors.lastname: Yang
authors.forename: B
authors.initials: B
authors.lastname: Yan
mesh_terms: D011232:Chemical Precipitation; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000737:chemistry*; D017616:Magnesium Compounds / Q000737:chemistry*; D008276:Magnesium Hydroxide / Q000737:chemistry*; D008674:Metals, Rare Earth / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification*; D059027:Recycling; D012995:Solubility; D000069877:Struvite; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D017616:Magnesium Compounds; D008674:Metals, Rare Earth; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D010758:Phosphorus; D000069877:Struvite; D008274:Magnesium; D008276:Magnesium Hydroxide