title: Assessment of nanofiltration and reverse osmosis potentialities to recover metals, sulfuric acid, and recycled water from acid gold mining effluent.
abstract: This work assessed the potential of nanofiltration (NF) and reverse osmosis (RO) to treat acid streams contaminated with metals, such as effluent from the pressure oxidation process (POX) used in refractory gold ore processing. NF and RO were evaluated in terms of rejections of sulfuric acid and metals. Regarding NF, high sulfuric acid permeation (∼100%), was observed, while metals were retained with high efficiencies (∼90%), whereas RO led to high acid rejections (<88%) when conducted in pH values higher than 1. Thus, sequential use of NF and RO was proved to be a promising treatment for sulfuric acid solutions contaminated by metals, such as POX effluent. In this context, a purified acid stream could be recovered in NF permeate, which could be further concentrated in RO. Recovered acid stream could be reused in the gold ore processing or commercialized. A metal-enriched stream could be also recovered in NF retentate and transferred to a subsequent metal recovery stage. In addition, considering the high acid rejection obtained through the proposed system, RO permeate could be used as recycling water.
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, PO Box 1294, Belo Horizonte, MG 30.270-901, Brazil E-mail: barbararicci.eq@gmail.com.
authors.forename: Bárbara C
authors.initials: BC
authors.lastname: Ricci
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, PO Box 1294, Belo Horizonte, MG 30.270-901, Brazil E-mail: barbararicci.eq@gmail.com.
authors.forename: Carolina D
authors.initials: CD
authors.lastname: Ferreira
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, PO Box 1294, Belo Horizonte, MG 30.270-901, Brazil E-mail: barbararicci.eq@gmail.com.
authors.forename: Larissa S
authors.initials: LS
authors.lastname: Marques
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, PO Box 1294, Belo Horizonte, MG 30.270-901, Brazil E-mail: barbararicci.eq@gmail.com.
authors.forename: Sofia S
authors.initials: SS
authors.lastname: Martins
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, PO Box 1294, Belo Horizonte, MG 30.270-901, Brazil E-mail: barbararicci.eq@gmail.com.
authors.forename: Míriam C S
authors.initials: MC
authors.lastname: Amaral
mesh_terms: D006046:Gold; D007220:Industrial Waste; D008670:Metals / Q000032:analysis; D008906:Mining; D009995:Osmosis; D059027:Recycling; D013464:Sulfuric Acids / Q000032:analysis; D014462:Ultrafiltration / Q000379:methods*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D014867:Water / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D007220:Industrial Waste; D008670:Metals; D013464:Sulfuric Acids; D014874:Water Pollutants, Chemical; D014867:Water; D006046:Gold; C033158:sulfuric acid