Membrane selection for the Gold mining pressure-oxidation process (POX) effluent reclamation using integrated UF-NF-RO processes

• Published in: Journal of environmental chemical engineering Vol. 8; no. 5; p. 104056
• Main Authors: Ramos, Ramatisa L., Grossi, Luiza B., Ricci, Bárbara C., Amaral, Míriam C.S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020
• Subjects: Commercial membranes; Industrial wastewater treatment; Nanofiltration; Pressure oxidation effluent; Reuse water; Reverse osmosis; RR; ΔT; A; ΔV; Cf; σ; FDChem.rev; J; FDCP; Cp; Vf; Commercial membranes; UF; Nanofiltration; As; R; Vp; Reuse water; Pressure oxidation effluent; FDFouling; Lp; FDChem.irrev; Jef; Δπ; Jw; PVDF; AP; Jalf; MWCO; FDTotal; NF; POX; Reverse osmosis; ΔP; μ; DA; RO; Industrial wastewater treatment; Jalq
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2020.104056

•Commercial membranes were evaluated for POX effluent reclamation in UF-NF-RO route.•DK and SG membranes showed the highest potential for POX effluent treatment.•The 2 average concentration factor was observed in the NF for metals concentration.•The acid stream and reuse water generated in the RO can be applied in the industry.•Lime demand for streams neutralization was 41 % reduced compared to regular process. The UF-NF-RO integrated route has emerged as a reclamation alternative for mine effluent from the pressure-oxidation processing (POX), producing concentrate metals stream, recover acid and water for reuse. Despite the route potentiality, it is still necessary to seek for more chemically stable membranes to increase the process sustainability, particularly because the membranes are exposed to aggressive conditions (acid effluent) and a high rejection is desired. Thus, in this study, commercial NF membranes (NF90, NF270, MPF34, DK, and Duracid) and RO membranes (BW30, LP, TFC-HR, XN45, and SG) were evaluated in terms of key performance parameters, such as permeate flux, metals rejection, acid recovery, fouling potential, maximum permeate recovery (RR), and chemical stability. The DK and SG, as NF and RO membranes respectively, showed the highest potential for POX effluent treatment application. In the NF process, an average concentration factor of 2 was observed for metals concentration retentate at 50 % permeate RR. For metals, particularly for cobalt, nickel, and copper, this concentration was favorable to subsequent recovery processes. The RO generated a retentate with sulfuric acid 2.5 times more concentrated and low impurity content (0.00058 g L−1) and 40 % RR was chosen for the process considering the permeate quality, which can be used as reuse water. Besides that, the amount of lime demanded for neutralization in the proposed route is approximately 41 % lower compared to regular process. The results showed that for the designing system the membrane selection is a critical part, mainly due the effluent characteristics.