title: Downstream processing of reverse osmosis brine: Characterisation of potential scaling compounds.
abstract: Reverse osmosis (RO) brine produced at a full-scale coal seam gas (CSG) water treatment facility was characterized with spectroscopic and other analytical techniques. A number of potential scalants including silica, calcium, magnesium, sulphates and carbonates, all of which were present in dissolved and non-dissolved forms, were characterized. The presence of spherical particles with a size range of 10-1000 nm and aggregates of 1-10 microns was confirmed by transmission electron microscopy (TEM). Those particulates contained the following metals in decreasing order: K, Si, Sr, Ca, B, Ba, Mg, P, and S. Characterization showed that nearly one-third of the total silicon in the brine was present in the particulates. Further, analysis of the RO brine suggested supersaturation and precipitation of metal carbonates and sulphates during the RO process should take place and could be responsible for subsequently capturing silica in the solid phase. However, the precipitation of crystalline carbonates and sulphates are complex. X-ray diffraction analysis did not confirm the presence of common calcium carbonates or sulphates but instead showed the presence of a suite of complex minerals, to which amorphous silica and/or silica rich compounds could have adhered. A filtration study showed that majority of the siliceous particles were less than 220 nm in size, but could still be potentially captured using a low molecular weight ultrafiltration membrane.
authors.affiliation: School of Chemical Engineering, The University of Queensland, St Lucia, 4072, Queensland, Australia.
authors.forename: Masuduz
authors.initials: M
authors.lastname: Zaman
authors.affiliation: School of Chemical Engineering, The University of Queensland, St Lucia, 4072, Queensland, Australia.
authors.forename: Greg
authors.initials: G
authors.lastname: Birkett
authors.affiliation: Department of Agriculture, Fisheries and Forestry, 203 Tor St, Toowoomba, 4350, Queensland, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Pratt
authors.affiliation: Australia Pacific LNG, 135 Coronation Drive, Milton, 4064, Queensland, Australia.
authors.forename: Bruce
authors.initials: B
authors.lastname: Stuart
authors.affiliation: School of Chemical Engineering, The University of Queensland, St Lucia, 4072, Queensland, Australia. Electronic address: s.pratt@uq.edu.au.
authors.forename: Steven
authors.initials: S
authors.lastname: Pratt
mesh_terms: D002119:Calcium Carbonate / Q000032:analysis / Q000737:chemistry; D002133:Calcium Sulfate / Q000032:analysis / Q000737:chemistry; D011232:Chemical Precipitation; D003031:Coal; D003460:Crystallization; D005374:Filtration / Q000295:instrumentation / Q000379:methods; D007700:Kinetics; D008670:Metals / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D059206:Natural Gas; D009995:Osmosis; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000737:chemistry*; D012492:Salts / Q000032:analysis / Q000737:chemistry*; D012822:Silicon Dioxide / Q000032:analysis / Q000737:chemistry; D012995:Solubility; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D003031:Coal; D008670:Metals; D059206:Natural Gas; D052638:Particulate Matter; D012492:Salts; C017082:brine; D012822:Silicon Dioxide; D002119:Calcium Carbonate; D002133:Calcium Sulfate
keywords: Brine; Filtration; Reverse osmosis; Scaling compound