scholarly journals Case study modelling for an ettringite treatment process

Water SA ◽  
2018 ◽  
Vol 44 (1 January) ◽  
Author(s):  
C Germishuizen ◽  
S Franzsen ◽  
H Grobler ◽  
GS Simate ◽  
CM Sheridan
Keyword(s):  
Acid Mine Drainage ◽  
Case Studies ◽  
Treatment Process ◽  
Mine Drainage ◽  
Feed Water ◽  
Aluminium Sulphate ◽  
Ettringite Formation ◽  
Water Ph ◽  
Treat Acid Mine Drainage

Several technologies have been developed to treat acid mine drainage (AMD) and attention is shifting towards the removal of sulphate. The formation of ettringite, a hydrous calcium aluminium sulphate mineral, is an option to treat AMD and can reduce the sulphate concentration to well below the discharge specifications. The process modelled in this study includes the formation of ettringite and the recovery of gibbsite through the decomposition of recycled ettringite. The modelling of this process was done using PHREEQC and the results presented in this paper are based on the outcome of different case studies that investigated how the process is affected by a change in parameters. These include, changing the feed water pH, altering the split fractions in the hydrocyclone for the gibbsite recovery and varying the pH for ettringite formation.

HYPERSPECTRAL SENSING OF ACID MINE DRAINAGE – TWO COLORADO CASE STUDIES

2006 ◽  
Vol 2006 (2) ◽  
pp. 738-763
Author(s):  
Phoebe L. Hauff ◽  
Douglas C. Peters ◽  
David W. Coulter ◽  
Matthew A. Sares ◽  
David A. Bird ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Case Studies ◽  
Mine Drainage ◽  
Acid Mine ◽  
Hyperspectral Sensing

Effects of acid mine drainage on clay minerals suspended in the Tinto River (Río Tinto, Spain). An experimental approach

Clay Minerals ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 99-108 ◽  
Author(s):  
E. Galan ◽  
M. I. Carretero ◽  
J . C. Fernandez-Caliani
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Drainage Basin ◽  
Acid Rock Drainage ◽  
Chemical Degradation ◽  
Acid Rock ◽  
Tinto River ◽  
Acid Mine ◽  
Mineral Stability ◽  
Water Ph

AbstractThe Tinto river is one of the most polluted stream environments in the world, as a result of both acid mine drainage and natural acid rock drainage. Two representative samples from the phyllosilicate-rich rocks exposed in the drainage basin (Palaeozoic chlorite-bearing slates and Miocene smectite-rich marls) were treated with acid river water (pH = 2.2) for different times to constrain the effects of extreme hydrogeochemical conditions on clay mineral stability. Illite and kaolinite did not show appreciable variations in their crystal chemistry parameters upon treatment. Chlorite underwent an incipient chemical degradation evidenced by the progressive loss of Fe in octahedral positions coupled with a shortening of the b unit-cell parameter, although no weathering products of chlorite were observed. Smectite and calcite were rapidly and fully dissolved thus neutralizing the water acidity, and subsequently Fe and Al oxy-hydroxides and opaline silica precipitated from the aqueous solution, together with a neoformed amorphous silicate phase largely enriched in Al and Mg.

Field multi-step limestone and MgO passive system to treat acid mine drainage with high metal concentrations

2009 ◽  
Vol 24 (12) ◽  
pp. 2301-2311 ◽  
Author(s):  
Manuel A. Caraballo ◽  
Tobias S. Rötting ◽  
Francisco Macías ◽  
José Miguel Nieto ◽  
Carlos Ayora
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Passive System ◽  
Metal Concentrations ◽  
Acid Mine ◽  
High Metal ◽  
Treat Acid Mine Drainage

Acid Mine Drainage (AMD): causes, treatment and case studies

2006 ◽  
Vol 14 (12-13) ◽  
pp. 1139-1145 ◽  
Author(s):  
Ata Akcil ◽  
Soner Koldas
Keyword(s):  
Acid Mine Drainage ◽  
Case Studies ◽  
Mine Drainage ◽  
Acid Mine

scholarly journals Synthesis and Application of Cationised Cellulose for Removal of Cr(VI) from Acid Mine-Drainage Contaminated Water

2020 ◽  
Author(s):  
Anita Etale ◽  
Dineo S. Nhlane ◽  
Alseno K. Mosai ◽  
Jessica Mhlongo ◽  
Aaliyah Khan ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
13C Nmr ◽  
Quaternary Ammonium ◽  
Mine Drainage ◽  
Contaminated Water ◽  
Acid Mine ◽  
13C Nuclear Magnetic Resonance ◽  
Cellulose Fibrils ◽  
Water Ph ◽  
Pseudo Second Order

Cationised hemp cellulose was prepared by etherification with two quaternary ammonium salts: 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) and glycidyltrimethylammonium chloride (GTMAC) and examined for (i) the efficiency of Cr(VI) removal under acid mine-drainage (AMD) conditions, and (ii) antibacterial activity. Adsorbents were characterised by electron microscopy, Fourier transform infrared (FTIR), CP-MAS 13C nuclear magnetic resonance (NMR) spectroscopy, elemental composition and surface charge. FTIR and solid state 13C NMR confirmed the introduction of quaternary ammonium moieties on cellulose. 13C NMR also showed that cationisation decreased the degree of crystallisation and lateral dimensions of cellulose fibrils. Nevertheless, 47 % - 72% of Cr(VI) ions were removed from solutions at pH 4, by 0.1 g of CHPTAC and GTMAC-cationised cellulose, respectively. Adsorption kinetics followed the pseudo-second order model and isotherms were best described by the Freundlich and Dubinin-Radushkevich models. When GTMAC-modified cellulose was applied to AMD contaminated water (pH 2.7), however, Cr(VI) uptake removal decreased to 22% likely due to competition from Al and Fe ions. Nevertheless, cationised materials displayed considerable antibacterial effects, reducing the viability of Escherichia coli by up to 45 % after just 3 hours of exposure. Together, these results suggest that cationised cellulose can be applied in the treatment of Cr(VI)-contaminated mine water particularly if pre-treatments to reduce Fe and Al concentrations are applied.

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