- Email: [email protected]
Bioadsorption in remediation of metal mine drainage: The use of dealginated seaweed in the BIOMAN project
A482
Goldschmidt Conference Abstracts 2006
Enriched in Oxygen and Aluminium fluoride-calcium melts in ongonites I.S. PERETYAZHKO, V.YE. ZAGORSKY, E.A. TSAREVA Institute of Geochemistry, SB RAS, Irkutsk, Russia (pgmigor@ igc.irk.ru)
Bioadsorption in remediation of metal mine drainage: The use of dealginated seaweed in the BIOMAN project W.T. PERKINS1, S. HARTLEY1, N.J.G. PEARCE1, E. DINELLI2, R. EDYVEAN3, L. SANDLANDS3 1
The ongonite massif Ary-Bulak (Eastern Transbaikalia, Russia) forms a domal stock about 0.8 km2, cross-cutting sedimentary-volcanogenic rocks. The center of the massif is composed of porphyric ongonites holding phenocrysts of quartz, sanidine, albite, sometimes topaz and mica. The matrix of rocks consists of quartz grains (20–30 lm), tabular albite (30–80 lm) rimmed with sanidine (5–20 lm) and the spicular topaz. In the endocontact zone, porphyric rocks are replaced by glassy aphyric rocks lying 50–200 m from the contact with hosting schists. The porphyric ongonites incorporate varieties with high CaO (3.3–21.8 wt%) and F (2.7–16 wt%). The rocks of this type occur are mostly abundant in the marginal zone. High CaO (7.8–18 wt%) and F (7.1– 15.5 wt%) are characteristic of aphyric rocks. The porphyric and aphyric Ca-rich rocks display direct correlation between Ca and F. The interstices between minerals of the matrix of this rocks are filled with submicron concretions of glassy ‘‘fluorite’’ and ‘‘potash feldspar’’ phases. The ‘‘fluorite’’ phase commonly contains impurities (wt%): O (3–12), Al (0.5–3.3), Si (0.2–1.5), infrequently Sr (up to 1.3), Na (up to 0.5) and S (up to 0.3). The albite phenocrysts are partially or completely replaced with ‘‘fluorite’’ phase, in places together with ‘‘potash feldspar’’ phase, prosopite and mineral of dickite type. Besides, dickite forms the ingrowths in ‘‘fluorite’’ phase. The aphyric rocks have numerous separations of rock-forming prosopite CaAl2F4(OH)4 (from 6 to 26 wt%). It is assumed that ‘‘fluorite’’ and ‘‘potash feldspar’’ phases result from partial crystallization of micro-emulsion of immiscible O- and Al-rich fluoride-calcium and alumosilicate melts. The crystallization of degree of fluoride-calcium glass varying from 20% to 83% was defined by X-ray method. It was proposed that the O and Al admixtures are primarily concentrated in fluoride-calcium glass (O2 + Al3+ ! F + Ca2+). The O- and Al-rich fluoridecalcium and alumosilicate residual melts coexisted at the temperature below b ! a transition of quartz (585–595 °C at 0.8– 1 kbar). Crossing veinlets in the aphyric rocks, filled with ‘‘fluorite’’ phase with prosopite and aqueous Ca-alumofluorides (gearksutite, carlhintzeite), also suggest presence of fluoride-calcium melts enriched with O, Al and fluid at <450–500 °C after crystallization of overwhelming part of the Ary-Bulak massif. These unusual melts are close to supercritical fluid in their high penetrating ability (low viscosity). Now conditions are obscure wherein such melts can appear and exist. It is proposed that presence of O and Al stabilizes this fluoride-calcium melt and prevents crystallization of fluorite from it.
Acknowledgment The study was supported by the RFBR Grants (04-05-64389 and 04-05-64109). doi:10.1016/j.gca.2006.06.1426
Institute of Geography and Earth Sciences, University of Wales, Aberystwyth, Wales, UK ([email protected]; szh@ aber.ac.uk; [email protected]) 2 Department of Earth and Geoenvironmental Sciences, Bologna University, Italy ([email protected]) 3 Department of Chemical and Process Engineering, University of Sheffield, UK (r.edyvean@sheffield.ac.uk; L.sandlands@ sheffield.ac.uk) Dealginated seaweed (DS) is a waste product from the industrial extraction of alginates. Dealginated seaweed has ion exchange properties which can be exploited to remove potentially harmful elements (PHEs) from aqueous solutions. Laboratory scale tests demonstrate that DS shows optimum adsorption of PHEs at near neutral pH and with a contact time of at least 10 min. The tests show that DS has preferential adsorption of zinc, cadmium and lead over major cations in solution. Furthermore the tests reveal that the DS can be regenerated by washing with dilute acid and re-used as many as 10 times. Field trials of a prototype mine water treatment system have been successfully completed at two mine sites in mid-Wales where Pb/Zn mines were adandoned over 100 years ago. In the midWales orefield, the mine drainage is typically circum-neutral which is ideal for treatment with the DS systems. At Bwlch mine 1 L min1 of water was treated and the Zn was reduced from 27 to 0.4 mg L1, the Cd from 60 to 0.8 lg L1 and the Pb from 733 to 20 lg L1. After 24 h the adsorption of Zn diminished but Pb continued to be removed for 20 days. Dealginated seaweed from one supplier gave a pH of >12 when mixed with water. The fine-grained portion of this material has been used to treat acid mine drainage (AMD) from former Cu mines in Italy. Waters draining these mines have a pH of 2.6 and an Fe content of 550 mg L1. Laboratory tests show that DS powder generates stable Fe precipitates which reduce Fe to 5 mg L1, Cu from 125 to 3 mg L1, Zn from 33 to 2.6 mg L1 and Al from 180 to 5 mg L1. This precipitation stage is proposed as an initial treatment of the mine water before the bioadsorption using the prototype DS systems. This combination should remove the PHEs from these mine waters. These trials have been conducted as part of the BIOMAN project—an EU LIFE Environment funded collaboration. doi:10.1016/j.gca.2006.06.1427
Goldschmidt Conference Abstracts 2006
Enriched in Oxygen and Aluminium fluoride-calcium melts in ongonites I.S. PERETYAZHKO, V.YE. ZAGORSKY, E.A. TSAREVA Institute of Geochemistry, SB RAS, Irkutsk, Russia (pgmigor@ igc.irk.ru)
Bioadsorption in remediation of metal mine drainage: The use of dealginated seaweed in the BIOMAN project W.T. PERKINS1, S. HARTLEY1, N.J.G. PEARCE1, E. DINELLI2, R. EDYVEAN3, L. SANDLANDS3 1
The ongonite massif Ary-Bulak (Eastern Transbaikalia, Russia) forms a domal stock about 0.8 km2, cross-cutting sedimentary-volcanogenic rocks. The center of the massif is composed of porphyric ongonites holding phenocrysts of quartz, sanidine, albite, sometimes topaz and mica. The matrix of rocks consists of quartz grains (20–30 lm), tabular albite (30–80 lm) rimmed with sanidine (5–20 lm) and the spicular topaz. In the endocontact zone, porphyric rocks are replaced by glassy aphyric rocks lying 50–200 m from the contact with hosting schists. The porphyric ongonites incorporate varieties with high CaO (3.3–21.8 wt%) and F (2.7–16 wt%). The rocks of this type occur are mostly abundant in the marginal zone. High CaO (7.8–18 wt%) and F (7.1– 15.5 wt%) are characteristic of aphyric rocks. The porphyric and aphyric Ca-rich rocks display direct correlation between Ca and F. The interstices between minerals of the matrix of this rocks are filled with submicron concretions of glassy ‘‘fluorite’’ and ‘‘potash feldspar’’ phases. The ‘‘fluorite’’ phase commonly contains impurities (wt%): O (3–12), Al (0.5–3.3), Si (0.2–1.5), infrequently Sr (up to 1.3), Na (up to 0.5) and S (up to 0.3). The albite phenocrysts are partially or completely replaced with ‘‘fluorite’’ phase, in places together with ‘‘potash feldspar’’ phase, prosopite and mineral of dickite type. Besides, dickite forms the ingrowths in ‘‘fluorite’’ phase. The aphyric rocks have numerous separations of rock-forming prosopite CaAl2F4(OH)4 (from 6 to 26 wt%). It is assumed that ‘‘fluorite’’ and ‘‘potash feldspar’’ phases result from partial crystallization of micro-emulsion of immiscible O- and Al-rich fluoride-calcium and alumosilicate melts. The crystallization of degree of fluoride-calcium glass varying from 20% to 83% was defined by X-ray method. It was proposed that the O and Al admixtures are primarily concentrated in fluoride-calcium glass (O2 + Al3+ ! F + Ca2+). The O- and Al-rich fluoridecalcium and alumosilicate residual melts coexisted at the temperature below b ! a transition of quartz (585–595 °C at 0.8– 1 kbar). Crossing veinlets in the aphyric rocks, filled with ‘‘fluorite’’ phase with prosopite and aqueous Ca-alumofluorides (gearksutite, carlhintzeite), also suggest presence of fluoride-calcium melts enriched with O, Al and fluid at <450–500 °C after crystallization of overwhelming part of the Ary-Bulak massif. These unusual melts are close to supercritical fluid in their high penetrating ability (low viscosity). Now conditions are obscure wherein such melts can appear and exist. It is proposed that presence of O and Al stabilizes this fluoride-calcium melt and prevents crystallization of fluorite from it.
Acknowledgment The study was supported by the RFBR Grants (04-05-64389 and 04-05-64109). doi:10.1016/j.gca.2006.06.1426
Institute of Geography and Earth Sciences, University of Wales, Aberystwyth, Wales, UK ([email protected]; szh@ aber.ac.uk; [email protected]) 2 Department of Earth and Geoenvironmental Sciences, Bologna University, Italy ([email protected]) 3 Department of Chemical and Process Engineering, University of Sheffield, UK (r.edyvean@sheffield.ac.uk; L.sandlands@ sheffield.ac.uk) Dealginated seaweed (DS) is a waste product from the industrial extraction of alginates. Dealginated seaweed has ion exchange properties which can be exploited to remove potentially harmful elements (PHEs) from aqueous solutions. Laboratory scale tests demonstrate that DS shows optimum adsorption of PHEs at near neutral pH and with a contact time of at least 10 min. The tests show that DS has preferential adsorption of zinc, cadmium and lead over major cations in solution. Furthermore the tests reveal that the DS can be regenerated by washing with dilute acid and re-used as many as 10 times. Field trials of a prototype mine water treatment system have been successfully completed at two mine sites in mid-Wales where Pb/Zn mines were adandoned over 100 years ago. In the midWales orefield, the mine drainage is typically circum-neutral which is ideal for treatment with the DS systems. At Bwlch mine 1 L min1 of water was treated and the Zn was reduced from 27 to 0.4 mg L1, the Cd from 60 to 0.8 lg L1 and the Pb from 733 to 20 lg L1. After 24 h the adsorption of Zn diminished but Pb continued to be removed for 20 days. Dealginated seaweed from one supplier gave a pH of >12 when mixed with water. The fine-grained portion of this material has been used to treat acid mine drainage (AMD) from former Cu mines in Italy. Waters draining these mines have a pH of 2.6 and an Fe content of 550 mg L1. Laboratory tests show that DS powder generates stable Fe precipitates which reduce Fe to 5 mg L1, Cu from 125 to 3 mg L1, Zn from 33 to 2.6 mg L1 and Al from 180 to 5 mg L1. This precipitation stage is proposed as an initial treatment of the mine water before the bioadsorption using the prototype DS systems. This combination should remove the PHEs from these mine waters. These trials have been conducted as part of the BIOMAN project—an EU LIFE Environment funded collaboration. doi:10.1016/j.gca.2006.06.1427