The process of bioleaching marmatite using moderately thermophilic bacteria was studied by comparing marmatite leaching performance of mesophiles and moderate thermophiles and valuating the effect of venting capacity ...The process of bioleaching marmatite using moderately thermophilic bacteria was studied by comparing marmatite leaching performance of mesophiles and moderate thermophiles and valuating the effect of venting capacity as well as pulp density on marmatite leaching performance of moderate thermophiles. The results show that moderate thermophiles have more advantages over mesophilies in bioleaching marmatite at 45 ℃ and the pulp density of 50 g/L, and the zinc extraction efficiency reaches 93.1% in 20 d. Aeration agitation can improve the transfer of O2 and CO2 in solution and promote the growth of bacteria and therefore, enhance the leaching efficiency. Under the venting levels of 50, 200 and 800 mL/min, the zinc extraction efficiencies by moderate thermophiles are 57.8%, 92.5% and 96.0%, respectively. With the increase of pulp density, the total leaching amount of valuable metals increases, however, the extraction efficiency decreases due to many reasons, such as increasing shear force leading to poorly growth condition for bacteria, etc. The zinc extraction decreases remarkably to 58.9% while the pulp density mounts up 20%.展开更多
Fluctuations in food availability occur in many ecosystems and pose challenges to the organisms that inhabit them(Berg et al.2017).Because lizards have significantly lower field metabolic rates than endotherms,they ar...Fluctuations in food availability occur in many ecosystems and pose challenges to the organisms that inhabit them(Berg et al.2017).Because lizards have significantly lower field metabolic rates than endotherms,they are often considered "low energy specialists"that can cope with food shortages(Brown and Griffin 2005).However,active reptiles that maintain high body temperatures during periods of low prey availability can still incur significant energetic costs because metabolic rates scale with body temperature.To reduce these energetic costs,some reptile species select lower body temperatures and/or reduce their activity levels when food is scarce(Angilletta 2009).展开更多
基金Projects(50621063, 40646029) supported by the National Natural Science Foundation of ChinaProject(2004CB619204) supported by the Major State Basic Research Development Program of ChinaProject(NCET-06-0691) supported by the Program for New Century Excellent Talents in University
文摘The process of bioleaching marmatite using moderately thermophilic bacteria was studied by comparing marmatite leaching performance of mesophiles and moderate thermophiles and valuating the effect of venting capacity as well as pulp density on marmatite leaching performance of moderate thermophiles. The results show that moderate thermophiles have more advantages over mesophilies in bioleaching marmatite at 45 ℃ and the pulp density of 50 g/L, and the zinc extraction efficiency reaches 93.1% in 20 d. Aeration agitation can improve the transfer of O2 and CO2 in solution and promote the growth of bacteria and therefore, enhance the leaching efficiency. Under the venting levels of 50, 200 and 800 mL/min, the zinc extraction efficiencies by moderate thermophiles are 57.8%, 92.5% and 96.0%, respectively. With the increase of pulp density, the total leaching amount of valuable metals increases, however, the extraction efficiency decreases due to many reasons, such as increasing shear force leading to poorly growth condition for bacteria, etc. The zinc extraction decreases remarkably to 58.9% while the pulp density mounts up 20%.
基金The research was supported financially by the University of Technology Sydney.All procedures were approved by the UTS Animal Care and Ethics Committee(protocol ACEC 2012000256)a NSW National Parks and Wildlife Service scientific licence(SL 101013 toJ.K.W.).
文摘Fluctuations in food availability occur in many ecosystems and pose challenges to the organisms that inhabit them(Berg et al.2017).Because lizards have significantly lower field metabolic rates than endotherms,they are often considered "low energy specialists"that can cope with food shortages(Brown and Griffin 2005).However,active reptiles that maintain high body temperatures during periods of low prey availability can still incur significant energetic costs because metabolic rates scale with body temperature.To reduce these energetic costs,some reptile species select lower body temperatures and/or reduce their activity levels when food is scarce(Angilletta 2009).
