Bc. Anderson et al., Biological leaching of trace metals from stormwater sediments: Influentialvariables and continuous reactor operation, WATER SCI T, 38(10), 1998, pp. 73-81
Research was conducted on a bioremediation process for the treatment of urb
an stormwater sediments contaminated with trace metals. Referred to as biol
eaching, the process relies on specific strains of naturally occurring, aci
d-producing bacteria to reduce the pH of a sediment slurry, thereby solubil
izing adsorbed and particulate metals into the liquid phase, for collection
and processing. The research was first conducted at the bench-scale to inv
estigate the process and the influence of the variables substrate loading,
solids loading, temperature, starting pH, benefit of inoculation, mixing, a
eration and grade of substrate used. Of these, it was found that temperatur
e and substrate availability exerted the greatest influence on the acidific
ation process. This information allowed for the design of pilot-scale 100 L
continuous bioreactors for treating stormwater sediments. At retention tim
es as low as 1.3 days, these reactors achieved almost complete solubilizati
on of copper and zinc, while chromium and lead were partially removed. Thes
e results indicate that bioleaching is a promising alternative for the reme
diation of these contaminated sediments. (C) 1998 Published by Elsevier Sci
ence Ltd. All rights reserved.