Acidic bioleaching of heavy metals from sewage sludge |
| |
Authors: | Abdallah Shanableh Pushpa Ginige |
| |
Institution: | (1) School of Civil Engineering, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Qld 4001, Australia Tel. +61-7-3864 2510; Fax +61-7-3864 1515 e-mail: a.shanableh@qut.edu.au, AU |
| |
Abstract: | The overall objective of this study was to evaluate the use of controlled bio-acidification prior to land application as a
decontamination process to remove heavy metals from sludge. The sulfur-oxidizing bacteria were naturally available in the
sludge samples and were activated by providing sulfur and aeration at 28°C–30°C. Activation resulted in bio-acidification
to pH 2 within 5–11 days. Successive inoculation of fresh sludges with 5% acidified samples reduced the acidification time
to 2–3 days in most samples. Bio-acidification resulted in dissolving significant quantities of heavy metals from all sludge
types tested. The maximum solubilization results were: 86%–97% for Ni; 48%–98% for Pb; 26%–71% for Cr; 18%–91% for Zn; 16%–90%
for Cu; 7%–60% for Cd. Limited metal solubilization results were observed in the various control samples that accompanied
the bio-acidified samples. The leaching results in the control samples were limited to 2%–19% for Ni, 0%–7% for Pb, 0%–5%
for Cr, 0.3%–4% for Zn, 0.2%–4% for Cu and 0%–3% for Cd. The results confirmed that Ni and Pb were the easiest metals to dissolve
from the various sludge types. On the other hand, the lowest solubilization results were observed for Cu and Cd, and moderate
solubilization results were achieved for Cr. The bio-acidification process resulted in moderate gains in terms of improving
the suitability of tested sludges for land application.
Received: April 19, 1999 / Accepted: November 4, 1999 |
| |
Keywords: | Sewage sludge Heavy metals Bio-acidification Bioleaching Land application |
本文献已被 SpringerLink 等数据库收录! |
|