About Bioline  All Journals  Testimonials  Membership  News  Donations

Nigerian Society for Experimental Biology
ISSN: 0795-8080
Vol. 23, No. 1, 2011, pp. 41-48
Bioline Code: bk11007
Full paper language: English
Document type: Research Article
Document available free of charge

Biokemistri, Vol. 23, No. 1, 2011, pp. 41-48

 en Extraction of certain heavy metals from sewage sludge using different types of acids
Gaber, Seleem E.; Rizk, Mahmoud S. & Yehia, Mohamed. M.


The removal of heavy metal from sludge before disposal or application to farmland is a necessary step to achieve a more safe sludge usage or disposal. Chemical extraction using inorganic acids (nitric, hydrochloric) and organic acids (citric, oxalic) were tested for extraction of chromium, copper, nickel, lead and zinc from contaminated sewage sludge at different pH and reaction time. Results revealed that solubilization of metals using inorganic acids achieved its maximum extraction efficiency (Cr-88%, Cu-82%, Ni-86%, Pb-94%, Zn-89%) at pH value lower than 2 and acid contact times of 1hour. while in case of organic acids oxalic acid does not show good results comparing to citric acid that at pH 2.43 citric acid seemed to be highly effective in extracting Cu (86%), Zn(88%), mostly after 1 day of extraction time, Cr (90%), Ni (96%) at 5 days leaching time, while Pb(85%) removal at the same pH was at a longer leaching time 10 days. At pH 3, citric acid seemed to be also highly effective in extracting Cr (66%), Cu(48%), Pb (66%), Zn(69%) at 1 day, while higher removal was also attained for Ni(68%) at only 4 h leaching time. Finally the extraction efficiencies of citric acid for Cr, Cu, Ni, Pb, Zn, are high enough to reduce the heavy metal content in sludge to levels below the legal standards.

Acid leaching; Heavy metals; Metal precipitation; Sewage sludge.

© Copyright © 2011 Nigerian S°Ciety for Experimental Biology

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2018, Site last up-dated on 24-Sep-2018.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil