HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (18) Citing Articles via Google Scholar Google Scholar Articles by Mbila, M. O. Articles by Laird, D. A. Search for Related Content PubMed PubMed Citation Articles by Mbila, M. O. Articles by Laird, D. A. GeoRef GeoRef Citation Agricola Articles by Mbila, M. O. Articles by Laird, D. A. Related Collections Tropical Soil Management Municipal Waste Soil Chemistry

TECHNICAL REPORT
Waste Management

Distribution and Movement of Sludge-Derived Trace Metals in Selected Nigerian Soils

^a Agronomy Dep., Iowa State Univ., Ames, IA 50011-1010
^b Univ. of Nigeria at Nsukka, Nsukka, Nigeria
^c USDA-ARS, National Soil Tilth Lab., Ames, IA 50011

* Corresponding author (mlthomps{at}iastate.edu)

Received for publication May 26, 2000. Use of metal-rich sewage sludge as soil fertilizer may result in trace-metal contamination of soils. This study was conducted to evaluate the effects of long-term sludge application on trace-metal (Zn, Cu, Pb, and Ni) distribution and potential bioavailability in Nigerian soils under a tropical wet–dry climate. Total metal analyses, sequential chemical fractionation, and DTPA extractions were carried out on samples of control and sludge-amended pedons in Nigeria (a Rhodic Kandiustult and two Rhodic Kandiustalfs from Nigeria, respectively). The sewage sludge applied to the soils contained higher levels of Zn and Cu than Pb and Ni. The control pedon contained low levels of all four metals. Soil enrichment factors (EF) were calculated for each metal in the sludge-amended pedons. Compared with the control soil, the sludge-amended pedons showed elevated levels of Zn and Cu, reflecting the trace-metal composition of the sewage sludge. Zinc and Cu in the sludge-amended soils were strongly enriched at all depths in the profile, indicating that they had moved below the zone of sludge application. The sequential extraction and DTPA analyses indicated that the sludge-amended soils contained more readily extractable and bioavailable metal ions than the unamended soil.

Abbreviations: DTPA, diethylenetriamine pentaacetic acid • ICAP-AES, inductively coupled Ar plasma–atomic emission spectroscopy • UNN, University of Nigeria at Nsukka • CBD, citrate–bicarbonate–dithionite • EF, enrichment factor