Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Belgique → METAL CONTAMINATION IN IRRIGATED AGRICULTURAL LAND : CASE STUDY OF NAIROBI RIVER BASIN, KENYA

Universiteit Gent (2005)

METAL CONTAMINATION IN IRRIGATED AGRICULTURAL LAND : CASE STUDY OF NAIROBI RIVER BASIN, KENYA

Kamande Peter Njoroge

Titre : METAL CONTAMINATION IN IRRIGATED AGRICULTURAL LAND : CASE STUDY OF NAIROBI RIVER BASIN, KENYA

Auteur : Kamande Peter Njoroge

Université de soutenance : Universiteit Gent

Grade : Master of Science (MS) Physical Land Resources 2005

Résumé
This study was conducted to assess the impact of using polluted river water on the farmlands along the Ngong river in Nairobi. Soil samples were taken at depths of 0-20 cm, 20-40 cm and 40-60 cm. The total metal concentrations of Cd, Cr, Cu, Ni, Pb and Zn were determined with aqua regia extraction. Single extractions were used to establish the environmental risk and metal bioavailability : a 0.5 M HCl extraction assessed the labile phase while 0.05 M EDTA and 0.11 M acetic acid extractions assessed the fraction correlating with plant contents ; a 0.01 M CaCl2 extraction assess the exchangeable fraction. The metal contents were analysed by ICP-OES. Except for Ni, there was significant anthropogenic influence and a possible environmental risk. This calls for a reversal of the trend and further study about the effects on plant nutrition and the food chain, to prevent direct hazard to man.

Source : Pedon 17 - Physical Land Resources - Universiteit Gent

Page publiée le 2 janvier 2016, mise à jour le 24 janvier 2018