THE EFFECTS OF HEAVY METALS DISCHARGED INTO RIVER KADUNA ON THE QUALITY OF IRRIGATED FARMLANDS AT KADUNA METROPOLIS, KADUNA STATE

Abstract

The farmlands along River Kaduna used for irrigation farming, suffer enormous pollution as a result of addition of water
from the River Kaduna that had become contaminated. The study determines the concentration of selected heavy metals of
the surface waters, the soil physico-chemical characteristics of the irrigated farmlands and examines the implications of the surface water pollution on the soils of farmlands used for irrigation along River Kaduna. The water samples were collected using grab method along River Kaduna at five points – Bypass, Barnawa, Down quarters, Kakuri-Makera drains and
Kudendan at rainy season and dry season. Soil samples were also collected at the irrigated farmlands alongside the points.
The water samples were taken to the laboratory and analyzed for Cr, Ag, Fe, Cu, Be, Al, Cd, Cyanide and Zn using Atomic
Absorption Spectrophotometer and the soil samples were analyzed for pH, EC, OC, N, Ammonia, P, K, Ca, Na, Mg, Fe, Cu,
Zn and Al. The concentrations of the parameters were observed to be higher than WHO acceptable limits. This revealed that the soils have become contaminated by heavy metals discharged into the farmlands from the River Kaduna and may cause
serious ecological and health hazards. The paper recommends that there should be proper monitoring of effluents and there
is the need for mass education of people on the impact of indiscriminate waste discharge on the water quality.