TITLE:
Environmental Assessment of Acid Mine Drainage Pollution on Surface Water Bodies around Ngwenya Mine, Swaziland
AUTHORS:
A. O. Fadiran, C. L. Dlamini, J. M. Thwala
KEYWORDS:
Acid Mine Drainage; Heavy Metal Pollution; Redox Potential; Physico-Chemical Properties; Iron Speciation
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.2,
February
28,
2014
ABSTRACT: Twenty-three water samples
and three “yellow boy” samples were obtained from different water bodies
located at the foot of the Ngwenya Mountain on top of which the old Ngwenya
Iron Ore Mine is located. The samples were analysed for pH, electrical
conductivity (EC), redox potential (ORP) and temperature (T). The dominant Fe
species was determined using a UV-VIS spectrophotometer. Selected anions
namely: halogens (F-, Br-, Cl-), the nutrients
(NO2-,NO3-,PO43-) and
the best indicator for AMD pollution (SO42-) were
analysed using Ion Chromatography (IC) while the selected heavy metals, namely:
Cr, Mn, Fe, Ni, Co, Cu, Zn, Pb and Cd were analysed using Flame Atomic
Absorption Spectrometry (FAAS). The physico-chemical parameters ranges obtained
were pH (6.32 - 8.63), EC (11.00 - 585.33 μS/cm), ORP (-93.67 - 79.33 mV) and T (7.60°C - 18.57°C). The levels of the Fe species
(ppm) in the water samples were Fe2+ (0.56 - 3.17) and Fe3+ (0.00 - 0.73). Measured mean anion ranges in
ppm were F- (0.00 - 0.15), Cl- (1.5 - 11.19),