Removal of Some Selected Heavy Metal Using Modified Bagasse and Eucalyptus Bark from Gold Mining Waste Water: Case Study of Ezana (Meli) Gold Mining Development Plc Industries
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Date
2018-06
Authors
Journal Title
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Publisher
Addis Ababa University
Abstract
This study investigated the potential use of modified bagasse (MSB) and eucalyptus Bark (EB)
treated from sample wastewater in batch mode experiments. The discharge of untreated gold
mining wastewater contaminates with heavy metals such as Cu (II) and Pb (II), which is
threatening ecosystems, carcinogenic to the human & hinder development of plants. Since the
removal by adsorption is cost effective, not time consuming and environmentally friendly, it has
been widely studied by many scholars for remediation of heavy metals. Characterization of
bagasse and eucalyptus bark were analyzed using proximate analysis like MC (%), Ash value (%),
ƍ
b
(g/cm
3
), VM (%), fixed carbon (%) and % (C, N
2
). FTIR analysis revealed the presence of
multiple functional groups in the adsorbent, some of which were involved in the sorption process
and x-ray diffraction (XRD) used to measure the crystalline content of adsorbent materials. The
result indicated that the effluents discharged from Ezana Gold extraction were mainly contains
the following: TSS (ppm), turbidity (NTU), EC (µs/cm), TDS (ppm), COD (ppm), temperature(°C),
pH, cyanide WAD with <11°C (ppm) and heavy metals such as Fe > Cu >Pb >Mn > Cr (VI) >Zn
> Co > Ni > Cd (ppm). They were determined by atomic absorption spectroscopy. The major
pollutants selected from the process effluent were Cu
2+
and Pb
2+
due to exceeded standard
discharge limits. The objective of the study was removal of Cu
2+
and Pb
2+
from rich Ezana
wastewater using modified sugarcane bagasse and eucalyptus bark powder as an adsorbent. The
selected parameters were pH, adsorbent dose and time. A maximum removal of (Cu
2+
, Pb
2+
) by
modified bagasse (88.45%, 94%) and eucalyptus bark (92%, 99%) respectively was achieved. The
adsorption data were well fitted to the Langmuir isotherm model and pseudo-second order kinetic
model for both modified bagasse (Cu, Pb) and eucalyptus bark (Cu, Pb). This indicated that
Eucalyptus bark powder was more effective than modified bagasse (MSB) and it can be used as
an alternative low cost adsorbent for the removal of copper and lead from Ezana mining
wastewater.
Description
Keywords
Adsorption, Cu 2+ and Pb 2+, eucalyptus bark, Isotherm, kinetics, Modified bagasse and eucalyptus bark