Remediation of some selected heavy metals from water using modified and unmodified mushrooms
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Date
2016
Authors
Bii, Arap Thomas
Mwangi, Isaac W.
Wanjau, Ruth N.
Swaleh, Sauda
Manohar, Ram
Ngila, JC
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The dispersal of toxic heavy metals by water from natural and anthropogenic is a worldwide environmental
concern due to pollution. Despite some metals playing an important role in body, they are toxic when the level
exceeds the tolerance limits while others such as lead have no known physiological value to human beings. Since
heavy metals cannot be degraded, then their removal from drinking water is necessary. Mushrooms are readily
available in Bomet County and their metal removal ability was investigated. The study aimed at removing heavy
metals from water by adsorption using mushroom, as a cost-effective and sustainable method. The raw mushroom
was modified with sodium hydroxide and characterization of both the parent material and its modified form was
done using Fourier Transform Infrared spectrometry (FTIR). Sorption experiments were carried out using the
batch adsorption method and sorption parameters including pH, contact time, adsorbent dose and initial metal ion
concentration investigated. The results found out that the sorption capacity for cadmium ions ranged from 1.826-
25.285 mg/g by the unmodified edible mushroom (UEM), the modified edible mushroom (EM), unmodified toxic
mushroom (UTM) and modified toxic mushroom (TM). For copper ions, sorption capacity ranged from 0.002-4.097
mg/g, while that of the lead ions ranged from 1.345-2.593 mg/g by the UEM, EM, UTM and TM respectively. The
sorption capacity showed improvement on modification as sorption of cadmium increased from 1.826-25.285 mg/g
by the UEM, EM, UTM and TM. At a pH range of 4-6, the sorbent material was found to remove up to 90% of the
metals. The sorbent material had a removal efficiency of 95% of the metals in less than 20 minutes. The UEM and
UTM fitted well in Langmuir adsorption isotherm model for cadmium and lead ions. For copper ions, UEM, EM, UTM
and TM fitted in the Freundlich model. TM for lead ions best fitted in the Freundlich model. The bio-sorption kinetics
was determined by fitting first-order-Lagergreg and Pseudo-second-order kinetics models to the experimental data.
It was found that the data for lead was better described by the pseudo-second-order model. For copper ion, the
data was best described by Ho’s pseudo second order for UEM and UTM, cadmium ions for all sorbents was best
described by Lagergreg’s first-order kinetics. The FTIR analysis suggested the possibility of the participation of
carboxyl groups in metal uptake. The levels of dissolved organic carbon (DOC) were found to be 19.0 mg/L in the
raw material and 2.19 mg/L after modification. It was confirmed that modification minimized secondary pollution. This
indicated that mushrooms have a potential application for the remediation of metal polluted waters.
Keywords: Mushrooms; Alkali modification; Sorption; Dissolved
organic carbon
Description
doi:10.4172/2375-4397.1000162
Keywords
Mushrooms, Alkali modification, Sorption, Dissolved organic carbon
Citation
Journal of Pollution Effects & Control, http://dx.doi.org/10.4172/2375-4397.1000162