Abstract:
Chromium released into the environment primarily as a
result of industrial activity such as leather and electroplating
manufacturing process. This heavy metal has caused serious
contaminations of water and soils with significant environmental and
occupational concerns. Conventional methods of chromium removal
are expensive especially for developing countries. This study
investigates the use of pumice as a low cost and biosorbent material.
Sorption of hexavalent Chromium (Cr (VI) onto pumice were carried
out in batch at room temperatures, with parameters of initial
chromium concentrations, and contact time being investigated.
Removal of hexavalent chromium increased by increasing contact
time, and reduced with increasing initial chromium concentration.
Kinetic studies were conducted using the Pseudo-first-order and
Pseudo-second- order models, while equilibrium data were fitted
using Langmuir and Freundlich isotherm models. Fittings of obtained
data onto kinetic models show that the pseudo-second –order kinetic
model (R2=0.999) best describes the kinetic sorption of chromium
ions onto pumice. Results also showed that Langmuir (R2=0.999) and
Freundlich (R2=0.999) model agrees very well with experimental
data. The RL and n values has proved the favorability of hexavalent
chromium adsorption onto pumice
