REMOVAL
OF CHROMIUM FROM WASTE WATER WITH THE HELP OF MICROBES: A REVIEW
Asha
Lata Singh
Environmental
Science, Department of Botany, Banaras Hindu University,
Varanasi-221005, INDIA
ashalatabhu@rediffmail.com,
Ph:919935658465, 910542-2368946
Abstract
Chromium
VI (CrVI) is one of the highly toxic heavy metals. It is widely used in a number
of industries like metallurgical, electroplating, paints, pigments, inks,
fungicides and photography. It enters into the natural water bodies through the
industrial effluents creating water pollution. In trace amounts it is useful for
some of the metabolic activities like glucose, lipid, aminoacids and nucleic
acid. However at higher concentration it becomes toxic for microbes, plants and
humanbeings and causes a number of serious diseases. Therefore its removal
from waste water is considered to be very important. In the present article
chromium removal from waste water using bacteria by biosorption, reduction and
transport was reviewed. Published literature suggests that immobilized, free and
living cells, their extracellular metabolites even dead bacterial biomass play
an important role in chromium removal from waste water. Reduction of Cr (VI) is
one of the important mechanisms for its detoxification from waste water.It was
shown by the work published so far that chromium reduction was carried out by
aerobic and anaerobic bacteria and iron and sulphate reducing bacteria. pH
inside the bacterial cells plays an important role in the reduction of Cr (VI).
Review of literature suggests that different factors like pH, temperature, redox
potential and presence of other metals play an important role in the removal of
Cr (VI) from waste water using bacteria. We have carried out work in our
laboratory on Cr (VI) uptake from waste water by Bacillus mycoides and the
results obtained are also discussed in this communication.
Keywords:
Chromium;
biosorption; reduction; uptake; regulating factors
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