Project Info

Isolation and Identification of Cr(VI) Reducing Bacteria from Tannery Effluent.

Title of the proposed R&D project: Isolation and Identification of Cr(VI) Reducing Bacteria from Tannery Effluent.

Name and designation of Project Leader & Researcher associates: Project Leader: Md. Abu Hasan, SO Project Associates: Masud Parvez (SO), M.A.A Shofi Uddin Sarkar (SO).

Objective:
a. To isolate the microbes from tannery effluent
b. To assess the Chromium reduction capacity at different concentration of Cr (VI).
c. To investigate the kinetics of chromium reduction by indigenous bacteria.

Socio-economic importance of the project: Heavy metal pollution of water is a major environmental problem facing the modern world. The global heavy metal concentration in various environment is increasing due to increase in number of industries. Most of the industrial wastewaters contain heavy metals like cadmium, lead,
zinc, cobalt and chromium. Among heavy metals chromium is the major pollutant of the leather tanning industry and is toxic to plants and animals around the environment. The damage to the environment by the hazardous tannery effluent is becoming an acute problem in several countries. The chrome tanning process results in toxic metals, especially chromium III passing to waste water and are not easily eliminated by ordinary treatment process. Tannery waste waters are mainly characterized by high salinity, high
organic loading and specific pollutants such as chromium. The industrial effluent released directly or indirectly into natural water resources, mostly without proper treatment, poses a major threat to the environment. Among the different forms of chromium, the hexavalent chromium Cr 6+ is the most toxic and carcinogenic due to its high solubility in water,
rapid permeability through biological membranes and subsequent interactions with intracellular proteins and nucleic acids. The heavy metals in general cannot be biologically transformed to more or less toxic products and hence persist in the environment indefinitely. They are significantly toxic even in small amounts and can cause diseases in
humans and animals as they cause irreversible changes in the body, especially in the Central Nervous System. Soil contamination by heavy metals is often irreversible and may repress or even kill parts of the microbial community and it is generally assumed that the exposure to metals leads to the establishment of a tolerant/ resistant microbial
population. Microorganisms play a significant and vital role in bioremediation of heavy metal contaminated soil and wastewater. Indigenous bacteria
appear well suited for Cr (VI) transformation in tannery effluent and may accumulate chromium within its cells by adaptation to the High concentration of the metal. Very stable final chromium forms can be achieved as a result of microbial activity, with minimal risk of re-release of Cr (VI).

Project current status: Completed.