Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides
in the World. Due to its extensive use, long half-life and various toxic properties, it has very
high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water
whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard
there should not be any pesticide present in drinking water. Among many other treatment
processes available, Incineration, adsorption, chemical treatment, phytoremediation and
biodegradation are the most commonly used ones. Biological degradation of atrazine
depends upon various factors like the operating environment, external carbon and nitrogen
sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general
atrazine degradation pathways are available, the specific pathways in specific conditions are
not yet clearly defined.
In this paper extensive review has been made on the occurrence of atrazine in surface and
ground water bodies, probable sources and causes of its occurrence in water environment,
the toxicity of atrazine on various living organisms and its removal by biological processes.