Bioremediation of Industrial Effluents: Distillery Effluent - Applied Environmental Biotechnology: Present Scenario and Future Trends - page 19

2

Bioremediation of Industrial
Eluents: Distillery Eluent

Garima Kaushik

Abstract
Distilleries are one of the most polluting industries generating enormous
amount of wastewater from which an average of 10-15 L of effluent is
released with the production of 1 L of alcohol. The distillery wastewater
known as spent wash is characterized by its dark brown color, high tem-
perature, low pH, and high percentage of dissolved organic and inorganic
matter. It also contains nearly 2 % of the dark brown recalcitrant pigment
called melanoidin which imparts dark brown color to the effluent. Various
physical, chemical, and alternate treatment methods have been adopted for
the removal of color from this wastewater. But these methods only change
the form of contaminants rather than degrading them completely.
Biological methods produce relatively little amount of product after
treatment by resolving a large amount of organism elements into carbon
dioxide to be stabilized, or by removing organic matters contained in
wastewater with the generation of methane gas. In the biological treat-
ment methods, pollutants in wastewater can be resolved, detoxified, and
separated by using mainly microorganisms. Due to the relatively low cost
and the variations of work progress, the biological methods have been
most widely used all over the world. A number of fungi, bacteria, yeast,
and algae have been reported to have effluent treatment capabilities by the
process of absorption, adsorption, and enzymatic degradation techniques.
Toxicity studies of the biologically treated wastewaters also suggested that
the process is efficient enough to reduce the toxicity of the spent wash by
around 80 %. Hence, compared to the common and expensive physical or
chemical ways for decolorization, an efficient bioremediation system has
been found successful through biosorption and enzymatic ways of decol-
orization.

Keywords
Biodegradation ﾷ Distillery wastewater ﾷ Melanoidin

2.1 Introduction

Alcohol distilleries in India are one of the most
polluting industries; in addition, they are high
consumers of raw water. In India, major distill-