Monday, August 2, 2010
Pacific Concourse (Hyatt Regency San Francisco)
Textile and dyestuff industrial wastewaters are generally treated by physicochemical methods, like adsorption by activated carbon, ultrafiltration, coagulation, oxidation (with chlorine, hydrogen peroxide, and ozone), reduction, precipitation, electrochemical treatment, and ion-pair extraction. However some of these methods are expensive and produce toxic pollulants. Bioremediation is an ecofriendly process and has become increasingly popular, enzymes produced by microorganisms are the most employed, but enzymes from plants are a good alternative that has remained less explored. In this work was studied the ability of Pisum sativum (green pea) to decolorate sulfonated indigo at different pHs and dye concentration.
Methodology: P. sativum (1g) was blended with phosphates buffer solution (1mL, pH 6, 7, 8, 8.5 or 9.2), then centrifuged and filtered, the supernatant was mixed with the colorant (50, 100, 200 ppm) and stirred at room temperature until the color has disappeared, the decoloration was measured by the decrease in the absorbance at 610 nm.
The optimum pH for the decoloration of sulfonated indigo with P. sativum was 8.5. Complete discoloration of a solution of sulfonated indigo with 100 ppm, was achieved in 3 hours, while at pH 6.0 the 100% decoloration was reached in 9 h. At pH 8.5 a 50 ppm solution of sulfonated indigo was decolorated in 1.5 h, and a 200 ppm solution was decolorated in about 5 h.