Effect of Spent Mushroom Substrate on Azo Dye Removal and Effluent Treatment

Abstract

This study evaluated the removal mechanisms of azo dyes from synthetic textile wastewater using spent mushroom substrate (SMS). The simultaneous adsorption and enzymatic degradation were analyzed. The effect of pH, SMS concentration and temperature were studied. The maximum enzymatic degradation (16.36%) was obtained at pH 4 and 65 g SMS L^-1, whereas the maximum adsorption (62.86%) at pH 8 and 155 g SMS L^-1, both at 25°C. The simultaneous enzymatic degradation and adsorption led to the removal of 75.67%. with increased color change. The kinetic study showed that dye adsorption was obtained in the first 30 minutes while the enzymatic degradation increased slowly over the time. The treatment with SMS resulted in the removal of 28.75% of the true color and no increase of effluent toxicity.

Keywords:
Spent mushroom substrate; Enzymatic degradation; Adsorption.

HIGHLIGHTS

• SMS was applied to remove the mixture of two dyes in textile effluent.

• The best conditions of pH, temperature and SMS concentration were determined.

• The process resulted in color removal, but increased other parameters

• The treatment did not increase the toxicity.