Valorization of spent brewery yeast biosorbent with sonication-assisted adsorption for dye removal in wastewater treatment

The effluent of textile industries containing synthetic dyes contributed to substantial pollution to water bodies. The biosorption process of Congo Red dye was successfully performed by integrating ultrasonication in the adsorption step with spent brewery yeast as a novel and renewable biosorbent. The adsorption process was hindered when ultrasonication was employed together with the biosorbent, indicating that desorption process had occurred. The adsorption process showed that 4 g/L of biosorbent was the optimum dosage for adsorption of 50 mg/L of Congo Red dye, and that the adsorption equilibrium fitted to the Langmuir model, with kinetics best fitted with pseudo-second order model. The maximum capacity of the adsorption was 52.6 mg/g, showing the potential of spent brewery yeast to aid in removing wastewater pollutants. Maximal Congo Red dye recovery (100%) was achieved in the sonication-assisted desorption studies using 0.01M NaOH as the eluting agent. The ultrasonication effects contributed to the efficient recovery of dye and good conversion of spent brewery yeast to biosorbent can be beneficial for treating pollution from textile wastewater.

Automated summary

The research demonstrated that using spent brewery yeast as a biosorbent can effectively remove dye pollutants from textile wastewater, with the addition of ultrasonication improving dye recovery. The optimal dosage for adsorption was found to be 4 g/L of biosorbent, with adsorption equilibrium fitting the Langmuir model and kinetics best fitting pseudo-second order model.