Synergistic effect of Trichoderma reesei cellulases on agricultural tea waste for adsorption of heavy metal Cr(VI)

Abstract

This is the first attempt to study the synergistic effect between Trichoderma reesei cellulases and the abundant agricultural tea waste in absorption of heavy metal Cr(VI) as well as its kinetic model development. The properties of tea waste were first analyzed by near infrared spectroscopy (NIR), particle size distribution (PSD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) examination with EDX for comparison between its original (UN-TW) and cellulase-hydrolyzed (TRCEL-TW) conditions. Then, an advanced kinetic model in the form of -d[Cr(VI)]/dt = A[H+](n)e(-Ea/RT) [Cr(VI)](m)(0), which can successfully predict the time-dependent Cr(VI) concentration of various pHs, initial Cr(VI) concentrations and temperatures was developed. The demonstrated synergistic effects of T. reesei cellulases on tea waste suggested that cellulosic material provides more accessibility area for absorption of heavy metal. This study also provides an alternative approach to remove toxic Cr(VI) from aqueous solutions and extend the utilization of agricultural tea waste.

Keywords: Cr(VI) removal; Kinetic model; Synergistic; Tea waste; Trichoderma reesei cellulases.