Adsorption and recovery of aroma compounds from wastewater of clove oil distillation using coffee husk biosorbent

Abstract

Coffee husk was used as potential biosorbent in order to adsorb volatile compounds from wastewater of clove oil distillation and the oil was recovered from the wastewater. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used for the characterization of coffee husk. Coffee husk was carbonized and activated using hydrochloric acid. Identification of functional group by infrared spectrum on coffee husk showed the dominant peaks at 3327 cm -1 (O-H) and 1608 cm -1 (C--C, C--O). The activated carbonized coffee husk showed the OH-peaks weakly in the spectrum. SEM surface analysis showed an uneven surface on the coffee husk. The optimum adsorption of clove oil was determined by chemical oxygen demand (COD). Optimization of coffee husk adsorbent was obtained by waste volume of 10 ml, the weight of 1.5 g and contact time of 120 min. The adsorption efficiency of the organic compound from wastewater was 37.96%. Eugenol and eugenol acetate recovery of coffee husk adsorption were 79.44% and 54.05%, respectively. The recovery of clove oil in wastewater distillation was 0.31%.