Assessment of drying temperature of sugarcane bagasse on sorption of reactive blue 5G dye

Abstract

We studied the effect of drying temperature of sugarcane bagasse (SB) on sorption of reactive blue 5G (RB5G) dye to test whether SB is a suitable biosorbent for industrial dye removal. First we assessed a set of SB characteristics that could influence the sorption capacity of dried biomass. Kinetic drying of the SB biomass was measured at different drying temperatures, ranging from 30 o C to 80 o C. We used a static gravimetric method to perform equilibrium moisture sorption experiments at drying temperatures of 35-65 o C. In addition, we measured activation energy and net isosteric heat of sorption. SB biomass was characterized as a heterogeneous low-porous and hygroscopic material, with a series of functional groups on its surface. A Lewis thin-layer model best represented the kinetic drying data. In addition, moisture diffusion into the SB biomass was characterized by a rate-controlling step in the drying process. Equilibrium moisture sorption data showed the expected effects of temperature controlling the sorption capacity and a multilayer sorption process. A sigmoidal sorption isotherm data was best represented by a BET model. A high energy demand is required for moisture removal from biomass as suggested by the measured isosteric heat of moisture sorption. Drying temperature did not influence the RB5G adsorption capacity of bagasse, therefore any drying temperature in the range of 30 o C to 80 o C could be used to make this material feasible as an industrial adsorbent.

Biosorption of reactive yellow dye by malt bagasse

“…Infrared spectra of malt bagasse (before biosorption) present characteristics similar to several natural fibers such as the stretches -OH (3388 cm –1 ), C-H in methyl and methylene groups (2916 and 2861 cm –1 ), and C-O (1027 cm –1 ), characteristic of lignocellulosic materials. Similarly, the peak located at 1527 cm –1 indicates the presence of hydroxycinnamic alcohols, showing the presence of lignin in the natural fiber (Miranda, 2009; Scheufele, 2014; Zhang et al., 2013).…”

“…(2010), Cardoso et al. (2011), and Scheufele (2014), who used residual materials such as Brazil nuts shell (pH pzc = 6.57), cupuassu shell (pH pzc = 5.92), and sugarcane bagasse (pH pzc = 5.90), respectively, in the treatment of effluents.…”

“…As for peaks located between 2916 and 2861 cm –1 , there were no significant changes in absorption when spectra were compared before and after biosorption. These peaks indicate C-H vibrations of the methyl and methylene groups (Fontana et al., 2016a; Geçel et al., 2016; Pavia et al., 2010; Scheufele, 2014).…”

“…In the infrared spectra of malt bagasse after biosorption (Figure 5(b)), there is an indication of the presence of these reactive groups, as well as at 3388 cm –1 with the stretching -NH, which is a primary amine present in monochlorotriazine groups, and C = C vibrations at 1666 cm –1 typical of vinyl radicals, of the vinylsulfone groups. The peak located at 1527 cm –1 , in turn, reflects the azo characteristic of the dye, with stretching -N = N- (Holler et al., 2009; Pavia et al., 2010; Scheufele, 2014; Zhang et al., 2013).…”

“…Comparing this result to the pH pzc evaluation (Figure 2), we verified that, in fact, the removal was favored when the solution pH was lower than the pH pzc of the malt bagasse (pH pzc = 6.75). In contrast, for ranges higher than the pH of the biosorbent, the removal capacity is null, which may indicate that the biosorption of the YR-B2R dye is strongly influenced by ion–ion interactions (Al-Degs et al., 2008; Scheufele, 2014).…”