A Novel Biosorbent Lagenaria vulgaris Shell ‐ ZrO₂ for the Removal of Textile Dye From Water

Abstract

A new biosorbent, abbreviated as LVB-ZrO₂, was synthesized by chemically modifying Lagenaria vulgaris shell with ZrO₂. The removal of textile dye RB19 from aqueous solution by LVB-ZrO₂was studied. Characterization by SEM, FTIR and XRD confirmed the chemical modification of the biomaterial, which showed significant improvement of removal efficiency compared with unmodified Lagenaria vulgaris shell. LVB-ZrO₂point of zero charge is 5.49. The biosorption process is highly pH dependent and the optimal pH is 2.0, at which complete dye removal was attained. The results are the best by a pseudo-second order kinetic model. The optimal adsorbent dosage is 4 mg/dm³.The RB19 biosorption follows the Langmuir isotherm model (R² = 0.9978), with the maximum sorption capacity of 75.12 mg/g. LVB-ZrO₂is a mechanically stable, easy to synthesize, cost-effective, biocompatible and environmentally-friendly biosorbent with the high potential for the removal of RB19 from aqueous solution.

Evaluation and Predictive Modeling of Removal Condition for Bioadsorption of Indigo Blue Dye by Spirulina platensis

“…This result contrasts those reported in previous articles [34], where the authors analyzed the optimal pH of the microalga Scenedesmus and identified pH 7.5 as optimal for discoloring the indigo blue. Petrović et al [50] reported an optimal pH of 2.0 for a new biosorbent, synthesized by chemically modifying Lagenaria vulgaris shell with ZrO 2 and abbreviated as LVB-ZrO 2 with blue textile dye RB19.…”

“…The amount of absorbed dye as a function of time was measured for four different initial concentrations of indigo blue (25,50,75, and 100 mg/L) for 96 h. Figure 2 shows the observed experimental values (solid dots with error bars) and two fitted models for each initial concentration, where the dashed line is the first-order model in Equation 7and the solid line is the second-order rate model in Equation 8 [46]. Only one parameter was fitted to have more meaningful parameter values in all models [41,49,50]. For the first-order model, the fitted parameter was the adsorption rate, and the maximum adsorption (Qe) was fixed to 91% of the initial concentration (Ci) since we observed that the adsorption process reached equilibrium after three days and the amount of dye absorbed was consistently around an average of 91% of the initial concentration (C0) in all cases (Table 2).…”

“…Table 3. Fitted parameters for adsorption vs. time curves at different initial concentrations (25,50,75 and 100 mg/L): first-order model in Equation 7and a second-order rate equation (Equation (8)) [46]. (SE for square error, RMSE for root-mean square error, MSC for model selection criterion).…”

“…Adsorption curves of blue indigo dye for different initial concentrations C i(25,50, 75, and 100 mg/L). Points with error bars represent measurements with experimental errors.…”

Adsorbentes de origen vegetal y su aplicación en la remoción amigable de colorantes presentes en agua

“…Recientemente se han estudiado como adsorbentes para la remoción de colorantes en agua Lagenaria vulgaris (Petrović, Radović, Kostić, Mitrović, Bojić, Zarubica & Bojić, 2015), planta trepadora conocida comúnmente como calabaza de peregrino (figura 4a), y Mucuna pruniens (Igwegbe, Onyechi, Onukwuli & Nwokedi, 2016), leguminosa conocida con el nombre común de grano de terciopelo (figura 4b). L. vulgaris fue modificado químicamente empleando óxido de zirconio, lo cual dio como resultado un nuevo biomaterial adsorbente denominado LVZrO 2 , que removió de forma eficiente el colorante textil RB19.…”