Olive (Olea europaea) stone powder as a sustainable biosorbent for methyl violet 2B dye removal: multivariable optimization with desirability functions

• Published in: BIOMASS CONVERSION AND BIOREFINERY
• Main Authors: Jawad, Ali H.; Deris, Raja Razuan Raja; Agha, Hasan M.; Hapiz, Ahmad; Wu, Ruihong; Alothman, Zeid A.
• Format: Article; Early Access
• Language: English
• Published: SPRINGER HEIDELBERG 2025
• Subjects: Energy & Fuels; Engineering
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001405455100001

Herein, a sustainable and renewable biomass waste namely olive (Olea europaea) stone powder (OSP) was introduced to be a cost-effective biosorbent for removing the methyl violet 2B (MV 2B) dye from aqueous contaminated water. The main features of OSP were analyzed utilizing several methods such as XRD, FSEM-EDX, FTIR, and pHpzc. The optimization of MV 2B removal was done using the Box-Behnken design (BBD) with three crucial parameters such as OSP dosage (A, 0.02-0.1 g/100 mL), contact time (B, 20-240 min), and solution pH (C, 4-10). The desirability function from the RSM BBD design shows that the highest removal (94.57%) can be achieved under these experimental conditions including an OSP dose of 0.09 g/100 mL, contact time 173.7 min, and solution pH 9.3. The biosorption study including kinetic and isotherm shows that the process of MV 2B dye removal onto OSP closely fits the pseudo-second-order kinetic model and Freundlich and Temkin isotherm model, respectively. The Langmuir isotherm reveals that the maximum biosorption capacity of OSP was found to be 72.5 mg/g. The thermodynamic analysis findings show that the MV 2B dye uptake by OSP was a spontaneous and exothermic process. Several mechanisms were predicted to be involved in the biosorption process of MV 2B dye onto OSP including hydrogen bonding, pi-pi interaction, electrostatic forces, and pore filling. Overall, the findings show that OSP biosorbent has a good capacity to remove organic dye (MV 2B) from contaminated water.