Melia azedarach Activated Carbon and its Novel TiO2 Nanocomposite for Chemisorption and Photodecoloration of Reactive Orange 16: Isotherm and Kinetic Modeling

作者：Shah, Jehanzeb A.; Ashfaq, Tayyab; Khan, Muhammad S.; Riaz, Nadia; Shah, Khizar H.; Arshad, Muhammad; Shah, Sajid H.; Amin, Bilal A. Z.; Arfan, Muhammad; Zhang, Yongqing^*; Bilal, Muhammad^*

来源：Current Analytical Chemistry, 2021, 17(1): 107-119.

DOI：10.2174/1573411016999200715162006

• Activated carbon
• adsorption
• isotherm and kinetics
• Melia azedarach
• nanocomposite
• reactive orange 16
• thermodynamics

Background: Bulk generated textile wastewater loaded with dyes is posing a stern threat to aquatic health, especially when dumped without prior treatment. Lignocellulosic waste based activated carbon (AC) and Titania (TiO2) suspension can constitute the emerging technological solution. @@@ Objectives: Best lignocellulosic precursor biomass, Melia azedarach (Darek sawdust - DSD), was selected for ortho-phosphoric acid impregnated AC production and novel AC-DSD-TiO2 nanocomposite was developed. AC-DSD and AC-DSD-TiO2 nanocomposites were employed for reactive orange 16 (RO16) dye adsorption in batch and decoloration in photocatalytic reactors, respectively. @@@ Methods: Materials were characterized by Scanning electron microscope (SEM), energy dispersion X-ray (EDX) spectroscopy and Fourier transform infrared spectroscopy (FTIR). For AC-DSD production, the raw powdered biomass of DSD impregnated (value = 2) with H3PO4 at room temperature and after shaking. was placed in a muffle furnace at 100 degrees C for 12 h in glass tubes and subsequently carbonized at a high temperature of 400 degrees C for 30 min. Batch reactor parameters for the ACDSD-RO16 system were optimized as a function of contact time, adsorbent dose, temperature, initial dye concentration and pH. For AC-DSD-TiO2 nanocomposite synthesis, AC-USD and TiO2 paste was dried in the furnace at 90 degrees C and calcined at 300 degrees C and stored in a desiccator. @@@ Results: AC-DSD exhibited RO16 adsorption capacity of 92.84 mg/g. The experimental data were best described by Langmuir and Dubinin-Radushkevich isotherms with high R-2 of 0.9995 and 0.9895 and closeness of predicted adsorption capacities of 94.15 and 88.58 mg/g respectively. This determines the chemisorption nature for RO16 adsorption onto AC-DSD. The experimental data was well explained by the pseudo-second order kinetic model. Thermodynamic parameters also suggest the endothermic, chemisorption and spontaneous adsorption reaction. Photocatalytic studies of novel AC-DSD-TiO2 revealed the higher K-c = 0.1833 value over K-ad= 0.0572. @@@ Conclusion: Melia azedarach AC-DSD and its novel AC-DSD-TiO2 nanocomposite prove that these materials could provide an optimal solution for treating textile dye solutions effectively as the good adsorbent and photocatalyst.