Microwave assist sorption of crystal violet and Congo red dyes onto amphoteric sorbent based on upcycled Sepia shells

Abstract

A new sorbent based on Sepia shells (cuttlefish bones) has been synthesized (SSBC) and tested for the sorption of cationic dye (crystal violet, CV) and an anionic dye (congo red, CR). SSBC was produced by reaction of sepia shells powder with urea in the presence of formaldehyde. In the first part of the work, the sorbent was characterized using scanning electron microscopy, energy dispersive X-ray analysis, Fourier-transform infra-red spectrometry and titration (for determining pH PZC ). In a second step, sorption properties were tested on the two dyes through the study of pH effect, sorbent dosage, temperature and ionic strength; the sorption isotherms and uptake kinetics were analyzed at the optimum pH: Langmuir equation fits isotherm profiles while the kinetic profile can be described by the pseudo-second order rate equation. Maximum sorption capacities reach up to 0.536 mmol g −1 for CV and 0.359 mmol g −1 for CR, at pH 10.6 and 2.4, respectively. The comparison of sorption properties at different temperatures shows that the sorption is endothermic. Processing to the sorption under microwave irradiation (microwaved enforced sorption, MES) increases mass transfer and a contact time as low as 1 min is sufficient under optimized conditions (exposure time and power) reaching the equilibrium, while 2-3 h were necessary for "simple" sorption. Dye desorption was successfully tested using 0.5 M solutions of NaOH and HCl for the removal of CR and CV, respectively. The sorbent can be re-used for a minimum of four cycles of sorption/desorption. Finally, the sorbent was successfully tested on spiked tap water and real industrial wastewater.

Effect of agitation mode (mechanical, ultrasound and microwave) on uranium sorption using amine- and dithizone-functionalized magnetic chitosan hybrid materials

“…2, the sorption capacity predicted by the PSORE decreases with increasing the respectively). The enhancement of mass transfer properties in microwave-assisted sorption properties was already reported for the removal of metal ions [102,103] and dyes [64]. Contact times as short as 30-60 s were reported as sufficient for reaching equilibrium [64,103].…”

“…The enhancement of mass transfer properties in microwave-assisted sorption properties was already reported for the removal of metal ions [102,103] and dyes [64]. Contact times as short as 30-60 s were reported as sufficient for reaching equilibrium [64,103]. Mahmoud et al [102,103] identified both the effect of increased temperature and diffusion enhancement as the major causes of sorption enhancement.…”

“…Recently, ultrasonic treatment has retained great attention for designing fast and efficient sorption processes [17,[53][54][55][56][57][58]; the cavitation effects induced by ultrasonic exposition improve mass transfer properties and accessibility to reactive groups [59][60][61]. While microwave irradiation has been frequently investigated for activating synthesis procedures [62] or leaching processes [63], both in terms of kinetics and reaction yield, this process has been much less documented for sorption purpose [64][65][66][67].…”

Non-Woven Fabrics Based on Nanocomposite Nylon 6/ZnO Obtained by Ultrasound-Assisted Extrusion for Improved Antimicrobial and Adsorption Methylene Blue Dye Properties

“…Different materials have been reported for the adsorption of dyes between them magnetite nanoparticles [ 5 ], urea calcium alginate xerogel beads [ 6 ], metal/mineral materials such as CuO, zinc, iron, and zeolite [ 7 ]. Bioadsorbents have also been used as bivalve shells of anadara uropigimelana [ 8 ], sepia shells (cuttlefish bones) [ 9 ], to fabricate monolithic algal green powder (MAGP) based on the marine green macroalga enteromorpha flexuosa [ 10 ] as well as magnetically modify products of the coffee industry [ 11 ]. Nowadays, methodologies based on energy sources such as microwave or ultrasound radiation are exploited to accelerate different sorption processes.…”

Orange-derived and lemon-derived adsorbents with controlled grain for an efficient elimination of some cationic and anionic dyes

“…The adsorption mechanism is based in the capture or retention of a compound (adsorbate) in a liquid phase by a solid (adsorbent) (Mostafa et al , 2009; Park et al , 2010). In this sense, a wide range of low-cost materials have been studied to be used as potential adsorbents for dyes such as wood (Kelm et al , 2019; Naeem and Hassan, 2018), clay (Kausar et al , 2018), ashes (Mor et al , 2018), activated muds (Qu et al , 2012; Sarvajith et al , 2018), orange (Namasivayam et al , 1996), cuttlefish bones (Elwakeel et al , 2020), algae (Elgarahy et al , 2020) and banana peels (Temesgen et al , 2018). In these recent years, the concepts of reuse and recycling have taken an important role in our society and resulted in an increase in research and development in sustainable technologies.…”