Two-Stage Adsorber Design for Methylene Blue Removal by Coconut Shell Activated Carbon

The present work was aimed at evaluating the performance of two-stage adsorber for methylene blue removal by coconut shell activated carbon in minimizing the adsorbent mass and contact time. The Langmuir constants were used to evaluate the optimum mass, while the pseudo-second-order constants for contact time. Results show that the adsorbent mass can only be minimized by 0.01 % due to the high adsorbent affinity towards methylene blue, while the contact time has been optimized to 12.2 min at the studied conditions. The effect of adsorbent affinity in two-stage adsorber was analyzed to shed some light about its importance in the design of two-stage adsorber. The performance evaluation was also discussed to bring insight into wastewater treatment applications.

Development of Eco-friendly Adsorbent Pellets from Low Fire Clay and Potato Starch for Potential Use in Methylene Blue Removal in Aquaculture

Mesoporous clay-starch ceramic pellets have been prepared using silica-rich low fire clay and potato starch as a pore-forming agent. The ceramic pellets prepared using 30% starch, showed the highest porosity and lowest compressive strength among all the different pellets. Batch mode studies using the pellets showed higher methylene blue adsorption capacity with an increase in time and increased initial dye concentration. The adsorption capacity was found to decrease with increasing pellet dose, while pH had a negligible effect on methylene blue removal which makes them a suitable adsorbent in both acidic and basic mediums. Adsorption isotherm analysis of the process was followed by the Langmuir adsorption isotherm whereas the kinetics analysis fitted well with the pseudo-second-order kinetic model. A low-cost, simple device was made from a stainless-steel wire mesh with mesoporous ceramic pellets enclosed in it, which can easily be dipped and taken out of an aquarium and can remove methylene blue from water.