Potassium hydroxide-treated palm kernel shell sorbents for the efficient removal of methyl violet dye

Abstract

The present work was aimed to evaluate the removal of methyl violet dye by potassium hydroxide-treated palm kernel shell sorbents. The sorbents were prepared by dried impregnation, carbonization and chemical activation in a muffle furnace. The sorbents were characterized for specific surface area, surface morphology and functional groups. Resultsshow that the activated carbon displayed a specific surface area of 302 m 2 /g, which was 54 times greater than the impregnated sorbent. However, the latter showed a 42 mg/g maximum adsorption capacity of methyl violet, nearly 4 times better than the former. The equilibrium data was fitted well with the Langmuir isotherm, while the rate of sorption data obeyed the pseudo-second-order model. Adsorption of methyl violet was not specific surface areadependent. The rate-limiting step for methyl violet adsorption was mainly driven by film diffusion at lower concentration, and intraparticle diffusion at higher concentration. A simple impregnation using potassium hydroxide was a promising approach to yield sorbent rich in acidic groups for methyl violet removal.

Synthesis of porous iron – zirconium mixed oxide fabricated ethylene diamine composite for removal of cationic dye

“…Intra-particle diffusion involves mass transfer of molecules from the surface to the pores of adsorbent and diffusion of dye into the active sites of the adsorbent. The intra-particle diffusion plot shows the straight line deviated from the origin confirm that this is not only the rate limiting step in the adsorption process [40][41][42].…”

Role of bacterial extracellular polymeric substances (EPS) in uptake and accumulation of co-contaminants

“…Significant efforts have been made in search of effective methods and strategies for removal of contaminants from the polluted sites (Albadarin et al 2017;Al-Othman et al 2012;Hamedrez et al 2014;Ming-Twanga et al 2017;Naushad et al 2013Naushad et al , 2016Sharma et al 2018) only regarding the individual pollutants and rarely for removal/treatment of co-contaminants. Uptake and accumulation of pollutants by microbial biomass (with the ability of self-replenishment) and their biological products (either excreted by or derived from microbial biomass) offer an attractive alternative in terms of availability and stable costs compared to expensive conventional technologies (generating secondary pollutants and posing disposal issues) for removal of metals, dyes and organic wastes (Lau et al 2005;de Oliveira Martins et al 2008;Sultan et al 2012).…”

Characterization and adsorptive behaviour of snail shell-rice husk (SS-RH) calcined particles (CPs) towards cationic dye

“…Numerous adsorbents synthesized from low-cost natural materials such as wheat shell (Bulut and Aydin, 2006), eggshell (Akazdam et al., 2017), saw dust (Zafar et al., 2008), clay (Amin et al., 2015), bamboo charcoal (Zhu et al., 2009), guava leaf powder (Ponnusami et al., 2008), pinang frond (Ahmad and Alrozi, 2011) and so on had been used for the removal of coloured dyes from aqueous solution. In recent developments, nanocomposite iron-based adsorbent had been used for methylene blue and malachite green dyes (Alqadami et al., 2018), brown macroalga for methylene blue dye (Daneshvar et al., 2017), starch/poly(alginic acid- cl -acrylamide) nanohydrogel for coomassie brilliant blue R-250 dye (Sharma et al., 2017), amberlite IRA-938 resin for rose Bengal dye (Naushad et al., 2016), polyaniline Zr(IV) selenotungstophosphate nanocomposite for methylene blue and malachite green dyes (Pathania et al., 2015), potassium hydroxide-treated palm kernel shell for methyl violet dye (Ming-Twanga et al., 2017) and nanostructured TiO 2 /polyaniline nanocomposite for methyl orange and methylene blue dyes (Gnanasekaran et al., 2018) removal from aqueous solution.…”