Removal of methylene blue using lemon grass ash as an adsorbent

Abstract

Wastewater from textile industries is a major cause of water pollution in most developing countries. In order to address the issues of water pollution and high cost for treatment processes, the use of an inexpensive and environmentally benign adsorbents has been studied. The objective was to find a better alternative to the conventional methods. Lemon grass waste (ash) collected from a lemon grass stream distillation subunit in Bhutan was tested for dye removal from aqueous solutions. The study investigated the removal of methylene blue using the following operational parameters: initial concentration (100-600 mg/L), contact time, adsorbent dose (0.1-0.55 gm/100 mL), and pH (3-10). It was found that the percentage removal of dye increased with a decrease of the initial concentration and increased contact time and dose of adsorbent. The basic pH solution of dye showed better adsorption capacity as compared to the acidic dye solution. Langmuir and Freundlich adsorption isotherms were fitted to the data well. Data fitted better to Lagergren pseudo 2nd order kinetics than a 1st order kinetic model. Surface morphology was also examined via scanning electron microscopy. An elemental analysis was also carried out and the chemical composition and functional groups were analyzed using energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy techniques, respectively. The obtained results indicate that lemon grass ash could be employed as a low cost alternative to commercial activated carbon in wastewater treatment for the removal of dyes.

A Preliminary Study on the Removal of Methylene Blue from Aqueous Solution using Moringa Pods as Bioadsorbent under Column Operation

“…Additionally, a more regular structure is also observed, which indicates that the dye was uniformly adsorbed on the surface of the bioadsorbent. Similar results have been observed by other researchers [5].…”

“…. As methylene blue is a cationic dye, the -OH functional group on the surface of MP may increase the interaction between the adsorbent and the adsorbate, which contributes to the adsorption of methylene blue [5]. Also, can be observed a decrease of the intensity of the band at 1,634 cm -1 and a shifted slightly, due probably to the interaction between dye molecule and -OH and -COOH groups present on bioadsorbent surface.…”

“…This has recently prompted many studies on production of low cost alternatives adsorbents. A number of agricultural waste types and byproducts of cellulosic source have been studied for their capacity to remove dyes from aqueous solutions [5]. Some lignocellulosic materials with rough surfaces, pores of various sizes, and active functional groups on their surface may have a great potential as adsorbents, and they are abundant in nature [6].…”

Fabrication of a cost-effective lemongrass (Cymbopogon citratus) membrane with antibacterial activity for dye removal

“…Previous studies have demonstrated various forms of lemongrass such as powder, ash and extracted oil residual can absorb different metal ions and dye from the aqueous solutions. 17,19,20 Only one paper regarding lemongrass dye adsorption has reported that the lemongrass ash is an efficient adsorbent for the adsorption of methylene blue from wastewater. 20 However, there is a difficulty of separating ash from the water aer dye adsorption.…”

“…17,19,20 Only one paper regarding lemongrass dye adsorption has reported that the lemongrass ash is an efficient adsorbent for the adsorption of methylene blue from wastewater. 20 However, there is a difficulty of separating ash from the water aer dye adsorption. In this study, lemongrass was fabricated into membranes as dye absorbent to study their dye adsorption properties and resolve the separation problem of lemongrass powder or ash.…”