e-ISSN 2231-8542
ISSN 1511-3701
Nur Aqilah Zainal, Shariff Ibrahim and Borhannuddin Arifin
Pertanika Journal of Tropical Agricultural Science, Volume 25, Issue S, March 2017
Keywords: Acid dyes, adsorption, carbon, chemical activation, cocoa pod husks, zinc chloride
Published on: 05 Dec 2017
An agricultural waste, the cocoa pod husk was chemically modified using a dehydrating agent, zinc chloride (ZnCl²), carbonised and used for the remediation of acid dyes in an aqueous solution. The targeted acid dyes are: (i) Acid Violet 17 (AV17); (ii) Acid Yellow 36 (AY36); and (iii) Acid Blue 29 (AB29). The physicochemical properties of the zinc chloride-modified cocoa pod husk-based carbon (ZCPHC) were characterised by ash content, bulk density, pH slurry, pHpzc and Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-Ray (EDX) analysis. The bulk density and ash content of the prepared carbon is 0.55 g cm-1 and 7.0% respectively. The photograph of SEM shows distinct changes at the ZCPHC carbon surface as it has large pores formed due to ZnCl² modification. The adsorption tests were performed in a batch adsorption system using an aqueous solution of the understudy acid dyes. The influence of pH and dose of an adsorbent on the acid dye uptake was investigated and discussed. The adsorption was in favour at acidic condition with maximum removal observed at pH 2. The removal efficiency of the aqueous acid dye solution increased with the increase in adsorbent dosage. The kinetic experiment showed equilibrium time is less than 40 minutes and the kinetic data for all three understudy acid dyes fitted well with the pseudo-second-order model with a correlation coefficient (R²) values above 0.98.
ISSN 1511-3701
e-ISSN 2231-8542