Dendrobranchiata Chitin Deacetylation Degree and its Potency as Iron (III) Ion Adsorbent from Aqueous Solution

Abstract

Poisoning of water with heavy metals majorly comes from frequent discharge from industrial wastes. This contaminates the soil, poisons plants and at large, tampers with human lives. Adsorption has been considered to be an effective and economical technique in purifying water from heavy metals. In this study, prawn chitin of different deacetylation degree (DDA) was characterized and used as adsorbent for Fe3+ from prepared FeCl3 solution. Ground prawn shells were demineralized with 1 M HCl while deproteinization was performed by reacting demineralized shells with 1 M NaOH at 100 oC for 1, 2, 3, 4 and 5 h. increasing deproteinization time raises DDA from 24.2 to 43.8 %. Thermal stability of chitin as measured from thermogravimetic analysis (TGA) reduces from 309 – 161oC at increasing deproteinization time. Crystallinity calculation rom X-ray diffraction (XRD) shows that 84.5, 81.3, 78.3, 73.8 and 67.8 % are possessed by chitin produced from 1, 2, 3, 4 and 5 h deproteinization times respectively. Considering factors such as pH and contact time, chitin with the highest DDA displays the best sorption capacity for Fe3+ and this can be ascribed to the fact that more amino groups (RNH2) are prevalent in chitin with increasing DDA.