Mechanisms of Cr(VI) removal from water by various types of activated carbons

✍ Scribed by C Selomulya; V Meeyoo; R Amal

• Publisher: Wiley (John Wiley & Sons)
• Year: 1999
• Tongue: English
• Weight: 238 KB
• Volume: 74
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(199902)74:2<111::aid-jctb990>3.0.co;2-d

✦ Synopsis

The removal mechanisms of Cr(VI) from water using diþ erent types of activated carbons, produced from coconut shell, wood and dust coal, were investigated in this project. Diþ erent types of activated carbons have diþ erent surface characteristics. The coconut shell and dust coal activated carbons have protonated hydroxyl groups on the surface (H-type carbons), while the surface of the wood-based activated carbon has ionised hydroxyl groups (L-type carbons). The adsorption kinetics of chromium onto the activated carbons at pH values ranging from 2 to 6 were investigated. It was found that the optimum pH to remove total chromium was 2 for wood-based activated carbon, while for coconut shell and dust coal activated carbons, the optimum pH was around 3-4. The diþ erence in the optimum pH for diþ erent activated carbons to remove Cr(VI) from water can be explained by the diþ erent surface characteristics and capacity of the activated carbons to reduce Cr(VI) to Cr(III).