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Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/88740
- Adsorption of lignin onto amorphous aluminium hydroxide
- Cahayani, Chandrawati; Liang, Oei Ban; Lewis, David; Bowater, Ian; Harding, Ian
- Lignin adsorption onto colloidal, amorphous, aluminium hydroxide (am-AI(OH)3 was studied and found to decrease with increasing pH. Below a pH of approximately 4, lignin was insoluble and could be removed by simple precipitation. Between a pH of approximately 4 and approximately 7, lignin could be removed by adsorption or coprecipitation with amAI( OH)3. Above approximately pH 7, lignin was difficult to remove even in the presence of am-AI(OH)3 unless an excessive amount of substrate was used. Adsorption was found to be highly dependent on the induction time (i.e. the amount of time the lignin was in contact with the am-AI(OH)3 prior to analysis), and on the concentration of am-AI(OHh used). It is argued that adsorption efficiency is an important parameter to measure. When the concentration of colloid was increased, the percentage removal increased, leading to the assumption that 'more is better' and demonstrating that a higher concentration of colloid is more effective. However the adsorption efficiency (amount removed per gram of colloid) often decreased showing that the use of. increased concentration of colloid is not necessarily economical. A balance between the two parameters (effectiveness and efficiency) needs to be reached. Evidence was found that lignin is able to 'strip' aluminium from its hydroxide precipitate to form a lignin-aluminium complex. This complex may, or may not, be soluble depending on its molecular weight. The implications of such complexes to both adsorption and adsorbing colloid flotation are discussed.
- Publication type
- Book chapter
- Research centre
- Swinburne University of Technology. Faculty of Life and Social Sciences. Environment and Biotechnology Centre
- Water quality and waste treatment / Ian H. Harding and Marylou Molphy (eds.), Chapter 2.1, pp. 59-65
- Publication year
- Adsorption; Aluminium hydroxide; am-AI(OH)3; Lignin; Precipitation
- Environmental and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology
- Publisher URL
- Copyright © 2007 Swinburne University of Technology.
- Additional information
- This book contains research articles resulting from the Australian-Indonesian Environmental Science Project.
- Peer reviewed