Title: Synthesis and characterisation of new cationic polyelectrolytes by inverse emulsion polymerisation and their application in activated sludge dewatering

Authors: Jia Jun Fu, Bo Jiang, Wei Min Cai

Addresses: School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China. ' School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China. ' School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China

Abstract: Water soluble hydrophobically associated polyelectrolytes were copolymerised with dimethyl- [2-(2-methyl-acryloyloxy)-ethyl]-alkyl ammonium bromide (alkyl: propyl, hexyl, dodecyl) (DEACn) and acrylamide (AM) in inverse emulsion. Cationic hydrophobically modified polyacrylamides having different molecule weight and cationic degree were obtained by varying the total monomer concentration and DEACn/AM mole ratio. Polyelectrolytes were characterised by 1H-NMR and 13C-NMR. The dewatering indexes, such as CST, settling rate and water content in sludge cake were investigated and used to evaluate the dewaterability and settleability of activated sludge conditioned by these polyelectrolytes. Afterwards, some characteristics of sludge floc, such as: floc size, sludge viscosity and floc strength were measured. The function of hydrophobic association in sludge conditioning was elucidated by comparing dewatering performances with these polyelectrolytes

Keywords: hydrophobically associated polyelectrolytes; inverse emulsion; activated sludge; dewaterability; settleability; polymerisation; cationic polyacrylamides.

DOI: 10.1504/IJEP.2009.027272

International Journal of Environment and Pollution, 2009 Vol.38 No.4, pp.397 - 414

Published online: 19 Jul 2009 *

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