Effect of static magnetic field on synthesis of polyhydroxyalkanoates from different short-chain fatty acids by activated sludge

The effect of static magnetic field on the production of polyhydroxyalkanoates (PHAs) from different short-chain fatty acids by activated sludge process under aerobic dynamic feeding (ADF) technique was evaluated in four sequencing batch reactors (SBRs) with static magnetic field intensity of 42 mT (SBR1), 21 mT (SBR2), 7 mT (SBR3), 0 mT (SBR4), respectively. It was demonstrated that the static magnetic exposure had definitely influenced the biosynthesis of PHAs when acetate, butyrate and propionate were fed solely or each two mixture or three substrates mixture, and the effect was dependent on field strength: the maximum poly-3-hydroxybutyrate (PHB) production occurring at 7 mT, and the minimum one at 42 mT; the maximum poly-3-hydroxyvalerate (PHV) production occurring at 21 mT, and the minimum one at 0 mT. (C) 2007 Elsevier Ltd. All rights reserved.