A laboratory-scale biotrickling filter combined with a magnetic field (MF-BTF) and a single BTF (S-BTF) were set up to treat trichloroethylene (TCE) gas. The influences of phenol alone and NaAc-phenol as co-substrates and different MF intensities were investigated. At low MF intensity, MF-BTF displayed better performance with 0.20 g/L of phenol, 53.6-337.1 mg/m(3) of TCE, and empty bed residence times of 202.5 s. The performances followed the order MF-BTF (60.0 mT) > MF-BTF (30.0 mT) > S-BTF (0 mT) > MF-BTF (130.0 mT), and the removal efficiencies (REs) and maximum elimination capacities (ECs) corresponded to: 92.2%-45.5%, 2656.8 mg/m(3)h; 89.8%-37.2%, 2169.1 mg/m(3)h; 89.8%-29.8%, 1967.7 mg/m(3)h; 76.0%-20.8%, 1697.1 mg/m(3)h, respectively. High-throughput sequencing indicated that the bacterial diversity was lower, whereas the relative abundances of Acinetobacter, Chryseobacterium, and Acidovorax were higher in MF-BTF. Results confirmed that a proper MF could improve TCE removal performance in BTF. (C) 2017 Elsevier Ltd. All rights reserved.