This study describes an approach to improve an industrial scale biofilter as biological waste air cleaning plant for the treatment of VOC emissions created by dip spin coating of metallic components. The compounds in the waste air with equal ratios are mainly the hydrophilic methoxypropyl acetate and lipophilic xylene isomers. After a pilot-scale biofilter proved inefficient due to efficiencies lower than 20 %, the proposed solution was a combination of a bioscrubber and a downstream biotrickling filter. The system was stable and maintained a long term removal efficiency of 75 %.