Biotrickling filtration is a cost-effective, efficient and environment-friendly technique for the treatment of waste gases containing low and moderate concentrations of volatile organic compounds. This paper presents the results of investigations of biotrickling filtration of air polluted with vapors of hydrophobic cyclohexane. Process performance was evaluated and controlled using an electronic nose coupled with a modified multiple linear regression (MLR) data processing algorithm. Two methods of enhancing the removal efficiency of cyclohexane were investigated i.e. partial recycling of a treated gas stream and addition of hydrophilic volatile organic compound (n-butanol) to the feed stream. The results indicate that the proposed methods positively affect the process performance, leading to an increase of removal efficiency by about 20% and 40% when recycling approach and addition of n-butanol, respectively, are considered. The study shows that the treatments used to improve the removal efficiency of cyclohexane cause an increase in its removal to 85-90%.