An hybrid system of combined plasma with photocatalysis for treatment of hospital indoor air. Display omitted •A possible way for treatment of air from hospitals and swimming pools is proposed.•The destruction of CVOC in air by photocatalysis and plasma and coupling is studied.•The synergistic effect of the combined system is observed.•The effects of operating parameters on the performance of each process are tested.•TiO2 + UV showed high performance in the mineralization and ozone elimination. The purpose of this study is to evaluate the efficiency of non-thermal plasma and heterogeneous photocatalysis processes for indoor air treatment using cylindrical continuous reactor at pilot scale and high flow rates. Trichloromethane (CHCl3) also called chloroform was chosen as a model pollutant representing hospital indoor air. This pollutant is considered as carcinogenic, mutagenic and reprotoxic agent. The effect of several parameters such as inlet pollutant concentrations (25–300 mg m−3), flow rates (2–8 m3 h−1), relative humidity of the effluent (5, 30, 50 and 90%) as well as input of the plasma discharge (9–21 kV) on the photodegradation of trichloromethane is investigated. Our findings show that the increase of flow rate leads to a reduction of degradation efficiency, while the humidity promotes the degradation in the case of photocatalysis process due to the formation of OH radicals. Moreover, the addition of a photocatalyst under UV radiation in the discharge zone enhances the reduction of ozone and CO gases compared to plasma process alone. The combination of plasma DBD and photocatalysis enhances the removal efficiency with a synergetic effect, leading to removal efficiency higher than 10% if we consider the sum of the contribution of each process separately.