Constructed wetlands (CWs) are already applied to treat different kinds of wastewater, they are proved to be an alternative under distinctive conditions to traditional water treatment technologies concerning energy consumption. However, the treatment of water contaminated by volatile organic compounds (VOCs) was very limited. The aim of this work was to characterize and optimize the treatment process of water contaminated by VOCs in CWs. New variants of CWs - floating plant root mat (FPRM) and plant root mat filter (PRMF) were tested to treat benzene, methyl tert-butyl ether (MTBE) and chlorinated hydrocarbons in pilot scale. The FPRM showed similar treatment efficiencies as the planted CW for benzene but better for MTBE. Volatilization played an important role in MTBE removal in a new established FPRM. However, it decreased with the age of the root mat. In conclusion, PRMF and FPRM as variants of CWs without soil could be a cost competitive alternative for wastewater treatment.