Abstract The aim of this study is to prove technical feasibility of combined refuse derived fuel (RDF) torrefaction and oily wastewater treatment approach by using RDF derived biochar as a sorption media. Biochars prepared from refuse derived fuels in torrefaction, carbonization and pyrolysis modes were analysed as fuels and as hydrocarbon sorbents. Changes of elemental composition and properties of material during thermal treatment and subsequent washing process have been analysed. Experimental evaluation of sorption behaviour of toluene and diesel fuel on obtained biochar performed. Our results show that torrefaction/carbonization of RDF coupled with the subsequent washing of biochar is a method allowing to overcome absolute majority of the quality problems of waste derived fuels, including the most important one: high chlorine content. In spite the fact that optimal temperatures for upgrading waste derived fuels and to produce high quality sorbent does not coincide, technically it is possible to combine the washing of torrefied/carbonized waste derived fuels with the treatment of wastewaters that are polluted with oils or hydrocarbons.