In this study, the aqueous phases obtained from thermochemical treatment of SEKA solid waste with 15% acetic acid at 250-degrees-C, 300-degrees-C, and 350-degrees-C starting with 0.1 MPa initial pressure have been digested anaerobically. The anaerobic digestion has been carried out at 37-degrees-C in lab-scale fermenters for about 24 days. During digestion, samples were taken out at 3-day intervals and analyzed for the determination of the COD, BOD5, and pH values. The total amount of biogas produced was also determined. It was found that the COD decreases and BOD5 increases as a whole with digestion time. It can be concluded that the aqueous phases can be treated anaerobically for both biogas production and organic pollutant removal.