ANAEROBIC PURIFICATION OF THE CONCENTRATED WASTE-WATER OF THE PULP AND PAPER-INDUSTRY ON A PILOT-PLANT AT THE SYKTYVKAR LUMBER COMPLEX

A pilot (semiindustrial) plant for anaerobic purification of wastewate r was constructed at the Syktyvkar Lumber Complex to develop a method for anaerobic purification of the concentrated wastewater of the pulp and paper industry and demonstrate the potentials of this method. from 1993 to 1995, we performed anaerobic purification of recycled water u sed in the production of bleached coniferous chemothermomechanical pul p; the purification was carried out in laboratory and pilot Upflow Ana erobic Sludge Blanket (UASB) reactors seeded with the sludge taken fro m the wastewater treatment plant at a paper mill in Eerbek (the Nether lands) and adapted to the effluent of chemothermomechanical pulping. T he organic loading rate (OLR) achieved in the experiments was 9 kg COD /(m(3) day) at an influent COD of 1-2.5 g/l. The effect of the OLR and wastewater composition on the activity of the sludge methanogenic mic roflora was studied.