EFFECT OF SPECIFIC WATER-CONSUMPTION IN WASTE PAPER PROCESSING PAPER-MILLS

Two anaerobic solid-bed circulation plants are being operated in waste paper processing mills. The benefit of this stage in the process depends mainly on the specific water consumption of the paper mill. The COD decomposition reaction cannot be described using solely the parameters COD mass input flow or COD space load. It does however, become possible with the aid of a material transport kinetic model. This model produces a field of characteristic curves of the COD decomposition, achieved in solid bed circulation reactors. It could be shown that by reducing the specific water consumption, it was possible to attain COD throughput with one-third of the reaction volume, which would correspond to a 100% reaction volume at high specific water consumption. Further, that the excess biomass production of the effluent cleaning plant could be almost halved by reducing the specific water consumption.