Biological treatment of pulp and paper mill process and wastewaters under thermophilic conditions - A review
Tutkimustuotos › › vertaisarvioitu
|Julkaisu||Paperi ja puu|
|Tila||Julkaistu - 2001|
The pulp and paper industry generates high-temperature process and wastewaters, which are normally cooled down to about 40°C or less before external biological treatment. So far, treatment at high temperature has rarely been employed in the pulp and paper industry or other industrial wastewater treatment. High temperature is generally considered to suppress the performance of activated sludge and other processes. In this paper, we review some theories and recent findings from laboratory and pilot studies on biological treatment at high temperature. Experimental studies clearly indicate that biological (anaerobic, aerobic, and anaerobic-aerobic) treatment at high temperature (50-60°C) is feasible. The thermophilic process has been shown to be stable over long periods of operation, and the process removal efficiency and loading rates are comparable to, if not higher than, those achieved in the mesophilic process. Furthermore, the thermophilic process can be readily started with sludge from a mesophilic process. Biological treatment at high temperature is thus workable and may well obviate the need to cool wastewater altogether. Further studies and full-scale implementation will disclose in detail the effects of high temperature on loading potential and excess sludge production.