Zero Effluent by Application of Biological Treatment at High Temperature
For the production of high quality corrugated medium and test liner it has been shown since 1995 at a new large size mill in Germany, that no or practically no effluent discharge is necessary when the process water is treated in an anaerobic/aerobic conventional treatment plant, which is followed by sand filtration. In this paper, three different projects are described which show, that the number of process steps can be reduced in order to make the process more simple and compact. The first modification is, that thermo tolerant bacteria are cultivated and utilized for the treatment process and thus, previous cooling is not required anymore. Another improvement in comparison with the German mill is, that all reactor tanks are constructed in the form of vertical tanks with a small footprint and a third new view is, that not all produced effluents need to be of the same high quality standard. Besides further resource conservation and waste minimisation these improvements lead to an economically attractive process for the production of non de-inked recycle grades.