Abstract
Treatabilities of food-processing industrial wastewater containing raw starch were experimentally investigated in batch and continuous cultures with Aspergillus niger pellets.
In batch culture using wastewater of 10, 000 mg-TOC/l containing in raw starch of 25 g/l, the removal efficiencies of starch and TOC reached 90% and 44% for 10 days, respectively. An important information from practical point of view was that starch granules were rapidly incorporated into the pellet inside with growth of pellets. It can be assumed that high removal efficiency of starch is closely related to this incorporation.
In continuous culture using wastewater of 1, 000 mg-TOC/l containing raw starch of 1.25 g/l and soluble starch of 1.25 g/l, the removal efficiency of starch was held at over 77% during experimental period of 28 days by replacing the grown pellets with new ones.
By use of multi-stage reactor with fungal and activated sludge processes, the removal efficiencies of total sugar and TOC in the food-processing industrial wastewater containing raw starch were held at 100%and over 86%, respectively. This result clearly shows that the actual industrial wastewater can be effectively treated in multi-stage process with Aspergillus niger pellets and activated sludge.
