SOLID-LIQUID SEPARATION IN WASTE-WATER FROM A BARLEY SHOCHU DISTILLERY USING GEOTRICHUM SP M111 AND TREATMENT OF THE LIQUID COMPONENT WITH HANSENULA-ANOMALA AND ACTIVATED-SLUDGE

A method was developed for the treatment of wastewater discharged from a barley shochu distillery with yeast. First, solid-liquid separation of the distillery wastewater was effectively achieved by adding cellulose powder or residue from a citric acid fermentation process and Geotrichum sp. M111 cells, which possess the ability to accelerate the aggregation of insoluble solids in wastewater. The solid concentration was lowered to 0.33% from 2.95% by this solid-liquid separation procedure. The wastewater supernatant was a suitable medium for Mill, which showed a good yield when cultured in 2-fold-diluted supernatant (1.6 x 10(8) cells/ml medium). This yield was equivalent to that in YPD medium (1.2 x 10(8) cells/ml medium). The filtrate was treated with the waste-treatment yeast strain, Hansenula anomala J45-0, as a result of which 63% of the BOD was removed. Yeast cells remaining in the treated filtrate were digested by the yeast-lytic bacterium Rarobacter faecitabidus, which has lytic ability against strain J45-0. The wastewater treated with R. faecitabidus was diluted ca. 5-fold with tap water and subjected to activated sludge treatment. The BOD concentrations in the treated wastewater were reduced to less than 80 mg/l at volumetric BOD loading rates of 0.4-0.6g/l.d.