process for the purification of waste waters rich in carbohydrates and the simultaneous production of feed with high protein content

摘要

A method for purifying waste water high in carbohydrate while obtaining therefrom a high-protein feed product. The waste water is inoculated with yeast of the type that converts starch and sugars into more yeast. The pH is adjusted to desired levels, and then the inoculated waste is circulated and recirculated in conjunction with air in amounts that enhance the growth rate of the yeast. The purified liquid waste is then separated from moist solids, and a large proportion of the moist solids is harvested as feed material, while a smaller proportion is taken for use in recycle. The proportion to be recycled is sent to a treatment zone where the pH is lowered to approximately 3.5 and where antibiotics are added, the lowering of the pH and the antibiotics both serving to suppress a substantial portion of bacterial growth while enabling the yeast to grow. After a suitable dwell time, the treated material is used in the inoculating step as the inoculant.