Recovering proteinaceous fodder from agricultural waste - in an activated sludge process with solids removal before second stage

摘要

Process or preparing proteinaceous fodder from the liquid wastes (contg. org. and/or inorg. N) from agricultural operations, opt. with addition of synthetic fertilizer to the liquid phase of a none or more-stage high-intensity activated sludge system, comprises subjecting the waste to a preliminary removal of solid pollutants or recovery of useful solid fodder materin in the first stage, then the liquid, opt. with addition of fertilizer is transfered to a second stage (alternatively the fertilizers opt. together with org. components as required, are supplied to the 2nd stage in the temporary absence of the treated liquid) where biological breakdown takes place. Excess proteinaceous sludge, is then conventionally separated, concentrated and/or thermally conditioned and/or enriched with additional essential amino acids. For processing effluent from pig farms, breweries, dairies etc. where the solid content is variable. In the case of liquid manure from pigs protein recovery is 50-80 g/day/animal. The investment and operating costs of the relatively small plant required are low.