Pilot Evaluation of Single Cell Protein from Waste Activated Sludge Biomass as a Nutritional Supplement in Poultry

摘要

Large amounts of protein are destroyed from unlikely resources such as municipal biosolidsand single cell protein from waste activated sludge. Up to 95,000 metric tonne/yr couldpotentially be recovered from wastewater flows in Gauteng Province in South Africa forexample, almost the same order of magnitude of the national protein demand as animal feedsupplement. Single cell protein from wastewater sources has not been utilized because of thehigh content of toxic heavy metals and other potential carcinogenic pollutants in thewastewater streams and because of the negative public perception of using a short closed loopon human wastes. In this study, a pretreatment method, modified aqua regia dilute acid wash,was used to lower the metal content by approximately 60%. This resulted in 33% loss ofamino acids in the acid washed WAS. A feed substitution test in poultry with differentfishmeal:sludge ratios (0%, 25%, 50%, 75%, and 100%) showed no impact of sludge SCP onmortality rate. However, sludge substitution in the feed yielded weight gains and cost savingsup to 46%.