Alkaline hydrolysate of waste sheep wool aimed as fertilizer

Abstract

Suitable conditions were found for hydrolysis of sheep wool by a mixture of potassium hydroxide and some quantities of sodium hydroxide at elevated temperature (120° C) and pressure (2.03 atm). Because of the severe hydrolysis conditions (pH about 12 and high temperature) it is believed that the causes of some related diseases like “mad cow”, “swine fever”, bovine spongiform encephalopaty, Creutzfeldt-Jakob disease, that are called prions, and are proteins will be destroyed. The hydrolysate obtained is neutralized by orto-phosphoric acid. Beside organic nitrogen, the obtained hydrolysate contains also potassium and phosphate ions and threfore it is proposed this product to be used as fertilizer in the agriculture. Data are supplied showing the positive effect on rye-grass when the soil was additionally enriched with the new fertilizer. The alkaline hydrolysate contains about 75–80 water-soluble materials—peptides, amino acids, salts, dyes, lipids and some carbohydrates. The remaining part consists of insoluble partly degraded keratin. The latter is highly dispersed and therefore it is believed that it will be degraded by the soil microorganisms for relatively short time, thus feeding the plants additionally. The authors hope that if this way of utilization of the keratin wastes is used the environment around the leather and fur plants will be influenced positively and that the expenses for carrying away the wastes to controlled dung-hills and part of the expenses for sustaining the latter will be safed. © 2003 Taylor and Francis Group, LLC.