The processing of organic waste from vegetable and animal fat production

This paper presents a method of the after-production residues processing, i.e. the liquid waste and wastewater from secondary treatment of the by-product and waste vegetable fats as well as from the so called inedible products of animal origin and low risk materials of the third category. The hydrated waste is mixed in the precisely defined proportions and chemically treated with the use of orthophosphoric acid and burnt lime. Next, the product is separated and ripened to become a technical material of fertilizing qualities. A significant advantage of the method is a possibility to regulate the content of the preparation which is a mixture of calcium phosphates, calcium and ammonia phosphates, calcium sulfate, protein and organic fractions and calcium salts of fatty acids of (RCOO)2Ca type (where R: C16H33, C18H37, C18H35, C18H33, C18H31, C22H43). The developed method was tested on the pilot installation of the efficiency up to 25.0 m3 d-1 and consisting of such elements as: aerobic, storage-averaging tanks, a flotator, a reactor, centrifuges for separating protein-fatty fractions and a fertilizer. The solution permits a significant pretreatment of the wastewater so that it can be further treated with biological methods.