The research of resources reuse of scum in milk wastewater in hydrolytic acidification tank

Scum produced in the hydrolysis-acidification tank of the milk wastewater treatment process is considered to be resources based on the theory of circulating economy. Scum reuse technology method was determined through analyzing the composition of the scum and the optimal extraction method of fatty acid from scum. Suitable technical parameters of this method are the following: The application amount of acid is 3 ml/g and the HCl mass fraction is 12%. Reaction temperature is 50°C. Reaction time is 60 min. Reaction amount of mixed aether and petroleum (1:1) is 20 mL/g. Extraction efficiency and acid number are 54.3% and 215 mgKOH/g respectively. The main reuse products from scum are fatty acid, feedstuff, and fertilizer. This idea, especially corresponding method created great ecological and economic benefit.