Recovery of organic components from dairy effluents - Part 2: Investigations about the possibilities on reutilizing protein sludges

According to a previously described procedure proteins from model skimmilk effluents were isolated. In a pilot plant, well sedimented sludges were obt ained by precipitation, combining a cationic polymer with a clay mineral. A fter adjustment at different pH values (4, 7, 10), the sludges were mixed w ith wood fibres and processed by drying (65 degrees C and 105 degrees C) to samplers the mechanic properties of which were investigated later on. The use of protein sludges as binding agents for wood fibres allows the pro duction of fibre materials with a large pore volume and a satisfactory brea king strength and hardness. Firmness and fire properties are improved by th e sludge proportion in the moulding material. At lowering the pH value of t he moulding material the firmness increases whereas it decreases at higher drying temperatures. By using longer fibres as an additive to the moulding material, it is possible to further improve its mechanic properties. Thus t he use of the investigated materials may be of interest for insulation purp oses.