Regenerating used kieselguhr filter medium from brewing industry

摘要

Production-integrated process for regenerating and recycling organic-contaminated kieselguhr filter medium from clear filtration in the drinks industry comprises: (a) subjecting the filter sludge obtained from the process to dispersion with the addition of: (i) 1-10 l/t solids of a mixture of nonionic surfactants, especially alkylpoly glycosides, anionic surfactants, especially fatty alcohol sulphates, in a ratio of 1:3 to 6:1, and (ii) 0.1-1 l/t solids of proteolytic enzymes, preferably Bacillus proteases; (b) treating at pH 4-12 over a period of 10-60 minutes at 4-60 deg C and a solids content of 40- 150 g/l without mechanical stress, and then after sedimentation for 10-60 minutes (c) washing and clear rinsing the kieselguhr to recover a purified kieselguhr with a loss upon ignition of only 0.4-2 wt. %.