Comparative evaluation of three different membranes for the treatment of a brewery and a dairy treatment effluent

A laboratory-scale system with a capacity of 7L/h consisting of three different ultrafiltration membranes operating alternatively, was designed and installed at the Sanitary Engineering Laboratory (SEL) facilities. The purpose of this membrane system was to test the performance of alternative membranes in terms of secondary effluent treatment from a dairy and a brewery industry located in Patras industrial area. The three membranes selected after a literature review were a PVDF UF tubular membrane module, a ceramic UF tubular membrane module and a polysulfone HF UF tubular membrane module. The batch experiment protocol followed for each membrane consisted of a chemical cleaning procedure and a 5-hour continuous operation with secondary effluent from the two industries. The laboratory results showed that the permeate water complies with the limits set by Greek legislation for unrestricted irrigation. The PVDF membrane showed the best membrane performance in terms of effluent quality with better results in organic load removal. It also showed higher stability with very low standard deviation values. In terms of TMP increase and effluent drop during the 5-hour batch trials, the ceramic membranes showed lower values, while the PVDF membranes were more stable after the first hour of the trial and showed a very low increase for the rest of the trial.