Desalination by vacuum membrane distillation: The role of cleaning on the permeate conductivity

In this work, desalination tests were carried out by vacuum membrane distillation, with the aim of investigating the purity (in terms of conductivity) of the produced permeate. Consecutive experiments, with and without cleaning in between, were made on lab-prepared modules equipped with commercial capillary polypropylene membranes. In particular, byworking at fixed operating conditions (feed flowrate and composition, temperature and vacuumpressure) the effects of a partial and of a total cleaning procedure on the permeate conductivitywere analyzed and compared. Depending on the used approach, pure water or high-purity water can be obtained as permeate.