Membrane distillation process application using a novel ceramic membrane for Brackish water desalination

Membrane distillation (MD) is a useful technology for water desalination possible at low temperatures using inexpensive membranes offering high salt rejection. Therefore, in the present study, economically and ecofriendly Saudi red clay, tetraethyl orthosilicate, ammonia, and sodium alginate powder as a binder were used to fabricate a ceramic membrane for membrane distillation using an extrusion technique. The prepared membrane was tested using a vacuum membrane distillation (VMD) process and showed promising permeate flux and salt rejection results. The membrane was characterised by SEM, mechanical testing, contact angle, pore size distribution analysis, and VMD tests were performed using deionized water, magnesium sulphate solution, sodium chloride solutions, and hot raw well water. An average flux of 13.10 kg/(m(2).h) with 98.96% rejection was obtained using raw well water. During continuous well water desalination tests, the membrane exhibited a stable performance for 4 h. The average flux decreased by 16.5% after 10 h, possibly owing to fouling because of salts and suspended solids. The membrane performance was recovered after the salt water tests by applying a known cleaning procedure.

Automated summary

In this study, a ceramic membrane for membrane distillation was fabricated using Saudi red clay, tetraethyl orthosilicate, ammonia, and sodium alginate powder, showing promising results in terms of permeate flux and salt rejection in VMD tests. The membrane exhibited stable performance for 4 hours in continuous well water desalination tests, with a 16.5% decrease in flux after 10 hours which was recovered by a known cleaning procedure.