As worldwide concern about industrial
pollution grows, governments are imposing more rigid limits on the
discharge of effluents and are increasing the constraints on methods
of disposal. In the sugar refining industry, ion-exchange processes
result in high volumes of spent alkaline brine as effluent, and
the costs associated with disposal can be very high. It is becoming
increasingly attractive, therefore, to treat spent alkaline brine
so that it may be recycled and reused.
This project has demonstrated the feasibility
of salt recovery from ion-exchange resin generation effluents in
the sugar industry using nanofiltration ceramic membranes. The new
process is highly advanced compared to traditional recovery and
recycling processes, most of which have not been exploited commercially
due to their high cost.
This is the first time that ceramic membranes
have been used for nanofiltration, say partners, and the results
will include reduced consumption of sodium chloride and sodium hydroxide,
reduced water consumption and ultimately reduced operating and waste
treatment costs. Partners are now building an industrial-scale separation
unit based on their new technology to be installed for the first
time in a European sugar refinery. Applications in other sectors
are also being considered.