A novel system for continuous monitoring of salt rejection characteristics of individual membrane elements in desalination plants

Abstract

Abstract A novel integrated system is presented that permits remotely continuous monitoring of the rejection characteristics of spiral wound elements in desalination plants. The system is comprised of multi-sensor probes installed inside the permeate collection tube of each pressure vessel, and of special electronic hardware and computer software for signal processing and wireless transmission to a central control station. With this system, it is possible to monitor in detail an entire multi-vessel desalination plant and, in particular, to identify poorly performing or defective individual membrane elements, which degrade the permeate quality. For this purpose, a protocol was developed, which enables identification of problematic elements in an operating plant, by interpreting through the system software the monitored permeate conductivity and temperature from each vessel. Laboratory pilot testing of the multi-sensor monitoring system is outlined herewith, including the satisfactory results obtained under conditions simulating brackish water desalination. Other attractive features of the novel system include miniaturization of electronic hardware, ease of servicing and no interference with the usual plant operation. This system is considered essential for monitoring, thereby improving the performance and management of modern large and medium-size desalination plants.