Evaluation of Cleaning Spiral Wound Membrane Elements with Two-Phase Flow Process. Desalination and Water Purification Research and Development Program Report No. 101

摘要

A protocol to achieve the cleaning of 8-inch spiral elements using the Novaflux two-phase flow patented method has been established and validated. The technology has demonstrated capability of significantly improving the flux of 8-inch spiral elements, and decreasing pressure drop between the two ends of the modules to acceptable levels. In addition, the two-phase flow process was systematically validated for cleaning 2.5-inch and 4-inch spiral elements in series using a short 10-minute cycle. The main objective of this program was to define the operating parameters and to validate the cleaning of RO spiral elements using the two-phase flow process invented by Novaflux Technologies. The potential benefits of the Novaflux Process are: (i) rapid and efficient membrane cleaning, (ii) low-pressure drop of elements connected in series, (iii) high flux and output levels, (iv) minimal discharge of cleaning chemicals, and (v) low consumption of water needed for membrane cleaning operations. If the two-phase cleaning process is applied at an optimized frequency, the average flux can be maintained at significantly higher levels compared to current membrane cleaning practice. Notably, due to the ability of the Novaflux two-phase process to quickly and effectively clean RO elements in a short time, it appears possible to extend the reverse osmosis separation/treatment step to applications deemed impossible in the past.