Ways to reduce fouling of separation membranes and increase the performance of membrane apparatus (a review)

Summary

The widespread use of membrane technologies in the energy sector in water purification processes, wastewater treatment and other areas poses questions of their improvement in order to increase the economic efficiency, performance of membrane separation apparatus, reduce the amount of secondary waste, etc. Potentials are being sought to improve these indicators. Moreover, if the highest level has currently been reached in the development and production of membranes, and no further dramatic improvements are visible so far, then in relation to the design it is believed that there are still potentials. The paper discusses options for increasing the efficiency of membrane separation apparatus by means of the external effects on the processed water or on the membrane apparatus. This is the pulsation of the liquid flow, ultrasonic impact on it, rotation of special inserts or the membranes themselves, vibrations of the membrane element. The complexity of their design and the prospects of application for different stages of purification and concentration processes are estimated.

Key words

membrane module , membrane technology , concentration polarization , reverse osmosis and nanofiltration plants , separating diaphragms , LF oscillations , ultrasonic waves , rotation , membrane vibrations , Roсhem apparatus , New Logic Research , VSEP system

Pilot tests of VSEP technology to minimize the amount
of reverse osmosis concentrate

Summary

The results of pilot tests of the VSEP vibromembrane liquid separation technology for concentrating wastewater with high salinity from an industrial reverse osmosis plant are presented. VSEP technology provides for achieving high filtrate yields from salty wastewater eliminating pre-treatment and the use of antiscalants. As a result of membrane separation, demineralized water (filtrate) is obtained, that can be reused in the production cycle, as well as a highly concentrated solution of salts (concentrate), that also includes insoluble sludge. The tests were carried out at an industrial facility using a pilot plant of the VSEP Auto-LP series using reverse osmosis membranes. Procedures for choosing the brand of a polymer membrane and determining the optimal operating pressure were carried out. The experimental data on wastewater concentration cycles are presented to determine the conditions for the stability of the separation process and the duration of the installation flushing interval. The test results provide for designing an industrial wastewater return system for reuse.

Key words

reverse osmosis , pilot tests , membrane separation , VSEP technology , concentration polarization , reverse osmosis membrane

Vibromembrane filtration technology: eliminating the negative effect of concentration polarization (international experience)

Summary

Представлена уникальная технология мембранного разделения жидкостей VSEP, которая позволяет минимизировать негативное влияние концентрационной поляризации. Отличие технологии заключается в вибрации поверхности мембран. В результате достигается ряд ключевых преимуществ технологии. Все это существенно раздвигает границы использования мембранных методов и делает возможным применение мембран там, где ранее это было невозможно. Кроме того, процесс разделения различных жидкостей не требует использования антискалянтов, а рабочие значения удельной производительности установок и выхода фильтрата значительно превышают таковые в традиционных системах мембранного разделения. Технология уже находит массовое применение в мировой инженерной практике для самых различных отраслей промышленности.

Key words

membranes , nanofiltration , membrane filtration , VSEP technology , concentration polarization