Chemical cleaning membrane

Figure 6.16 Effect of chemical membrane cleaning membrane cleaning with (a) single solution and (b) two different reagents (Jq, pure water flux before chemical cleaning Ji, pure water flux after chemical cleaning). (Adapted from Kimura et al., 2(X)4.)...

Keywords Additional discharge streams Antisealants Chemical treatment Coagulation/flocculation Concentration factor Dechlorination Filtration High recovery Membrane cleaning Pretreatment Recovery rate... 

The majority of the discharge from a desalination processes is concentrated brine from the membrane process, and this may contain quantities of treatment chemicals used. Treatment of water is necessary in all desalination plans for variety of reasons feed water treatment, membrane protection, membrane cleaning, permeate treatment and concentrate treatment prior to discharge. Although non-chemical treatment is possible, chemical treatment is widely practiced. 

Chapter 13.2 discussed techniques and chemicals used for cleaning of RO membranes. This section discusses the merits of on-site verses off-site membrane cleaning. Table 15.4 summarizes the advantages and limitations of on-site and off-site membrane cleaning. 

Expert service More effective cleanings Documented results Higher cost Requires second set of membranes Membranes cleaned in situ—no need for replacement membranes Faster cleaning Less expensive Less efficient Capital outlay for cleaning skid Storage and handling of chemicals and waste... 

The techniques and chemicals described in Chapter 13.2 apply directly to on-site or Clean-In-Place (CIP) membrane cleaning. 

This is because the entire tank containing the submerged membrane cartridge must be filled with chemical to clean the membranes (note that spacers are used to occupy space to minimize this factor). 

The issue of chemical resistance Is relevant not only during applications but also in membrane cleaning procedures which often specify strong acids and bases and sometimes peroxides. Moreover, nonoxidc ceramic membrane materials are prone to reaction upon extended exposure to oxidizing environments. 

Membrane Cleaning Using Chemical Agents and Back Pulsing.337... 

Membrane cleaning involves the removal of a substance that is not an integral part of the membrane material [176]. The process must remove fouling deposits and must restore the normal capacity and separation characteristics of the equipment [175]. The cleaning process is usually divided into two main steps rinsing and chemical cleaning. 

Chemicals Commonly Used in Membrane Cleaning and Their Cleaning Actions... 

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