These elements are designed for reverse osmosis, a separation process that uses pressure to force pure water through a membrane. Fill tank with clean water and flush system to drain for 10 to 15 minutes. Membrane cleaning reverse osmosis filtration complete. More detailed procedures for cleaning a reverse osmosis ro system are typically included in the operating manual provided by the system supplier. A semipermeable ro membrane, under sufficient pressure, allows passage of. In general, remove biological growth and colloidal silt first using surfactants. Proper operation and maintenance of reverse osmosis ro system is key factors in maximizing longterm plant availability and efficiency, and minimizing fault. Because of the site specific nature of large ro systems, there is not a typical range of potential energy, water, and cost savings from system optimization. From small scale systems, through to very large scale desalination, ro and nf can handle most naturally occurring sources of brackish and seawaters. Then fill the wash tank with the desired amount of permeate to wash with. Influence of feed water organic composition on cleaning of organic fouled ro membranes.
Removing biofilm from membranes a practical approach. Mix chemicals in clean, high purity water, such as demineralized water, ro permeate water, or. Permasep b10 technical information manual, section iv projections, e. Chemical cleaning of organicfouled reverse osmosis membranes. Filmtec reverse osmosis ro and nanofiltration nf membrane technologies are widely recognized to offer highly effective and economical process options. Many ro systems have clean inplace cip equipment installed as an integral part of the system. Pdf the aim of this research was to establish a rationale for the. One essential maintenance step is cleaning a systems ro membrane, which is a reasonable alternative to costintensive replacements.
Smaller ro applications may contract to have a cip performed on an asneeded basis. One cannot forget that heat is generated and imparted by the ro cleaning pump. All reverse osmosis membranes will require periodic cleaning due to fouling andor scaling of the ro membrane that occurs over time as the membrane continues to reject impurities from the feed water. Please flush the membrane more than 2 hours after the process. Procedure details may differ depending on the system design. Mix chemicals in clean, high purity water, such as demineralized water, ro permeate water, or condensate. The cleaning procedure of a reverse osmosis system consists of the following process steps. Chemical cleaning of organicfouled reverse osmosis. This is why ro systems produce both clean drinking water and waste water that is flushed from the system. It is designed with the flexibility to closely match your treatment requirements from 3. Draft standard operating procedure ultrafiltration and reverse osmosis. The result is higher operating pressures, higher operating costs, less output and poorer quality. Acidic groups on the membrane molecule will dissociate at high ph and result in a more hydrophilic membrane. More detailed procedures for cleaning a reverse osmosis ro.
Implications for accreditation in water recycling amos branch 1, trang trinh 1, ben zhou 1, greg leslie 1, pierre leclech 1, 1. Pdf chemical cleaning of reverse osmosis membrane fouled by. The culligan g2 and g2 plus reverse osmosis system is a painted steel skidded system sized to serve many mediumsized applications that require highquality reverse osmosis water. Use of a clean inplace pump is reccommended for both cleaning and sanitizing procedures. Follow the membrane manufacturers recommended cleaning procedure.
An appropriate conditioning procedure consists of the following. A semipermeable membrane ro membrane is placed between two compartments. Complete water solutions provides offsite membrane cleaning services. Rinse the system until the concentrate ph is almost the same as the clean water ph.
This will prevent contamination of the cleaning solution with loose foulants and large suspended solids. Sanitation procedures for reverse osmosis systems with standard housings. Filmtec reverse osmosis ro and nanofiltration nf membrane technologies are widely recognized to offer the most effective and economical process options currently available. Reverse osmosis ro membrane cleaning ro membrane cleaning membranes lie at the heart of any reverse opsmiosis system, it is therefore essential that the membranes are maintained in a good clean condition and this should be considered to be an important part. Cleaning at low pressure is necessary to limit the production of permeate, so only concentrate is produced which maximizes the sweeping effect. Unesco centre for membrane science and technology, the university of new south. The plant achieved up to 99% removal of pollutants along the treatment stages by. Ro permeate is preferred, but prefiltered feed water may be used. Its a good idea to do complete the sanitization process during filter changes since most filters are replaced every 12 months.
In addition differences in ro system design, operating procedures and the ability of microorganisms to adapt and multiply successfully in membrane. Normally 5 to 10micron and is designed to remove foulants that have been displaced from the cleaning process. The users guide to reverse osmosis systems, this may be old information, but following are some practical suggestions for effective membrane cleaning from our friends at avista technologies. This may aid in membrane cleaning, depending upon the chemical nature of the fouling substance. Dispose of the cleaning solution after adjusting the ph per local regulations. The uf membrane used on the system are an outsidein configuration where the feed. For those of you who attended our training seminars, good to the last drop. In cases where the high pressure pump is used during cleaning, the cleaning procedure is less effective. During a chemical cleaning process, membranes are soaked with a solution of chlorine bleach, hydrochloric acid or hydrogen peroxide.
Theory of reverse osmosis membrane the phenomenon of osmosis is illustrated in the figure below. It should be emphasized that frequent cleaning is not required for a properly designed and properly operated ro system however, because of the ft30 membrane s distinct combination of ph range and. Ro membranes are generally cleaned separately at low and high ph, depending on the type of foulant on the membrane. Typical cip procedure here are steps normally associated. A balance of costs over the last two decades, reverse osmosis ro has become the process of choice for removing dissolved salts and other contaminants from a variety of water sources, including seawater, groundwater and wastewater effluents. Production of the cleaning fluid the fluids that are used for the cleaning process need to be of a certain ph and all chemicals must be dissolved and mixed before the cleaning fluid is added in the membrane. An ro membrane is consisted of a supporting layer with 50. First the solution soaks into the membranes for a number of minutes and after that a forward flush or backward flush is applied, causing the contaminants to be rinsed out. Check the solution with your ph strips or a digital ph meter.
The optimal temperature for cleaning is 35 to 45 o c. Performing an ro membrane cleaning when performing a cleaning, the first 20% of the cleaning solution is flushed through the membranes directly to drain, instead of circulating. Industrial ro membrane cleaning complete water solutions. Reduce reverse osmosis membrane fouling with good cip. Here you will find a collection of excellent technical documents written to help those involved with the operation and maintenance of ro systems. In the case of reverse osmosis ro membranes, a high ph cleaning solution will alter the membrane itself. In normal operation, the membrane in reverse osmosis membrane elements can become fouled by suspended solids, microorganisms and mineral scale. We provide technical assistance with membrane cleaning, either onsite using the customers clean inplace cip skid or by removing and returning the membranes to one of our membrane cleaning facilities. Ro fouling components metal oxides iron manganese aluminum scaling salts calcium carbonate calcium sulfate barium. Place the refill valve selector switch in the auto position. Cleaning procedures for filmtec ft30 elements tech manual. Cleaning procedures for am22 thin film composite ro membrane alkaline. Flush to drain with suitable quality water at low pressure and low permeate flow rate. Membrane cleaning requires knowledge of when and how you have to clean and what chemicals you have to use.
O chemical cleaning procedure free download as word doc. Install new cartridge filters on the cip system and make sure that the piping is clean, with no stagnant wa ter from previous cleanings and no microbiological buildup. The surface of ultrafiltration uf membranes is subject to the build up fouling of foreign materials present in feed water, such as suspended solids, colloids, organics and biological matter. Filmtecreverse osmosis ro and nanofiltration nf elements are water and other liquids purification products manufactured by filmtec corporation, a subsidiary of the dow chemical company dow. From smallscale systems, through to very largescale desalination, ro and nf can handle most naturally occurring sources of brackish and seawaters. Diy installation guide to ispring whole house water system and how to connect duration. Operation and maintenance manual uf6hf ultrafiltration system conserv manufacturing 805 west brannen road lakeland, fl 338. O chemical cleaning procedure membrane technology filtration.
More effective and efficient cleaning of biofilm, organic compounds and scale, achieved through the widest ph range in cleaning ph 1, made possible by the most advanced dow filmtec ro membrane sheet available today up to 10% energy savings at the same water productivity. A typical cip for polyamide membranes is outlined below. The subjects addressed in this chapter should serve as the basic foundation for a broader understanding of ro and nf processes as applied to potable water, industrial process water, tertiary. Instruction membrane cleaning of rosystem with the isave unit. When planning a membrane cleaning, it is important to consider the order in which the required cleaners should be used. The procedure of ro membrane chemical cleaning is similar to that for ro system flushing, except that the cleaning chemicals must be removed by flushing the ro system with pretreated raw water for 12 hour. Opportunities to reduce ro system operating costs by. A reverse osmosis system should be sanitized once each year.
1033 1440 1157 1340 1361 497 902 1008 265 1138 883 715 784 1104 458 446 1250 911 976 440 1358 559 918 1184 534 127 666 1040 1373 1241 1233 1233 1220 666 1407 324 1178 687 257 190 85 438 6 1106 342