Dow Offers FILMTEC Membrane Elements With Extended pH Limits For Cleaning
Development Leads to Increased Cleaning Efficiency and Improved Membrane Productivity
Midland, MI - FILMTEC membrane elements from FilmTec Corporation, a subsidiary of The Dow Chemical Company, are guaranteed to withstand a wider pH range of 1-13 for membrane cleaning solutions, leading to increased efficiency in the cleaning process, improved water treatment system performance and extended membrane life.
FILMTEC elements can be cleaned with the widest pH range in the industry, offering reverse osmosis (RO) and NF90 system owners lower cleaning costs and better system operation. Typical cleaning pH limits by other membrane manufacturers are in the range of 3.5-10, referring to limits of 2-12 as harsh cleanings.
The extended pH range of FILMTEC membranes increases the efficacy of foulant removal from the membranes and leads to longer operating time between cleanings and longer membrane lifespan. Fouling and scaling due to the presence of organic and inorganic contaminants in RO feedwater is a typical occurrence in water treatment systems.
"The pH and temperature tolerance of membrane elements are important factors in both selecting a membrane suitable for reliable long-term operation, and in determining an appropriate cleaning regimen for membranes. Both are critical choices to ensure successful RO operation," said Jon Goodman, market manager for the Americas for FILMTEC membranes. "The unique cleaning pH range of FILMTEC membranes is of value to system owners as it provides them with more cleaning options, increased flexibility in solutions, and reduced operating costs. Proper cleaning of reverse osmosis systems is essential and the characteristics of membrane elements play a role in cleaning capabilities."
The higher pH limit of 13 improves the removal of biofouling and organic fouling from the membranes, while the lower pH limit of 1 increases the efficiency of calcium carbonate removal. FilmTec Corporation's inherent design and process technology enables the membrane to withstand wider pH limits.
"FilmTec Corporation does not oxidize the membrane as part of its membrane manufacturing process. It is well known that oxidation of thin film composite membranes weakens the membrane structure, resulting in a salt passage increase during its operating life. Cleaning at aggressive pH further weakens oxidized membranes resulting in more accelerated membrane deterioration," continued Goodman. "Also, no membrane patching is applied in the FilmTec Corporation process and the element construction is robust."
Membrane patches such as tape or glue, applied by some membrane producers to cover up membrane defects, are weak spots. Operation and/or cleaning may loosen patches, resulting in salt passage increases. These factors have contributed to FILMTEC membranes having the widest cleaning pH limits in the industry.
SOURCE: The Dow Chemical Company