The core component of a household water purifier is the reverse osmosis (RO) membrane, whose lifespan and filtration efficiency directly determine the performance of the purifier. In practice, maintaining the long-term performance of RO membranes faces multiple challenges, and optimizing operating conditions and maintenance practices is essential for ensuring effective purification.
Membrane fouling is one of the main factors affecting membrane longevity. The surface of RO membranes easily accumulates bacteria, algae, and other microorganisms, forming biofilms, while colloids and organic matter in water can also deposit on the membrane surface. This buildup clogs membrane pores, impedes water passage, reduces flux, and weakens filtration efficiency. Over time, fouling can even cause localized membrane corrosion, seriously affecting membrane performance.
Insufficient pre-treatment also impacts the lifespan of RO membranes. If pre-filters such as polypropylene (PP) cotton or activated carbon have low filtration accuracy, they cannot effectively remove large particles or residual chlorine in the water. These contaminants can directly wash over the RO membrane. Large particles may scratch the membrane surface, while residual chlorine oxidizes the membrane material, accelerating aging and reducing its service life.
Improper chemical cleaning can further damage the membrane. RO membrane fouling often requires chemical cleaning to restore performance, but using incompatible cleaning agents, excessive concentrations, or overly long cleaning times can degrade membrane structure, reduce salt rejection, and even cause membrane perforation, affecting water quality.
To enhance the long-term performance of RO membranes, optimization is required across multiple aspects. In terms of pre-treatment, multi-layer composite PP cotton filters can intercept impurities of different sizes, and high-quality coconut shell activated carbon filters can effectively remove residual chlorine and organic matter. Regarding membrane material and structure, grafting hydrophilic polymers onto the membrane surface improves wettability and reduces contaminant adhesion. Optimized flow channel designs increase effective filtration area, enhance water flux, and reduce concentration polarization, thereby improving anti-fouling performance.
Chemical cleaning and routine maintenance should also follow standardized procedures. Specialized cleaning solutions should be selected based on the type of contamination, and cleaning concentration, duration, and temperature must be carefully controlled. Regular maintenance should include not only cleaning the RO membrane but also maintaining piping, pressure pumps, and other components, promptly addressing potential issues. By optimizing all these aspects, the lifespan of RO membranes can be significantly extended, ensuring household water purifiers operate efficiently over the long term.
