In the long-term operation of industrial water purification and pure water preparation scenarios, many industrial and mining enterprises and electronics processing companies in Shaanxi Province encounter the thorny problem of continuously declining desalination rates and substandard effluent water quality in their RO reverse osmosis equipment. Desalination rate is a core indicator directly determining the operational health of water purification equipment. Once the value continues to decline, it will directly breach the threshold for qualified production water, and in severe cases, it may even force the entire production line to shut down. Xi'an DIEN Water Treatment has been deeply involved in the treatment of high-hardness water in Northwest China for over ten years. Based on firsthand fault records from nearly a thousand local projects, they have identified specific core causes, targeted maintenance solutions, and refined daily maintenance techniques tailored to local operating conditions to address the common problem of declining desalination rates. This helps companies quickly pinpoint the root cause of the fault and restore stable water purification performance.
RO Reverse Osmosis Equipment
The core causes of declining desalination rates in Northwest China can be precisely categorized into four main types. The first type is irreversible damage to the core membrane element. As the core water purification component of the equipment, the reverse osmosis membrane, when exposed to high-hardness well water for extended periods, will experience oxidation, fouling, and physical damage, which is the primary cause of a sharp drop in desalination rate. The second type is complete failure of the pretreatment system. Expired filter cartridges and caking of activated carbon media in quartz sand filters prevent the effective interception of silt, colloids, and heavy metal impurities. Untreated raw water directly flushes the membrane element, causing rapid fouling and clogging. The third type is long-term deviation of operating parameters from the rated range. Insufficient inlet water pressure, excessively low inlet water temperature in winter, and blindly exceeding wastewater recovery rates directly disrupt the equipment's operational balance, significantly reducing filtration and desalination efficiency. The fourth type is improper daily maintenance. Overdosing on scale inhibitors and other chemicals, or failing to clean membrane elements for more than six months, will cause stubborn scaling and excessive microbial growth on the membrane surface, directly impairing the equipment's desalination performance.
Targeted repair and refined maintenance methods can achieve low-cost repair for these faults. In the troubleshooting process, the operating status of each membrane element is checked individually. Membrane modules with minor fouling are subjected to targeted professional chemical cleaning. Membrane modules with physical damage or irreversible performance degradation are replaced immediately. The entire pretreatment filter cartridge is replaced, and the caked filter media inside the filter tank is thoroughly flushed to fully restore the purification and interception capacity of the pretreatment section. The entire equipment's operating parameters are recalibrated, and the inlet water pressure, inlet water temperature, and concentrate discharge ratio are precisely adjusted to perfectly match the actual on-site water usage conditions. For routine maintenance, the RO reverse osmosis equipment undergoes regular automatic flushing. After long-term shutdowns, residual water in the membrane housing is promptly drained. Chemicals are precisely proportioned according to real-time water quality monitoring data to avoid overdosing and causing scale buildup. A dedicated equipment inspection log is established to proactively identify all potential hidden faults.
A precision electronics processing plant in Xi'an experienced a typical fault like this: after two years of operation, the desalination rate of the equipment dropped from an initial 98% to 92%, and the pure water resistivity completely failed to meet standards, severely impacting the production yield of precision components. After a thorough on-site inspection by DIEN's technicians, the underlying fault was precisely identified: the pretreatment filter cartridge had not been replaced for eight months, leading to impurity buildup and a large amount of calcium scale adhering to the membrane surface. Simultaneously, the equipment's operating parameters had been consistently mismatched.
RO Reverse Osmosis Equipment
We customized a comprehensive rectification plan for the client: replacing the entire set of gradient pretreatment precision filter cartridges; using a specialized composite cleaning agent for closed-loop cleaning of the reverse osmosis membrane to thoroughly remove scale and microbial contaminants from the membrane surface; recalibrating the equipment's inlet water pressure and concentrate discharge ratio; optimizing the precise dosing of chemicals; and providing comprehensive practical training for the company's maintenance personnel, along with a customized quarterly maintenance plan.
After the rectification, the equipment's desalination rate quickly recovered to the rated standard value of 98.5%, and the effluent water quality has remained stable and compliant without fluctuations. Customer feedback: "Previously, the water quality fluctuated wildly, and multiple self-inspections failed to pinpoint the root cause. After contacting DIEN Water Treatment for on-site repair, the equipment completely returned to normal. Their subsequent regular maintenance guidance was also very professional, significantly improving equipment operating efficiency and completely solving our production water problem."
In general, a decrease in the desalination rate of RO reverse osmosis equipment is mostly due to improper operation and maintenance or localized aging of components; there is absolutely no need to blindly replace the entire unit. Xi'an DIEN Water Treatment specializes in the repair, maintenance, and upgrade services of various water treatment equipment. Targeting the high-hardness water characteristics of Northwest China, we provide on-site inspection, rapid fault repair, and customized full-cycle maintenance solutions to help businesses achieve long-term stable equipment operation and reduce long-term maintenance costs.
