Single-stage reverse osmosis effluent standards and applicable scenarios
Single-stage reverse osmosis is the basic equipment for industrial water purification. It has the advantages of high cost performance, simple operation and maintenance but not complicated, and low failure rate.According to industry research data in 2025. more than 60% of small and medium-sized food processing plants in the country use single-stage equipment, and more than 60% of boiler users in the country also use single-stage equipment.
Reverse osmosis equipment manufacturers look for DIEN water treatment
The normal conductivity value of the effluent produced by the single-stage reverse osmosis equipment under conventional working conditions is 10µS/cm to 50µS/cm, and the corresponding TDS value is in the range of 5 to 25mg/L, and the removal ratio of salt, colloids, sediment and bacteria in the water can reach 95% to 98%.Such a set of standards has been written into the national standard "GB/T 19249-2023 Reverse Osmosis Water Treatment Equipment".This kind of water quality is fully adaptable to ordinary industrial scenarios, and it is more common in boiler water replenishment, workshop cleaning water, food rough processing, circulating cooling water and other working conditions.For example, there is a food factory in Shandong. After adopting single-stage equipment, the product pass rate has increased from 87% to 96%, saving more than 150.000 yuan in waste product losses every year.
Two-stage reverse osmosis pure water standards and high-end water requirements
Facing the field of high-precision production, the purification accuracy of single-stage reverse osmosis is far from sufficient. At this time, it is necessary to have two-stage reverse osmosis water treatment equipment, with the help of two reverse osmosis filtration, the water quality is deeply desalinated and purified.In the newly revised "Purified Water Standard for the Pharmaceutical Industry" in 2026. it is clearly stipulated that the conductivity of water used in key processes should be less than 2µS/cm.
The water conductivity produced by the two-stage reverse osmosis equipment is stable between 1µS/cm and 5µS/cm. Under the condition of high-quality commissioning, it can be controlled within 2µS/cm, and its TDS value is lower than 1mg/L, which belongs to the standard category of industrial primary pure water.There is an electronics factory in Shenzhen. After upgrading the two-stage equipment, the yield rate of chip cleaning has jumped sharply from 91% to 99.3%.The electronic manufacturing industry has extremely high requirements for the purity of water quality, and the trace amount of salt in the water will affect product quality. The same is true for the pharmaceutical industry, the cosmetics production industry, and the precision instrument cleaning industry. This is also the case for such scenarios. Two-stage equipment must be used. A pharmaceutical factory in Jiangsu was fined 1.8 million yuan for using single-stage equipment, which caused impurities in infusion products to exceed the standard. The two-stage system was replaced after being fined 1.8 million yuan.
The cause and solution of the high conductivity of the effluent
When the equipment is running, many users have reported that its operating conditions are normal, but the conductivity has suddenly increased and the water quality has deteriorated. In fact, most of it is not that the equipment has failed, but that the daily operation and maintenance work has not met the requirements. Common problems and corresponding solutions are extremely clear.In 2025. a survey of 300 factories showed that 65% of abnormal water quality problems were caused by negligence in maintenance.
Reverse osmosis equipment
At the beginning, the reverse osmosis membrane was aging and clogging occurred.Membrane elements are core filtration components. Long-term use will accumulate scale and impurities, which in turn will reduce the desalination capacity. Regular cleaning or replacement of membrane elements can quickly restore water quality. Generally speaking, it is recommended to replace the membrane every 2 to 3 years, which can be shortened to 1.5 years based on the hardness of raw water.
Then there is the failure of the pretreatment system. The quartz sand and activated carbon filter elements have not been replaced for a long time, and the raw water impurities and residual chlorine cannot be intercepted. This will directly cause damage to the membrane body and affect the water quality of the effluent. Therefore, it is recommended to replace the filter element regularly in accordance with the water consumption.There was a user from Zhejiang who did not replace the filter element for half a year, which eventually caused the membrane element to be scrapped in advance and unusable, for which 6.800 yuan was spent on maintenance costs.
Comparison and selection recommendations of water quality standards in different industries
The general requirement of the chemical industry is that the conductivity should be less than 20µS/cm. In the case of the food industry, it needs to be controlled within 10µS/cm. However, the electronics industry often requires less than 1µS/cm.Before choosing equipment, we must first compare industry regulations and the needs of our own products to prevent blindly pursuing high parameters and wasting budgets.
Reverse osmosis equipment manufacturers look for DIEN water treatment
When in the selection stage, it is necessary to focus on the three elements of raw water TDS value, daily water consumption and effluent purity.When raw water belongs to the category of groundwater, its TDS often exceeds 500mg/L. In this case, it is recommended to use a two-stage or EDI system; if the raw water is tap water and the TDS is less than 300mg/L, then single-stage equipment is sufficient.
The price of reverse osmosis equipment will vary greatly depending on the configuration. The market price of single-stage equipment is in the range of 15.000 to 50.000 yuan, while the two-stage equipment is in the range of 50.000 to 150.000 yuan.Specifically, it is necessary to customize the quotation of the equipment model according to the actual working conditions and raw water conditions. It is recommended that you choose a manufacturer like our DIEN water treatment that can provide free water quality testing and commissioning services. It will be more cost-effective in the long run.
