Pure water equipment should reduce the turbidity of the inlet water: When the water contains suspended solids, colloids, microorganisms, and other impurities, it will cause a certain degree of turbidity. These turbid substances obstruct the transmission of light, and this optical effect is related to the quantity, size, and shape of the impurities. Different fields have different requirements for water supply turbidity. For example, for general domestic water, the turbidity should not exceed 5 degrees. Since turbidity measurement involves passing light through the raw water and measuring the amount of light reflected by particles in the water, factors such as color, opacity, particle size, quantity, and shape all affect the measurement. The relationship between turbidity and suspended solids is random. For particles smaller than a few micrometers, turbidity cannot accurately reflect their presence. In membrane treatment processes, the precise microstructure captures particles at the molecular or even ionic level, making turbidity an inadequate indicator of water quality. In reverse osmosis processes, pretreatment is essential, such as using quartz sand, activated carbon, or filters with various filter media. For water with high hardness, a softening filter is required. There is no fixed approach for the specific treatment process, as it depends on the water source, and thus pretreatment methods vary. For example, for tap water or groundwater with low turbidity, using a 5–10 μm precision filter (such as honeycomb, melt-blown, or PE sintered tube filters) can generally reduce turbidity to around 5. Before the precision filter, flocculants must be added, and a dual or multi-layer media filter should be used. Generally, the filtration speed should not exceed 10 m/h, with 7–8 m/h being ideal. The slower the filtration speed, the better the filtered water quality. The reverse osmosis system is the core component of reverse osmosis pure water equipment, and its design primarily considers the number and brand of membrane elements, as well as three major issues.Ranking of Pure Water Equipment Manufacturers

Cleaning of reverse osmosis membranes: Although the feedwater undergoes various pretreatment measures, deposits and scaling may still form on the membrane surface after long-term use, clogging the membrane pores and reducing water production. Therefore, regular cleaning of contaminated membranes is necessary. However, the reverse osmosis membrane system should not be cleaned only when contamination is severe, as this increases the difficulty of cleaning, extends the cleaning steps, and prolongs the cleaning time. It is essential to correctly determine the timing of cleaning and address fouling promptly. Cleaning principles: Understand local water quality characteristics, conduct chemical analysis of pollutants, and use the results to select appropriate cleaning agents and methods, providing a basis for identifying the best approach under specific water supply conditions. Cleaning conditions: a. Product water output decreases by 5%–10% compared to normal levels. b. To maintain product water output, the temperature-adjusted feed pressure increases by 10%–15%. c. The conductivity of the permeate water (indicating increased salt content) rises by 5%–10%. d. For multi-stage RO systems, the pressure drop across different stages increases significantly. Cleaning methods: Start with system backwashing; proceed with negative pressure cleaning; if necessary, perform mechanical cleaning; then conduct chemical cleaning. Since chemical cleaning is more effective, and other methods are sometimes difficult to implement, the cleaning agents provided by various suppliers, though differing in name and usage, generally follow similar principles. Cleaning steps for a single-stage system: (1) Prepare the cleaning solution; (2) Input the cleaning solution at low flow rate; (3) Circulate; (4) Soak; (5) Circulate with a high-flow pump; (6) Rinse; (7) Restart the system. Specialized cleaning for specific pollutants includes: cleaning salt scale, cleaning carbonate scale, cleaning iron and manganese contamination, and cleaning organic contamination. The service life of reverse osmosis membranes in Nantong reverse osmosis ultrapure water equipment depends on the membrane's chemical stability, physical stability, water source quality, pretreatment, cleaning frequency, and operational management level.Ranking of Pure Water Equipment Manufacturers