1. High efficiency of water-salt separation, with significant effects on reduction and resource recovery

Low-temperature evaporation achieves wastewater evaporation through "vacuum boiling point reduction" (typically 40-70℃). The water vapor can be directly recycled into fresh water after condensation, while the remaining salt is discharged in the form of concentrated solution or crystals. The core advantages are reflected in:

High salt removal rate: For high-salt wastewater (such as reverse osmosis concentrate and desulfurization wastewater) with a salt content of 10%-30%, the salt removal rate generally reaches over 95%. Some equipment, combined with crystallization modules, can achieve "near-zero emissions" - with a fresh water recovery rate of ≥85% and a concentrated salt slurry moisture content of ≤50%, significantly reducing the amount of hazardous waste disposal (e.g., the original wastewater volume can be reduced to less than 1/10).

Fresh water can be directly reused: The TDS (Total Dissolved Solids) of the recycled fresh water is usually controlled below 100mg/L, with turbidity <5NTU. It can be used for workshop flushing, circulating cooling water makeup, etc. without requiring complex advanced treatment, reducing the procurement cost of fresh water for enterprises and meeting the requirements of the "water conservation and emission reduction" policy.

Salt resources are recoverable (in specific scenarios): If the wastewater contains a single component (such as only NaCl and Na₂SO₄, without heavy metals or toxic impurities), by optimizing evaporation temperature and stirring rate, the purity of the discharged salt crystals can reach 90%-98%. These crystals can be recycled as industrial by-product salt (such as raw material supplementation in the chemical industry), realizing the concept of "turning waste into treasure".

II. Protective components for low-temperature operation to avoid secondary pollution and equipment damage

Traditional high-temperature evaporation (such as multi-effect evaporation, which often requires temperatures above 100℃) is prone to causing changes in wastewater composition or equipment corrosion, while the "low-temperature environment" of low-temperature evaporation can avoid such issues:

Protecting heat-sensitive pollutants and reducing the release of odors/toxic substances: When treating "high-salt + heat-sensitive" wastewater such as biomedical fermentation wastewater and concentrated food processing wastewater, low temperatures can prevent the denaturation of proteins, polysaccharides, and other substances. At the same time, it can prevent ammonia, hydrogen sulfide, and volatile organic compounds (VOCs) from decomposing intensely due to high temperatures, reducing secondary odor pollution and easing the pressure on subsequent waste gas treatment.

Reduce equipment corrosion risk: High-salt wastewater at high temperatures (especially when containing Cl⁻ and F⁻) significantly increases the corrosion rate of metal equipment (for example, the corrosion rate of carbon steel in 80°C high-salt water is 2-3 times higher than at room temperature). Operating at lower temperatures can slow down corrosion, extend the service life of evaporators (mostly made of 304/316L stainless steel), and reduce equipment maintenance and replacement costs (typically extending equipment life by 1-2 years).

III. Better energy consumption and cost, suitable for small and medium-sized processing needs

Compared to traditional high-energy consumption evaporation technology, low-temperature evaporation equipment has a more advantageous balance between "energy consumption - cost", especially suitable for small and medium-sized processing scenarios:

Energy consumption is relatively controllable: Although the energy consumption of single-effect low-temperature evaporation (about 50-80 kW·h/m³ of wastewater) is higher than that of MVR (about 20-40 kW·h/m³), it does not require complex steam compressors or multi-effect heat exchange systems. The initial equipment investment is only 1/3-1/2 of that for MVR (for example, the investment for a low-temperature equipment with a processing capacity of 2 m³/d is about 150,000-250,000 yuan, while MVR requires 400,000-600,000 yuan). This makes it more friendly to small and medium-sized enterprises with limited budgets.

Low operating costs and simple operation: Low-temperature equipment is mostly automated and controlled by PLC systems, eliminating the need for 24-hour personnel monitoring. Regular checks on water replenishment and filter cleaning are sufficient, resulting in low labor costs. Additionally, there are no high-temperature or high-pressure components, minimizing safety risks and eliminating the need for additional safety protection facilities (such as high-temperature alarms, pressure safety valves, etc.).

IV. Modular design, adaptable to decentralized and complex scenarios

The structural characteristics of low-temperature evaporation equipment make it far superior to traditional equipment in terms of "installation flexibility" and "scenario adaptability":

Small footprint and convenient installation: Most equipment is integrated modular (such as containerized or vertical integrated machines). Equipment with a single processing capacity of 0.5-5m³/d occupies only 5-10㎡ of space, eliminating the need for complex civil engineering work (such as excavating pools or building factories). It can be installed on a flat surface and requires a short commissioning period (1-2 weeks to be put into production), making it suitable for scenarios with limited space, such as corners of workshops or remote mining areas.

Dealing with Decentralized High-Salinity Wastewater: For "small-batch, decentralized" wastewaters such as those from small-scale electroplating plants, mine water in mining areas, and concentrated rural domestic sewage, there is no need to transport the wastewater to centralized treatment plants (saving transportation costs). Instead, "on-site collection and on-site treatment" can be achieved, avoiding the risk of leakage during long-distance transportation.

5. Low pre-treatment requirements to reduce process complexity

Traditional evaporation equipment has extremely high requirements for wastewater pretreatment (such as the need to completely remove suspended solids and hardness ions, otherwise scaling and blockage are likely to occur), while the pretreatment threshold for low-temperature evaporation equipment is lower:

Resistance to certain suspended solids and hardness: Some low-temperature equipment (such as forced circulation low-temperature evaporators) can withstand suspended solids (such as sediment and colloids) in wastewater with a concentration of ≤500mg/L through "high-speed stirring + turbulence design", without the need for additional precision filtration (such as ultrafiltration). It also has higher resistance to hardness ions (Ca²⁺, Mg²⁺) (allowable concentration ≤1000mg/L), requiring only simple dosing for softening (such as adding sodium carbonate), thus reducing pretreatment process steps and costs.

Compatible with high COD and high salt wastewater: When treating "high salt + high COD" wastewater from the chemical and pesticide industries, there is no need to degrade the COD first (traditional biochemical methods are difficult to treat high salt wastewater). Fresh water can be directly separated through low-temperature evaporation, and the concentrated high COD liquid can be disposed of through incineration, solidification, or other methods, simplifying the overall treatment process.