The original desalinated water production capacity of the enterprise's system was 300 TPH. Due to increased production demand for desalinated water, renovations were required within the original workshop to achieve a desalinated water output of 1,000 TPH. Meanwhile, the project faced technical challenges such as low reuse water utilization rate in the industrial desalinated water system and high hardness in reverse osmosis concentrate, which posed significant treatment difficulties. The client required that system recovery rate be increased by over 20% from the original level without expanding the footprint.
Adopting AQFILM AFP-H8080 Product
The AFP series external pressure filter membranes are manufactured using proprietary TIPS (Thermally Induced Phase Separation) technology, forming a homogeneous sponge-like structure in the filtration layer. This structure has achieved significant breakthroughs in water production stability and pollution recoverability, enabling the membranes to withstand broader water quality pollution and shocks while maintaining excellent chemical cleaning recovery capabilities. On this basis, the modular technology and process of "Key Technologies for Low-Energy-Consumption and High-Water-Utilization Industrial Desalinated Water Preparation" have been developed.
First, a high-recovery UF unit is adopted.Using membrane modules with high contamination tolerance and excellent durability, the design of the module flow channels is optimized to enhance the contamination retention capacity of the modules,to strengthen the intensity of air scrubbing,to improve the effect of physical cleaning,to reduce self-consumption of water,to optimize the backwashing method.These measures enable the ultrafiltration unit to achieve a recovery rate of over 95%.
Second, high-turbidity water is recycled.High-turbidity water such as backwash water from self-cleaning filters (concentrated approximately 20 times) and backwash water from UF (both forward and reverse) is simply filtered and reused in the raw water tank. The backwash water from sand filters is used to discharge the suspended solids intercepted and concentrated in the raw water. This enables the high-speed sand filter reuse unit to achieve a recovery rate of over 97%.
Third, high-salinity water is recycled.A proprietary chemical hardness removal high-density tank is used. By optimizing the tank structure, improving the operation mode, and determining the optimal mixed reaction sedimentation state, high-salinity and high-hardness water such as RO concentrate (concentrated 4–5 times) undergoes advanced hardness removal before desalination and reuse via concentrated water RO. This enables the concentrated water RO to achieve a recovery rate of 80%, while its produced water has a hardness of less than 0.3 mmol/L.
Based on the anti-pollution ultrafiltration membrane process, this project has developed a specialized process package technology. It continuously supplies approximately 8 million tons of qualified demineralized water to users each year. The system's water utilization rate has been increased from the conventional ~70% to over 92%, and power consumption has dropped from the conventional 2.4 kWh/ton of demineralized water to 1.28 kWh/ton. This has achieved annual water savings of 2.7 million tons and reduced sewage discharge by 480,000 tons.