Name：Hangzhou Shangtuo Environmental Technology Co.,LTD.
Address: 11# Haishu Road Future Sci-tech City, Hangzhou, Zhejiang, China
Desulfurization wastewater have the characteristics of high suspended substance, high hardness, high salt content, are unstable and large fluctuation range of water quality and quantity and low acidity.
Desulfurization Wastewater is the terminal wastewater of the power plant with the worst water quality and most difficult for treatment. Real zero liquid discharge of whole plant’s circulating water is only possible if the zero liquid discharge of desulfurization wastewater can be realized.
² Tube Microfiltration (TMF): adopts unique composite membrane tube: The PVDF membrane could crosslink or embedded into the inner surface of PE supporting tube with PVDF supporting tube inner surface, allowing high particle removal efficiency and membrane flux of membrane tube under a high operating pressure or backwashing pressure, thus reducing the footprint area of the system. The system could remove hardness, silica and turbidity from water, with silica removal rate of more than 90%.
² Nanofiltration (SCNF): SCNF is a type of membrane separation technique uses pressure difference as the driving force, intercepting nanoscale particles in the water which is between reverse osmosis and ultrafiltration. Compared with ultrafiltration and reverse osmosis, the removal rate of monovalent ions and organics which the molecular weight is less than 200 is poorer for nanofiltration, but the removal rate of divalent or polyvalent ions and organics which the molecular weight is between 200 to 500 is higher. The system could remove divalent ions and separate salt from raw water, with divalent ions removal rate of more than 95%.
² High-Pressure Anti-Pollution Reverse Osmosis (SCRO): Reverse osmosis, a membrane separation operation that uses pressure difference as driving force to separate a solvent from a solution. Pressure is applied to the liquid on one side of the membrane. When the pressure exceeds its osmotic pressure, the solvent reversely penetrates against the direction of natural permeation. Thus, permeate is obtained on the low-pressure side of the membrane and concentrate is obtained on the high-pressure side. The system could desalinate raw water and reduce the quantity of concentrate, the desalination rate could reach more than 95%.
² Ultrahigh-Pressure Disk Tube Reverse Osmosis (DTRO): DTRO membrane is the core components of realizing the separation of fresh water and impurities. It is made of polymer materials; aromatic polyamide has excellent chemical properties and is selected as the material of the disc diaphragm. Wastewater is pressurized by the inlet pump to obtain initial pressure and filtered by cartridge filter, then pressurized by high-pressure pump to provide pressure difference. The circulation pump provides large flow rate to meet the flow rate requirement of DTRO membrane surface, the liquid flow “S” shape in the disk channel, small molecular particles, dissolved ions, and the like in the liquid are trapped on the concentrated water side, and the permeated fresh water is collected to become a clean filtrate. The system could reduce the concentration quantity from last stage, the TDS of concentrate could reach 12%.
（1）Full Membrane Technology: Adopts microfiltration, nanofiltration, reverse osmosis and ultrahigh-pressure reverse osmosis technology, the whole process is a physical process, no phase change and secondary pollution;
（2）Wide range of adaptation: The technology could treat 15000 mg/L to 70000 mg/L high salination wastewater, especially desulphurization wastewater from power plants with large fluctuations in water quality;
（3）Ultra-flexible Design: The system is divided into pre-treatment softening module, salt separation module, concentration module and evaporative crystallization module, which can be operated separately, and flexibly assembled according to inlet water quality.
（4）Short Construction Period: Using modular design, individual module is integrated in the factory, reducing on-site work, realizing containers assembly, reducing civil construction period, thus reducing construction period.
（5）Low Operating Cost: Membrane concentrate reduction module added between pre-treatment and evaporative crystallization, can greatly reduce the amount of evaporation, save operating costs, and invest cost-effectively;
（6）Zero Wastewater Discharge: Using MVR evaporative crystallization, to obtain a high purity refined salt and achieve zero discharge of waste water, thus make zero liquid discharge of power plant’s circulating water possible.
Guodian Hanchuan Power Plant Desulfurization Wastewater Project
Guodian Hanchuan Phase III 2*1000MW Expansion Project Desulfurization Wastewater Advanced Treatment of Concentrated Salt Wastewater Membrane Treatment Integrated Device
Guodian Hanchuan Power Plant
Desulfurization Wastewater Triple Tank Effluent
2*1000MW (Million-watt Unit)
TMF + SCNF + SCRO + DTRO + Evaporative Crystallization
Crystalline Salt Purity
≥97.5% (Achieve industrial refined salt standards)
System Desalination Rate
Membrane System Recover Rate
Overall Recover Rate
＞97% (3% salt content, achieve zero wastewater discharge)
Reuse Fresh Water Conductivity
＜100μs/cm (Achieve reuse water standards)
Project Characteristics and Highlights
1. Million-watt Unit: Zero wastewater discharge project of desulfurization wastewater from million-watt unit of thermal power plant;
2. Full Membrane Technique: Wastewater pre-treatment of softening and concentration adopts full membrane technique;
3. Nanofiltration salt separation: Salt recovery of desulfurization wastewater achieved by nanofiltration salt separation;
4. Zero Liquid Discharge: Zero liquid discharge, produce refined salt and low operating cost.
The project has been successfully accepted and is currently operating well.