It mainly introduces the following aspects:

1. Project Introduction

Frozen crystallization wastewater treatment technology realizes the separation of water, organic pollutants and salt during the growth process of ice crystals and salt crystals in a water-organic-salt multi-component system at low temperatures. Water molecules repel non-aqueous components during crystallization at the freezing point. As the ice crystals grow, the liquid water content in the system gradually decreases, and the salt in the system gradually condenses and separates out. The key to the technology is to meet the process control in terms of mass transfer and heat transfer of freeze concentration crystallization. It is suitable for solid-liquid separation technology under the conditions of freeze concentration crystallization technology to achieve efficient solid-liquid separation of crystallization compounds, ice crystals and concentrates. This technology has the characteristics of low corrosion to equipment, long operating life, safety and no explosion risk, low VOCs emissions, and low operating costs. It is suitable for the treatment and resource utilization of process waste mother liquor or wastewater containing high salt and high organic matters.

2. Cooperation content

(1) Brief introduction of the main relevant technologies involved

Freezing concentration wastewater treatment technology is based on the solid-liquid equilibrium theory in physical chemistry. It is a new concentration technology that realizes concentration of solutes while obtaining recycled water. At low temperatures, the freezing point of the solute in the solution is lower than the freezing point of water. The water in the solution is first separated out in the form of solid ice crystals, while the solute remains in the form of an aqueous solution in the concentrate. Then the ice crystals (purified water) and the concentrate are separated by a certain solid-liquid separation method to obtain purer ice crystals (purified water), and the concentrate is further processed.

Taking ethylene waste lye (a kind of wastewater with high organic concentration and difficult to biodegrade) as an example, when the original waste liquid COD reaches 264000mg/L, after three-stage freezing treatment (the ice-forming rates of the three stages are 80%), the COD of the third-stage effluent is only 9200 mg/L, and the COD removal rate reaches 96.5%; the COD of the first-stage concentrate is 657000mg/L, and the concentration ratio is 2.5.

Since the latent heat of condensation of water is 3.35×10⁵J/kg, only its latent heat of vaporization is 2.4×10⁶One-seventh of J/kg, the energy required by the freezing process itself is much lower than that of other waste liquid treatment methods that require high temperatures (such as wet air oxidation, incineration, etc.). In addition, freezing treatment of waste liquid also has great advantages in terms of equipment number, primary investment, and operating costs.

In addition to having great advantages in energy consumption, this green technology also has the characteristics of low corrosiveness to equipment, long operating life, safety without explosion risks, low VOCs emissions, and low operating costs. It is suitable for treatment and resource utilization of process waste mother liquor or wastewater containing high salt and organic matter.

(2) Proposed cooperation areas and partners

Frozen crystallization wastewater treatment technology is suitable for regions and enterprises that need the treatment and resource utilization of process waste mother liquor containing high salt and high organic matters or high-concentration refractory organic wastewater. It is especially suitable for areas with insufficient water resources. The water resources in wastewater and waste liquid can be efficiently recycled through frozen crystallization wastewater treatment technology to reduce the consumption of water resources in the production process.

(3)quasi-cooperation model

This green technology generally adopts the "design-procurement-construction" business model. It can be entrusted by the owner to implement the whole process or several stages of contracting the design, procurement, construction, commissioning, etc. of the engineering construction project in accordance with the contract, and under the total price contract conditions, be responsible for the quality, safety, cost and progress of the contracted project.

3. Cooperation cases

This green technology has established freeze concentration projects for high-concentration and high-salt wastewater from the pharmaceutical intermediates and resin industries in Shanghai Huayi Group and Guangdong Sanben Chemical, with a treatment scale of 20t/d.

IV. Environmental impact assessment

Due to the unique technical characteristics of this green technology, the energy required by the freezing process itself is much lower than that of other waste liquid treatment methods that require high-temperature operation.(such as wet air oxidation, incineration, etc.), the energy consumption for wastewater and waste liquid treatment can be greatly reduced compared with traditional technologies, which is about one-sixth of that of incineration and about one-third of that of oxidation methods; Due to the low temperature of the treatment process, fully enclosed equipment, and small VOCs emissions, the environmental impact is much less than that of traditional wastewater and waste liquid treatment technologies; In addition, freezing methods also have great advantages in treating wastewater and waste liquid in terms of equipment quantity, primary investment, and operating cost.