How to treat industrial high-salt wastewater? High-saline wastewater refers to wastewater containing organic matter and at least 3.5% (mass concentration) of total dissolved solids (TDS). This kind of waste water comes from a wide range of sources. One is the chemical, pharmaceutical, petroleum, paper making, dairy processing, food canning and other industrial production processes, which will discharge a large amount of waste water. The water contains not only many organic pollutants with high concentration, but also a large amount of calcium, sodium, chlorine and sulfate plasma. So how to treat this kind of wastewater? How to treat industrial high-salt wastewater 1. Double-membrane pretreatment process First, use a semi-permeable membrane with a pore size of 20-2000Ao (10-6.5-10-4.5cm) for ultrafiltration, which can intercept proteins, various enzymes, bacteria and other colloidal substances and macromolecular substances in the concentrated solution, while water, solvents, small molecules and salt forming ions can pass through the membrane and enter the permeable water. As the water content of the permeate decreases, but the salt content does not change, the salt concentration of the permeate increases. At this time, a semi-permeable membrane with a pore size of 1-20Ao (10-7.5-10-6.5cm) is used for reverse osmosis. Inorganic salts, sugars, amino acids, BOD, COD, etc. are trapped in the concentrated solution. Only water and solvent enter the permeate water. The concentration of salt in the concentrated solution is further increased and sent to evaporation crystallization for desalination. The advantage of double-film desalination is that the water volume of evaporative crystallization desalination is greatly reduced, thus significantly reducing the operating cost and investment of evaporative crystallization desalination.
This week, the 2021 (the second) waste salt, waste acid and alkali and high concentration organic waste liquid exchange conference was held in Yangzhou. The event was hosted by the China Hazardous Waste Industry Network, with the theme of "innovative development and common development". The relevant leaders of Shanghai Solid Waste Management Center, China Recycling Economy Association, Chinese Academy of Sciences and other relevant leaders, as well as representatives of more than 300 environmental protection enterprises at home and abroad gathered together, To jointly discuss the new treatment and disposal technology of "waste salt, waste acid and alkali and high concentration organic waste liquid", with a view to promoting development through technical exchange, learning from each other's strengths and making up for each other's weaknesses. Yixing Fuding Environmental Protection Engineering Co., Ltd. was invited to participate.
Yixing Fuding Environmental Protection I Cheng Co., Ltd. was selected as the "high-quality environmental protection equipment manufacturing enterprise" this time, which means that the comprehensive strength and development potential of the enterprise are highly recognized by the government and the market. The acquisition of this certificate of honor enhances the pride of the employees of the enterprise, strengthens the sense of responsibility of the employees, and better achieves the craftsman spirit of "keeping improving".
As the Spring Festival approaches, in order to let the lonely elderly in Qiting Town Home for the Elderly celebrate the Spring Festival, Yixing Miaohuasheng Charity Fund and Yixing Fuding Environmental Protection Engineering Co., Ltd. came to Qiting Street Home for the Elderly to carry out the warm activities, and sent the greetings and blessings of the Spring Festival to the elderly in advance.
High-saline wastewater refers to wastewater with a total salt content of at least 1%. It mainly comes from chemical plants and oil and natural gas collection and processing. This wastewater contains a variety of substances (including salt, oil, organic heavy metals and radioactive substances). Saline wastewater is produced in a wide range of ways, and its water volume is also increasing year by year. It is very important to remove the impact of organic pollutants in saline sewage on the environment. The biological method is used for treatment, and the high concentration of salt substances has inhibitory effect on microorganisms. The physical and chemical method is used for treatment, which has large investment, high operating costs, and is difficult to achieve the expected purification effect. Biological treatment of such wastewater is still the focus of research at home and abroad. According to the different production processes, the types and chemical properties of organic substances in organic wastewater with high salt content vary greatly, but the salt substances are mostly Cl -, SO42 -, Na+, Ca2+and other salt substances. Although these ions are essential nutrients for microbial growth, they play an important role in promoting enzyme reaction, maintaining membrane balance and regulating osmotic pressure during microbial growth. However, if the concentration of these ions is too high, they will have inhibition and toxicity on microorganisms, mainly including high salt concentration, high osmotic pressure, and dehydration of microbial cells, resulting in the separation of cell protoplasm; The activity of dehydrogenase was decreased by salting out; High chloride ion is toxic to bacteria; With high salt concentration, the density of wastewater increases, and the activated sludge is easy to float and lose, which seriously affects the purification effect of biological treatment system.
In order to obtain crystal salt from high-salt wastewater treatment, it needs to go through three stages: 1. separating monovalent salt and bivalent salt with nanofiltration membrane; 2. DTRO membrane is used for high salt water concentration; 3. The highly concentrated and concentrated brine is concentrated and crystallized in the evaporation crystallizer to obtain sodium chloride and sodium sulfate with relatively high purity.