​Salt wastewater treatment

It is well known that water pollution has a great impact on human production and life. Therefore, we need to pay great attention to polluted water sources. Of course, there are many types of water pollution, including pollution from metal elements, pollution from domestic wastewater, etc. One type of wastewater is saline wastewater. As the name suggests, this type of wastewater contains a high salt content. Because this type of wastewater is produced in a wide range of ways, its treatment is also a research focus. So what are the current methods for treating saline wastewater?

1.Multiple-effect evaporation

Evaporation is the most traditional method for treating high-salt wastewater. It has very high operating costs and generally uses a multi-effect evaporator. Its advantages are simple structure, easy operation, and good quality of the resulting fresh water. However, there are also methods that use steam compression condensation technology. However, due to its high cost and extremely high operating costs, this method is basically not used except in power plants in areas with severe water shortages!

2. Biochemical treatment

1. Dilution concentration

High-salt wastewater refers to wastewater with a salt content of at least 1% by mass, which generally makes it difficult for bacteria that treat the wastewater to survive. Here we can first add tap water, or mix it with domestic sewage, to dilute the concentration of the wastewater. Of course, from a cost perspective, domestic sewage is the right choice. Moreover, the COD is not high and the biodegradability is strong, which is conducive to subsequent biochemical treatment!

2. Highly salt-tolerant bacteria

After the dilution concentration, the salt content of the wastewater is still very high, so we need to use highly salt-tolerant bacteria. You can buy them here, but they are relatively expensive. It is best to domesticate ordinary bacteria into highly salt-tolerant ones.

3. Membrane treatment method: Membrane treatment method can achieve a higher desalination rate, generally above 95%. The desalination rate of nanofiltration membrane is 95%~98% for divalent salt and 90%-95% for monovalent salt. However, the high salinity also greatly reduces the life of the membrane. Therefore, we must do a good job of pretreatment and try to reduce the salinity! !

4. Use multiple methods together

Obviously, each method has its own advantages and disadvantages. Mixing them is naturally the best choice. Of course, the process selection for high-salt wastewater must be analyzed based on actual conditions! It depends on water quality, site conditions and discharge standards!