How to treat industrial waste salt by wet method

In wet treatment, waste salt is dissolved in water first, and organic pollutants are degraded by oxidation technology in the field of water treatment to achieve waste salt treatment.

Common organic oxidation techniques include oxidation, wet catalytic oxidation and hydrothermal oxidation.

The hydroxyl radical is the main body of the oxidation process, and the chain oxidation reaction triggered by the hydroxyl radical rapidly destroys the molecular structure of organic matter, so it can oxidize and degrade high concentration organic wastewater with a high probability. The industrial waste salt disposal technology believes that the salt concentration has negligible influence on this method.

The disposal technology of industrial waste salt can be divided into wet oxidation, supercritical water oxidation and other catalytic oxidation methods according to different free radical generation methods and conditions. Wet oxidation refers to the oxidation of organic matter in water into small molecular organic matter or inorganic matter with air or oxygen as oxidant under high temperature and high pressure.

General wet oxidation temperature is 120-320℃, pressure is 0.5-20MPa. If the temperature and pressure of the reaction are raised above the critical point of water (temperature 374.3℃, pressure 22.05MPa), the basic properties of water will change greatly, showing similar properties to those of non-polar organic compounds. The reaction under these conditions is called supercritical water oxidation.

Supercritical water can be miscible with non-polar substances and other organic matter, and supercritical water can also be miscible with air, carbon dioxide and other gases. However, inorganic substances, such as salts, have low ionization constant and low solubility in supercritical water. Most salts can be separated and have little influence on oxidation reaction.

Therefore, when supercritical water oxidation is used to treat wastewater, hydroxyl radicals with strong oxidation ability can degrade organic pollutants. This wet treatment technology can oxidize and degrade various pollutants. No thermal process such as incineration, high reliability. The disadvantages of industrial waste salt disposal technology are harsh reaction conditions, high equipment requirements, high operating costs, can not be applied to ultra-high concentration organic wastewater, limiting its wide application.