Wastewater from petrochemical and chemical enterprises is relatively difficult to treat because the wastewater from different chemical product devices not only has complex components but also is toxic and harmful. Therefore, wastewater treatment processes and technologies are diverse and varied.

This article summarizes most of the wastewater treatment methods and technologies, which can be regarded as a complete collection, detailed and comprehensive, and is shared with everyone.

10 methods

1. "Chemical Spray Tower" Process

Suitable for treating acid and alkali waste gas.

2. Biotrickling Filter Method

Biotrickling filter method: After the waste gas undergoes pretreatment processes such as dust removal, humidification, or cooling, it passes upward from the bottom of the filter bed through the filter bed composed of filter materials. The waste gas is transferred from the gas phase to the water-microbe mixed phase, and is decomposed through the metabolic action of microorganisms attached to the filter materials.

3. UV Ultraviolet Method

The UV ultraviolet method uses specially designed high-energy, high-ozone UV ultraviolet light beams to irradiate waste gas, changing the molecular structure of the waste gas, so that the organic or inorganic high-molecular waste gas compound molecular chains are degraded and converted into low-molecular compounds under the irradiation of high-energy ultraviolet light beams.

The advantages of this waste gas treatment equipment are its small footprint, low operating cost, and low equipment investment.

4. Adsorption Method

This method physically combines or chemically reacts the organic components in the waste gas with the adsorbent to achieve the purpose of cleaning. It is suitable for the treatment of organic waste gas VOCs with medium and low concentrations and high recycling value, and can be used to purify waste gas containing solvents or organic matter discharged from the production of coatings, paints, plastics, and rubber.

Currently, the commonly used adsorbent is activated carbon, which has a high adsorption rate, low operating energy consumption, low cost, safety and reliability, is suitable for some dangerous places, and the adsorbent can be recycled, saving energy and protecting the environment.

5. Absorption Method

The absorption method refers to the contact between waste gas and scrubbing liquid to remove VOCs from the waste gas, and then neutralize, oxidize, or destroy VOCs by other chemical reactions. This method is suitable for treating high water-soluble organic waste gas VOCs.

Using the absorption method to purify gaseous pollutants can not only reduce or eliminate the emission of gaseous pollutants into the atmosphere, but also convert pollutants into useful products.

6. Condensation Method

The condensation method is to cool the waste gas to below the dew point of the VOCs components, so that it condenses into a liquid state and is then recovered. This method is suitable for treating organic waste gas VOCs with high concentration and relatively simple components.

In theory, the condensation method can achieve a very high purification degree, but when its concentration is lower than a certain level, deep freezing needs to be adopted, which will greatly increase the operating cost. Usually, in the treatment of VOCs, condensation can be used as a pretreatment step for incineration, washing, and adsorption.

7. Separation Method

Membrane separation is a new treatment technology. According to the different permeabilities of organic matter, specific membranes can be selected to separate organic matter. This method is suitable for treating high-concentration organic waste gas VOCs.

8. Catalytic Combustion Method

The working principle of catalytic combustion is that under the action of a catalyst, the hydrocarbons in organic waste gas are rapidly oxidized into water and carbon dioxide at a lower temperature. This achieves the purpose of treating waste gas.

The catalytic combustion method has a wide range of applications and is currently one of the more advanced VOCs treatment technologies in China, capable of treating most organic waste gases.

9. Multiphase Catalytic Oxidation Technology

Multiphase catalytic oxidation technology uses high-energy ultraviolet light to excite the catalyst to generate super-strong oxidizing active free radicals, which completely decompose and oxidize pollutants into harmless substances such as water and carbon dioxide.

This technology combines UV quantum photolysis, ultraviolet photocatalytic oxidation, and advanced oxidants to improve the efficiency of organic matter treatment and achieve higher treatment efficiency.

This technology is an organic combination of multiple technologies, with a wide range of applications, a small equipment footprint, high safety performance, can be carried out under normal temperature and pressure, and low operating costs.

10. Plasma Technology

In the low-temperature plasma discharge process of corona discharge, the plasma generates particles rich in extremely high chemical activity, such as electrons, ions, free radicals, and excited molecules. The pollutants in the waste gas react with these active groups with higher energy, and are finally converted into substances such as CO2 and H2O, thereby achieving the purpose of purifying the waste gas.

Applicable scope: Wide applicable scope, high purification efficiency, especially suitable for multi-component odorous gases that are difficult to treat by other methods, such as chemical industry, medicine, dehumidification, etc.

Advantages:

1. High electron energy, can react with almost all odorous gases.

2. Wide range of inlet gas requirements, short process chain.

3. Easy operation, ready to use. Low operating cost.