The adsorption and detoxification functions of activated carbon benefit from the many small pores and large surface area distributed on its surface. Generally, according to the appearance, it can be divided into four types: powder activated carbon (PAC), Granular Activated Carbon (GAC), Compressed Activated Carbon (CTO), and activated carbon fiber (ACF). Activated carbon has high requirements for water treatment, and the price of activated carbon is also high. Therefore, in wastewater treatment plants, activated carbon achieves deep purification by removing trace pollutants in wastewater.
Let's take a look at the application of activated carbon in wastewater treatment:
1. Activated carbon treatment of chromium-containing wastewater
Chromium is widely used as a metal raw material for electroplating. In wastewater, Cr (Ⅵ) will exist in different forms according to the change of pH value. Activated carbon has a high developed porous structure, large specific surface area, strong physical adsorption capacity, and can effectively absorb Cr. In addition, there are many electrostatic ionic groups on the surface of activated carbon, such as hydroxyl (-OH), carboxyl (-COOH), etc., which will also have a chemical adsorption effect on Cr. Therefore, the active carbon physical adsorption, chemical adsorption, and chemical reduction can work together to achieve the best removal effect of chromium in wastewater.
2. Activated carbon treatment of phenol-containing wastewater
In industrial production, petrochemical plants, resin plants, cooking plants and oil refining plants all produce phenol-containing wastewater. Experimental studies have shown that temperature and pH are the main factors affecting the adsorption effect of activated carbon on phenol. The adsorption equilibrium time of activated carbon on phenol will be shortened with the increase of temperature, but too high temperature will damage the adsorption capacity. The pH value has a signification impact on the adsorption effect of phenol in wastewater. When the pH value is less than or equal to 7, the content of phenol in the wastewater does not change much; when the pH value is greater than 7, the content of phenol will decrease significantly, and if the alkalinity is too strong, the adsorption effect will become worse.
3. Activated carbon to treat oily wastewater
As a non-polar adsorbent, activated carbon is the most commonly used material to purify oily wastewater. Compared with other adsorbents, activated carbon has a large specific surface area and a rich microporous structure, so it has good oil absorption and can remove dispersed oil, emulsified oil, dissolved oil and other organic substances in wastewater.
Activated carbon has strong adsorption capacity, outstanding chemical invariance, high mechanical strength, renewable properties, etc., and is widely used in chemical environmental governance, sanitation, food and other neighborhoods. In today's serious water pollution situation, activated carbon can effectively remove most of the organic pollutants, heavy metals, odors and colors in the water. It has important scientific significance and has a wide range of application possibilities in the field of wastewater treatment.