However, if the wastewater containing emulsified oil is discharged without proper treatment during use, it will cause serious pollution to the environment. Therefore, the effective treatment of emulsified oil wastewater has become an important issue in the field of environmental protection, and activated carbon has shown unique advantages in this process.
What is emulsified oil wastewater?
Emulsified oil wastewater is the most difficult type of oily wastewater to treat because of its small oil droplet size (<20μm) and strong system stability. It is difficult to achieve oil-water separation through conventional methods such as gravity and flotation. The emulsified oil in the wastewater is in a stable dispersed state, and its surface carries an electric charge, forming a double electric layer structure, which makes the oil droplets repel each other and are not easy to aggregate and settle. At the same time, the presence of emulsifiers further enhances this stability and increases the difficulty of treatment.How does activated carbon purify emulsified oil wastewater?
Activated carbon is a type of microcrystalline carbon material made of carbon-containing materials. It has a black appearance, a well-developed internal pore structure, a large specific surface area, and a strong adsorption capacity. It is mainly composed of carbon elements and also contains a small amount of hydrogen, oxygen and other elements. Activated carbon has a large specific surface area, microporous structure, strong adsorption capacity and high surface activity, which makes it have a unique multifunctional adsorption effect.Activated carbon has a significant effect on the treatment of emulsified oil wastewater, which is mainly reflected in the following aspects:
• It can efficiently adsorb dissolved oil, effectively remove soluble organic matter in emulsified oil, and greatly reduce the chemical oxygen demand (COD) in wastewater;
• It has a wide range of applicability. It can not only adsorb emulsified oil, but also adsorb other organic pollutants, showing excellent versatility;
• In multi-stage wastewater treatment systems, activated carbon is often used as the last line of defense to remove residual pollutants and ensure that the effluent water quality meets the standards.
Combination of activated carbon with other technologies
In order to overcome the limitations of activated carbon in emulsified oil treatment, it is often combined with other technologies:• Demulsification technology
The stability of the emulsified oil is destroyed by chemical agents (such as demulsifiers or acid-base adjustment) to separate the oil droplets from the water. After demulsification, activated carbon can be used to adsorb residual oil.
• Flotation technology
The emulsified oil after demulsification is combined with the flotation system to remove large oil droplets and reduce the load on the activated carbon.
• Membrane separation technology
Ultrafiltration (UF) or nanofiltration (NF) technology can effectively remove particulate pollutants in the emulsified oil, while activated carbon is used to treat dissolved organic matter after membrane filtration.
This combined process can significantly improve the treatment efficiency of emulsified oil while reducing the amount of activated carbon used and operating costs.
Factors affecting the adsorption effect of activated carbon
1. Types of activated carbon:
Activated carbon made of different materials, such as coal, wood, coconut shell, etc., has different pore structures, specific surface areas and surface chemical properties, and has different adsorption effects on emulsified oil. Generally speaking, coal-based activated carbon shows better adsorption performance when treating certain emulsified oil wastewater.2. Dosage:
The dosage of activated carbon has a significant effect on the adsorption effect. Within a certain range, increasing the dosage of activated carbon can increase the removal rate of emulsified oil. However, when the dosage exceeds a certain level, the increase in removal rate will gradually decrease, and the treatment cost will increase.3. Adsorption time:
As the adsorption time increases, the adsorption amount of activated carbon on emulsified oil gradually increases, and the removal rate increases. However, after reaching adsorption equilibrium, continuing to extend the time has little effect on improving the removal rate.4. Nature of wastewater:
The pH value, temperature, emulsified oil concentration and the presence of other impurities in wastewater will affect the adsorption effect of activated carbon. For example, the pH value of wastewater affects the charge properties of the activated carbon surface, thereby affecting the adsorption of emulsified oil.Conclusion:
Activated carbon plays an important role in the treatment of emulsified oil wastewater. Although there are some shortcomings, it is expected to play a greater value in the future environmental protection field through technological innovation and process optimization, and provide a more effective solution to the problem of emulsified oil wastewater pollution.If you are looking for a solution for efficient handling of emulsified oils, pls contact us without hesitation!
