Application Cases of Activated Carbon in Water Treatment

Drinking Water Treatment

• A Water Treatment Plant in Los Angeles, USA
  • Challenges: The raw water source was contaminated by trace organic pollutants and residual chlorine, resulting in poor taste and odor of tap water. Moreover, residual chlorine might react with organic matter in water to form harmful disinfection by – products.
  • Solutions: After the conventional coagulation, sedimentation, and filtration processes, the plant added an activated carbon adsorption process. A granular activated carbon filter was used, allowing the pre – treated water to pass through the activated carbon layer. The activated carbon adsorbed organic pollutants and residual chlorine in the water.
  • Results: The content of organic pollutants in the treated drinking water decreased significantly, and the residual chlorine content met the national drinking water hygiene standards. The taste and odor of the water improved significantly, and residents’ satisfaction with the drinking water quality increased greatly.
• A Direct – Drinking Water Treatment System in a Residential Community in China
  • Challenges: The water source of the community was municipal tap water. However, due to aging pipelines, the water might contain rust, bacteria, viruses, and some organic compounds, which affected the safety and quality of direct – drinking water.
  • Solutions: An activated carbon filtration device was installed in the direct – drinking water treatment system. High – quality coconut shell activated carbon, which has a rich microporous structure and good adsorption effect on small – molecule organic matter and odors, was used. The water first passed through the activated carbon filter and then went through subsequent in – depth treatment processes such as ultrafiltration and reverse osmosis.
  • Results: After the pre – treatment with activated carbon, rust and odors in the water were significantly reduced. The load of subsequent in – depth treatment processes also decreased accordingly, prolonging the service life of ultrafiltration membranes and reverse osmosis membranes. The direct – drinking water provided to residents met the national direct – drinking water standards.

Industrial Wastewater Treatment

• A Dyeing Factory’s Wastewater Treatment
  • Challenges: The wastewater discharged from the dyeing factory contained a large amount of organic pollutants such as dyes, auxiliaries, and slurries, with a deep color and high chemical oxygen demand (COD). Direct discharge would cause serious environmental pollution.
  • Solutions: A combined process of activated carbon and biological treatment was adopted. First, the wastewater passed through an activated carbon adsorption tower. The activated carbon adsorbed some dyes and organic matter, reducing the color and COD of the wastewater. Then, the wastewater treated by activated carbon was sent to a biological treatment tank, where microorganisms further decomposed the remaining organic matter. Finally, a secondary activated carbon adsorption for in – depth treatment ensured that the effluent water quality met the standards.
  • Results: After treatment, the color removal rate of the wastewater reached over 95%, and the COD removal rate reached over 80%. The effluent water quality met the national dyeing wastewater discharge standards, and partial reuse was achieved, greatly reducing the fresh water intake and wastewater discharge of the enterprise, as well as its production cost and environmental pressure.
• A Comprehensive Wastewater Treatment Plant in a Chemical Industrial Park
  • Challenges: There were many enterprises in the chemical industrial park, and the wastewater had a complex composition, containing various toxic and harmful organic compounds, heavy metal ions, and salts, making it difficult to treat.
  • Solutions: An activated carbon fixed – bed adsorption device was installed in the treatment process. The pre – treated wastewater passed through the activated carbon fixed – bed, and the activated carbon adsorbed organic matter and some heavy metal ions in the wastewater. At the same time, other treatment processes such as chemical precipitation and ion exchange were combined to remove salts and remaining heavy metal ions in the wastewater.
  • Results: The activated carbon adsorption process effectively reduced the concentration of organic matter and heavy metal ions in the wastewater, reducing the burden of subsequent treatment processes. After comprehensive treatment, the effluent water quality met the reuse standards stipulated by the industrial park, realizing the recycling of water resources and providing strong support for the sustainable development of the chemical industrial park.

Upgrade and Reconstruction of Sewage Treatment Plants

• A Sewage Treatment Plant in a European City
  • Challenges: With the development of the city and the improvement of environmental protection requirements, the original sewage treatment process could not effectively remove emerging pollutants in the water, such as pharmaceuticals, personal care products, and endocrine disruptors. As a result, the effluent water quality could not meet stricter discharge standards.
  • Solutions: The sewage treatment plant was upgraded and reconstructed. A powdered activated carbon dosing system was added after the secondary biological treatment. Powdered activated carbon was evenly dosed into the mixed liquid to adsorb emerging pollutants in the water. Then, the activated carbon was separated from the water through sedimentation and filtration processes.
  • Results: After the upgrade and reconstruction, the removal rate of emerging pollutants in the effluent of the sewage treatment plant increased significantly. The effluent water quality met stricter environmental protection discharge standards, reducing the ecological risks to the receiving water bodies and protecting the water environment quality.