Hybrid Adsorbent & Electrochemical AOP for Challenging Wastewater

Industrial processes can produce effluents that are challenging in terms of strength, variability and composition. Treatment of industrial effluent is complex and depends very much on the load and process nature of the wastewater stream. Advanced oxidation processes (AOP) are commonly used to deal with recalcitrant COD as a final polishing step in water treatment. However, conventional AOP consumes a significant amount of energy. This technology relates to an advanced water treatment method that is capable of breaking down persistent organic compounds, micropollutants, COD and colour through a combination of adsorption and electrochemical oxidation. The contaminants are bound to the adsorbents while an electric current is passed through the adsorbents, oxidizing the adsorbed pollutants to water, hydrogen and carbon dioxide which can be safely vented away.  The hybrid process utilizes lesser energy compared to conventional AOP processes. 

The technology provider is keen to work with potential technology adopters through technical collaboration and licensing agreement to deploy the technology.

The advanced water treatment combines adsorption and electrochemical oxidation process in a single system. The wastewater percolates through a bed of graphite-based adsorbents and binding the organic contaminants to the media. Concurrently, a current is passed through the medium, oxidizing the organics bound to the adsorbent media, generating free radicals from the organic waste in the process, and propagates the oxidation reaction in the process. 

• Can be integrated either upstream or downstream from other processes to remove specific contaminants strategically before they react with other compounds in the wastewater
• Recalcitrant COD reduction from 1000 to 30 mg/L COD
• Continue to work effectively even when the concentration is low
• Removal of micropollutants from ppm to ppt levels and in some cases beyond the limit of detection 
• 5 to 10 times lesser bromate by-product formation compared to ozone-based AOP
• Does not require any chemical dosing
• Does not produce any toxic sludge 
• Low maintenance required as the media regenerates itself during the process 
• 2-4% adsorbent media top-up is required annually
• Lower energy consumption compared to conventional AOP
  • 20 -40 kWh/kg COD for average COD removal processes for industrial wastewater
  • 0.4 - 1.0 kWh/m³ for micropollutant removal 

This technology can be applied to the following industries:

• Pharmaceuticals
• Fine/Specialty chemicals
• Agrochemicals
• Petrochemicals
• Semiconductors
• Food and beverage
• Textiles

The global market for advanced oxidation technologies for purification applications should reach $6.5 billion by 2021 from $4.4 billion in 2016 at a compound annual growth rate (CAGR) of 8%, from 2016 to 2021. Regulations for the use of chemicals and organic compound have been tightening up around the world. Coupled with the increasing cost of incineration, the industry are forced to look for alternative new water treatment technologies to reduce cost and comply with regulations.

• Simple design & easy to operate
• Safe & Easy to Operate - removes the risk of handling ozone and other dangerous chemicals like hydrogen peroxide
• Easy to install modular ‘plug and play’ design 
• Continuous process with minimal downtime
• Onsite treatment as a low cost alternative to incineration