Controlled Photocatalytic Advanced Oxidation Process




Challenging wastewaters from the industry are usually treated with a combination of chemical and biological methods. In some cases, the contaminants cannot be degraded by conventional means and require advanced technologies such as advanced oxidation processes (AOP) to break down the organics. This technology relates to an AOP wastewater treatment solution that is able to handle highly concentrated petrochemical wastewaters contaminated with hard to treat phenolic compounds. Using UV and reactive chlorine species catalyst, the technology is able to precisely control the oxidation state of the reactant in the water. For phenolic wastewaters, the AOP system is able to polymerize and precipitate phenolic content from the water, separating the water from the majority of the pollutant.  By separating waste from the wastewater, this technology proposes an alternative to highly concentrated petrochemical wastewater incineration. The ideal partner and users of such technology will be petrochemical industries, chemical industries, and the waste disposal industry.


Compared to conventional AOP technologies, the controlled AOP uses less energy and does not require the addition of chemicals to oxidized wastewater completely into carbon dioxide and water. The contaminants can be oxidized in a controlled manner and the resultant oxidized pollutants can be easily removed from the wastewater after it is precipitated into polymers or larger complex compounds. Alternatively, the contaminants can be broken down into more biodegradable substances.  The controlled AOP technology is at least 2-3 times cheaper compared to direct incineration when treating highly concentrated petrochemical wastewaters. Unlike Fenton oxidation, controlled AOP technology is much safer as it does not require the use of any dangerous chemicals. It is also significantly more cost-effective as the energy (or chemical energy) required to perform controlled oxidation is much lesser than complete oxidation.


The primary application will be used for treating petrochemical wastewater reducing the amount of wastewater sent for incineration. The resultant sludge or polymers from the controlled AOP technology may also have other uses and can be valorized accordingly. As such the controlled AOP technology may also serve as a tool to reduce overall carbon emission, and reduce plastic wastes from source (the petrochemical industries). This technology may have the potential for pharmaceutical industries' wastewater. Wastewaters generated from pharmaceutical industries should consist of complex organic substances, such as synthesized polymers or aromatic compounds. Controlled AOP technology can remove or reduce these substances from the wastewater stream.   It is estimated that the value of petrochemical wastewater disposal in Singapore is at least SGD 100 -150 million every year. (considering only high concentrated petrochemical wastewater)


Cheaper as compared to incineration by at least 2-3 times Reduce overall carbon emission from petrochemical wastes Recovered sludge valorization