Acids are used in many industrial production processes and are often contaminated with residues introduced into the production process after use. These residues can be of various kinds and are usually problematic substances that limit the possibilities for further use or recycling of the respective acid.

With customer- and application-specific Advanced Oxidation Processes (AOP), enviolet UV systems (UV oxidation) can reliably break down many types of unwanted residues (e.g. dyes or by-products of certain reactions) in situ in the process solution using AOP and purify the acid by means of UV oxidation. Following the UV oxidation process, the production solution treated by the AOP process can then often be used in other industrial applications (e.g. in wastewater treatment) or continue to be used in its original application.

Due to the aggressive nature of the acids and production solutions to be recycled, these UV oxidation systems optimised for AOP recycling processes place very high demands on the materials used in the AOP systems that come into contact with the media.
Enviolet develops and manufactures customised AOP solutions for UV oxidation recycling processes using suitable materials such as highly fluorinated polymers such as PVDF or ECTFE.

Examples of UV recycling processes successfully implemented to date using advanced oxidation:

• H₂O₂ removal by AOP from spent solutions (peroxomonosulphuric acid / Caro's acid)
     from piranha etching of wafers in the semiconductor industry
• Decomposition of organic residues in sulphuric acid by means of UV oxidation
• Elimination of organic residues in hydrochloric acid (e.g. benzaldehyde) by advanced oxidation
• Degradation of organic residues in phosphoric acid using AOP processes
• Degradation of dyes in phosphoric acid using UV oxidation