Removal of persistent COD with Advanced Oxidation Process (AOP)

For the removal of organic waste water constituents, biological process steps are preferably combined and used for waste water treatment. However, the organic compounds present in waste water, measured as chemical oxygen demand (COD), often cannot be biologically degraded, or are degraded only partially. Therefore, organic residues remain in the treated waste water, which cause a non-degradable COD, also known as persistent COD. In order to remove these impurities, further processing steps are required, for example oxidation with a strong oxidising agent or adsorptive separation.

The oxidative attack on these compounds can lead to partial or, if necessary, complete degradation, the so-called mineralisation. If the degradation is incomplete, the organic compounds are converted into bioavailable fragments. These can then be removed from the waste water stream in a downstream biological stage, for example in a biofilter.

Oxidation with ozone is one way of partially degrading these compounds. Depending on the origin and composition of the waste water, however, stronger oxidation conditions based on radical reaction mechanisms may also be required. For the selection of the appropriate Advanced Oxidation Process (AOP), the organic constituents must be further analysed and the degradability must be checked.


Our references

Germany 2023

Wastewater treatment at a chemical site rich in tradition

InfraLeuna GmbH and its associated companies are the owners and operators of the infrastructure facilities at Leuna, a chemical site rich in tradition. InfraLeuna GmbH pursues the goal of shaping and developing the framework conditions for the production operations of its customers at the site. This involves the supply of necessary media such as energy and water, disposal through the central wastewater treatment plant and analytical services in its modern laboratory.

Austria 2020

High-End UPW Plant for the Semi-Conductor Industry

The task was to implement a high-end ultrapure water plant for the treatment of well water for a well-known semiconductor manufacturer in Central Europe.

Estland 2020

Award Winner: AS Estonian Cell

In 2020, AS Estonian Cell was declared the winner of the competition ”Environmentally Friendly Company of the Year in Estonia“. With H+E components Estonian Cell came a significant step closer to its goal of becoming the best producer of pulp in the world.

Malaysia 2014

Offshore High Pressure High Performance Produced Water Treatment Package

A high-pressure high-efficiency produced water treatment system of Petronas an Sapura Energy designed to meet strict overboard discharge limits while accommodating onerous space and weight constraints imposed by offshore design requirements.

Denmark 2014

Oily Water Treatment Offshore

For an oil rig, Ørsted needed a treatment plant for treating oily water from various sources. Ørsted, Denmark, is the world market leader in offshore wind energy and offers innovative energy solutions for public utilities and industry.

For an oil rig, Ørsted needed an oily water treatment plant to treat water from various sources to remove oil down to <10 mg/l and 95% of solids >100 μm, making the water suitable for discharge into the sea. This application was a particular challenge due to the small droplet diameters and emulsified oils from the various sources. H+E met the challenge by providing their coalescer design with a solids removal system upstream of the coalescer technology.

Germany 2012

New AOP application in a German paper mill

MD Papier GmbH, which belongs to the UPM Group, is one of Germany’s largest manufacturers of high-quality magazine papers. Due to a shift of production to higher-grade and higher bleached products, the percentage of persistent, non-biodegradable wastewater constituents has increased.