Technologies
Overview of Treatment Processes
Conventional mechanical-biological wastewater treatment plants are not designed to remove a broad range of micropollutants. As a result, micropollutants such as pharmaceuticals, pesticides, household chemicals, and many other substances, which occur in wastewater at low concentrations ranging from a few nanograms to micrograms per litre, are discharged into receiving waters. There, they may pose a threat to the environment and potentially to human health.
Adsorptive Processes
In these processes, the substances to be removed from the wastewater are adsorbed onto the surface of a solid material (adsorbent). Activated carbon is used as the adsorbent. Compared with other adsorbent materials, activated carbon is more cost-effective and capable of adsorbing a broad range of substances. However, activated carbon has a limited adsorption capacity. Once this capacity is exhausted, the activated carbon must be replaced.
Oxidative Processes
In these processes, micropollutants are chemically transformed by adding an oxidising agent. The micropollutants are oxidised and thereby lose their original properties. The aim of these processes is to break down micropollutants as far as possible so that they no longer have harmful effects on the environment.
Combined Processes
In principle, the various processes can be combined, allowing for numerous possible combinations.