Many industrial processes produce wastewater with a high amount of inorganic micropollutants, where the main part is constituted of heavy metals, such as zink, nickel or cadmium. These metals are not allowed to discharge to nature, as they are poisonous to and accumulate in marine life. The heavy metals are not totally unwanted in nature, as they are also seen as being essential for natural processes to occur. The border between being a micro pollutant and a micro nutrient is thin, which is the reason for having discharge limits.

The main process for heavy metal removal is chemical precipitation, where heavy metals are precipitated as an insoluble complex and bound in particles.

Using coagulation and flocculation, the heavy metals are removed in a physical-chemical process. Other processes for heavy metal removal are adsorption to an ion exchange resin or our own mineral Lexinite.