They are distinguished by an increased content of heavy metal compounds and surfactants, pathogenic microflora and helminth eggs. These factors determine the features of disposal and processing of sediments.
The main purpose of chemical treatment is usually the stabilization and compaction of the sludge. For this, quicklime is most often used, which is added in a ratio of 10-30% of the sediment volume. This allows you to get rid of the smell (by increasing alkalinity) and pathogens, as well as salmonella. Rainfall dries faster.
Along with lime, ferric chloride is often used, as well as iron and aluminum sulfates.
For disinfection (short-term) use peroxide compounds and chlorine. Along with them, thiazon or dazomet are used, which are applied in a ratio of 0.2-2% to the total mass of precipitation with an exposure of at least three days. Treated with thiazon and aged (up to 30 days in heaps covered with film) in this way, the substrate can be applied to the soil after harvest.