Primary sludge

As primary sludge refers to the solid constituents of the waste water , which in the primary clarifier of a sewage treatment plant sediment . It occurs during the primary treatment , i.e. in the first stage of the cleaning process, through purely mechanical processes. In municipal wastewater, the primary sludge consists of faeces , leftover food, paper and similar substances. The primary sludge is then fed to a further sludge treatment. If it is not treated further, this primary sludge quickly begins to rot and thus causes a strong odor nuisance. see: sewage sludge