Sedimentation water treatment. Municipal and industrial wastewater goes to the wastewater treatment plants where it is purified and the waste is dried and disposed of.

First the wastewater goes through a preliminary treatment that consists of solidification, stabilization, conditioning, destruction of colloidal structures of sediment and dehydration.

The first step of wastewater treatment is filtering with removal of large particles by passing the water through nets and smaller particles through the screen of the filters. It is followed by clarification and settling of sludge. These processes remove about 50-60% of suspended solids, and the deposited sludge contains a substantial amount of organic matter.

Sedimentation water treatment. Then, the wastewater is subjected to secondary and tertiary treatment (biological treatment), with introduction of the aerobic (or anaerobic) microorganisms that feed on the remains of organic suspended solids, destroying them. Thereafter the wastewater goes into the secondary settling tank  where it deposits 90% of organic matter. Dehydration and drying of the settled sediment requires further energy costs. The process of drying can be performed by the clinker heat and the rotary kiln gases. The whole alternative fuel on the basis of sewage sludge was created for the cement and energy industry in Poland.

The resulting sediment can be used as fertilizer, fuel, heat or electricity, capable of replacing similar traditional products.

In the firing of Portland cement clinker the dried sediment is used as an alternative fuel and burned together with coal. Maximum sediment flow rate must not exceed 5% of the capacity of clinker production.