Cradle to Gate
Identity ID
f5b72e08-7bc5-4b64-8fcf-145a8634b62b
Waste treatment
Associated ID
6058e805-8930-400f-848e-703672aa0828
Included activities starts
Included activities ends
Description
The initial sludge (95% moisture content) is first thickened and then dewatered via centrifugation with the addition of polyacrylamide (PAM), reducing its moisture content to 75%. The removed water is treated with a certain amount of FeCl3 and discharged after meeting regulatory standards. The dewatered sludge is then dried or semi-dried in a fluidized bed, significantly reducing its moisture content. The dried sludge undergoes further treatment through various processing methods.
Activity Description
During the treatment process, sludge first undergoes a thickening stage to reduce its volume and increase its solids content. The thickened sludge is then dewatered, where flocculants are applied to further reduce its moisture content. The separated water is treated with flocculants and discharged after meeting regulatory standards. The dewatered sludge proceeds to the drying stage, where thermal energy is used to reduce moisture, enhancing stability and facilitating subsequent treatment or utilization. The dried sludge is further processed through various treatment technologies.
Process Description
"Sewage sludge" is a byproduct generated during the urban wastewater treatment process. 100% sewage sludge, with a moisture content of 97%. 5%, "sludge" consists of the following components: microorganisms, animal and plant residues, inorganic minerals, potential heavy metals, micropollutants, and pathogens. Treatment methods for this by-product include sanitary landfilling, municipal incineration, and use as a raw material for clinker production. Additionally, sludge can be converted into bioenergy through anaerobic digestion or applied to land following stabilization. In the HiQ database, treatment methods for this by-product include incineration, landfilling, aerobic composting, anaerobic digestion, wet oxidation, pyrolysis/hydrothermal carbonization, and land application. Furthermore, this by-product is utilized in the following processes: clinker production, among others.
Time period
2022
2026
Geography
China
Geography comment
National statistics, literature research
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
In China's sludge treatment processes, the thickening stage mainly increases the solid content of sludge through gravity thickeners. Commonly used equipment in the dewatering process includes centrifugal dewatering machines, belt press filters, and plate-and-frame filter presses. Sludge drying technologies include direct heating, indirect heating, or hybrid heating methods.