1. Field of science and technology 

This project belongs to the field of comprehensive utilization of waste.

2. Project background 

With the rapid development of social economy and the continuous improvement of urbanization level, urban sewage treatment rates have increased year by year, and the sludge output rate of sewage treatment plants has also increased sharply. Sludge that is not properly treated and disposed of causes huge environmental pressure and economic burden to cities. How to safely and reasonably consume sludge has become an urgent problem to be solved in urban infrastructure construction.    

The cement production process is an important platform for treating urban waste. The cement rotary kiln is not only harmless treatment of waste, but also a carrier for realizing waste resource utilization. Urban sludge generally contains toxic and harmful substances. If it is not treated and piled up everywhere or directly landfill, it will cause secondary pollution to groundwater, ecological environment, etc. Using cement kilns to co-treat urban sludge is an important way to resource, reduce and harmless sludge, and is one of the best routes to treat sludge.

3. Main research contents and results achieved 

In this project, the sludge first uses chemical conditioning and mechanical pressure filtration methods to reduce the moisture content of the sludge from 80% to 50%. The chemical conditioner does not contain chlorine, potassium, sodium and other components. Then, the cement kiln is used to coordinate treatment of the deeply dehydrated sludge. The dehydration power consumption is less than 80KWh/t, which minimizes the impact of processed sludge on the cement kiln. After novelty search and retrieval by Shanghai City Information Institute, this technology has reached the international advanced level. The project has passed the scientific and technological achievement appraisal organized by the Shanghai City Diplomatic Relations Commission (Technical Character 2012-08-006).

4. Application promotion and economic and technical indicators: 

A deep dehydration demonstration line has been built in Jinshan District. The dehydrated sludge filter cake is sent to the sludge incineration and disposal production line of Wan'an Company for thorough treatment. The annual treatment capacity of sludge and other wastes reaches 20,000 tons, solving the problem of urban sludge disposal in Jinshan District; It plays a role as a demonstration for urban sludge disposal in Shanghai City and the whole country.