Sludge biological treatment includes: urban domestic sludge, river and lake sludge, municipal sludge and municipal pipeline sludge.

The invention patent (zl201010252137.8) of "biological drying method of urban domestic sludge" held by the company has solved the problems of harmless, reduced, stabilized and resourceful treatment of urban domestic sludge. With the corresponding supporting patent equipment, various sludge can be treated in a large-scale, convenient and low-cost manner. The technology was "pilot tested" in the sludge disposal center of Nanchong Economic and Technological Development Zone in December 2021, and the results were reviewed and approved by the * group meeting consisting of * * in the industry.

The production process principle of this technology: urban domestic sludge generates heat (fermentation heat) in the fermentation process, and the temperature is higher than 50 ℃ for more than 120 hours, which can completely eliminate ascaris eggs and fecal coliforms in materials. For some special bacteria, it can also degrade harmful heavy metal elements. The fermentation heat generates steam, which can be discharged by proper methods to realize the drying of sludge.

According to the technological requirements of this technology, we have also studied and completed the equipment connection and production of a full set of production lines supporting this technology, and realized the industrial production of the production line.

The main advantages and characteristics of this technology are as follows:

1. The production cycle is short. It only takes 7-9 days to reduce the water content of sludge from 80% to 30%, or even to 20%. In addition, the process does not require energy consumption and additional drying. It can be completed only through on-site fermentation.

2. High degree of harmless treatment. The treated sludge is no longer thin and sticky, loose and breathable, with a slightly sauce flavor, and can fully meet the * "Control Standard for Agricultural Sludge Pollutants" (GB4284-2018).

3. Low production cost. With the sludge treatment process reaching the same standard, the existing treatment cost is more than 380 yuan per ton, and the treatment cost of this technology can be reduced by about 30%.

4. The workshop covers a small area. At present, the treatment plant for 500 tons of sludge per day generally covers an area of more than 100 mu, and the production plant of this technology covers an area of no more than 50 mu.

5. The treatment yield is large. The urban domestic sludge of 10 million people reaches about 5000 tons every day, which is difficult to meet with the existing technology. The daily processing capacity of this technology can meet the daily processing capacity of more than 1000 tons.

6. There is no secondary pollution in the treatment process. The existing technology cannot eliminate the harmful substances in the sludge, especially the incineration of sludge will bring new environmental pollution. In the process of sludge treatment, except for discharging water vapor and a small amount of ammonia, the * technology of the invention basically does not discharge other harmful gases and carbon, and does not discharge any other harmful substances that pollute the environment, including odorous gases. It is suitable for building plants in or close to densely populated cities to reduce the transport distance of sludge.

7. Less investment in infrastructure. According to the existing drying and incineration technologies, the project of treating 500 tons of sludge per day will cost about RMB 2-3 billion; With the same production capacity, only about 50 million yuan will be invested to adopt this technology.

Before sludge treatment, the moisture content of sludge is 80%, and the black color is mostly presented in lump or flocculent form, with a strong pungent smell. During treatment, special supporting equipment is used for biological treatment of urban domestic sludge. After treatment, the moisture content is less than 30%, and the material is loose and breathable, showing a powder with a slightly sauce flavor.

Process description:

1、 Liquid fermentation in sludge tank (storage tank). Add water to make the water content ≥ 90%; 1 ‰ of the treatment capacity with biological agents; Use a special mixer to mix 2~3 times a day, and enter the second stage on the third day.

2、 The water content of filter mud shall be no more than 60% after filter press dehydration. 70% filtered water is reused; 30% of the filtered water is discharged into the municipal sewage pipe network or the reclaimed water after the biological treatment reaches the standard.

3、 Material mixing. The auxiliary materials added are 5-10% of the treatment capacity; 1 ‰ of the treatment capacity is added with biological agents; Return material (adjust the initial moisture content of fermentation material).

4、 Heap fermentation. The fermentation will be completed in 7 days by turning materials 1-2 times a day with a special turning machine.

5、 The finished products are used for landscaping, tailings restoration, desert control, etc.