Reading guidance：Reading guidance : before final disposal of sludge, sludge is supposed to be preheated. The disposal of sludge generally adopts a method to reduce the moisture content of sludge. According to our natio

Reading guidance: before final disposal of sludge, sludge is supposed to be preheated. The disposal of sludge generally adopts a method to reduce the moisture content of sludge. According to our national policy, the disposal of sludge is supposed to realize harmlessness.
    Before final disposal of sludge, sludge is supposed to be preheated. The disposal of sludge generally adopts a method to reduce the moisture content of sludge. According to our national policy, the disposal of sludge is supposed to realize harmlessness, reduction and stabilization. With proper conditions, taking advantage of residual heat of flue gas can not only save energy consumed, but also can realize the harmlessness and reduce the moisture content of sludge. Therefore, using residual heat of flue gas can get environmental benefits. Meanwhile, this technology has been applied to many projects. This article briefly analyses environmental benefits led by this sludge disposal technology.
    During taking advantage of residual heat of flue gas to dry sludge and fulfill granulation, all processes including pretreatment, sludge drying, granulation and conveying of sludge are carried out in a micro negative-pressure state. Gas emissed from sludge will be sent to furnace and biological soil filter bed for being eliminated by high temperature or by soil microbe. Thus, there is no obvious peculiar smell. The drying and pelletizing process of sludge are finished under low-temperature state. In the process, just a little amount of tail gas is produced. Also, owing to high moisture content of sludge, flue gas will keep contact with sludge directly in a specially made drying and pelletizing device for a long time. As a result, sludge can absorb a great amount of flue dust in flue gas after electrostatic precipitator and can fix these flue dust in sludge pellets. On one hand, because residual heat emissed from heat power plants is made use of, atomesphere pollution is got reduced. On the other hand, because majority of residual dust in flue gas is absorbed by sludge, emission of large amount of particulate matter is reduced.
    The project example of Jiangyin shows that by taking advantage of residual heat in flue gas, the processed amount of printing and dyeing sludge can reach to 100 t/d. The investment for main machine and auxiliary equipment is about 6 million yuan. Running cost for the project (include power consumption, labor force and mechanical loss) is about 60 yuan/t. With low investment and running cost, this project can not only realize complete harmlessness, reduction and reclamation, but can also make full use of residual heat in heat power plants. In addition, it can reduce atmospheric pollution and flue dust emission, which presents fully advantages of this technology. The thermal efficiency of coal in thermal power generation plants is lower than 40%. The thermal efficiency of oil is about 50%. A great amount of residual heat is emissed to atmosphere through chimney. These flue gas will be disposed as residual heat resources. With no new energy consumed, on one hand, municipal sludge gets totally disposed. On the other hand, the exhaust gas in thermal power plants gets utilized, which achieves the aim circular economy target (use waste to dispose waste). This technology will definitely bring to obvious social, environmental and economic benefits.
    According to what mentioned above, use residual heat to dry sludge and realize reduction of sludge is a good technology. Zhenghou taida drying equipment co,. Ltd is a professional company. We adopt low-temperature thermal drying technology which has been applied to some to some areas. Our company cooperates with some famous universities at home and abroad to develop sludge dispose technology. Modified conditioning and sludge press filtration have been successfully applied to sludge disposal project. Also, this technology can find out proper sludge disposal methods for customers. 

：Sewage sludge contains persistent organic pollutants; sludge marine dumping is strictly restricted ：Sludge disposal in china is with much difficulties;agricultural use is supposed to be considered cautiously