Sludge, as its name suggests, is formed by the precipitation of organic matter and non-degradable materials during sewage treatment. Sludge, which was not treated harmlessly in nearly 50% of cities five years ago, is now on the way to continuous improvement. At the same time, the short board of heavy water and light mud in the construction of urban sewage treatment plant has been gradually filled up.
It should be the last kilometer of tamping urban and rural sewage treatment, but sludge disposal is regarded as a hot potato.
For a long time, sludge disposal has been a common problem faced by sewage treatment industry at home and abroad, which has become an important bottleneck restricting the benign development of sewage treatment plants. According to the source, sludge is mainly divided into municipal sewage sludge and industrial wastewater sludge. Statistics show that, as a derivative of municipal sewage treatment, the annual output of municipal sludge in China increases year by year. According to statistics from the Ministry of Construction, the country's sewage treatment volume reached 178 million cubic meters per day in 2017. So far, the number of urban sewage treatment plants in China has broken through 2000, and the annual sewage treatment capacity has increased by more than one time than during the 15th five-year plan period.
But this and sludge treatment of the rapid growth of the demand is still a serious mismatch. Also in 2017, the target completion rate of sludge harmless disposal rate in China was less than 45%. With the increase of sewage treatment capacity and the upgrading of sewage plants, it is expected that in 2020, the annual capacity of 60 million tons (80% moisture content) will be exceeded, and the daily production of wet sludge (80% moisture content) will reach 140,000 tons. If these sludge has not been treated, it is bound to explode the environmental crisis; Time bomb; . In fact, although sludge disposal has been promoted for many years, there are still unsolved problems in China, such as focusing on water and sludging, low disposal rate and unknown responsibility subject.
How much does it cost to dispose of sludge? Public information shows that the operating cost of sludge treatment and disposal accounts for about 20-30% of the operating cost of sewage treatment, resulting in the operating pressure of sewage treatment plants to a certain extent. As the city