The sludge is produced by the sewage treatment process.
Semisolid precipitate
It contains "organic matter, bacterial bacteria, inorganic particles".
Sludge is in the process of sewage treatment.
Caused by decomposition or transfer of pollutants
According to the source, it can be divided into domestic sludge and industrial sludge.
Domestic sludge comes from domestic sewage, which has a high content of organic matter and is easy to decay and stink; industrial sludge comes from industrial wastewater, and there are many toxic and harmful substances, most of which belong to hazardous wastes (such as electroplating sludge).
The moisture content of sludge is very high.
High moisture content of sludge takes up special space.
Sludge treatment
The primary goal is dehydration.
Reduce moisture content
The moisture content of a barrel of sludge is 99%.
If the moisture content is reduced to 96%, the volume of sludge is 1 inch 4.
If the moisture content is reduced to 80%, the volume of sludge is 20% of the original one.
Common dehydration methods are
Gravity concentration
Gravity concentration through sludge thickener
The moisture content of sludge is about 99% to 96%.
Mechanical dehydration
Dewatering by filter press, stacked screw centrifuge or belt
The moisture content of sludge is about 96% and 80%.
Deep dehydration
With gravity concentration and mechanical dewatering at the front end, it is still difficult to remove "capillary water" and "attached water" from the sludge.
Therefore, in the past two years, the state began to introduce relevant policies to encourage sludge reduction and resource utilization; sludge deep dewatering has become a necessary part of sewage treatment!
After "deep dewatering", the moisture content of the sludge is reduced to 20%, which greatly reduces the storage space and makes pretreatment for the resource utilization of the sludge.
Where does the sludge end up?
Hazardous waste sludge will be sent to qualified disposal units
Solidification, incineration, landfill
Domestic sludge is sanitary landfill.
But due to the tension of the venue,
Some of the sludge has begun to take the route of resource utilization.
Used in the production of building materials, incineration, land use