The invention discloses a method for utilizing high-load
earthworm biological filter to treat decentralized
sewage in countries, and relates to a
sewage treatment method. The treatment method comprises the following steps: the decentralized
sewage in the countries is firstly collected;
suspended matter and floating matter are removed by a pretreatment tank; BOD5 is led to be 110 to 160mg / L, COD is 120 to 150mg / L and SS is 90 to 130mg / L; then the obtained mixture is pumped into the high-load
earthworm biological filter according to hydraulic loading of 4 to 6m<3>(m<2>
question mark d); after passing through a first
earthworm biological filtering layer and a second earthworm biological filtering layer which are filled with light shale spherical porcelain granules (7) filtering media with the
diameter of 3 to 7mm and 15000 to 28000 eisenia foetidas (8) are added on the surface of the filtering media per
square meter, the water which is discharged from a
settling tank (6) and has BOD5 of less than 15mg / L, COD of less than 60mg / L and SS of less than 15mg / L reaches the national
water quality standard for field
irrigation; little amount of residue
sludge which is collected by the
settling tank (6) and contains wormcast is used for improving the soil or is used as fertilizers. The method has large hydraulic loading, small occupy area, is hard to be blocked, has simple process and operation, good water outlet quality and low construction cost and
operating cost and can be widely used for treatment of the waste water in rural areas.