The integrated buried domestic sewage treatment equipment is primarily based on the A/O biochemical process, integrating biological degradation, sewage sedimentation, oxidation disinfection, and other processes for domestic sewage and similar industrial wastewater. The equipment features a compact structure, minimal land occupation, full underground installation, economical operation, strong resistance to impact concentration, high treatment efficiency, and convenient management and maintenance. Through user applications, all performance aspects of the equipment meet relevant requirements. This product is technologically mature, easy to operate, and is bound to contribute to the human living environment.

II. Equipment Features

1、Can be buried below the surface, with the upper part planted with flowers, trees, or lawns, or installed indoors.

2、No impact on the surrounding environment, minimal sludge production, noise level below the standard for Class II areas.

3、Fully automatic control, no need for professional management.

4、Easy operation, convenient maintenance, advanced technology, effective results, long service life.

5、Equipment can be arranged according to standard layouts or customized based on terrain needs.

III. Scope of Application

1、Treatment capacity: Standard type 1.0～80.0 (m3/h), designs exceeding 80.0 (m3/h) require custom planning.

2、Raw water concentration: BOD5: Standard type ≤250mg/L, enhanced type ≤400mg/L, concentrations above 400 mg/L require custom design.

3、Mainly suitable for domestic sewage and similar industrial wastewater from residential areas, hotels, docks, airports, shopping malls, highways, sanatoriums, schools, factories, and mines.

IV. Material Selection for Sewage Treatment Equipment

1、Full stainless steel structure

2、A3 steel plate structure

3、(Q235) steel plate and fiberglass reinforced plastic (FRP) composite structure

4、Fiberglass reinforced plastic (FRP) circular

5、Reinforced concrete structure    

V. Schematic Diagram of Process Flow

VI. Equipment Process Description

 The equipment is designed primarily for treating domestic sewage and industrial organic wastewater. The main treatment method employs the mature biochemical treatment technology of the contact oxidation tank. Water quality design parameters are based on an influent BOD5 of 250mg/L and an effluent BOD5 of 20mg/L. It consists of seven parts: (1) Primary sedimentation tank; (2) Anoxic tank; (3) Contact oxidation tank; (4) Secondary sedimentation tank; (5) Disinfection tank and disinfection device; (6) Sludge tank; (7) Blower room.

⑴Primary sedimentation tank: A vertical flow sedimentation tank where the upward flow velocity of sewage is 0.3～0.4 mm/sec. Settled sludge is lifted to the sludge tank. Models SFW-5 and below do not include a primary sedimentation tank.

⑵Anoxic tank: Set up for denitrification, equipped with YDT three-dimensional elastic filler as a carrier for denitrifying bacteria. Nitrate and nitrite in the nitrified liquid are reduced to nitrogen gas by denitrifying bacteria, achieving denitrification. The effective retention time is 2.5～3.5h, with dissolved oxygen controlled at ≤0.5mg/L.

⑶Contact oxidation tank: Sewage flows by gravity into the contact tank for biochemical treatment. The contact tank is divided into three stages with a retention time of 8h (enhanced models can have 6～10h). The filler is a novel elastic type, easy to form biofilm and resistant to clogging. The air-to-water ratio in the contact oxidation tank is about 15:1.

⑷Secondary sedimentation tank: Treated sewage flows into the secondary sedimentation tank, which is a vertical flow type with a surface load of <1.0 m3/m2·h. Sludge is discharged and lifted to the sludge tank.

⑸Disinfection tank and disinfection device: The disinfection tank follows the "TJ14-74" standard with a retention time of no less than 30 minutes. For hospital sewage, the retention time can be extended to 1～1.5h.

Disinfection uses solid chlorine tablets that dissolve on contact. The disinfection device adjusts the dosage based on the effluent flow rate, ensuring more chemical for more water and less for less. Other disinfection devices can be configured as needed.

VII: Electrical Control

The sewage treatment equipment system is fully automated with microcomputer control and includes fault alarm indication功能.

wdsType Equipment Installation, Use, and Maintenance

Equipment can be placed in two ways:一、Above ground;二、Below ground.

The foundation must bear an average pressure >5 t/m2 and be level. For underground installation, the foundation's relative elevation to the ground should match the equipment height. Once positioned, fill the equipment with water to prevent floating due to groundwater.

Before use, check the electrical system of the equipment for normal operation and ensure the blower oil meets requirements until fully qualified.

Establish a regular maintenance schedule. The blower must not reverse. Regularly check the blower oil and clean the air intake. Maintain the blower and pump every 5000 hours of operation.

VIII: Buried Sewage Treatment Project Site Examples