The requirement for wastewater treatment systems must achieve a minimum removal efficiency of 90% of suspended solids, 96-97% for COD, BOD and more than 99% of harmful microorganisms.
Treatment technology: The wastewater treatment process is selected according to the 3-step treatment plan in order to minimize the waste content.
Processing
Preliminary: Trash collection, sand settling, balancing, flotation
Tier 1: Anaerobic treatment in UASB tanks
Tier 2: Aerobic aerobic treatment
Tier 3: Converting, settling, sterilizing
It includes following steps:
- Garbage filtering by automatic refuse machine
- Waste water collection, balance and open oil separation
- Level 1 of treatment by anaerobic method in UASB tank
- Level 2 of treatment by aerobic biological method in AEROTEN tank
- Level 3 of treatment by physicochemical methods: flocculation, deposition and sterilization.
Sludge is sucked into the mud compartment, sludge decomposition tank and eventually sucked into the landfill or used to fertilize the plant.
Technology line: Wastewater → Scrap net → Basin → Flotation basin → Basin → Basin with anaerobic sludge → Activated sludge tank → Sediment tank → Sterilizer → Water after treatment (TCVN 5945-2005 type A).
Technology Interpretation
Wastewater is collected by solid waste before being collected into the tank. From the collection tank, wastewater is collected through flotation equipment and then flows into the air conditioning tank (usually using the flotation method: the solution is too saturated and the pressure is reduced. The air bubbles are separated from the solution, causing the dirt to build up).
Air conditioners regulate flow and concentration. From the wastewater treatment tank is continuously pumped into the anaerobic biological tank containing the contact material, then the hydraulic effluent flows into the activated sludge tank. The organic matter present in the waste water disintegrates by aerobic bacteria, which is suspended in a high density (activated sludge) suspended in aeration. Next, the wastewater is passed through the settling tank before being discharged into the sterilizer. Wastewater is disinfected with chlorine, then filtered before being discharged into the environment.
The sludge in the settling tank is led into the silt reservoir. Here a part of the mud is recirculated to the activated sludge. The excess sludge is drawn periodically.
For treatment of aquatic wastewater, especially bloody catfish, many open with high concentration of pollutants must simultaneously apply many methods as above: physicochemical methods (separation of garbage, split open by flotation , sedimentation, sterilization, pressure filtration); biochemistry (anaerobic principle: biofilter with buffer material; aerobic principle: aeration aerator with an activated sludge with microbial enzyme).
Construction works include construction items and equipment as follows:
- Waste water tanks and pumps
- Floating tank, air compressor, high pressure pump, driving motor
- Air conditioners, pumps
- Anaerobic digesters, sewage pumps
- Activated sludge tank, air blower
- Sedimentation tank, speed reducer
- Sludge tank, circulating pump
- Disinfection tank, dosing pump, chemicals
