Domestic wastewater treatment

 

Domestic wastewater treatment with SBR technology

Choosing domestic wastewater treatment technology for BUILDINGS AND RESIDENTIAL AREAS based on pre-treatment wastewater characteristics and post-treatment domestic wastewater requirements to choose modern technology , saves construction area, low initial investment costs, convenient and low future operating costs. SBR Technology is the top choice solution.

Introduction to domestic wastewater treatment methods

SBR technology explanation

• Step 1. Pre-treatment

Wastewater from the kitchen and food court goes through the grease separator tank and wastewater from the septic tank and other functional areas flows through the collection system to the air conditioning tank.

Here the wastewater is flowed through a garbage separator to remove solid residue larger than 20mm in size and sand from the waste stream.

At the equalization tank, two submersible pumps are arranged to pump wastewater from the equalization tank to the biological system. In addition, the air conditioning tank is equipped with an aeration system. This is to create disturbance in the wastewater to avoid sedimentation. At the same time, anaerobic digestion occurs in this tank. Create a uniform environment for the waste stream before going through the next treatment steps.

• Step 2. ASBR batch biological treatment

The biological treatment tank system includes a Selector buffer tank. Two ASBR batch aerobic biological tanks

The Selector buffer tank is intended to ensure environmental stability for the subsequent microbial treatment cluster. At the same time, add nutrients such as Phosphorus and Carbon sources (sugar/molasses…). In addition, the slector tank design significantly reduces the growth of filamentous bacteria in the batch aerobic treatment tank. The strong growth of filamentous bacteria is the main cause of difficult sludge settling and post-treatment wastewater quality. poor reason.

Wastewater after passing through the buffer tank is evenly distributed to the ASBR biological treatment system.

The biological treatment process in the combined ASBR tank is carried out in a system consisting of 2 tanks in series.

In the tank, a gas distribution pipe system is installed. Air is blown in from blowers to provide oxygen for the biological treatment process. Decanters are also installed to collect wastewater after settling and transfer it to the disinfection tank.

The tank has the following functions: both a biological reaction tank and a sedimentation tank. Wastewater is put into each compartment depending on the cycle.

Excess activated sludge generated during the treatment process is automatically discharged by valve with the wastewater cycle into the system.

In an ASBR tank, a cycle includes 3 separate processes: Filling – reactive aeration (50% of the entire process), settling without aeration (25% of the process) and draining (25% of the process), over a period of 6 hours/cycle.

These three processes take place sequentially in the same SBR tank, according to the principle of repeating each batch. At the same time, each tank will perform different processes in a treatment cycle. At the same time, ensure wastewater is continuously treated. The stages are as follows:

• Filling and reaction (3 hours): The amount of time aeration or agitation is applied to achieve the desired biological treatment effect.
• Settlement (1.5 hours): Aeration or agitation is temporarily stopped to allow solids to settle to the bottom of the tank. Leave a clear layer of treated water on top.
• Water collection (1.5 hours): The water will be drained out and go into the disinfection tank.

Here, most of the pollutants in wastewater such as BOD, COD, N, P are removed thanks to the biological treatment process taking place in the ASBR tank.

Then, the wastewater will flow to the disinfection tank. Here wastewater is exposed to Chlorime chemicals at appropriate doses. Follow the zigzag flow to create contact time between wastewater and disinfectant chemicals. Treated wastewater is always guaranteed to meet type B discharge standards according to QCVN 14: 2008/BTNMT.

Sludge and residue treatment: Sludge is generated in the ASBR tank and the sediment is pumped to the treatment tank mud management. With appropriate retention time, the sludge in the sludge treatment tank is compressed from a concentration of 1% to 2%, and is periodically sucked to landfill or fertilized with green plants according to regulations.

Technology review in domestic wastewater treatment

SBR technology chosen in domestic wastewater treatment has the following advantages:

• Meet the technical requirements of the BUILDING
• Meet the fluctuations of input wastewater, the quality of treated water is stable and highly effective.
• Can handle nitrogen and phosphorus compounds.
• The system is designed to be semi-automatic
• Output water is guaranteed to meet required quality
• Less sludge produced.