[Hongjie Water Service] One Minute Overview [Sewage Treatment Process]

1、 What is a sewage treatment process?

The sewage treatment process refers to the use of various methods to separate pollutants contained in sewage or convert them into harmless substances, thereby purifying the sewage.

2、 What are the main methods of sewage treatment?

Common sewage treatment methods can be divided into four categories: physical method+chemical method+physicochemical method+biological method.

3、 What is the physical method of sewage treatment?

Physical method refers to the physical or mechanical separation process, mainly including sedimentation, filtration, oil separation, air flotation, centrifugal separation, etc.

4、 What is the chemical method of sewage treatment?

Chemical method refers to the process of chemical reaction between the addition of chemical substances and harmful substances in wastewater, mainly including coagulation precipitation, neutralization, redox, chemical precipitation, etc.

5、 What is the physicochemical method of sewage treatment?

Physical chemical method refers to the separation process of physical chemistry, mainly including adsorption, ion exchange, extraction, blowing off, etc.

6、 What is the biological method for sewage treatment?

Biological method refers to the metabolic process of microorganisms oxidizing and decomposing organic matter in wastewater, mainly including activated sludge, biofilm, anaerobic biological treatment, and biological treatment under natural conditions.

7、 Can you focus on biological methods?

Of course! The biological method mentioned above refers to the metabolic process of microorganisms oxidizing and decomposing organic matter in wastewater.

There are mainly activated sludge, biofilm, anaerobic biological treatment, and biological treatment under natural conditions. Let's talk about it separately and in detail~~

1. Understanding the Activated Sludge Process

Activated sludge method refers to the continuous mixed cultivation of sewage and various microbial communities under artificial oxygenation conditions to form activated sludge, which utilizes the biological coagulation, adsorption, and oxidation of activated sludge to decompose and remove organic pollutants from sewage.

The activated sludge method is also divided into SBR method, CASS method, AO method, AAO method, and oxidation ditch method.

(1.1) SBR method

The SBR sewage treatment process, also known as the sequencing batch activated sludge method, is also known as the sequencing batch activated sludge method.

It is a wastewater biological treatment activated sludge process based on the degradation of organic matter, ammonia, nitrogen and other pollutants in wastewater by suspended microorganisms under aerobic conditions. A sewage treatment technology widely recognized and adopted globally, which operates in a timely and intermittent aeration manner to change the growth environment of activated sludge.

The common process is divided into five stages: influent, aeration reaction, sedimentation, effluent, and idle.

(1.2) CASS method

The CASS sewage treatment process is a continuous process activated sludge system. It is known for its efficient removal of organic matter and nitrogen and phosphorus, and is a mature biological treatment process.

The common process is divided into five stages: sewage inflow, aeration tank, sedimentation tank, ammonia nitrogen oxidation tank, and filter tank.

(1.3) AO method

AO process, also known as anaerobic aerobic process, A is the anaerobic stage used for nitrogen and phosphorus removal, and O is the aerobic stage used for organic matter removal in water.

Its advantage is that in addition to degrading organic pollutants, it also has a certain function of nitrogen and phosphorus removal. It uses anaerobic hydrolysis technology as a pre-treatment of activated sludge, so AO method is an improved activated sludge method.

(1.4) AAO method

The AAO method, also known as A2O method (anaerobic anoxic aerobic), is a commonly used sewage treatment process that can be used for secondary or tertiary sewage treatment, as well as reclaimed water reuse, with good nitrogen and phosphorus removal effects.

(1.5) Oxidation ditch method

The oxidation ditch process, also known as the oxidation ditch process, is named after its structure being a closed circular ditch. Due to the continuous circulation and flow of sewage and activated sludge in the aeration channel, some people call it a "circulating aeration tank" or "endless aeration tank".

2. Understanding the biofilm method

The biofilm method refers to the use of membrane like biological communities fixed on the surface of inert materials to treat wastewater or waste gas.

The biofilm method can be further divided into: biofilter method, biological rotary disc method, and biological contact oxidation method.

(2.1) Biological filter

A biological filter is a bioreactor used for treating wastewater, which is filled with inert filter materials and has a biological community growing on the surface to treat pollutants.

(2.2) Biological turntable

A biological rotating disc is a bioreactor for aerobic treatment of wastewater, consisting of a water tank and a set of discs. The lower part of the disc is submerged in water, while the upper part of the disc is exposed to air. The surface is covered with biological communities, and the rotating disc repeatedly contacts the wastewater and oxygen in the air, purifying the wastewater.

(2.3) Biological contact oxidation

Biological contact oxidation, its structure includes a pool body, filler, water distribution device, and aeration device.

The working principle is to set up fillers in the aeration tank as carriers for the biofilm. The wastewater to be treated flows through the filler at a certain flow rate after being oxygenated, and comes into contact with the biofilm. The biofilm and suspended activated sludge work together to purify the wastewater.

3. Understanding anaerobic biological treatment methods

Anaerobic biological treatment is a biotechnology that has the ability to degrade macromolecular organic compounds in wastewater.

Anaerobic biological treatment method is an organic wastewater treatment method that utilizes facultative and specialized anaerobic bacteria to degrade macromolecular organic compounds in wastewater into low molecular compounds, and then convert them into methane and carbon dioxide. It is divided into two stages: acidic digestion and alkaline digestion.

In the acidic digestion stage, the external enzyme action secreted by acid-producing bacteria transforms macromolecular organic matter into simple organic acids and alcohols, aldehydes, ammonia, carbon dioxide, etc.

In the alkaline digestion stage, the metabolites of acidic digestion are further decomposed into biogenic gases such as methane and carbon dioxide under the action of methane bacteria. This treatment method is mainly used for the treatment of high concentration organic wastewater and fecal wastewater.

Mainly including anaerobic digestion, hydrolysis acidification tank, UASB, etc.

4. Understanding Biological Treatment Methods under Natural Conditions

There are two main biological treatment methods under natural conditions: water purification method and soil purification method. The purification process and mechanism of the water purification method are similar to that of the activated sludge method under artificial conditions; The purification process and mechanism of soil purification method are similar to that of biofilm method under artificial conditions.

(4.1) Biological pond

In natural or artificially renovated ponds, facilities that utilize microorganisms growing in the pond water to treat organic wastewater are called biological ponds.

(4.2) Land Treatment Law

A general term for methods of improving water quality using soil and plants, while utilizing the water and nutrients of wastewater to nourish the land.

Land treatment methods mainly include irrigation, flood irrigation, and high irrigation rate infiltration. Modern sewage treatment technology can be divided into primary, secondary, and tertiary treatment according to the degree of treatment.

As for the cost of a set of sewage treatment equipment, it depends on the customer's water production capacity, the required configuration, and the price. Hongjie Water has 10 years of experience in producing pure water treatment equipment, rich production experience, professional technology, and after-sales service team. The equipment components are all of well-known brands, with guaranteed quality and after-sales service.