Urban sewage treatment package
What is Urban Wastewater?
This wastewater from various places such as domestic sewage, agricultural effluent, surface water from rain runoff and ice melting are all among the sub-sets of wastewater treatment. Now, in order to be able to use urban sewage again and to reduce the intensity of its pollution and to minimize its environmental risks, it must be subjected to urban sewage treatment. Ati Sazan Arsham Sanat Company, having capable experts in the field of wastewater treatment, offers all kinds of wastewater treatment packages.
The steps of wastewater treatment with urban wastewater treatment package
Various levels have been considered for urban wastewater treatment. These stages with maximum quality and minimum pollution and toxicity, a part of it enters the cycle of reuse and a part of it that contains useful substances, further processing is done on them. Other industries should be used and the parts that have very little pollution should be disposed of. The municipal wastewater treatment levels are:
The pre-treatment or physical stage of wastewater
This stage of urban wastewater treatment includes screening and separation of sand or granulation, which removes heavy, inorganic and sand-like solids so that they do not deposit in the canal and do not interfere with the urban wastewater treatment process, and do not damage the mechanical components of the device.
Primary or preliminary wastewater treatment
In this step, suspended solids are also removed. Also, settled materials called primary sludge are formed. From the bottom of the circular tanks, a clarifier is removed and the effluent is removed from the top for further urban wastewater treatment processes. At this stage, chemical methods are used to remove phosphorus, etc.
Secondary or biological treatment stage
The secondary stage of municipal wastewater treatment is done by biological method. In this stage, those microorganisms are used to decompose the pollution that use oxygen for their decomposition process, which requires the use of an aeration blower, or they work without oxygen. Also, at this stage, secondary sludge is formed.
Tertiary or advanced wastewater treatment
In this step, micro-organisms and viruses are disinfected or disinfected. Of course, the useful types that are used for biological treatment return to the primary tanks after sedimentation. Also, if biological decomposition has been done with the help of oxygen in the previous stages. Oxygenation will also take place. After completing this stage of municipal wastewater treatment, primary and secondary activated sludge will be recycled for use as fertilizer and so on.
The basic objectives of urban and residential wastewater treatment
Various industries and hospital environments are among the most polluted wastewaters of any country, especially in the type of hospitals that contain a large amount of pathogens and pathogenic agents. For this purpose, in advanced systems, after pre-treatment on site, they are poured into the municipal sewage system. Up to 99% reduction in risk and toxicity as well as reusability is provided.
Production of secondary useful materials
The activated sludge that is created during the treatment of urban sewage can be further processed on them so that they can be reused as fertilizer.
Reduction of nutrients
Finally, after the completion of urban wastewater treatment, the treatment materials will enter the environment such as rivers and lakes. If the amount of nutrients such as phosphorus and nitrogen is high. They are consumed and grow explosively by aquatic organisms such as algae. As a result, the oxygen level of the waters is low and the lives of living beings are endangered.
Prevent environmental hazards
The entry of toxic and polluted substances is dangerous for aquatic and terrestrial organisms. In addition, these substances will cause the spread of various viral, bacterial and microbial diseases.
Reduction of water reserves
If urban wastewater treatment is not carried out so that useful and healthy water can be reused, the use of underground water resources will inevitably increase. This has caused the current situation of the world and its most important challenge to be the water shortage crisis.
Municipal wastewater treatment methods
In the previous titles, we have fully explained the different stages and levels of urban wastewater treatment. But from another point of view, he organized the treatment of urban sewage with the help of three physical, biological and chemical methods.
Physical wastewater treatment method
In the physical method of wastewater treatment, the main goal is to clean the effluent or wastewater. Processes such as screening, deposition and surface removal are performed in this stage. No chemicals will be used. One of the sedimentation techniques in urban wastewater treatment is the stage of giving the mixture of heavy and insoluble and suspended substances and water to settle and separate so that they can be separated from each other.
Also, the aeration technique (aeration blower, etc.) to increase the amount of oxygen and the filtration method, especially the “sand filter” to separate the insoluble particles and to separate the surface fat and oil particles, are also carried out in the physical method of municipal wastewater treatment by a grease trap for separation.
Biological method of wastewater treatment
At this stage of municipal wastewater treatment, aerobic (needing oxygen), anaerobic (no need for oxygen) or facultative anaerobic (using another molecule such as sulfate, nitrate, nitrite, selenate, and selenite for growth and respiration) wastewater treatment microorganisms help is taken to eliminate organic and inorganic pollutants and pathogens.
Chemical method of wastewater treatment
In the chemical stage of municipal wastewater treatment, chemicals are used to remove or reduce nutritional chemicals to prevent the growth of algae and protozoa, as well as chlorine, UV lamps and ozonation (ozone generator device) to eliminate all pathogens and pathogens. becomes After that, with sedimentation, the beneficial microorganisms are returned to the primary tanks for biological treatment.
Aerated lagoon
Oxygen is provided mechanically in the aeration lagoon in the industrial wastewater treatment package. The depth of this model of ponds is generally between 2 and 5 meters and their retention time is between 3 and 10 days. Surface aerators are used to supply the required oxygen to the aeration lagoon of the urban wastewater treatment package.
Aeration lagoons in the municipal wastewater treatment package have many advantages over stabilization ponds. One of the most important advantages of the aeration lagoon is its small space requirement. The reason for the small space required by the lagoons is the increase in retention time and also the deeperness of the aerated lagoon pools. In most countries, aeration lagoons are used more than stabilization ponds, and the reason is the ease of construction and operation of this system.
Advantages of aeration lagoon in urban wastewater treatment package
The aeration lagoon does not require much surface space.
The aeration lagoon in the urban sanitary wastewater treatment package does not pollute the environment and does not emit odors. Not polluting the environment and not releasing odor is a factor to prevent insect attacks.
The problems that the aeration lagoon has. It is much less than similar methods.
Disadvantages of using an aeration lagoon in the urban wastewater treatment package
Unlike stabilization ponds, the aeration lagoon in the municipal wastewater treatment package requires basic electronic devices and mechanical equipment.
The energy consumption of the aeration lagoon is higher than that of stabilization ponds, and this reduces the cost-effectiveness of the method.
It does not have the ability to withstand incoming shocks as much as stabilization ponds.
It does not have the ability to remove nitrates.
Complete mixing aeration lagoon process
The complete mixing aeration lagoon in the municipal wastewater treatment package works similar to the extensive aeration activated sludge process. This method is different from the EAAS wide aeration method of wastewater treatment and it is used in the pond material. The aeration lagoon pond is mainly made of brick and… but in wastewater treatment with the EAAS wide aeration wastewater treatment method, the pond is made of concrete.
In the complete mixing aeration lagoon, the aerators are selected in such a way. Not only provide enough oxygen for the aerobic process of microorganisms. They can also provide optimal conditions for complete mixing in the aeration lagoon. During this process, the wastewater stay time is longer than similar processes, especially the activated sludge wastewater treatment process using the extensive aeration method of EAAS.
In the aeration lagoon in the urban wastewater treatment package, suspended microorganisms settle at the bottom of the sedimentation pond. Some of them return to the system again. Ati Sazan Arsham Sanat Wastewater Treatment Company, with the aim of protecting the environment, has provided a platform where, in addition to selling municipal sewage treatment packages and various types of sewage treatment packages, you can get information about sewage treatment packages.
Urban wastewater treatment package video
Watch the process of urban sewage treatment in Aparat
