Process of Wastewater Treatment

There are two types of wastewater treatment plants: chemical or physical treatment plants and biological wastewater treatment plants. Chemical or physical treatment plants are the most common. Biological waste treatment plants break down waste matter by utilising biological matter and bacteria. As an alternative, physical waste treatment plants treat wastewater through the use of chemical reactions as well as mechanical procedures. While biological wastewater treatment systems are ideal for treating wastewater from residential and commercial properties, physical wastewater treatment plants are most commonly used to treat wastewater from industries, factories, and manufacturing facilities, among other things.

Process

Phase separation (such as sedimentation), biological and chemical processes (such as oxidation), and polishing are all examples of processes that are commonly used. The primary by-product of wastewater treatment plants is a type of sludge, which is usually treated in the same or another wastewater treatment plant after it has been generated. 

Biogas is another by-product of anaerobic treatment processes that can be produced. It is possible that some wastewater will be highly treated and repurposed as reclaimed water. The primary goal of wastewater treatment is to ensure that treated wastewater can be safely disposed of or reused after it has been processed. However, before the wastewater is treated, it is necessary to consider the options for disposal or reuse in order to ensure that the most appropriate treatment process is used on the wastewater.

Treatment plants are classified into several categories.

It is possible to distinguish between wastewater treatment plants based on the type of wastewater that needs to be treated. Depending on the type and extent of contamination, a variety of wastewater treatment processes can be used to treat it. Physical, chemical, and biological treatment processes are all included in the treatment process.

The following are examples of wastewater treatment plants:

• Sewage treatment plants

• Wastewater from Modern Industries

• Agricultural wastewater treatment plants

• Leachate treatment plants

Sewage treatment plants

There are a large number of different sewage treatment processes from which to choose. From decentralised systems (which may include on-site treatment systems) to large centralised systems (which may include sewerage), these systems can transport sewage to a treatment plant through a network of pipes and pump stations (referred to as sewerage). It is expected that the sewers will also transport stormwater to the sewage treatment plant in cities that have combined sewers. Sewage treatment is typically divided into two stages: primary treatment and secondary treatment. Advanced treatment may also include a tertiary treatment stage, which may include polishing processes and nutrient removal, in addition to the two main stages. When organic matter (measured as biological oxygen demand) from sewage is reduced through aerobic or anaerobic biological processes, secondary treatment can be performed.

Treatment using various living organisms

Many different sewage treatment technologies, the majority of which use biological treatment processes, have been developed over time. When selecting a suitable technology, engineers and decision makers must take into consideration technical and economic criteria, as well as quantitative and qualitative aspects of each alternative when making their decision. Using a treatment plant, wastewater from an industrial process can be converted to solids and treated water that can be reused.

Wastewater from industries

Industrial wastewater treatment refers to the processes that are used to treat wastewater that is produced as a by-product of industrial operations and is therefore undesirable. Following treatment, treated industrial wastewater (or effluent) may be reused or discharged into a sanitary sewer or a surface water body in the environment for further treatment. Sewage generated by some industrial facilities can be treated in sewage treatment plants, which are located near the facilities.

 In most industrial processes, such as petroleum refineries or chemical and petrochemical plants, there are dedicated wastewater treatment facilities in place to ensure that pollutant levels in treated wastewater comply with local, state, and federal regulations regarding wastewater disposal into sewers, rivers, lakes, or the ocean.

Industries that generate wastewater with high concentrations of organic matter (for example, oil and grease), toxic pollutants (for example, heavy metals and volatile organic compounds), or nutrients (for example, ammonia) should be considered. The wastewater from some industries is treated in a pre-treatment system to remove some pollutants (for example, toxic compounds), and the partially treated wastewater is discharged into the municipal sewer system.

The following is a flow chart and diagram of the wastewater treatment process:

The majority of industries generate some amount of wastewater. Recent trends have been toward reducing the amount of such production or recycling treated wastewater back into the manufacturing process. Manufacturers in some industries have had success in redesigning their manufacturing processes in order to reduce or eliminate pollutants. Chemical precipitation and filtration are examples of solids removal processes. Other processes include removal of biodegradable organics, other organics, acids and alkalis, and toxic materials. Brine treatment is one of the most common treatment processes.

Conclusion

There are three types of nonpoint source pollution: sediment runoff, nutrient runoff and pesticides. A number of sources of point source pollution exist, including animal waste, silage liquor, milking parlour (dairy farming) waste, slaughterhouse waste, vegetable washing water, and firewater. Many farms generate nonpoint source pollution from surface runoff, which is not controlled by a treatment plant, and this pollution is harmful to the environment.