Introduction

Waste water treatment plants play a critical role in maintaining the cleanliness of our environment. Sewage and other types of wastewater are treated in these facilities and are released back into the environment to prevent pollution of natural water bodies. But, how exactly do these treatment plants work? In this article, we will explore the different mechanisms involved in waste water treatment plants.

Preliminary Treatment

The first stage of the waste water treatment process is the preliminary treatment stage. During this process, large debris, such as branches and plastics, are removed from the water to prevent damage to pumps and other mechanical equipment. In addition to this, grit and sand are also removed from the wastewater to prevent abrasion on pumps and other equipment.

Primary Treatment

In the primary treatment stage, large solid particles and organic matter are allowed to settle in large tanks. The organic matter sinks to the bottom of the tanks while grease and scum rise to the surface. These solids are then removed from the tanks to prevent the accumulation of sludge, which can cause issues with the treatment process.

Secondary Treatment

After the primary treatment stage, the remaining wastewater undergoes the secondary treatment stage. The aim of this process is to remove any dissolved or suspended biological matter from the wastewater. The wastewater is aerated and stirred to allow microorganisms, such as bacteria, to break down the organic matter. Once the microorganisms have had enough time to break down the organic matter, the wastewater is allowed to settle once again. The microorganisms settle to the bottom of the treatment tank as sludge while the treated wastewater is passed on to the next stage of treatment.

Tertiary Treatment

Tertiary treatment is the final stage of the waste water treatment process. During this stage, the remaining impurities, such as dissolved nutrients, are removed from the wastewater. This process involves the use of chemicals, such as chlorine, to eradicate any remaining bacteria or viruses. Once the chemicals have had enough time to neutralize the impurities, the treated wastewater is discharged back into the environment.

Sludge Treatment

The solids that are removed from the wastewater during the primary and secondary treatment stages are known as sludge. This sludge is usually thick and difficult to manage. The sludge is, therefore, treated further to separate the liquid portion from the solid portion. The liquid portion of the sludge is typically returned to the wastewater treatment process, while the solid portion is dewatered and disposed of in landfills or incinerated.

Conclusion

In conclusion, waste water treatment plants use a series of processes to treat sewage and other types of wastewater. The treated wastewater is then released back into the environment, free from harmful impurities. These plants play a vital role in ensuring the cleanliness of the environment and protecting public health.