### Introduction to Wastewater Treatment

Wastewater treatment involves cleaning used water. This process removes contaminants before the water goes back to the environment. It includes several stages that help clean the water effectively. Wastewater comes from homes, businesses, and industries. Without proper treatment, it can harm the environment and human health. The goal is to reduce pollution and make water reusable.

### Primary Treatment

The first stage is primary treatment. Here, solids are removed from the wastewater. The water flows into large tanks where solids settle at the bottom. This process is called sedimentation. Grease and oils float to the top and are skimmed off. Primary treatment removes about 60% of solids from the water. This step is important because it prepares the water for additional treatment. It is a simple yet crucial part of the process.

### Secondary Treatment

Secondary treatment uses biological processes. Microorganisms are added to the water. They eat the organic matter left in the water. This process happens in aeration tanks. These tanks supply oxygen to support microorganism growth. It helps break down waste naturally. After, the water moves to another tank where microbes settle. This process clears up to 90% of impurities. Secondary treatment is vital for reducing water pollution.

### Tertiary Treatment and Disinfection

Tertiary treatment is the final cleaning stage. It makes water safe to return to nature. This stage targets remaining pollutants that secondary treatment missed. It might involve filtration or chemical processes. After this, disinfection takes place. Disinfection kills harmful bacteria and viruses. Chlorine or ultraviolet light are common methods. The treated water is now clean and can be released into rivers or reused. Improving water safety requires all these steps. Wastewater treatment protects both the environment and public health.