TRATAMENTO DE ESGOTO

Summary

This video explains the importance of sewage treatment and the process of cleaning wastewater to prevent pollution and protect public health. It covers the steps involved in the treatment of sanitary sewage, including the removal of large debris, sand, and heavier solids, followed by aeration tanks where microorganisms break down organic matter. The process ends with the release of clean water into rivers, while the activated sludge is recycled to continue purifying incoming wastewater. The video also highlights the role of sewage treatment in basic sanitation and its environmental benefits.

Takeaways

• 😀 Over 100 million people in Brazil generate raw sewage that is dumped into rivers daily, causing serious environmental and health problems.
• 😀 The untreated sewage leads to water pollution, which harms aquatic life, flora, and poses health risks to humans, even causing deaths in some cases.
• 😀 It's crucial to treat sewage before releasing it into rivers to prevent environmental damage and protect public health.
• 😀 Sewage is first collected from homes and businesses through underground pipes and sent to a treatment plant.
• 😀 After treatment, the sewage is much cleaner and can safely be released into rivers without causing harm to the environment.
• 😀 The treatment of sewage is part of basic sanitation, an essential service that ensures public health and environmental protection.
• 😀 There are different methods for treating sewage, and the method used depends on the physical, chemical, and biological properties of the wastewater.
• 😀 The activated sludge method, commonly used in São Paulo, is ideal for treating large volumes of sewage.
• 😀 The sewage treatment process starts with screening to remove large debris like plastic, paper, and other solid waste.
• 😀 The sewage then passes through a sand box to remove sand and other dense particles.
• 😀 In the primary settling tank, heavier particles and solids float or sink and are removed before the sewage goes to aeration tanks where microorganisms help break down organic matter.
• 😀 In the aeration tanks, activated sludge is formed from microorganisms that consume the organic material, further cleaning the sewage.
• 😀 After aeration, the sewage moves to the secondary settling tank, where remaining solids and sludge are removed.
• 😀 By this point, about 90% of impurities have been removed from the liquid part of the sewage, making it safe to release into the river.
• 😀 The activated sludge is recirculated back to the aeration tanks to continue breaking down new sewage, and any old sludge is disposed of safely, often used for fertilizer or landfills.

Q & A

What is wastewater treatment and why is it important?

Wastewater treatment is the process of cleaning sewage and other wastewaters to remove harmful contaminants before releasing it into rivers or oceans. It is important to prevent water pollution, protect public health, and safeguard ecosystems.

How does untreated sewage affect the environment and public health?

Untreated sewage can cause severe environmental damage by polluting rivers, harming aquatic life, and disrupting ecosystems. It also poses significant health risks to humans, including waterborne diseases that can lead to serious illnesses and even death.

What is the first step in the wastewater treatment process?

The first step is screening, where large debris such as paper, plastic, and other solid objects are removed from the wastewater. This is done using a series of screens and grids.

What happens to the sand and gravel found in the wastewater?

After screening, the wastewater flows into a sand trap or 'sand box', where sand and heavier particles settle at the bottom. These materials are then removed and disposed of.

How does the primary sedimentation (decantation) process work?

In the primary sedimentation tank, the heavier solids and floating debris settle to the bottom of the tank due to gravity. This process removes a significant portion of the solid waste from the wastewater.

What is aeration in the wastewater treatment process?

Aeration is the process of adding oxygen to the wastewater to encourage the growth of microorganisms that break down organic matter, such as food waste and other biodegradable materials.

What is 'activated sludge' and how is it formed?

'Activated sludge' is a mixture of microorganisms (bacteria, protozoa, and other microbes) that feed on organic matter in the wastewater. It is formed in aeration tanks, where microorganisms multiply rapidly due to the presence of oxygen.

What happens in the secondary sedimentation tank?

In the secondary sedimentation tank, the remaining solid particles, including much of the activated sludge, settle to the bottom. The clarified water on top is then collected and can be safely released into rivers or other bodies of water.

Why is activated sludge recirculated in the treatment process?

Activated sludge is recirculated to ensure that enough microorganisms are present to continue breaking down organic matter in the wastewater. This recirculation increases the efficiency of the treatment process.

What happens to the waste sludge after treatment?

The excess sludge is removed from the secondary sedimentation tank and can be sent to specialized companies for disposal. It is often transported to landfills or used in agricultural processes as compost or fertilizer.

What is the environmental impact of properly treated wastewater?

When wastewater is properly treated, the harmful contaminants are removed, and the water released back into rivers is much cleaner. This helps protect aquatic ecosystems, reduces the risk of waterborne diseases, and supports overall public health.