Trickling Filters

Summary

The video explains the secondary wastewater treatment process using trickling filters, where microbes break down organic matter in wastewater. The process begins by distributing the wastewater over rotating filter arms, with the filters themselves being large, honeycomb-like structures. The microbes feed on the organic material, converting it into carbon dioxide, water, and energy. Once they've consumed the waste, the microbes die, fall off the filters, and exit as secondary sludge. This biological treatment process helps efficiently clean wastewater using minimal space, with a large surface area provided for microbial growth.

Takeaways

• 😀 The wastewater treatment process involves both primary (mechanical/physical) and secondary (biological) treatment steps.
• 😀 Secondary treatment occurs in large trickling filters, where wastewater is biologically treated by microbes.
• 😀 Wastewater is pumped to the top of trickling filters and distributed evenly by revolving pipes called distribution arms.
• 😀 The trickling filters are 86 feet in diameter and 46 feet tall, and the media inside the filter has a cross-flow design.
• 😀 The microbial growth within the filters, called zoogloeal mass, breaks down organic waste in the water.
• 😀 The microbes consume the organic matter, converting it to carbon dioxide, water, and energy for growth and reproduction.
• 😀 The surface area of each trickling filter is 3,830,000 square feet, equivalent to the size of 80 football fields.
• 😀 Microorganisms, such as nematodes, ciliates, and rotifers, help decompose the organic waste in the wastewater.
• 😀 Once the biological treatment is complete, the microbes die from lack of oxygen and fall off the filter media.
• 😀 The dead microbes form a solid known as humus or secondary sludge, which exits the filter for further processing.

Q & A

What is the purpose of the trickling filters in the wastewater treatment process?

The trickling filters are used in the biological treatment phase of wastewater treatment, where microbes consume organic matter in the wastewater and convert it into carbon dioxide, water, and energy for their growth.

How does the wastewater get distributed across the trickling filters?

Wastewater is spread evenly across the surface of the trickling filters through revolving pipes called distribution arms, which have holes, or ports, to allow the wastewater to flow over the filter media.

What is the role of the microbes in the trickling filter process?

Microbes in the trickling filter consume the organic matter in the wastewater, breaking down chemical bonds and converting the waste into simpler compounds, including carbon dioxide, water, and energy for their growth.

What type of media is used in the trickling filters for the microbes to grow on?

The microbes grow on plastic cross-flow type media, which has a honeycomb-like structure and provides a large surface area for microbial growth.

How deep is the media in each trickling filter?

The media in each trickling filter is 22 feet deep.

Why is the cross-flow design of the trickling filter media significant?

The cross-flow design allows for more biological treatment to be accomplished in a smaller space by increasing the surface area available for microbial growth.

What is the surface area of the media in each trickling filter?

Each trickling filter has a surface area of 3,830,000 square feet, which is equivalent to the area of 80 football fields.

What is the slimy growth on the trickling filter media called?

The slimy growth on the trickling filter media is called a zoogleal mass, which is where the microbes live and break down the organic material in the wastewater.

What happens to the microbes after they consume the organic matter?

After consuming the organic matter, the microbes eventually die due to lack of oxygen, fall off the trickling filter media, and exit as a solid known as humus, or secondary sludge.

What types of microbes are involved in the biological treatment process on the trickling filters?

The biological treatment process involves various microbes, such as nematodes, ciliates, and rotifers, which help break down the organic material in the wastewater.