Sewage Treatment & Recycling Objectives: *Describe how sewage system can make water safe to return to the environment or fit for human use **Describe how limited resources and non-renewable resources can be recycled Starter: What is sewage?

Sewage Treatment Sewage is human waste. With a growth in population, it is important that sewage is processed carefully to avoid pollution and disease.

Where does it all go! Where does the water from the washer go? When you flush the toilet where does the contents go? Where does the water from the washer go? By gravity flow, the waste is on its way to your local wastewater treatment plant!

Why treat wastewater? Causes a demand for dissolved oxygen (lower DO levels of streams) Adds nutrients (nitrate and phosphate) to cause excessive growth Increases suspended solids or sediments in streams (turbidity increase)

Levels of Treatment Primary Secondary removal by physical separation of grit and large objects (material like paper, twigs to landfill for disposal) by using filters and the grit and organic solids are allowed to settle in large tanks Secondary aerobic microbiological process (sludge) organic matter + O2  CO2 + NH3 + H2O NH3  NO3- lowers suspended solids content (into sludge) Mostly dead microbes aquatic nutrient

Secondary process 1 To tertiary process Settling collects sludge From primary process Activated sludge process Aeration and rapid mixing with aerobic bacteria, fungi and protoctists which respire aerobically breaking carb, fat and protein to CO2. H2S changes to SO4 ions and urea to NH3 and then NO3 ions. Settling collects sludge on bottom air diffuser

Secondary process 2 Or Trickle filter Beds of gravel covered with microbes get sprayed by liquid from primary treatment from large rotating arms. As the liquid trickle through the gravel the microbes break down the organic matter

Levels of Treatment continued Tertiary (advanced) _ Settle out to form more sludge _ anaerobic microbiological process with a different microbe where bacteria anareobically break organic matter to methane. It is used as fuel to operate machines in sewage plant. NO3-  N2 (escapes to atmosphere) PO4-3 if not removed in sludge in secondary process PO4-3 + Al+3  AlPO4 (s) (into sludge dumped in sea bed or on land as soil conditioner) aeration to strip N2 and re-oxygenate (add dissolved oxygen) Water leaving the plant will be treated with Cl or O3 to kill microbes and is safe to use.

to keep suspended and O2 out Tertiary process From secondary process add methanol as food source Effluent Settling collects sludge on bottom Slow mixing to keep suspended and O2 out

When the treatment is done… Effluent back to stream after a final carbon filtration and chlorination/dechlorination Sludge – very nutrient rich applied directly to land as fertilizer incinerated (good fuel after drying) composted (Compro® from WSSC) Note – Leafgro® is composted leaves and grass from MES

A NEED TO RECYCLE, REDUCE , AND REUSE

A NEED TO RECYCLE WHAT DOES IT MEAN TO RECYCLE? WHY SHOULD WE REUSE ITEMS? WHAT DOES IT MEAN TO REDUCE? WHY SHOULD WE RECYCLE? HOW CAN WE HELP?

WHAT DOES IT MEAN TO RECYCLE? RECYCLING MEANS TO USE MATERIALS AGAIN TO MAKE SOMETHING NEW!

WHY SHOULD WE REUSE ITEMS? PRODUCTS THAT STAY USEFUL REDUCE THE DEMAND FOR NEW PRODUCTS REUSING ITEMS ALSO EXTEND THE PRODUCTS NEED TO BE RECYCLED OR THROWED AWAY

WHAT DOES IT MEAN TO REDUCE? REDUCTION MEANS TO MAKE SOMETHING SMALLER USE SOMETHING LESS OFTEN

Where does it go? Much of our garbage ends up in landfills. Sometimes the garbage is taken to an Incinerator where it is burned.

HOW CAN WE HELP? We can help by learning more about and Practicing the three “R”s of management: Reduce, reuse, and recycle.

RECYCLING

We all depend on the planet to support us but we must support the planet too!

By recycling you are helping the environment in the long term.

Every time you buy something it has to be replaced on the shelf Every time you buy something it has to be replaced on the shelf. Factories produce more and more to meet our needs.

We add to pollution indirectly by increasing the demand for manufactured goods. toys electrical goods for entertainment electrical goods for convenience clothing footwear cosmetics furniture

Shops encourage us to buy more goods than we really need. They want to make as much profit as they can. We like to try new things too. We are consumers.

Factories which produce more and more manufactured goods pollute the atmosphere directly with gas and airborne particles.

Avoid goods which are expensively Non bio-degradable packaging also pollutes the environment. Packaging is expensive. Why pay more for expensively packaged goods, when the package is then just thrown away? Such packaging ends up in a landfill site and takes many, many years to biodegrade. Avoid goods which are expensively packaged

We also add to air pollution directly by using our cars when it is not always necessary to do so. Walking is healthier Cycling keeps you fit too!

Acid rain is damaging buildings, crop sand vegetation. while global warming affects the environment and weather patterns. Acid rain is damaging buildings, crop sand vegetation. The earth’s atmosphere is overheating due to the hole in the ozone layer

This is also known as the greenhouse effect.

What can we do to help?

Of course! To make the most out of what we produce we must… R E C Y C L E

These materials can be easily separated for recycling at home. glass plastic newspaper

Use paper bags and cardboard boxes for carrying your shopping Use paper bags and cardboard boxes for carrying your shopping. They can be recycled, and they are also biodegradable. Most plastic carrier bags are not eco friendly because they are made from polythene which can take many years to rot. Very few are biodegradable. Others can be returned to the shop and replaced when worn out.

Our bins are overflowing with more and more rubbish Our bins are overflowing with more and more rubbish. How many bags does your family produce every week?

Pollution harms the environment Pollution harms the environment. The environment is a life support system that all living things depend on. If the environment is harmed, so are all living things.

Recycle your old clothes by handing them down to others and then donating them to a charity shop such as Oxfam .

Recycle ink cartridges by returning them to a factory for reuse Or find out about local hospices and charities which will accept these for recycling, as they are very valuable.

STOP THE DROP!

Cut down on pollution by encouraging your family to leave the car at home and either walk, cycle or take public transport

and avoid frustrating traffic jams

Take responsibility to help the planet!

RECYCLE PLEASE!

Blue Longman p26 - 27 Copy “Sewage” from p27 Answer question 8 Copy and complete the summary.