Unsafe Drinking WaterBy: Ann Duong

Worldwide Need

• More than 4,900 people die each day from waterborne illness; 90% are children under the age of five. Over 1.1 billion people worldwide (20% of the world population) must walk more than one kilometre to find water that is often unsafe to drink. Poor water and sanitation leads to illness, keeping children from school and parents from work, making access to improved water and sanitation the first step toward sustainable communities and the end of poverty.

http://cawst.org/index.php?id=63

Biosand Filter

Removes:

• More than 96% of fecal coli forms

• 100% of protozoa and helminthes

• 50-90% of organic and inorganic toxicants

• Greater than 75% of iron and manganese 

• Suspended sediments, in all or part

http://cawst.org/index.php?id=128#BSF

Diffuser PlateProtects the biological layer from damage when water ispoured into the filter.Outlet Pipe – 6 mm (¼”) inner diameter (I.D.) Conducts water from filter base to outside.Biological Zone: Develops at the top 5-10 cm (2-4”) of thesand surface. The sand absorbs pathogens, iron, and othersmall particles.Sand Zone: Contains virtually no living microorganismsdue to lack of nutrients and oxygen.Gravel Zone: Holds the sand in place which protects theoutlet pipe from clogging and allows for the smooth flow ofwater.

Biosand Filter

http://www.cawst.org

Biosand Filter

http://www.cawst.org

Aluminum Potassium SulfateAluminum Potassium Sulfate or Alum is a flocculating agent that helps to clarify water by coagulating particles or grouping together particles in larger masses to create heavier particles that will sink.

Raw water

Aluminum Potassium Sulfate

Questions:• How much alum is needed to clarify the water in a 30min

or less period?• How much will the alum cost per year?• Is it possible to use the alum through two rounds of

clarifying water? Three rounds?• Does the Alum have to be dissolved in distilled water first

before adding it to the raw water?– Or can the Alum crystals be put straight into the raw water?

• How many pathogens are being removed by the alum?

Aluminum Potassium Sulfate

Aluminum Potassium Sulfate

The particles that have settled at the bottom.

Raw water

Tap water

Aluminum Potassium Sulfate

Raw Water Raw Water with Alum

Water Testing

• Procedure

The first step that we took in testing water was to take a Petri dish and put 1.7ml of broth in it. Next, we sterilized the tweezers and the top of the Millipore filter and took a Millipore paper and put it on top of the filter. Afterwards, we placed a cup over the paper on the top and obtained 5ml of raw water using a pipette and squeezed it out into the cup. Then we took a syringe and sucked all the water off the top and was left behind with bacteria on top of the paper. After that, we took the tweezers and carefully placed it in the Petri dish on top of the broth. Lastly, we placed the Petri dish in the incubator at 37C

Water Testing

Lake Macatawa Water

E-coli colonies

Water Testing

Lake Macatawa Water with Alum

No E-coli colonies

Acknowledgements

• Hope College• Dr. Brown• Andy Zendler• Ricky Kelley• Dr. Moses Lee• Karen Nordell Pearson• Kara Barney• Alyson

                                

      

                         

     

THANK YOU TO OUR STUDENTS OF

REACH 2008