Nitrates, Phosphates, Hardness

Nitrate

i. What is this contaminant?

Nitrate is a colorless, odorless, and tasteless compound in some groundwater. The term nitrate refers to a salt or ester chemical compound. These chemicals are often found in the ground, so that is how they get into our water supply. Nitrates contain nitric acid and fit into the chemical group ONO2 or NO3. It is a polyatomic ion with the molecular formula NO3−and a molecular mass of 62.0049 g/mol. Nitrates also describe the organic functional group RONO2. These nitrate esters are a specialized class of explosives.

ii. How does it hurt us?

High nitrate levels in water can cause blue baby syndrome, a condition found especially in infants under six months. The stomach acid of an infant is not as strong as in older children and adults. This causes an increase in bacteria that can readily convert nitrate to nitrite (NO₂).

Nitrite is absorbed in the blood, and hemoglobin (the oxygen-carrying component of blood) is converted to methemoglobin. Methemoglobin does not carry oxygen efficiently. This results in a reduced oxygen supply to vital tissues such as the brain. Methemoglobin in infant blood cannot change back to hemoglobin, which normally occurs in adults. Severe methemoglobinemia can result in brain damage and death.

People deficient in the enzyme that changes methemoglobin back to normal hemoglobin are all susceptible to nitrite-induced methemoglobinemia. The most obvious symptom of methemoglobinemia is a bluish color of the skin, mostly around the eyes and mouth. Other symptoms include headache, dizziness, weakness or difficulty in breathing.

iii. How does this get in our water?

The major sources of nitrates in drinking water are runoff from fertilizer use; leaking from septic tanks, sewage; and erosion of natural deposits, so when we use fertilizers they get in the soil and from there to the underground water supply. Nitrate contamination occurs when there is more nitrate in the soil than plants can use and when water can move easily through the soil and underlying rock. The excess nitrate is carried through the soil into groundwater supplies by irrigation, rainwater, and snowmelt. This occurs particularly where the soil is sandy, gravely, or shallow over porous limestone bedrock.

iv. How do we get rid of them?

While it may be technically possible to treat contaminated groundwater, it can be difficult, expensive and not totally effective. Because of this, prevention is the best way to ensure clean water. Water treatments include distillation, reverse osmosis, ion exchange or blending.

Distillation boils the water, catches the resulting steam, and condenses the steam on a cold surface (a condenser). Nitrates and other minerals remain behind in the boiling tank.

• Reverse osmosis forces water under pressure through a membrane that filters out minerals and nitrate. One-half to two-thirds of the water remains behind the membrane as rejected water.
• Ion-exchange takes another substance, such as chloride, and trades places with nitrate.
• Blending Mix contaminated water with clean water from another source to lower overall nitrate concentration.

Proper management of fertilizers, manures, and other nitrogen sources can also minimize contamination of drinking water supplies.

Works Cited

http://www.ask.com/question/what-are-nitrates-and-how-do-they-get-into-our-water-supply
http://en.wikipedia.org/wiki/Nitrate
http://answers.yahoo.com/question/index?qid=20090311154632AARgJHk
http://www.ext.colostate.edu/pubs/crops/00517.html
http://aces.nmsu.edu/pubs/_m/m-114.html

Phosphates
i) What is this contaminant?

• A phosphate, an inorganic chemical, is a salt of phosphoric acid. Some examples of phosphates are fertilizer, bleach, laundry detergent, etc.

ii) How do they hurt us?

• Phosphates do not hurt human beings, and phosphorus is actually a good thing that your body needs.  Phosphorus helps the body absorb vitamin B, helping the body create energy, and strengthening of bones and teeth. Phosphates do hurt water sources by growing to much algae/ other plant life and take over the animals in that water source.

iii) How do they get in our water?

• Most phosphates get in our water by using water over and over again. But another way that phosphates can get in our water is by runoff water. The phosphates come off of rocks and other minerals.

iv) How do we get rid of them?

• There are two processes mainly used. One is Phosphate precipitation; where chemicals are used and put in the water that attach to the phosphates and cause them to turn into a crystal form. The other process is Biological processes; where the water goes through sludge wasting to remove the minerals in it. 
•  http://www.lenntech.com/phosphorous-removal.htm  

Hardness in Water

By: Alex Veneman

• What are these Containments?

Ø Water that is “hard” is water that is high in dissolved minerals and these minerals are calcium and magnesium. The more of these dissolved minerals that are apparent, the harder the water becomes. So the minerals that are in water affect the hardness of the water.

v How do they hurt us?

Ø Hardness in water really can’t hurt us it actually somewhat does the opposite. Again hardness in water is the amount of calcium and magnesium that water contains. Calcium in something that our body loves due to it strengthening our bones. So the calcium that in in hard water is actually a good thing that will strengthen our bones and help give us our daily requirement of calcium. Although they don’t pose any health concerns it does do some harm to some of the appliances you may have to help clean your dishes, laundry, and others.

v How do they get in our water?

Ø These minerals that define the hardness in water get in our water naturally. Water will naturally get these minerals such as calcium and magnesium just as any other type of natural occurrence.

v How do we get rid of this?

Ø To get rid of the hardness in water you have to use one of a few techniques to do so. One that is known to probably be the best technique is by using water softener. You just add this water softener to the water and it will make the water softer and obviously hardness is the opposite of softness. To do this you must install an ion-exchange system.

http://www.chemistry.wustl.edu/~edudev/LabTutorials/Water/FreshWater/hardness.html
http://www.watersystemscouncil.org/VAiWebDocs/WSCDocs/1683274HARDNESS.PDF