Home Water and Bottled Water

Ceramic Filtration Carbon Ion Exchange Water Filters 3-stage water filtration

Purified Water Inlet Carbon Block Water Filters

Activated Carbon Activation by heating Extremely porous with high surface area: 500 m 2 /g Surface areas as high as 1500 m 2 /g are achievable 3 grams activated carbon

Activated Carbon Filtration Particle size removal > 0.5 microns Bacteria range in size from microns in width and up to 1-10 microns in length Giardia and Cryptosporidium parasites removed, also

Activated Carbon Absorption: spontaneous movement of primarily organic contaminants from water to carbon matrix. Pesticides, volatile organics Carbon matrix

Treatment Residuals Trichloromethane(chloroform)CHCl 3 DibromochloromethaneCHClBr 2 BromodichloromethaneCHCl 2 Br Tribromomethane (bromoform)CHBr 3 Trihalomethanes (organics) All are carcinogens Formed as a byproduct of disinfection with chlorine Effectively removed by carbon block filtration

Chlorine Removal 2OCI - + C → 2Cl - + CO 2 Hypochlorite OCI - 2Cl - + CO 2 OCI -

Polyester mesh (particulates) Iodine-impregnated beads (bacteria) Activated Carbon (parasites, iodine, organics) 185 gallons of water,

Metals Metals are not effectively removed by carbon filtration They can be removed by ion exchange resins and by reverse osmosis processes

Ion Exchange Filters Neg. Charge Na Pb 2+, Hg 2+ Neg charge Na Pb 2+ Hg 2+ Na 4 Na + Finite Capacity Metals

Neg. Charge Na Water Softeners Ca 2+, Mg 2+ Neg charge Na Mg 2+ Ca 2+ Na 4 Na + Hardness Ions Calcium Deposits

Reverse Osmosis Extremely Effective

Osmosis Salt molecule Membrane permeable to Water only Net movement of water Spontaneous movement of water No salts

Reverse Osmosis Membrane permeable to Water only Purified water Contaminants to drain pressure

Energy intensive Saline/contaminant by-product inefficient: high volume reject water Drawbacks:

Chlorine Activated Carbon Filters Tastes Odors Organic chemicals Ion Exchange Resins Removal of charged Contaminants (metals) Reverse Osmosis Sediments, viruses, bacteria, dissolved solutes 2OCI - + C → 2Cl- CO 2

What about Bottled Water?

According to a NRDC study, U.S. consumers paid between 240 and 10,000 times more per gallon for bottled water than for tap water For the price of one bottle of Evian, Americans can receive 1,000 gallons of tap water The global consumption of bottled water reached 41 billion gallons in 2004, up 57 percent in just five years. More than 5 trillion gallons of bottled water is shipped internationally each year. In 2007, US consumers purchased more than 33 billion liters of bottled water Supplying Americans with plastic water bottles for one year consumes more than 47 million gallons of oil

What’s the Source? More than 25 percent of bottled water comes from a public source. If water is packaged as "purified" or "drinking water," It likely originated from a municipal water supply, and unless the water has been “substantially” altered, it must state on the label that the water comes from a municipal source. Both Aquafina (Pepsi) and Dasani (Coca-Cola) originate from municipal water systems National Resource Defense Council

Other terms used on the label about the source, such as “glacier water” or “mountain water," are not regulated standards of identity and may not indicate that the water is necessarily from a pristine area Artesian water, groundwater, spring water, well water - water from an underground aquifer which may or may not be treated. Well water and artesian water are tapped through a well. Spring water is collected as it flows spontaneously to the surface or via a borehole. Ground water can be either. Distilled water - steam from boiling water is re-condensed and bottled. Distilling water kills microbes and removes water’s natural minerals Drinking water – water intended for human consumption and sealed in bottles or other containers with no ingredients except that it may optionally contain safe and suitable disinfectants. Fluoride may be added within limitations Purified water - water that originates from any source but has been treated to meet the U.S. Pharmacopeia definition of purified water. Purified water is essentially free of all chemicals. Reverse osmosis is often used.

Is it safe? Most bottled water appears to be safe. (NRDC independent testing of 1000 bottles) EPA sets standards for tap water provided by public water systems; the Food and Drug Administration sets bottled water standards based on EPA's tap water standards Most bottled water is treated more than tap water; however, some is treated less or not treated at all. About 22 percent of the brands tested by NRDC contained, in at least one sample, some chemical contaminant

can leach into bottled water overtime. polyethylene terephthalate (PET) bottles PET phthalates known to disrupt testosterone and other hormones, One study found that water that had been stored for 10 weeks in plastic bottles contained phthalates, suggesting that the chemicals could be coming from the bottle, the plastic cap or the liner It also appears possible that some as-yet unidentified chemicals in plastics have the potential to interfere with estrogen and other reproductive hormones

The study stressed that amounts of antimony were well below official recommended levels. But it also discovered that the levels almost doubled when the bottles were stored for three months The study collected 48 brands of water in PET bottles from its source in the ground at a German bottling plant. The water had 4 ppt of antimony before being bottled, the contents of a new bottle had 360 ppt and one opened three months later had 700 ppt. The health effects of antimony ingestion are not well known Royal Society of Chemistry Publication Antimony The U.S. EPA has established 6.0 parts per billion (ppb) as a safe level

88% of water bottles are not recycled In 2005, 2 million tons of plastic water bottles were not recycled In 2006, 2 billion half-liter bottles of water were shipped to U.S. ports Where are all the old bottles?

Your grades will be posted this afternoon There are: 28 sets of Lecture Questions (100 pts) 4 Homework Assignments (100pts) 21 sets of Bonus Questions (20 pts) 4 total Exams (200 pts. Each) Your lowest exam grade of the 4 will be dropped