Drinking Water Treatment

1. Drinking Water Treatment

2. Intakes Surface Water Reservoirs Groundwater

3. Aeration: The water is mixed to liberate dissolved gases and to suspended particles in the water column. Flocculation: The materials and particles present in drinking water (clay, organic material, metals, microorganisms) are often quite small and so will not settle out from the water column without assistance. To help the settling process along, "coagulating" compounds are added to the water, and suspended particles "stick" to these compounds and create large and heavy clumps of material. Filtration: The water is run through a series of filters which trap and remove particles still remaining in the water column. Typically, beds of sand or charcoal are used to accomplish this task. Disinfection: The water, now largely free of particles and microorganisms, is treated to destroy any remaining disease-causing pathogens. This is commonly done with chlorination or ultraviolet radiation.

4. Initial Treatment 90 – 99% viruses screens Sedimentation (flocculation) Filtration

5. Final Treatment Disinfection and Fluoridation Sodium Fluoride (NaF) Sodium fluorosilicate Chlorine Gas Hypochlorite

6. Home Water Quality

7. Florida’s Drinking Water

8. Confined Aquifer Pumped well Plio-pliestocene (sands) Miocene (clays) Eocene Limestone Limestone

9. Potential Problems: • Hardness • Iron + manganese • Sulfur (sulfides) • Salt/Salinity • Pathogens (bacteria/viruses) • Metals • Organics Can be toxic or nuisance contaminants

10. Nuisance Contamination Hardness Iron Turbidity Color Odor Taste

11. Hardness Calcium Deposits Calcium + Magnesium Soap scum, scale, cooking problems

12. Hardness Treatment Water softeners 35 gal/day/person Hard water Cation Exchange Resin Soft water

13. Cation Exchange Resins Ca2+, Mg2+ Na Na Na Na Na Mg2+ Na Na Na Neg. Charge Neg charge Na Na Na Na Na Ca2+ Na Na Na Na Na Na Na Na 4 Na+

14. Water Hardness and Soap Scum

15. Soap/Detergent SO4- SO4- SO4- Oil drop (C,H,O) SO4- SO4- SO4- SO4- SO4-

16. -SO4 -SO4 -SO4 Sodium dodecylsulfate Extremely soluble Na+ Ca+2 + Less soluble

17. Harmful Contaminants

18. Drinking Water Potable Water Free of • Pathogens • Harmful Minerals/Metals • Organic Chemicals

19. Toxicity • Within 48 hours • Long term • Frequent exposure • Small amounts • Pb, As, Hg Acute Toxicity Chronic Toxicity

20. Contaminants

21. Heavy Metals MetalMCL (mg/L) Lead 0.05 Silver 0.05 Mercury 0.0002 MCL = Maximum Contaminant Level

22. Other Metals Trace Metals required metabolic catalysts Manganese Iron Cobalt Copper Zinc Molybdenum Chromium Toxicity = > 40 x requirement

23. Nitrates NO3- MCL = 10 mg/L Agriculture Organic Waste Disposal bacteria NO3- NO2- Methemoglobin is a form of hemoglobin that does not bind oxygen. Infants under 6 months are particularly susceptible

24. Pathogens Coliform bacteria MCL < 1 bacterium / 100 ml (fecal contamination) Non-coliform bacteria MCL < 200 bacteria / 100 ml Single required test: Sanitary Quality Suggested test: mineral/metal content

25. Treatment Sanitation/Disinfection Chlorination Most common Boiling UV Radiation

26. Ultraviolet Radiation Scrambled DNA Bacteria Viruses Mold Yeast Algae

27. Home Treatment

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

29. Ion Exchange Filters Metals Pb2+, Hg2+ Na Na Na Na Na Pb2+ Na Na Na Neg. Charge Neg charge Na Na Na Na Na Hg2+ Na Na Na Na Na Na Na Na Finite Capacity 4 Na+

30. Most Common Filtration Solid Carbon Block faucet mountfilters The solid carbon block faucet mount filters are reasonably effective in       reducing contaminants. These filters, by nature, are quite smalland because filter effectiveness is       dependent on contact time of the water with the filter media, a larger, high-quality       solid carbon block filter will be more effective at reducing contaminants at the       same flow rate.         a high-quality solid block activated carbon replacement filter will filter water for       between 7 and 10 cents per gallon.  2 gallons of filtered water per day would cost       between $50 and $100 per year

31. Activated Carbon Activation by heating Extremely porous with high surface area: 500 m2/g

32. Activated Carbon Filtration Particle size removal > 0.5 microns (bacteria, fungi)

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

34. Carbon Filter Removal Ethylbenzene Monochlorobenzene MTBE O-Dichlorobenzene P-Dichlorobenzene Styrene Tetrachloroethene Toluene Trichloroethene VOCs Antidepressants Steroids/Hormones Prednisone, Prednisolone, Progesterone, Testosterone, Cortisol/Hydrocortisone Antibiotics 2,4-D 2.4.5-TP (Silvex) Alachlor Atrazine Carbofuran Chlordane Endrin Heptachlor Epoxide Lindane Methoxychlor Simazine Toxaphene Benzene Carbon Tetrachloride Chlorobenzene

35. Reverse Osmosis Extremely Effective

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

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

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

39. Activated Carbon Filters Tastes Odors Chlorine Organics Ion Exchange Resins Removal of charged Contaminants (metals) Reverse Osmosis Sediments, viruses, bacteria, dissolved solutes

40. What about Bottled Water?

41. The global consumption of bottled water reached 41 billion gallons in 2004, up 57 percent in just five years. In 2007, US consumers purchased more than 33 billion liters of bottled water More than 5 trillion gallons of bottled water is shipped internationally each year. Supplying Americans with plastic water bottles for one year consumes more than 47 million gallons of oil 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 energy required to produce 33 billion liters is equivalent to 32-54 million barrels of oil

42. What’s the Source? More than 25 percent of bottled water comes from a public source. National Resource Defense Council 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

43. 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 recondensed 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. 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

44. 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

45. PET polyethylene terephthalate (PET) bottles phthalates known to disrupt testosterone and other hormones, can leach into bottled water overtime. 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

46. Antimony Royal Society of Chemistry Publication 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 U.S. EPA has established 6.0 parts per billion (ppb) as a safe level The health effects of antimony ingestion are not well known

47. Where are all the old bottles? 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