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3a. Water System. Chapter 8; Appendix B (Wentz) and 8.1- 8.3 (Toa). 4.11 Analysis and Design of Construction Systems - Mechanical (6 hrs). Water Systems. Plumbing Systems CNST 305 Environmental Systems 1 Dr. Berryman. Earth’s Water Supply.
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3a Water System Chapter 8; Appendix B (Wentz) and 8.1- 8.3 (Toa) 4.11 Analysis and Design of Construction Systems - Mechanical (6 hrs) Water Systems Plumbing Systems CNST 305 Environmental Systems 1 Dr. Berryman
Earth’s Water Supply 97% of the earth’s water is inaccessible. Mostly in the polar caps or ocean water That 3%… • Aquifers • Cisterns • Rivers/Lakes
Aquifers – Water Table Water Table Nebraska Aquifers 0’ – 260’ Cost to drill a well - $8.00/ft + pump ($2500 for 1.5 hp submersible) Drilled Well
Cisterns Used in areas where potable water is difficult to obtain
Water Quality • Based on • Physical characteristics • Limited amount of suspended material (cloudiness, clarity, acceptable taste, odor, temp) • Measured in turbidity units (<5 TU) • Chemical Characteristics • Limited to the amount of dissolved matter • Preferred hardness (< 200ppm or <11.7 grains per gallon) • Biological and Radiological Characteristics • Should be practically free of bacteria, viruses, and radioactive material
Water Analysis 1 ppm = mg/l = 1 mg/kg divide by 17.1 to get grains per gallon (gpg) • Sulfate • Over 300 – 500 ppm produce a laxative effect for those that have not adapted • Nitrate • Over 10 ppm – health problem for infants • > 50 ppm – very undesirable, health risks • Fluoride • Control tooth decay at 0.9 – 1.5 ppm • Concentrations over 3.0 cause mottling of the teeth
Water Analysis (cont.) • pH • Between 6.5 – 8 is acceptable • Iron and Manganese • Stain cloths and plumbing fixtures • Problems (iron>0.3 ppm;manganese>0.2 ppm) • Sodium • Problem w/ salt diets (more than 100 ppm not desired) • Calcium Carbonate
Calcium Carbonate • Calcium Carbonate • Desirable <200 ppm • Less than 100 ppm: – soft water • 100 – 200 ppm: reasonably soft • 200 – 300 ppm: avg hardness • 300 – 400 ppm: very hard • Over 400 ppm: extremely hard • Too hard • More soap required to produce lather • Causes rings in bathtubs and sinks • Chemical deposits in pipes • Poor laundry results • Hard water not considered detrimental to health
Water Quality Improvements • Sedimentation • Coagulation (or flocculation “floc”) • Aeration • Disinfection • Fluoridation • Filtration • Softening
RO systems • Micro pre-filter • Carbon pre-filter • RO membrane • Carbon post filter commercial residential
There are four components to a softener unit: a control valve (1), a saline tank (2), a resin bed (3), and a resin tank (4). The resin tank holds the resin bed, the brine tank holds water and dissolved salt solution (brine). The control valve sits on top of the tank. Water Softeners • The most common method for point-of-entry (POE) treatment is cation exchange. A cation is a positively charged ion, both the hardness minerals calcium (Ca) and magnesium (Mg) are cations. To remove them from water the hardness cations are exchanged with sodium ions (also a cation).
Cross Connections • Any connection or arrangement between two otherwise separate piping systems, one of which contains potable water and the other contains water of questionable safety, whereby flows from one system to the other. FILM
Cross Connection Prevention • Check Valves • Air Gaps • Vacuum Breakers • Backflow Preventors • Double check valve system w/ vacuum breakers
3bc Water System Chapter 8; Appendix B (Wentz) and 8.1- 8.3 (Toa) 4.11 Analysis and Design of Construction Systems - Mechanical (6 hrs) Next Time • Hot Water • Engineering Design