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WATER QUALITY TEST
DEQ OKLAHOMA
| Question | Answer |
|---|---|
| Ability to resist changes in pH in response to dilute acids && act as buffers | ALKALINITY |
| Chemical ions that form alkalinity are | HYXROXIDE, CARBONATE, BICARBONATE |
| Metal ions that contribute to alkalinity | Calcium, Magnesium, Sodium, and Potassium |
| End point | Phenomena in the chemical laboratory which has the following definition: a chemical is added drop by drop to a sample until a color change occurs |
| Two types of alkalinity measurement | Total alkalinity && Phenolphthalein Alkalinity |
| Laboratory Safety- Clothes | Never Work Alone && Protective Eye wear && Lab Coats && Gloves |
| Laboratory Safety - Chemical | Proper storage and labeling && date && ventilated area |
| Oxygen levels && Permissible | 19.5 to 23.5 % |
| Methane levels && Permissible | <0.5 % |
| Hydrogen Sulfide && Permissible | <10 ppm |
| Carbon Dioxide && Permissible | <10,000 ppm |
| Safe Drinking Water Act | 1974 && Passed as law in the same year |
| Primary Contaminants | The contaminants identified by EPA as harmful to human health |
| Maximum Contaminant Level M.C.L. | primary contaminants must not exceed certain specified levels known as M.C.L. |
| Hardness | Mainly caused by Calcium and Magnesium |
| Hard Water Standards | 100 mg/L in hardness |
| Soft Water Standards | 60 mg/L in hardness |
| Chromium Salt | used extensively for industrial processes and may enter a water supply through the discharge of waste |
| Hexavalent Chromium Parameters | Holding Time - none Preservation - 24 hours |
| Spectrophotometry | quantitative measurement of the transmission properties as the function of wavelength |
| Widely Distributed in Rocks and Soil | Manganese |
| Manganese Spectrometer Reading | 525 nm |
| Trace Amounts of chloride are eliminated by... | mercuric sulfate as a special reagent |
| Ferrous Iron | Dissolved in Water |
| Manganous Iron | Dissolved in Water |
| Oxidized Iron... | forms iron rust |
| A pressure chamber used to sterilize equipment and supplies by subjecting them to high pressure... | autoclave |
| Used to measure the relative clarity of fluid by evaluating the amount of light scattered | Turbidimeter |
| An instrument which measures the amount of light of a specified wavelength that passes through a medium | Spectrophotometer |
| Sampling methos | A. Vital Part of studying the water quality B. Source of Error in the process of obtaining water quality information |
| Grab Sample | single water sample collected at no specific time |
| Composite Sample | collection of individual samples obtained at regular intervals |
| One of the most important aspects of laboratory procedures | Results are no better than the sample |
| Preservation must be checked for the following characteristics | Required Volume Type of Container Preservation Maximum Holding Time |
| Separation methods | decanting, centrifuging, decanting, filtering |
| Conductivity in water | ability of a water to conduct an electrical current |
| Calcium Carbonate Saturation | industrial heat exchanges && domestic water heaters |
| Over Saturated Calcium Carbonate in water | would form precipitate |
| Under Saturation Calcium Carbonate in water | would dissolve |
| Corrosive Water | pH && alkalinity tends to be slightly lower than 'stable' |
| Calcium Carbonate Saturated Water | Neither precipitate nor dissolved |
| Corrosive Water | undersaturated |
| Super Saturated | Scale Deposit |
| Zero Net Alkalinity | Stable Water |
| Results in presence of metal ions in the water | Color |
| Ways to remove true color from the water: | coagulation, chlorination, or ozonation |
| Maximum Contaminant Levels For chlorine are... | 0.08 ppm |
| Fast Chlorine Detection Method | DPD Method |
| Higher Temperatures in DPD lead to... | false positive results |
| Turbidity is removed by | distillation |
| Fluoride Holding Time | 28 days |
| Fluoride Spectrophotometer reading | 570 nm |
| Chemicals Used For Fluoridation | Sodium Fluoride Sodium Fluorosilicate Fluorosilicic Acid |
| Ways to remove alkalinity | Add hydrochloric or nitric acids |