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WATER QUALITY

WATER QUALITY. Water quality!??. What does “GOOD water quality” mean to you?. Can we check for them?. Is checking enough?. Environment Impact: Pollution. Toxic pollution. Sediment pollution. Bacteria pollution. Nutrient pollution. Environment Impact. Water contamination sources.

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WATER QUALITY

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  1. WATER QUALITY

  2. Water quality!?? What does “GOOD water quality” mean to you?

  3. Can we check for them? Is checking enough? Environment Impact: Pollution Toxic pollution Sediment pollution Bacteria pollution Nutrient pollution Environment Impact

  4. Water contamination sources Point-source:contained point of discharge Nonpoint-source:no local point of discharge

  5. Quality checks & monitoring • Chemical monitoring • A snapshot in time of certain parameters in a water sample • Comparison to a water quality standard • Usually involves a lab… so it is costly and time consuming

  6. Quality checks & monitoring • Biological monitoring or bio-monitoring • Evaluation of the amounts of some organisms in the stream • An overall assessment of the health of the stream based upon the ecological conditions of the stream

  7. Quality checks & monitoring • Physical measuresof stream health • Measure of flow, pebble counting, and habitat evaluations

  8. Chemical testing

  9. BACTERIA ACTIVITY Dissolved Oxygen (DO) • Why oxygen? • Respiration: C6H12O6 + O26 CO2 + 6 H20 + Energy • Decomposition (oxidation) • How much is needed? Up to about 10ppm of oxygen in water 5-6ppm: sufficient for most species < 3ppm: stressful to most aquatic species < 2ppm: fatal to most species • How does it get into water? • Absorption from the atmosphere: contact with water • Photosynthesis: Light + 6 CO2 + 6 H2O (CH2O)6 + 6O2)

  10. Dissolved Oxygen (DO) • Testing? • Oxido-Reduction: Reduced_form+ + O2 + H2O  Oxided_form + H3O+ • Tips? • Do not introduce additional oxygen in the sample!! • Testing on site!! • Note time, date, weather, shade, … and temperature!!!

  11. Biochemical Oxygen Demand (BOD) • Where does Demand come from? • Bacterial decomposition = oxygen consumption • Measure of the amount of organic matter in water • Measure of the amount of oxygen to be consumed • How much is needed? Below 5ppm of O2, life is threatened!!

  12. Biochemical Oxygen Demand (BOD) • Testing? • Oxido-Reduction: Reduced_form+ + O2 + H2O  Oxyded_form + H3O+ • Tips? Comparison!!! • Testing 5 days after!! • Do not introduce additional oxygen in the sample!! • Note time, date, weather, shade, etc… !!!

  13. Nitrate • What is nitrate? • N2 forms 70% of Earth’s atmosphere, 80% of the air • Part of proteins, DNA, RNA, vitamins, hormones, enzymes • Where does nitrate come from? Higher organisms depend on plants to get complex forms of nitrogen (e.g. amino acids, nucleic acids) • Continuous recycle: fixed by algae and bacteria before plants use • And… ???? • How does it get into water? Non-point source pollution • NO3- is one of the most water soluble anions known • Nitrate does not bind to soils • washed into streams or rivers (i.e., surface waters) • through time, leached down through the soil into porous rock aquifers (i.e., groundwaters)

  14. Nitrate • What are the problems? • Because they do not evaporate, nitrates/nitrites are likely to remain in water until consumed by plants or other organisms • Health issues!!! Public and livestock!!! • Environmental harm • Drinking water (& food!) Nitrate NO3- is converted in the gut to nitrite NO2-NO2- combines with hemoglobin to metheglobin blood ability to carry oxygen decreases • “Blue baby syndrome“ or methemoglobinemia • Cancers • Physical defects in the fœtus, miscarriages, low birth weight, and slow weight gain “Only two substances pose an immediate threat to health whenever they are exceeded: bacteria and nitrate.” 10 mg/L nitrate-nitrogen (NO3-N) = 44.3 mg/L nitrate (NO3- )

  15. Nitrate • Testing? • Reduction of nitrate to nitrite NO3- + 2 H3O+ NO2- + 3 H2O • + sulfanilamide + N-(1-napththyl)-ethylenediamene-dihydrochloride (NED) reddish purple Rural communities are the most threatened populations • Tips? • NTR Nitrate is the limiting factor in marine eutrophication (e.g.,estuaries, coastal waters)

  16. Nitrate… exercises • What is the nitrate cycle? • What are the causes of nitrate polluiton? Treatments? • What are the consequences for the environment & industries?… Eutrophication? • What are the standard acceptable level of nitrate for the environment? • What are the standards in Egypt? In your watershed?

  17. Phosphate • Why phosphate? necessary components of life • Part of DNA, RNA, ADP and ATP • Where does phosphate come from? • Natural P deposits occur primarily as phosphate mineral apatite. • P is only freely soluble in acid solutions under reducing conditions. In the soil, it is rapidly immobilized as calcium or iron phosphate. Most of the P in soils is adsorbed to soil particles or incorporated into organic matter. • P in water exist in a particulate phase or a dissolved phase: • E.g. particulate matter: plankton. • E.g. dissolved phase: includes inorganic P, organic P excreted by organims • And???

  18. Phosphate • What are the problems? • Health Effects • P itself does not have any notable health effects • However, a phosphate level > 1.0 mg/L may interfere with coagulation in water treatment plants organic matter and attached microorganisms may not be completely removed from the treated water • Environmental Effects • … • How much is needed? • …

  19. Phosphate • Testing? • phosphate with acidified molybdate reagent PO43- + 12 MoO42- + 27 H+ H3PO4 (MoO3)12 + 12 H2O • Reduction of phosphomolybdate heteropolyacid H3PO4 (MoO3)12 Phosphomolybdenum blue Mo(V)  Blue color • Tips? • When algae is prevalent (summer…), some phosphate will bound up in the algae. This phosphate is not available for use by other plants and should not be included in the measurement.

  20. Phosphate… exercises • What is the phosphate cycle? • What is special to lake?…Hypolimnion • What are the causes of phosphate pollution? Treatments? • What are the consequences for the environment & industries?… • What are the standard acceptable level of phosphate for the environment? • What are the standards in Egypt? In your watershed?

  21. acids bases 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 acid rain ammonia normal stream water sea water most fishes die most fishes die mosquito larvae die fish repro. affected best for algae pH • Why pH and what pH?

  22. pH • What are the problems? • Health Effects: • Low pH water pipes corrosion in potable water plants • Release of (heavy) metal ions such as copper, lead, zinc, and cadmium into the treated drinking water… • Replacement costs! • Environment impact: • ???

  23. pH Synergy effect!!! • Other factors? • Important in surface waters: • E.g.: 4.0 mg/l of iron at pH=4.8  not toxic 0.9 mg/l of iron at pH=5.5  fish die • Special significance in wastewater treatment:The steps involved in water and wastewater treatment require specific pH levels. In order for coagulation (a treatment process) to occur, pH and alkalinity must fall within a limited range. Chlorination, a disinfecting process for drinking water, requires a pH range that is temperature dependent.

  24. pH • Testing? Litmus paper: • Litmus: purple lichen which is red in acid solution and blue in alkali. • Invented by a gentleman who wanted to measure how acid his beer was. To make beer or wine, you have to use yeast, and yeast uses enzymes… Enzymes only work if the pH is right.What he discovered was that acids and alkalis make the colours in plants change. Grind up some red cabbage. You get a red liquid. Pour some ammonia: what is the color of the liquid now?… Universal indicator paper can change from blue to green to yellow to red. Universal indicator is a mixture of dyes which all change when you change the pH • Tips? • Don’t pollute the tester!!

  25. pH… exercises • What are the impact of pH changes? • What are the consequences for the environment & industries?… • Are there treatment or prevention measures? • What are the standards in your watershed?

  26. Coliform bacteria • Why coliform bacteria? • Live in large numbers in the intestines of animals: aid in the digestion • Some might be infected with diseasese.g. waterborne pathogenic diseases: typhoid fever, gastroenteritis, hepathite A, diphteria, tuberculosis • How does it get into water? • Overflow or poor treatment of domestic sewage • Non-point source of human and animal waste • What is an acceptable limit? 200 colonies per 100ml Bacteria are removed by disinfection and/or filtration

  27. Coliform bacteria • Testing? • Counting using filter • "Presence/Absence method“: • Enzymatic substrates + incubation for 24hr • Change of yellow color = presence of Coliform bacteria • Fluorescence under ultra-violet = presence of E.Coli bacteria • Tips? • Fermentation means incubation too!! • Keep the tube vertical!!! • Note weather conditions!…

  28. Coliform bacteria Separate or combined sewer system? • Other factors? • Sanitary wastes (from toilets, washers, and sinks) flow through sanitary sewers and are treated at the wastewater treatment plant • Storm sewers carry rain and snow melt from streets, and discharge untreated waters directly into rivers • Heavy rains and melting snow wash bird and pet wastes from sidewalks and streets into storm drains • In a combined sewer system, both sanitary waste and storm runoff are treated at a wastewater treatment plant. After a heavy rain, untreated or inadequately treated waste may be diverted into the river to avoid flooding the wastewater treatment plant. To avoid this problem, some cities have built retention basins to hold excess wastewater and prevent untreated waste from being discharged into rivers. Without retention basins, heavy rain conditions can result in high fecal coliform counts downstream from sewage discharge points.

  29. Coliform bacteria… exercises • Are there treatment or prevention measures? • What are the standards in your watershed?

  30. Turbidity A physical measure • What is turbidity? • A measurement quantifying the degree to which light traveling through a water column is scattered by the suspended organic (including algae) and inorganic particles. suspended load  =light scattering  • The velocity of the water resource largely determines the composition of the suspended load. Suspended loads are carried in both the gentle currents of lentic (lake) waters and the fast currents of lotic (flowing) waters.Even in flowing waters, the suspended load usually consists of grains less than 0.5 mm in diameter. Suspended loads in lentic waters usually consist of the smallest sediment fractions, such as silt and clay.

  31. Turbidity • What are the problems? WHY??

  32. Turbidity problems…

  33. NTU Turbidity • Testing? Secchi disk (JTU) • Tips? • Testing on site!!! • Avoid glaring effect!!! Avoid your shadow!!!

  34. Turbidity… exercises • What are the units of turbidity measurements? • Are there treatment or prevention measures? • What are the standards in your watershed?

  35. Temperature • Why temperature? A physical measure • t°  DO: affect DO, and chemical reactivity in general • Different temperature environments  different species • All species are negatively impacted by rapid fluctuations • Why does temperature vary? • Season, day/night, weather,… • Current, hot sources (geothermie) • Depth (Hypolimnion…) • Human activites: cities, removal of vegetation, plume, stream widening or shallowing, industry, global warming, etc…

  36. Temperature • What are the problems? • Lack of oxygen (DO capacity , blooms in matter organic decomposition) • Species not adapted to rapid fluctuation  physiological damages • Shift of population • Shift of reproduction timing such that predators are most abundant during the early stages of life, or no even not triggered. • E.g., the green crab in Maine (U.S.A) was not reduced by the natural winter die-off predator/prey ratio un-balanced • Higher temperatures, higher coagulation and flocculation rates more effective water treatment!!!

  37. Temperature • Testing? • Thermometer Units? • Tips? • Testing on site!!! • Don’t hold the container!!! • Be careful the way you hold the thermometer!!

  38. Temperature… exercises • What are the units of t° measurements? • Are there treatment or prevention measures? • What are the standards in your watershed?

  39. Hardness • What is hardness? • The sum of polyvalent cations dissolved in the water,i.e., calcium (calcite CaCO3) & magnesium (magnesite MgCO3 ) + iron (Fe), strontium (Sr), manganese (Mn) • Usually reported as an equivalent quantity of CaCO3 • Where does dissolved minerals come from? • As water moves through soil and rock, it dissolves very small amounts of minerals and holds them in solution= primarily a function of the geology of the area within which the surface water is flowing

  40. Hardness • What are the effects? • Health: • Good effect!!: “water could be a major contributor of Ca and Mg to the diet” • Skin irritation, dull hairs, etc… • Environment & industry: • Scale… in pipe, tanks… on glasses & clothes… • Chemical processes affected, e.g. lathering & washing • More detergents used…

  41. Hardness • How much is needed? In the U.S.A: Classification mg/l or ppm Soft 0 - 17.1 Slightly hard 17.1 - 60 Moderately hard 60 - 120 Hard 120 - 180 Very Hard > 180

  42. Hardness… exercises • Are there treatment or prevention measures? • What is the classification in your watershed? • Is your watershed affected?

  43. Salinity • What are salts? • In natural waters, they are anions such as carbonates, chlorides, sulfates, and nitrates (primarily in ground water), and cations such as potassium (K), magnesium (Mg), calcium (Ca), and sodium (Na) • Needed for life • Where do salts come from? • Natural concentration largely influenced by the underlying geology… • Faults might allow brine formation • Through time, salts are removed from the sedimentary rocks by wind and water erosion. While evaporation will create salt precipitation • Salts are present in the rain

  44. Salinity • What are the problems? • Health: • Sodium sulfate and magnesium sulfate above 250 mg/l in drinking water may produce a laxative effect. • Excess sodium affect low sodium diets and pregnant women suffering from toxemia • High blood pressure? • Environment & industry: • Shift in water population • Chemical processes affected (especially within plant…) • Dissolved salts may encrust or corrode metallic surfaces

  45. Salinity • What do cause salinity variation? • Weather • Irrigation with inadequate drainage or excessive evaporation from agricultural fields may lead to an accumulation of salts in the soil • Runoff from urban areas after rain or where salt is used for de-icing • Inorganic chemical industry may release dissolved cations in effluent waters

  46. Salinity… exercises • What is the salinity situation of your watershed?

  47. Testing… exercises • The units • Standards in Egypt and in your watershed • Point source vs. non-point source • Chain reaction…

  48. Testing tips • Blank tube • Coloured sample?!! compared to one or more reference points (e.g., distilled water, untreated sample, and reagent blank - i.e., treated distilled water) • Use of the same tube • eliminates glassware errors • Comparison • concert among you when comparing to chart • Sampling from tap: • Leave water running for few minutes

  49. Biological monitoring

  50. Environment impact: bio-monitoring • What is bio-monitoring?One type of bio-monitoring is to evaluate the benthic invertebrates that live in the stream: • Benthic means bottom-dwelling • Invertebrates are organisms without a backbone • Macro means that are visible to the naked eye; Micro…

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