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Oceanography Chapter 7 WATER QUALITY “What You Need To Know To Keep Your Fish Alive” Adapted from Gary Fornshell, University of IdahoTerry Patterson,

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Presentation on theme: "Oceanography Chapter 7 WATER QUALITY “What You Need To Know To Keep Your Fish Alive” Adapted from Gary Fornshell, University of IdahoTerry Patterson,"— Presentation transcript:

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2 Oceanography Chapter 7 WATER QUALITY “What You Need To Know To Keep Your Fish Alive” Adapted from Gary Fornshell, University of IdahoTerry Patterson, College of Southern Idaho

3 To a great extent, the success or failure of fish culture is determined by water quality

4 Water Quality – Why Is It Important? Your fish live in it Are supported by it Receive their oxygen from it And excrete in it

5 Water Quality – Why Is It Important? Water quality factors influence and interact with each other What may cause problems in one situation may be harmless in another Influences effectiveness/toxicity of treatments

6 Water Quality – Why Is It Important? Most disease problems can be avoided with proper management of water quality This includes maintaining water quality at a level that provides an environment conducive to fish health and growth

7 Water Quality Variables Temperature Dissolved oxygen Total ammonia-nitrogen, NH 3, NO - 2 Alkalinity Hardness pH Carbon dioxide

8 Fig. 7-6, p. 192

9 Temperature

10 For each 10°C (18°F) rise in temperature the metabolic rate doubles Controls the reaction rate of chemicals Influences solubility of gases in water Influences toxicity of ammonia and therapeutants Optimum temperature for tilapia growth is 85-88 °F Water Quality Variables Temperature

11 28State Agricultural Response Team Direct effect on metabolism, feeding and survival Species-specific optimum levels –Protect from heat and cold Metabolism –Temp leads to rapid metabolism –Temp leads to O 2, food demand Acclimation –Gradual changes –Minimizes temperature stress Stress signs: Lethargy, abnormal behavior, increased ventilation, death Temperature Temperature has a greater impact on fish development and health than any other factor

12 Dissolved Oxygen “DO”

13 Water Quality Variables Dissolved Oxygen First limiting factor for growth and fish health Solubility decreases with increasing temperature and elevation Respiratory rate increases with increasing temperature, activity and feeding In general the minimum DO should be ≥ 60% of saturation or ≥ 5 ppm (mg/L) > 2 ppm in biofilter effluent

14 25State Agricultural Response Team Refers to oxygen gas dissolved in water Sources of oxygen –Chemical, photosynthesis, mechanical, diffusion –Smaller bubble size is better due to slower rise and greater surface area for oxygen diffusion Depletion –Animal and plant respiration –Organic decomposition –Diurnal cycle of DO Tolerance of low DO is species specific –Rule of thumb – 5 ppm minimum Clinical signs of low DO –Gulping at surface, lethargy, loss of appetite, increased ventilatory effort, death Air -- Dissolved Oxygen (DO)

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16 27State Agricultural Response Team Factors that Influence Dissolved Oxygen More Dissolved Oxygen at Higher Temperature Higher Pressure Lower Salinity Less Dissolved Oxygen at Lower Temperature Lower Pressure Higher Salinity

17 Gas Concentrations Vary with Depth How concentrations of oxygen and carbon dioxide vary with depth. Oxygen is abundant near the surface because of the photosynthetic activity of marine plants. Oxygen concentration decreases below the sunlit layer because of the respiration of marine animals and bacteria, and because of the oxygen consumed by the decay of tiny dead organisms slowly sinking through the area. In contrast, because plants use carbon dioxide during photosynthesis, surface levels of CO2 are low. Because photosynthesis cannot take place in the dark, CO2 given off by animals and bacteria tends to build up at depths below the sunlit layer. CO2 also increases with depth because its solubility increases as pressure increases and temperature decreases.

18 26State Agricultural Response Team Diurnal DO Cycle Dissolved Oxygen DO (ppm) Hour of the Day DO (% saturation) 0 2 4 6 8 10 12 14 16 0 20 40 60 80 100 120 140 160 0 24 12618 Dissolved Oxygen Level

19 Nitrogen Cycle NH 4 – No 2 – No 3

20 Water Quality Variables Total Ammonia-Nitrogen Usually the second limiting factor – nitrogenous waste: feces & feed TAN includes ammonium ion (NH 4 + ) and ammonia (NH 3 ) The proportion of NH 3 increases with increasing temperature and pH < 0.05 mg/L NH 3 < 0.5 mg/L nitrite-N (NO - 2 ),

21 Water plants Food Excess food Fishes Peptides Amino acids Urine Urea Ammonia (NH ) Algae Nitrate (NO ) Nitrite (NO ) Feces 2 3 3 The Nitrogen Cycle

22 23State Agricultural Response Team Biological Filtration Water Quality Group 1 Nitrifying Bacteria Group 2 Nitrifying Bacteria Biofilter + O 2 Feed Nitrogen Gas (N 2 ) Ammonia NitriteNitrate NH 3, NH 4 + NO 2 – NO 3 = Fish Uneaten Feed Rotting Material Denitrifying Bacteria Plants Water Changes

23 0.8 0.6 0.4 0.2 0.0 2610141822 8 6 4 2 0 Ammonia (mg/l) Nitrites & Nitrates (mg/l) NH NO 2 3 3 Time in Days Time Required for Bio-Filter to Mature

24 22State Agricultural Response Team Nitrogen Cycle Water Quality Group 1 bacteria begin converting ammonia to nitrite Group 2 bacteria begin converting nitrite to nitrate Ammonia Nitrite Nitrate Concentration (ppm) Time

25 Water Quality Variables - Alkalinity Is the buffering capacity of water – absorbs acids and/or bases High alkalinity prevents wide pH fluctuations Maintain levels between 75-120 mg/L as CaCO 3 7 grams of alkalinity consumed by 1 gram of NH 3

26 Fig. 7-10, p. 197

27 100 50 0 4 5 6789101112 Free CO HCO CO Percent of Total CO 2 3 -= 2 3 pH Effects of pH on Various Buffers

28 Fig. 7-11, p. 198

29 Fig. 7-12, p. 198

30 Stressors Poor water quality Environmental conditions Improper handling

31 Most Fish Diseases Are Stressed Mediated Stress is a physiologic state caused by a procedure, environmental condition or other factor which interferes with the fish’s ability to maintain a “normal” state. It extends the adaptive responses of an animal beyond the normal range or which disturbs the normal functioning.

32 Low Level Mortality 100% MORTALITYMORTALITY 0% Peracute Acute Chronic Time Usually the first sign of water quality/environmental problems

33 Loading Effects Number of fish which can successfully live and grow in a given amount of water depends on: DO level Metabolic rate of the fish Amount being fed Pathogen load Water exchange rate

34 Management Recommendations Low DO: increase aeration; stop feeding High CO 2 : increase aeration; add air stripping column Low pH: add sodium bicarbonate; reduce feeding rate; check ammonia & nitrite High NH 3 : exchange system water; reduce feeding rate; check biofilter, pH, alkalinity & DO in biofilter High nitrite: exchange water; reduce feed; add 6 ppm chloride per 1 ppm nitrite; check biofilter, pH, alkalinity & DO in biofilter

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36 Oceanography Chapter 7 “ Properties of Water ”

37 Fig. 7-CO, p. 184 Antoine-Laurent Lavoisier is credited on 6/24/1783 for first separating water into its 2 components, hydrogen and oxygen gas.

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39 Water Water- H 2 0 H-O-H -is polar: molecule with unequal distribution of charge……positive and negative end -”The universal solvent” -connected by a hydrogen bond: opposite charges attract -  + Uniqueness of water: -high surface tension-capillary action -high heat of vaporization-resists temperature change -water expands-found in 3 states on Earth (?)

40 Water Is a Powerful Solvent A simplified hydrologic cycle. Water moves from ocean to air, onto land, to lakes and streams and groundwater, back to the sky and ocean, in a continuous cycle. The numbers indicate the approximate volumes of water in cubic kilometers per year (km 3 /yr). Water is also stored in the ocean, ice, groundwater, lakes, and the atmosphere.

41 Mixture: combinations where individuals retain their own properties Solution: -mixture in which one or more substances distributed evenly in another substance Solute + Solvent Solute: substance being dissolved Solvent: substance receiving another “dissolved substance” “H 2 0 universal solvent- can receive solutes”

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43 Water Is a Powerful Solvent Salt in solution. When a salt such as NaCl is put in water, the positively charged hydrogen end of the polar water molecule is attracted to the negatively charged Cl - ion, and the negatively charged oxygen end is attracted to the positively charged Na + ion. The ions are surrounded by water molecules that are attracted to them and become solute ions in the solvent.

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46 Oceanography Chapter 7 “ pH - Acids & Alkalinity ”

47 pH Scale Soren Sorensen (1868 - 1939)

48 Fig. 7-5, p. 191

49 The Ocean’s Acid-Base Balance Varies with Dissolved Components and Depth What are acids and bases? An acid is a substance that releases a hydrogen ion in solution. A base is a substance that combines with a hydrogen ion in solution. A solution containing a base is called an alkaline solution. Acidity or alkalinity is measured on the pH scale.

50 The Ocean’s Acid-Base Balance Varies with Dissolved Components and Depth (right) The pH scale. A solution at pH 7 is neutral; higher numbers represent bases, and lower numbers represent acids.

51 The Ocean’s Acid-Base Balance Varies with Dissolved Components and Depth

52 pH- How acidic or basic a solution is Acid- any substance that forms Hydrogen ion (H + ) in water Base- any substance that forms hydroxide ions (OH - ) in water acid base pH scale: 0---------7---------14 hydrogen chloride sodium hydroxide HCL + H20 NaOH + H2O = = H + Cl - Na + OH - Hydrochloric Acid

53 pH pH = -log [H 1+ ] Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 285

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56 Color of Indicator Substance Blue Litmus Red Litmus pH Paper Approximate pH of substance Fresh Water Salt Water Vinegar Lemon Juice Milk Cleaner: _______ Soda: ________ Soapy Water Hydrogen Peroxide Lemon/ Alka-Seltzer

57 Fig. 7-9, p. 196 Acidic Neutral Basic pH scale

58 How Do We Measure pH? We measure pH by using special strips of paper called pH paper 57

59 How Does It Work? The paper is treated with chemicals that change color to show the pH. When the paper touches the substance being tested, it turns a specific color to tell if the substance is an acid or a base. 58

60 Acid/Base indicator results FreshwaterBlueRed Salt WaterBlueRed Vinegar RedRed Lemon JuiceRedRed MilkBlueBlue CleanerBlueBlue SodaRedRed Soapy WaterBlueRed Hydrogen PeroxideBlueRed Alka-SeltzerBlueBlue

61 Acid Any substance which has a pH of value of less than 7 is considered an acid 0--------------7---------------14 Acid Neutral Base 60

62 Base Any substance which has pH value greater than 7 is a base 0--------------7---------------14 Acid Neutral Base 61

63 pH 7 A pH of 7 is called neutral—neither acid nor base. 0------------7------------14 Acid Neutral Base 62

64 Acidic or Basic If the number is less than 7 the soil or water is acidic If the number is more than 7 the soil or water is basic 63

65 The pH Scale pH scale ranges from 0 -14 pH 7 is neutral; neither acid nor base Pure water is pH 7 Low pH = acid High pH = base The closer to the ends of the scale, the stronger the solution is 64

66 pH Values for Substances Windex6ACID Grapefruit3ACID School H2O4ACID White Vinegar2-3ACID Egg White7NEUTRAL 0.1M HCl1ACID 0.1M NaOH9BASIC(ALKALINE) Mylanta7NEUTRAL Lemon Juice2ACID Oil4-5ACID

67 The pH Scale 66

68 The pH Scale Each pH unit is 10 times as large as the previous one A change of 2 pH units means 100 times more basic or acidic Each pH unit is 10 times as large as the previous one A change of 2 pH units means 100 times more basic or acidic x10x100 67

69 The pH Scale Careful measurement is important A mistake of one pH unit means 10 times too much or too little! x10x100 68

70 Color of Indicator Substance Blue Litmus Red Litmus pH Paper Approximate pH of substance Fresh Water Salt Water Vinegar Lemon Juice Milk Cleaner: _______ Soda: ________ Soapy Water Hydrogen Peroxide Lemon/ Alka-Seltzer

71 Acid/Base indicator results FreshwaterBlueRed Salt WaterBlueRed Vinegar RedRed Lemon JuiceRedRed MilkBlueBlue CleanerBlueBlue SodaRedRed Soapy WaterBlueRed Hydrogen PeroxideBlueRed Alka-SeltzerBlueBlue

72 pH Values for Substances Windex6ACID Grapefruit3ACID School H2O4ACID White Vinegar2-3ACID Egg White7NEUTRAL 0.1M HCl1ACID 0.1M NaOH9BASIC(ALKALINE) Mylanta7NEUTRAL Lemon Juice2ACID Oil4-5ACID

73 Why is pH important? Soil has to be in a certain pH range for plants to grow and stay healthy. Fish can’t live if the pH is too high or too low 72

74 pH and People Water that has too high or low pH may contain harmful dissolved chemicals. Water plant operators keep a careful watch on the pH of our drinking water, to keep it safe. 73

75 74 Two papers, two charts The yellow paper reads from pH 6.5- 13.0 (base). The colors on this side start with yellow (6.5) The orange paper reads from pH 0-6.0 (acid). Use the side of the dispenser that begins with pH 0.0. It’s easy to recognize because the colors begin with shades of orange. Using two different papers gives a more precise reading. 74

76 pH Scale Acid Base 0 7 14 Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 515 [H + ] pH 10 -14 14 10 -13 13 10 -12 12 10 -11 11 10 -10 10 10 -9 9 10 -8 8 10 -7 7 10 -6 6 10 -5 5 10 -4 4 10 -3 3 10 -2 2 10 -1 1 10 0 0 1 M NaOH Ammonia (household cleaner) Blood Pure water Milk Vinegar Lemon juice Stomach acid 1 M HCl Acidic Neutral Basic

77 pH of Common Substances Timberlake, Chemistry 7 th Edition, page 335

78 pH of Common Substance 14 1 x 10 -14 1 x 10 -0 0 13 1 x 10 -13 1 x 10 -1 1 12 1 x 10 -12 1 x 10 -2 2 11 1 x 10 -11 1 x 10 -3 3 10 1 x 10 -10 1 x 10 -4 4 9 1 x 10 -9 1 x 10 -5 5 8 1 x 10 -8 1 x 10 -6 6 6 1 x 10 -6 1 x 10 -8 8 5 1 x 10 -5 1 x 10 -9 9 4 1 x 10 -4 1 x 10 -10 10 3 1 x 10 -3 1 x 10 -11 11 2 1 x 10 -2 1 x 10 -12 12 1 1 x 10 -1 1 x 10 -13 13 0 1 x 10 0 1 x 10 -14 14 NaOH, 0.1 M Household bleach Household ammonia Lime water Milk of magnesia Borax Baking soda Egg white, seawater Human blood, tears Milk Saliva Rain Black coffee Banana Tomatoes Wine Cola, vinegar Lemon juice Gastric juice More basic More acidic pH [H 1+ ] [OH 1- ] pOH 7 1 x 10 -7 1 x 10 -7 7

79 Acid – Base Concentrations pH = 3 pH = 7 pH = 11 OH - H3O+H3O+ H3O+H3O+ H3O+H3O+ [H 3 O + ] = [OH - ] [H 3 O + ] > [OH - ] [H 3 O + ] < [OH - ] acidic solution neutral solution basic solution concentration (moles/L) 10 -14 10 -7 10 -1 Timberlake, Chemistry 7 th Edition, page 332

80 pH Calculations pH pOH [H 3 O + ] [OH - ] pH + pOH = 14 pH = -log[H 3 O + ] [H 3 O + ] = 10 -pH pOH = -log[OH - ] [OH - ] = 10 -pOH [H 3 O + ] [OH - ] = 1 x10 -14

81 pH = - log [H + ] pH = 4.6 pH = - log [H + ] 4.6 = - log [H+] - 4.6 = log [H+] Given: 2 nd log 10 x antilog multiply both sides by -1 substitute pH value in equation take antilog of both sides determine the [hydronium ion] choose proper equation [H + ] = 2.51x10 -5 M You can check your answer by working backwards. pH = - log [H + ] pH = - log [2.51x10 -5 M] pH = 4.6 Recall, [H + ] = [H 3 O + ]

82 Acid Dissociation monoprotic diprotic polyprotic HA(aq) H 1+ (aq) + A 1- (aq) 0.3 M pH = - log [H + ] pH = - log [3M] pH = - 0.48 e.g. HCl, HNO 3 H 2 A(aq) 2 H 1+ (aq) + A 2- (aq) 0.3 M0.6 M0.3 M pH = - log [H + ] pH = - log [6M] pH = - 0.78 e.g. H 2 SO 4 Given: pH = 2.1 find [H 3 PO 4 ] assume 100% dissociation e.g. H 3 PO 4 H 3 PO 4 (aq) 3 H 1+ (aq) + PO 4 3- (aq) ? Mx M pH = ?

83 Given: pH = 2.1 find [H 3 PO 4 ] assume 100% dissociation H 3 PO 4 (aq) 3 H 1+ (aq) + PO 4 3- (aq) X MX M0.00794 M Step 1) Write the dissociation of phosphoric acid Step 2) Calculate the [H + ] concentration pH = - log [H + ] 2.1 = - log [H + ] - 2.1 = log [H + ] 2 nd log - 2.1 = log [H + ] 2 nd log [H + ] = 10 -pH [H + ] = 10 -2.1 [H + ] = 0.00794 M [H + ] = 7.94 x10 -3 M 7.94 x10 -3 M Step 3) Calculate [H 3 PO 4 ] concentration Note: coefficients (1:3) for (H 3 PO 4 : H + ) 7.94 x10 -3 M 3 = 0.00265 M H 3 PO 4

84 How many grams of magnesium hydroxide are needed to add to 500 mL of H 2 O to yield a pH of 10.0? Step 1) Write out the dissociation of magnesium hydroxide Mg 2+ OH 1- Mg(OH) 2 Mg(OH) 2 (aq)Mg 2+ (aq) 2 OH 1- (aq)+ Step 2) Calculate the pOH pH + pOH = 14 10.0 + pOH = 14 pOH = 4.0 Step 3) Calculate the [OH 1- ] pOH = - log [OH 1- ] [OH 1- ] = 10 -OH [OH 1- ] = 1 x10 -4 M 1 x10 -4 M0.5 x10 -4 M5 x10 -5 M Step 4) Solve for moles of Mg(OH) 2 x = 2.5 x 10 -5 mol Mg(OH) 2 Step 5) Solve for grams of Mg(OH) 2

85 PROCEDURE: 1. Various 100/250 ml beakers will be obtained during lab 2. Dip plastic pipette into the beaker and obtain one drop on tip. 3. DO NOT DRAW SOLUTION INTO PIPPETT!!!!! 4. Place drop on Blue Litmus, repeat onto Red Litmus, repeat onto pH paper 5. Based on the color change you observe in the pH paper, approximate the pH of the fresh water. Record this value in the Data Table 6. Taking care to rinse and dry pipette thoroughly, repeat steps 1-5 for each beaker, Record all I nformation in appropriate data space.

86 1.0 battery acid (sulfuric acid) 1.8-2.0 limes 2.2-2.4 lemon juice 2.2 vinegar (acetic acid) 2.8-3.4 fruit jellies 2.9-3.3 apple juice, cola 3.0-3.5 strawberries 3.7 orange juice 4.0-4.5 tomatoes 5.6 unpolluted rain 5.8-6.4 peas 6.0-6.5 corn 6.1-6.4 butter 6.4 cow's milk 6.5-7.5 human saliva 6.5-7.0 maple syrup 7.0 distilled water 7.3-7.5 human blood 7.6-8.0 egg whites 8.3 baking soda 9.2 borax 10.5 milk of magnesia 11.0 laundry ammonia 12.0 lime water 13.0 lye 14.0

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