3.1 Water Chemistry PDF

11/26/2024 MODULE 3 ENG 201 Intended Learning Outcomes - ILOs Explain the key physical and...

11/26/2024 MODULE 3 ENG 201 Intended Learning Outcomes - ILOs Explain the key physical and CHEMISTRY of the chemical properties of water. ENVIRONMENT Discuss key water quality 3.1 Water Chemistry parameters. FACULTY OF ENGINEERING Discuss water contaminants UNIV E RS IT Y OF S ANTO TOM AS and pollutants and the M ANIL A, P HIL IP P INE S consequences. UST FACULTY OF ENGINEERING 1 2 3.1.1 WATER Hydrogen Bonds Unusually strong type of dipole force ▪ One of the most important ▪ Strong hydrogen bonds occurs among polar covalent substances on Earth. molecules containing H and one of the three small, highly electronegative elements, F, N,O ▪ Can dissolve many different ▪ H from one molecule can associate itself with the substances. negative end of the dipole of another ▪ A polar molecule because of ▪ Dipole arises from the difference in the electronegativity between H and N, O, or F its unequal charge distribution. ▪ Small size of H allows the unshared pair from the negative end of the dipole to approach the H closely ▪ HF, H2O, and NH3 - Unusually high boiling points as a result of hydrogen bonding 3 4 3 4 Water Intermolecular Forces in H2O Hydrogen bonding in water accounts for: Water: ▪High specific heat One molecule can participate ▪High boiling point in four hydrogen bonds with other molecules. ▪Higher density of the liquid phase relative to the solid Because of the hydrogen bond, water has a boiling point 100oC higher than if the bond were not present. 5 6 5 6 1  11/26/2024 Learning Activity | Instructions 1. Each learner shall use a clean sheet of paper. Intermolecular Forces in H2O 2. Each learner is given one instruction: “Create a drawing of the water cycle with appropriate labels for each item or component or process included.” 3. The learners are given 5 minutes to complete the task. 4. At the end of the given time, the instructor will Permanent dipole-dipole interactions occur between polar covalent facilitate the scoring and evaluation through molecules because of the attraction of the + atoms of one molecule to the - atoms of another molecule. self-checking or peer-checking (paper exchange). 7 UST FACULTY OF ENGINEERING 8 7 8 Water Learning Activity | Evaluation Part 1 The instructor/professor instructs the learners to check his/her work for items and Cycle processes as listed below. One point for each item or process that is present in the drawing: 1. Any water body like oceans, lakes, rivers, ponds 2. Atmosphere represented by the sky or clouds 3. Land represented by landmass or landscape 4. Plants represented by trees and vegetation 5. The sun Not in the photo is infiltration and percolation UST FACULTY OF ENGINEERING 9 UST FACULTY OF ENGINEERING 10 9 10 Learning Activity | Evaluation Part 2 Water The instructor/professor instructs the learners to check his/her work for items and processes as listed below. One point for each item or process that is present in the drawing: Cycle 6. Evaporation: The process of water turning from liquid to gas, usually shown as arrows pointing upward from water bodies to the atmosphere. 7. Condensation: The process of water vapor cooling and turning into liquid water droplets, often represented as cloud formation. 8. Precipitation: The falling of water from the atmosphere to the Earth's surface, including rain, snow, sleet, and hail. 9. Runoff: The flow of water over land surfaces, often shown as arrows flowing from land to water bodies. 10. Infiltration/Percolation: The process of water seeping into the ground, depicted as arrows pointing downward from the land surface. 11. Transpiration: The release of water vapor into the atmosphere from plants, Not in the photo is often shown as arrows pointing upward from plants to the atmosphere. infiltration and percolation UST FACULTY OF ENGINEERING 11 UST FACULTY OF ENGINEERING 12 11 12 2  11/26/2024 3.1.2. Water Quality Parameters Water Hardness ✓ Water Hardness Water Hardness ✓ pH  Is the amount of dissolved calcium and magnesium in the water ✓ Phosphates (PO43-)  is caused by divalent ions, especially Ca2+ and ✓ Nitrites and Nitrates (NO2-, NO3-) Mg2+ ✓ Ammonium (NH4+) Concerns ◦ Scaling ✓ Dissolved Oxygen ◦ Cleaning ✓ Turbidity ◦ Public Health UST FACULTY OF ENGINEERING 13 UST FACULTY OF ENGINEERING 14 13 14 Water Hardness Water Hardness Rating mg/L as CaCO3 Degree of Hardness 0-60 Soft water 61-120 Moderately hard water 121-180 Hard water >180 Very hard water From USGS UST FACULTY OF ENGINEERING 15 UST FACULTY OF ENGINEERING 16 15 16 pH pH is criteria of acidity and basicity of water. pH = -log [H30+] [H30+] > 10-7 => pH < 7 (acid) [H30+] = 10-7 => pH = 7 (neutral) [H30+] < 10-7 => pH > 7 (base) FACTORS THAT AFFECT pH in WATER. algal blooms, bacterial activity, water turbulence, chemicals flowing into the water body, sewage overflows, pollution. UST FACULTY OF ENGINEERING 17 UST FACULTY OF ENGINEERING 18 17 18 3  11/26/2024 Algal Bloom Sewage Overflow UST FACULTY OF ENGINEERING 19 UST FACULTY OF ENGINEERING 20 19 20 Estuary pH of natural waters Sea water due to humic acid Limestone, marble, CO3 rich Pure rain, snow Modified from www.waterwatch.org Modified from www.waterwatch.org http://www.vic.waterwatch.org.au/fortheteacher/manual/sect4f.htm http://www.vic.waterwatch.org.au/fortheteacher/manual/sect4f.htm UST FACULTY OF ENGINEERING 21 UST FACULTY OF ENGINEERING 22 21 22 Phosphates (PO43-) Natural unpolluted water contains less than 0.1mg/L of all the PO43- (higher concentrations are caused by human pollution). Sources of pollution: ◦ phosphoric manures ◦ laundry detergents ◦ sewage ◦ synthetic fertilizers Blue green algae UST FACULTY OF ENGINEERING 23 UST FACULTY OF ENGINEERING 24 23 24 4  11/26/2024 Nitrites and Nitrates (NO2-, NO3-) Nitrates (NO3-) are the major polluters of ground water and also of many effluent and influent waters. Sources of pollution: ◦ fertilizers ◦ manures ◦ intensive livestock breeding ◦ poor urban infrastructure (domestic sewage) Can lead to: eutrophication of natural water systems (overproduction of vegetation) UST FACULTY OF ENGINEERING 25 UST FACULTY OF ENGINEERING 26 25 26 Ammonium (NH4+) Dissolved Oxygen The presence of ammonium in water shows that the water was in contact with rotting organic materials, fecals, food wastes, etc. ▪DO is the measurement of oxygen High ammonium contents in surface water and shallow dissolved in water and available for groundwater are typically attributed to anthropogenic sources such fish and other aquatic life. as sewage from industrial emission or leakage of manure and fertilizers from agricultural activities (Du et al., 2017). ▪Indicates health of an aquatic system. ▪Can range from 0-18 ppm. ▪Most natural water systems require 5-6 ppm to support a diverse population. UST FACULTY OF ENGINEERING 27 UST FACULTY OF ENGINEERING 28 27 28 Dissolved Oxygen Dissolved Oxygen Increase in organic waste Potential Causes of Low Dissolved oxygen Natural Increase in algae/plant increased sunlight or other climate factors vegetation increased nutrient availability Decrease in DO available Changes in ocean properties Changes in river input (e.g.: drought) to organisms Changes in weather conditions Leads to changes in ecosystem as Artificial organisms needing lots of DO are human loading of nutrients or organic material replaced by organisms needing little. Changes in river input (eg: diversion) UST FACULTY OF ENGINEERING 29 UST FACULTY OF ENGINEERING 30 29 30 5  11/26/2024 Turbidity Measures how “murky” the water is Estimates: Mineral fraction Organics Inorganics Soluble organic compounds Plankton Microscopic organisms UST FACULTY OF ENGINEERING 31 UST FACULTY OF ENGINEERING 32 31 32 Turbidity Measuring Turbidity ▪Nephelometric Turbidity Unit (NTU) The WHO (World Health Organization), establishes that the turbidity of drinking water should not be more than 5 NTU, and should ideally be below 1 NTU. https://www.lenntech.com/turbidity.htm#:~ :text=The%20WHO%20(World%20Health %20Organization,ideally%20be%20below %201%20NTU. UST FACULTY OF ENGINEERING 33 UST FACULTY OF ENGINEERING 34 33 34 Causes of High Turbidity Effects of Highly Turbid Water In open waters, phytoplankton Modify light penetration 3.1.3 Water Pollution Closer to shore, particulates re- Increase sedimentation rate Water pollution occurs when harmful substances are released into suspended bottom sediments Settling clay particles can the water in large quantities which cause damage to people, (wind) suffocate newly-hatched larvae wildlife, or habitat or indirectly into water bodies without proper Organic detritus from stream treatment to remove harmful compounds. and/or wastewater discharges. Fine particulate material also can damage sensitive gill indianwater Dredging operations structures Floods Decrease organism resistance to disease Too many bottom-feeding fish (such as carp) Prevent proper egg and larval development Reduced photosynthesis can lead to lower daytime release of oxygen UST FACULTY OF ENGINEERING 35 UST FACULTY OF ENGINEERING 36 35 36 6  11/26/2024 Source: https://www.linkedin.com/pulse/what-difference-between- pollutant-contaminant-mohammad-hadi-bazrkar Contaminants in Water Contaminants may include organic and inorganic substances Inorganic water pollutants include: 1. Acidity caused by industrial discharges (especially sulfur dioxide from power plants) 2. Ammonia from food processing waste 3. Chemical waste as industrial by-products 4. Fertilizers containing nutrients - nitrates and phosphates - which are found in storm water run off from agriculture, as well as commercial and residential use 5. Heavy metals from motor vehicles (via urban storm water runoff) and acid mine drainage 6. Silt (sediment) in runoff from construction sites, logging, slash and burn practices or land clearing sites. UST FACULTY OF ENGINEERING 37 UST FACULTY OF ENGINEERING 38 37 38 Consequences of Water Pollution Consequences of Water Pollution Eutrophication in a body of water… Eutrophication is characterized by excessive plant and algal growth due to the increased availability of one or more limiting growth factors needed for photosynthesis such as sunlight, carbon dioxide, and nutrient fertilizers. The consequence is the creation of dense blooms of noxious, foul-smelling phytoplankton that reduce water clarity and harm water quality. Water without oxygen is called anoxic UST FACULTY OF ENGINEERING 39 UST FACULTY OF ENGINEERING 40 39 40 Consequences of Water Pollution Consequences of Water Pollution Eutrophication in a body of water… Bioaccumulation and Biomagnification Bioaccumulation is the intake of a chemical and its concentration in the organism by all possible means, including contact, respiration and ingestion. Biomagnification occurs when the chemical is passed up the food chain to higher trophic levels, such that in predators it exceeds the concentration to be expected where equilibrium prevails between an organism and its environment UST FACULTY OF ENGINEERING 41 UST FACULTY OF ENGINEERING 42 41 42 7  11/26/2024 Consequences of Water Pollution Consequences of Water Pollution Bioaccumulation and Biomagnification “ Minamata is a small Japanese fishing town living in the shadow of the chemical factory of the Chisso Corporation. When the factory began dumping large amounts of mercury in the bay in 1956 thousands of people began to develop symptoms of mercury poisoning. Almost all the towns cats went insane... Birds fell out of the sky. Panic gripped the city. In time, thousands of people would die from the poisoning.” UST FACULTY OF ENGINEERING 43 UST FACULTY OF ENGINEERING 44 43 44 Minamata, Japan UST FACULTY OF ENGINEERING 45 UST FACULTY OF ENGINEERING 46 45 46 Minamata, Japan Additional readings: The financial compensation was too little too late for the Water Properties https://www.usgs.gov/special-topics/water-science-school/science/water- thousands of victims properties In a tremendous “loss of face”, corporate official were Water Quality Monitoring Manual Volume 1 https://water.emb.gov.ph/wp-content/uploads/2017/09/Water-Quality- forced to apologize in public Monitoring-Manual-Vol.-1-ambient_14aug08.pdf What is Water Pollution? https://education.nationalgeographic.org/resource/what-water-pollution/ UST FACULTY OF ENGINEERING 47 UST FACULTY OF ENGINEERING 48 47 48 8  11/26/2024 MODULE 3 ENG 201 CHEMISTRY of the ENVIRONMENT 3.1 Water Chemistry FACULTY OF ENGINEERING UNIV E RS IT Y OF S ANTO TOM AS M ANIL A, P HIL IP P INE S 49 9