Notes for Hydrology.pdf

Hydrology the study of the distribution and movement of water both on and below the Earth's surface, as well as the impact of human activity on water availability and conditions WATER ‒ A clear, colorless, odorless, and tasteless liquid essential for most plant and animal life ‒ scientific name for...

Hydrology the study of the distribution and movement of water both on and below the Earth's surface, as well as the impact of human activity on water availability and conditions WATER ‒ A clear, colorless, odorless, and tasteless liquid essential for most plant and animal life ‒ scientific name for water: dihydrogen monoxide Some Chemical and Physical Properties of Water ‒ Water is a liquid at standard temperature and pressure. ‒ The intrinsic color of water and ice is a very slight blue hue, although both appear colorless in small quantities. Water vapor is essentially invisible as a gas ‒ Water is a good solvent and is often referred to as the universal solvent. ‒ Substances that dissolve in water, e.g., salts, sugars, acids, alkalis, and some gases – especially oxygen, carbon dioxide (carbonation) are known as hydrophilic (water-loving) substances, while those that do not mix well with water (e.g., fats and oils), are known as hydrophobic (water-fearing) substances. ‒ The boiling point of water (and all other liquids) is dependent on the barometric pressure. (On the top of Mt. Everest water boils at 68 °C, compared to 100°C at sea level). ‒ Conversely, water deep in the ocean near geothermal vents can reach temperatures of hundreds of degrees and remain liquid. ‒ The maximum density of water occurs at 3.98 °C. It has the anomalous property of becoming less dense, not more, when it is cooled down to its solid form, ice. ‒ It expands to occupy 9% greater volume in this solid state, which accounts for the fact of ice floating on liquid water, as in icebergs. WATER TRIVIA AND FACTS ✓ Only 3% of Earth’s water is fresh water, 97% is salt water ✓ Over 90% of the world's supply of fresh water is located in Antarctica ✓ The total amount of water in the body of an average adult is 37 liters ✓ Human brains are 75% water ✓ A person can live about a month without food, but only about a week without water. If a human does not absorb enough water dehydration is the result ✓ Hot water weighs more than cold water ✓ Frogs do not need to drink water as they absorb the water through their skin ✓ Although Mount Everest, at 29,028 feet, is often called the tallest mountain on Earth, Mauna Kea, an inactive volcano on the island of Hawaii, is actually taller. Only 13,796 feet of Mauna Kea stands above sea level, yet it is 33,465 feet tall if measured from the ocean floor to its summit ✓ Water is the only substance that is found naturally on earth in three forms: liquid, gas, solid ✓ In a 100-year period, a water molecule spends 98 years in the ocean, 20 months as ice, about 2 weeks in lakes and rivers, and less than a week in the atmosphere Hydrology │ 1 Prepared by: Engr. MAAbellera HYDROLOGY ‒ The study of water and its movement along its various pathways within the hydrological cycle. ‒ It is applied by engineers who use hydrological principles to compute river flows from rainfall, water movement in soils from knowledge of soil characteristics, evaporation rates from water balance or energy balance techniques. THE HYDROLOGICAL (WATER) CYCLE ‒ The hydrological cycle is central to hydrology ‒ As shown, water evaporates from the earth’s oceans and water bodies and from land surfaces. (About seven times more evaporation occurs from oceans than from the earth’s land surfaces) ‒ The evaporated water rises into the atmosphere until the lower temperatures aloft cause it to condense and then precipitate in the form most globally as rain but sometimes as snow. ‒ Once on the earth’s surface, water flows into streams, lakes, and eventually discharge into surface waters. ‒ Through evaporation from surface waters or transpiration from plants, water molecules return to the atmosphere to repeat the cycle. The term evapotranspiration is used referring to combined evaporation and transpiration. Transpiration - the process where water contained in liquid form in plants is converted to vapor and released to the atmosphere. Much of the water taken up by plants is released through transpiration. ‒ In general, of 100 units of rain that falls on grassland in temperate zones, 10 to 20 units will go to groundwater, 20 to 40 units will transpire and 40 to 70 units will become stream runoff. Hydrology │ 2 Prepared by: Engr. MAAbellera GROUNDWATER SUPPLIES ‒ Ground water is both an important direct source of water supply and a significant indirect source since a large portion of the flow to stream is derived from subsurface water. ‒ Near the surface of the earth in the zone of aeration, soil pore spaces contain both air and water. Moisture from this zone cannot be tapped as water supply source since this water is held on soil particles by capillary forces and is not readily released. ‒ Below the zone of aeration is the zone of saturation, in which the pores are filled with water. Water within this zone is referred to as Groundwater. A stratum containing a substantial amount of groundwater is called an aquifer and the surface of this saturated layer is known as the water table. If the aquifer is underlain by an impervious stratum, it is called an unconfined aquifer. If the stratum containing water is trapped between two impervious layers, it is known as confined aquifer. SURFACE WATER SUPPLIES ‒ Surface water supplies are not as reliable as groundwater sources because quantities often fluctuate widely during the course of a year or even a week, and the quantity of surface water is easily degraded by various sources of pollution. WATER QUALITY ‒ Water in nature is most nearly pure in its evaporation state, however, it acquires impurities once condensed and additional impurities are added as the liquid water travels through the remainder of the hydrologic cycle and comes into contact with materials in the air and on or beneath the earth’s surface. ‒ In addition, human activities contribute further impurities in the form of industrial and domestic wastes, agricultural chemicals, and other less obvious contaminants. These impure water returns to the atmosphere as relatively pure molecules through evaporation. ‒ The impurities accumulated by water throughout the hydrologic cycle and as a result of human activities may be both suspended (larger particles) and in dissolved form (molecules, ions). ‒ Colloids are also very small particles that are suspended but often exhibit many characteristics of dissolved substances. ‒ Water Quality means the characteristics of water, which define its use in characteristics by terms of physical, chemical, biological, bacteriological or radiological characteristics by which the acceptability of water is evaluated. Classification of Water ▪ Potable water: It is safe to drink, pleasant to taste, and usable for domestic purposes. ▪ Palatable water: It is esthetically pleasing; it considers the presence of chemicals that do not cause a threat to human health. ▪ Contaminated (polluted) water: It is that water containing unwanted physical, chemical, biological, or radiological substances, and it is unfit for drinking or domestic use. ▪ Infected water: It is contaminated with pathogenic organism Hydrology │ 3 Prepared by: Engr. MAAbellera PHYSICAL WATER – QUALITY PARAMETERS 1. Suspended Solids Sources: ▪ inorganic material – clay, silt, and other soil constituents ▪ organic material – plant fibers and biological solids (algal cells, bacteria, etc) ▪ Other suspended material may result from human use of water (Domestic wastewater usually contains large quantities of suspended solids that are most organic in nature. Industrial use of water result in a wide variety of suspended impurities of either organic or inorganic in nature). Impacts: objectionable in water, aesthetically displeasing and provides adsorption sites for chemical and biological agents. Measurement: ▪ Total solids – all solids in water, suspended and dissolved, organic and inorganic. This parameter is measured by evaporating a sample to dryness (104°C) and weighing the residue expressed as mg/L. ▪ Total Suspended solids – solids removed by filtration. This parameter is measured by filtering the water sample, drying the residue and filter paper to a constant weight and determining the mass of the residue retained in the filter paper. This is expressed as dry mass per volume (mg/L) ▪ Dissolved solids – solids that passes through a filter paper also expressed as mg/L. This parameter is the difference between total solids and suspended solids of a water sample. Total solids = suspended solids + dissolved solids ▪ In the laboratory: Filterable residues – pass through the filter along with the water and relate more closely to dissolved solids Nonfilterable residues – retained on the filter and relate more closely to suspended solids ▪ The residue of TSS and TDS after heating to dryness for a defined period of time and at a specific temperature is defined as fixed solids. Volatile solids are those solids lost on ignition (heating to 550°C) Use: helpful to the operators of the wastewater treatment plant because they roughly approximate the amount of organic matter existing in the total solids of wastewater, activated sludge, and industrial wastes Water can be classified by the amount of TDS per liter as follows: ▪ freshwater: <1500 mg/L TDS; ▪ brackish water: 1500–5000 mg/L TDS; ▪ saline water: >5000 mg/L TDS Hydrology │ 4 Prepared by: Engr. MAAbellera 2) Turbidity ‒ A measure of the extent to which light is either absorbed or scattered by suspended material in water. Turbidity is not a direct quantitative measure of suspended solids. Sources: ▪ caused by suspended material such as clay, silt, organic material, plankton, and other particulate materials in water ▪ results from erosion of colloidal material – clay, silt, rock fragments, metal oxides from soil ▪ vegetable fibers and microorganisms ▪ soaps, detergents, emulsifying agents Impacts: ▪ aesthetically displeasing (opaqueness or “milk coloration” is apparent) ▪ Suspended particles provide adsorption media for heavy metals such as mercury, chromium, lead, cadmium, and many hazardous organic pollutants such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and many pesticides causes undesirable taste and odor ▪ interfere with light penetration and photosynthetic reactions in streams and lakes ▪ accumulation results in sediment deposits which affects the flora and fauna of streams Measurement: ▪ measured photometrically by determining the percentage of light of a given intensity that is either absorbed or scattered (use of turbidimeter) ▪ Turbidity is measured by an instrument called nephelometric turbidimeter, which expresses turbidity in terms of NTU or TU ▪ Turbidity more than 5 NTU can be visible to the average person while turbidity in muddy water, it exceeds 100 NTU. ▪ Groundwater normally has very low turbidity because of the natural filtration that occurs as the water penetrates through the soil. 3) Color ▪ Pure water is colorless ( as perceived by the naked eye) but water in nature is often colored by foreign substances. Apparent Color – the entire water sample color and consists of both dissolved and suspended components color True Color – color contributed by dissolved solids that remain after the removal of suspended solids Sources: ▪ yellowish brown water – after contact with organic debris (leaves, weeds, wood etc.), water pick up tannins, humic acid and humates ▪ reddish water – iron oxides cause it ▪ brown or black – due to manganese oxides ▪ industrial wastes add substantial color in water Hydrology │ 5 Prepared by: Engr. MAAbellera Impacts: ▪ not aesthetically acceptable to the general public. ▪ Phenolic compounds, which are common constituents of vegetative decay products produce objectionable taste and odor with chlorine. ▪ Some compounds of chlorine with naturally occurring organic acids are suspected to be carcinogenic Measurement: ▪ comparison with standardized colored materials, use of tubes containing standards (results expressed in TCUs – true color units) ▪ Spectrophotometric techniques – used by industries in measuring color. 4) Taste and Odor ‒ Substances that produce an odor in water will almost invariably impart a taste as well however, there are many mineral substances that produce taste but no odor Sources: ▪ minerals, metals, and salts from soil, products of biological reactions ▪ Inorganic substances produce taste unaccompanied by odor ✓ alkaline – imparts bitter taste to water ✓ metallic salts – give a salty taste to water ✓ Organic substances produce both taste and odor- petroleum based products and biological decomposition of organics like SO2 (imparts a rotten egg odor) Impacts: ▪ aesthetically displeasing, water is supposed to be tasteless and odorless. Odors produced by organic substances may be carcinogenic. Measurement: ▪ Gas or liquid chromatography is used for organics. Human senses of taste and smell (Threshold odor Number or TON) Use: ▪ Associated with drinking (potable water). A TON of 3 has been recommended by the Public Health Office 5) Temperature ‒ One of the most important parameter ‒ Temperature of surface waters governs the biological species present and their rates of activity ‒ Temperature has an effect on most chemical reactions that occur in natural water ‒ Temperature has an effect on the solubility of gases in water Sources: ▪ Ambient temperature – shallow bodies of water are more affected than deeper bodies of water ▪ The use of water for dissipation of waste heat in industry and its subsequent discharges may result to dramatic temperature changes in receiving streams Hydrology │ 6 Prepared by: Engr. MAAbellera Impacts: ▪ At lower temperature, biological activity (utilization of food supplies, growth, reproduction) is slower. ▪ An increase of 10°C is usually sufficient to double biological activity if essential nutrients are present. ▪ At elevated temperatures and increased metabolic rates, organisms that are more efficient at food utilization flourish while others decline and are perhaps eliminated. ▪ Accelerated growth of algae often occurs in warm water and become a problem because Eutrophication will occur. ▪ Fishes are affected by temperature and dissolved oxygen levels. ▪ Temperature changes also affect the reaction rates and solubility of chemicals as well as other physical properties of water such as viscosity, density, etc. 6) Electrical conductivity ‒ measures how well a sample of water or similar solution can carry or conduct electrical currents. ‒ Conductivity levels will increase as the amount of ions in the water increases ‒ High conductivity means that the water contains a high amount of contaminants. ‒ On the other hand, potable water and ultra-pure water are practically unable to conduct an electrical current. ‒ Electrical Conductivity is measured in micromhos per centimeter (µmhos/cm) or microsiemens per centimeter (µs/cm) Hydrology │ 7 Prepared by: Engr. MAAbellera CHEMICAL WATER – QUALITY PARAMETERS 1. pH ‒ It is defined as the negative logarithm of the hydrogen ion concentration ‒ Pure water is neutral, with a pH close to 7.0 at 25°C. ‒ Normal rainfall has a pH of approximately 5.6 (slightly acidic) owing to atmospheric carbon dioxide gas. ‒ Safe ranges of pH for drinking water are from 6.5 to 8.5 for domestic use and living organisms need ‒ A high pH makes the taste bitter and decreases the effectiveness of the chlorine disinfection, thereby causing the need for additional chlorine. ‒ The amount of oxygen in water increases as pH rises. ‒ Low-pH water will corrode or dissolve metals and other substances Effects of pH on animals and plant: ‒ Most aquatic animals and plants have adapted to life in water with a specific pH and may suffer from even a slight change. ‒ Even moderately acidic water (low pH) can decrease the number of hatched fish eggs, irritate fish and aquatic insect gills, and damage membranes. ‒ Water with very low or high pH is fatal. A pH below 4 or above 10 will kill most fish, and very few animals can endure water with a pH below 3 or above 11. ‒ Amphibians are extremely endangered by low pH because their skin is very sensitive to contaminants. Some scientists believe that the current decrease in amphibian population throughout the globe may be due to low pH levels induced by acid rain Effects of pH on other chemicals in water: ‒ Heavy metals such as cadmium, lead, and chromium dissolve more easily in highly acidic water (lower pH). This is important because many heavy metals become much more toxic when dissolved in water ‒ A change in the pH can change the forms of some chemicals in the water. Therefore, it may affect aquatic plants and animals. 1.a. Acidity ‒ refers to the measure of how much acids are in a specific solution ‒ Acidity in water is usually due to carbon dioxide, mineral acids, and hydrolyzed salts such as ferric and aluminum sulfates ‒ Acids can influence many processes such as corrosion, chemical reactions and biological activities ‒ Carbon dioxide from the atmosphere or from the respiration of aquatic organisms causes acidity when dissolved in water by forming carbonic acid 1.b. Alkalinity ‒ Quantity of ions in water that will react to neutralize hydrogen ions. ‒ It is a measure of the ability of water to neutralize acids ‒ This includes CO32-, HCO31-, OH1-, HSiO31-,HPO42-,H2PO41-,HS1-, and NH3 Hydrology │ 8 Prepared by: Engr. MAAbellera Sources: ▪ results of the dissolution of mineral substances in soil and atmosphere ▪ Phosphates may originate from detergents in wastewater, from fertilizers and insecticides from agricultural lands ▪ Sulfides and ammonia may be products of microbial decomposition of organic material Impacts: ▪ Alkalinity imparts bitter taste to water, precipitates can foul pipes and other water – system Measurement: ▪ Titration of the water with an acid and determining the hydrogen equivalent expressed as mg/L of CaCO3 Use: ▪ Included in the analysis of natural water to determine buffering activity 2. Hardness ‒ a term used to express the properties of highly mineralized waters ‒ mainly caused by the presence of magnesium and calcium ions ‒ They enter water mainly from contact with soil and rock, particularly limestone deposits ‒ These ions are present as bicarbonates, sulfates, and sometimes as chlorides and nitrates. ‒ Generally, groundwater is harder than surface water. Two types of Hardness: a. Temporary hardness which is due to carbonates and bicarbonates can be removed by boiling b. Permanent hardness which is remaining after boiling is caused mainly by sulfates and chlorides Total Hardness = Temporary Hardness + Permanent Hardness Hydrology │ 9 Prepared by: Engr. MAAbellera Impacts: ▪ Soap lathering problem, pipes and boiler scaling ▪ Mg 2+ hardness – laxative effect on persons not used to it Measurement: ▪ spectrophotometric techniques, chemical titration to determine Ca2+ and Mg2+, titrated with EDTA (ethylenediaminetetracetic acid) using EBT (eriochrome black T) as indicator. 1 mL of 0.01M EDTA measures 1 mg of hardness as CaCO3. Use: ▪ Analysis on natural waters and on water intended for drinking and certain industrial uses 3. Total Dissolved Solids ‒ The material remaining in the water after filtration. This material is left as a solid residue upon evaporation of the water and constitutes a part of total solids. Dissolved solids may be organic or inorganic Sources: ▪ Results from solvent action of water on solids, liquids, and gases ▪ Materials from decay products of vegetation ▪ organic chemicals and organic gases Measurement: ▪ weight of the residue remaining after evaporation of water sample that has been filtered to remove suspended solids. The organic fraction can be determined by firing the residue at 550°C in a muffle furnace Total Dissolved Solids: ‒ Ca, Mg, Na, K, anions such as chlorides, sulfates, bicarbonates Common measure of water salinity ▪ Fresh water - less than 1500 mg/L ▪ Brackish water – can have values up to 5000 mg/L ▪ Saline waters – above 5000 mg/L ▪ Sea water – 30,000 to 34,000 mg/L Indicator of the usefulness of water for various applications Upper limits for livestock (quoted by the US Geological survey) ✓ Poultry = 2860 mg/L ✓ Pigs = 4290 mg/L ✓ Beef cattle = 10,100 mg/L For crops: ✓ Tolerance = 1500 mg/L ✓ Not suitable for irrigation >2100 mg/L Hydrology │ 10 Prepared by: Engr. MAAbellera 4) Fluorides ‒ Seldom found in appreciable quantities in surface waters ‒ Appear in ground water in a few geographical regions ‒ Toxic to humans and animals in large quantities, small concentrations are beneficial Levels: 1.0 mg/L – can help prevent dental cavities 2.0 mg/L – can cause discoloration of teeth (mottling) <1.5 mg/L – rare mottling > 5 mg/L – can cause bone fluorosis 1.5 mg/L – recommended limit in drinking water ❖ Bone fluorosis – accumulation of fluoride which can contribute to osteoporosis 5) Metals ‒ Metals are opaque, lustrous elements that are good conductors of heat and electricity ‒ Metals are usually malleable and shiny, that is they reflect most of incident light ‒ Basically, all metals are soluble to some extent in water ‒ Excessive amounts may present health hazards Toxic Heavy Metals – those metals that are harmful in relatively small amounts. ‒ HM can be absorbed and can be accumulated in the body ‒ Can be eliminated by the kidney Kidney - complex filters whose primary purpose is to eliminate toxic substances ✓ The kidneys contain millions of excretory units called nephrons. ✓ Nephrotoxins – chemicals that are toxic to the kidneys. ✓ Cd, Pb, and Hg are nephrotoxic metals. Impacts of HM on the body include: ✓ nervous system breakdown, ✓ kidney damage, ✓ creation of mutation, ✓ induction of tumors. Sources: ▪ Include dissolution from natural deposits, and discharges from domestic, industrial or agricultural wastewaters Non – toxic metals: ✓ Calcium and Magnesium – hardness ions ✓ Sodium, Iron, Manganese, Aluminum, Copper and Zinc – nontoxic metals found in water Hydrology │ 11 Prepared by: Engr. MAAbellera Non- toxic metals a. Sodium ‒ most abundant in natural waters and in the earth’s crust. ‒ It is highly reactive with other elements. ‒ Excessive concentration cause a bitter taste in water and a health hazard to cardiac and kidney patients. ‒ It is also corrosive to metal surfaces and is toxic to plants in large concentrations. b. Iron and Manganese ‒ impart a noticeable bitter taste to drinking water even at very low concentration ‒ cause color problems in water at concentrations of 0.3 mg/L Iron and 0.05 mg/L Manganese ‒ Bacteria use these metals as source of energy, so the resulting slime growth produce taste and odor problems ‒ metals usually occur in groundwater in solution as ferrous (Fe2+) and manganous (Mn2+) ions ‒ These ions can also cause black or brown stains on laundry and plumbing fixtures ‒ measured by many instrumental methods such as atomic absorption spectrometry, flame atomic absorption spectrometry, cold vapor atomic absorption spectrometry, electrothermal atomic absorption spectrometry, and inductively coupled plasma (ICP) c. Copper and Zinc ‒ nontoxic if found in small concentrations ‒ both essential and beneficial for human health and growth of plants and animals ‒ can cause undesirable tastes in drinking water ‒ At high concentrations, zinc imparts a milky appearance to the water ‒ measured by the same methods used for iron and manganese measurements Toxic metals ‒ Toxic metals comprise a group of minerals that have no known function in the body and, in fact, are harmful ‒ Mainly produced by industrial activities, and deposit slowly in the surrounding water and soil ‒ Most common heavy metals toxicity: lead, mercury, cadmium, and arsenic ‒ Toxicity may occur through ingestion, inhalation, or dermal exposure ‒ Toxicity is either acute or chronic ‒ Metallic taste is ingested except arsenic which is tasteless ‒ Can cause both local and systemic effects ‒ Most metals cause diarrhea except lead which causes constipation ‒ The antidotes are called Chelators Hydrology │ 12 Prepared by: Engr. MAAbellera a. Lead (Pb) ‒ Most common metallic poison ‒ Occurs in organic an inorganic forms ‒ Absorption of ingested lead in children is much more than in adults (50% children and 10% adults) ‒ Probably the most important chronic environmental illness affecting children ‒ In children, probably no organ system is immune to the effects of lead poisoning Source and method of exposure: ▪ Inhalation of lead particles generated by burning materials containing lead, for example during smelting, recycling, stripping leaded paint and plastic cables containing lead and using leaded aviation fuel; and ▪ Ingestion of lead-contaminated dust, water (from leaded pipes) and food (from lead-glazed or lead-soldered containers) and from hand-to-mouth behavior. Effects due to Lead Exposure: ‒ Acute toxicity may cause renal colic ‒ Alters uric acid excretion resulting in hyperuricemia and gout ‒ Direct effect on CNS causing lead encephalopathy especially in children ‒ Delayed or reversed development, permanent learning disabilities ‒ Abortion, stillbirth, neurodevelopmental problems ‒ May cause decreased sperm count, and increased number of abnormal sperms ‒ Triggers hypermineralization ‒ Inhibits the conversion of vitamin D into its active form Hydrology │ 13 Prepared by: Engr. MAAbellera b. Cadmium (Cd) ‒ used in metal plating, active ingredient in rechargeable batteries ‒ Cadmium contamination of a water source can be through natural erosion of cadmiumcontaining rocks, industrial dust/waste (impurity in zinc), fertilizer (contaminant in phosphate rock), pigment production, mine tailings or spoils, smelting, and plasticizers production. ‒ Extremely toxic even in low concentrations, and will bioaccumulate in organisms and ecosystems Hydrology │ 14 Prepared by: Engr. MAAbellera “Itai-itai” or “Ouch-ouch” Disease The strange disease that appeared in the downstream basin of the Jinzu River around 1912 was called by locals "itai-itai byo" ("itai" being what Japanese people say when inflicted with pain and "byo" literally meaning disease). In came by this name because of the way victims cried out "itai-itai" under the excruciating pain they endured. Women were mostly afflicted with pain across their entire body and more severe cases suffered broken bones when trying to move on their own. However, because the disease was first taken as an endemic sickness, it wasn't until the 1950's that outright research began. c. Mercury ‒ Only metal that is liquid at room temperature ‒ Greek word Hydrargyrum – “water silver” ‒ a naturally occurring element that is found in air, water and soil. ‒ It exists in several forms: ▪ elemental or metallic mercury ▪ inorganic mercury compounds ▪ organic mercury compounds Methods of Exposure a. Elemental Mercury ‒ Barometers, batteries, dental amalgams, electroplating, fingerprinting products, fluorescent and mercury lamps, infrared detectors, jewelry industry, manometers, neon lamps, paints, photography, silver and gold production, thermometers b. Organic Mercury ‒ Antiseptics, bactericidal, fungicides, insecticidal products, laundry products, diaper products, paper manufacturing, seed preservation, and wood preservatives c. Inorganic Mercury ‒ Cosmetics, disinfectants, explosives, ink manufacturing, mirror silvering, perfume industry, photography, tattooing inks, and wood preservation Hydrology │ 15 Prepared by: Engr. MAAbellera Minamata Disease ‒ is a large-scale mercury poisoning that results from methylmercury contamination, usually in seafood. ‒ The original case to gain recognition began when a factory in Minamata City released discharge that included methylmercury, a by-product of acetaldehyde production, into Minamata Bay. History (1908-1955) ‒ The Chisso Corporation opened a chemical factory in Minamata in 1908 ‒ Minamata is a city located in Kumamoto Prefecture, Japan ‒ Chisso chemical factory initially produced fertilizers ‒ Following the nationwide expansion of Japan’s chemical industry, the company branched out into the production of acetylene, acetaldehyde, acetic acid, vinyl chloride and octanol ‒ The Minamata factory became the most advanced all over Japan ‒ The rapid expansion of the Minamata factory spurred on the local economy. ‒ Chisso prospered, so did Minamata ‒ In 1932, Chisso Minamata factory first started acetaldehyde production (producing 210 tons per year). ‒ By 1951, production had jumped to 6,000 tons per year ‒ The chemical reaction used to produce the acetaldehyde used mercury sulphate as catalyst ‒ A side reaction of the catalytic cycle led to the production of methyl mercury ‒ Wastewater from Chisso factory were released into Minamata Bay Bioaccumulation is the process by which toxins enter the food web by building up in individual organisms, while biomagnification is the process by which toxins are passed from one trophic level to the next (and thereby increase in concentration) within a food web. Hydrology │ 16 Prepared by: Engr. MAAbellera d. Chromium – natural impurity in coal, used in the manufacture of stainless steel. Chromium causes a suite of adverse health effects. Hexavalent e. Arsenic ‒ is a naturally occurring chemical element that is widely distributed in the Earth’s crust. ‒ it can be found in water, air, and soil ‒ Arsenic levels tend to be higher in groundwater sources, such as wells, than from surface sources, such as lakes or reservoirs ‒ Increased level in water, air, and soil may be due to mining and fracking, coal-fired power plants, arsenic-treated lumber, and arsenic-containing pesticides Hydrology │ 17 Prepared by: Engr. MAAbellera 6) Nutrients (nitrogen and phosphorus) Elements essential to the growth and reproduction of plants and animals and aquatic species depend on the surrounding water to provide the nutrients ‒ Nitrogen ‒ Phosphorus a. Nitrogen ▪ The element nitrogen does not normally exist as a single atom, but is usually combined with another nitrogen atom very tightly in a triple bond, This molecule, nitrogen gas, N2, is the predominant gas in our atmosphere, making up over 79% of air ▪ The bond is so tight that it is only broken by very energetic natural events, like lightning. When this happens, and it happens often, various compounds of nitrogen and oxygen are formed in a process called nitrogen fixation. ▪ Sometimes, fixed nitrogen is called reactive nitrogen. ▪ The most oxidized form is called nitrate Sources: ‒ animal wastes, chemical fertilizers, and wastewater discharges ‒ Over–enrichment problems may also lead to Eutrophication (natural aging process in which the water is organically enriched leading to increasing aquatic weeds – algal bloom) Impacts: ‒ Excessive nitrogen can cause nitrate poisoning on babies (blue baby syndrome or methemoglobinemia) b. Phosphorus ▪ Next to calcium, phosphorus is the most abundant mineral in the body. These 2 important nutrients work closely together to build strong bones and teeth ▪ About 85% of phosphorus in the body can be found in bones and teeth, but it is also present in cells and tissues throughout the body ▪ Phosphorus is one of the key elements necessary for growth of plants and animals. Phosphates PO4--- are formed from this element. ▪ Phosphates exist in three forms: orthophosphate, metaphosphate (or polyphosphate) and organically bound phosphate. Each compound contains phosphorous in a different chemical formula. ▪ Phosphorus enter waterways from human and animal waste, phosphorus rich bedrock, laundry, cleaning, industrial effluents, and fertilizer runoff. These phosphates become detrimental when they over fertilize aquatic plants and cause stepped up eutrophication. ▪ Phosphate will stimulate the growth of plankton and aquatic plants which provide food for fish. This may cause an increase in the fish population and improve the overall water quality. However, if an excess of phosphate enters the waterway, algae and aquatic plants will grow wildly, choke up the waterway and use up large amounts of oxygen 7) Organics Sources: Come from natural sources or results from human activity ▪ Natural organics – decay products of organic solids ▪ Synthetic organics – result of wastewater discharges or agricultural practices Hydrology │ 18 Prepared by: Engr. MAAbellera 2 Categories of dissolved organics in water: a. Biodegradable Organics ‒ organics that can be utilized for food by naturally occurring microorganisms within a reasonable length of time ‒ in dissolved form, these materials usually consist of starches, fats, proteins, alcohols, acids, aldehydes, and esters ‒ end product of initial microbial decomposition of plant or animal tissues, or from domestic or industrial wastewater discharges. Microbial decomposition of organics is accompanied by: ▪ Oxidation – addition of oxygen to or removal of hydrogen from elements of the organic molecule ▪ Reduction – addition of hydrogen to or removal of oxygen from elements of the organic molecule ▪ ▪ Decomposition is either aerobic or anaerobic Aerobic – denotes the presence of oxygen. End – products of microbial decomposition of organics are stable and acceptable compounds Anaerobic – denotes the absence of oxygen. Decomposition results in unstable and objectionable end - products b. Non – biodegradable / Refractory organics ‒ organics resistant to biological degradation ‒ examples include tannic and lignin acids, cellulose and phenol Characteristics of Refractory Organics: ‒ molecules with exceptionally strong bonds ‒ ringed structure Example: ABS (alkyl benzene sulfonate) – a detergent compound which causes frothing and foaming in wastewater. It is now being substituted by LAS (linear alkylbenzene sulfonate) which is biodegradable Pesticides: ▪ chemicals that kill organisms which humans consider undesirable ▪ includes more specific categories of insecticides, herbicides, rodenticides, and fungicides. Main Groups of Organic Pesticides ▪ Organochlorines – chlorinated hydrocarbons ▪ Organophosphates ▪ Carbamates ▪ DDT (dichloro-diphenyl-trichloroethane) ‒ persistent, they last long in the environment before being broken down into other substances ‒ quite soluble in lipids (meaning they easily accumulate in fatty tissue) ‒ DDT biomagnify or bioconcentrate in fatty tissues ‒ Half life = 10 – 15 years Hydrology │ 19 Prepared by: Engr. MAAbellera ‒ DDT is the first pesticide manufactured by man ‒ Used to kill insects (flies & mosquitoes) 8) Dissolved Oxygen ‒ a key test of water pollution ‒ The higher the concentration of dissolved oxygen, the better the water quality. ‒ actual amount of dissolved oxygen varies depending on pressure, temperature, and salinity of the water. ‒ Dissolved oxygen has no direct effect on public health, but drinking water with very little or no oxygen tastes unpalatable to some people. 9) Biochemical Oxygen Demand (BOD) ‒ is the amount of dissolved oxygen needed (i.e., demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period ‒ The more organic material there is in the water, the higher the BOD used by the microbes will be. ‒ BOD is used as a measure of the power of sewage; strong sewage has a high BOD and weak sewage has low BOD 10) Chemical Oxygen Demand (COD) ‒ is a parameter that measures all organics: the biodegradable and the non-biodegradable substances ‒ It is a chemical test using strong oxidizing chemicals (potassium dichromate), sulfuric acid, and heat, and the result can be available in just 2h ‒ COD values are always higher than BOD values for the same sample 11) Radioactive substances ‒ Potential sources of radioactive substances in water include wastes from nuclear power plants, industries, or medical research using radioactive chemicals and mining of uranium ores or other radioactive materials. ‒ When radioactive substances decay, they release beta, alpha, and gamma radiation. ‒ Exposure of humans and other living things to radiation can cause genetic and somatic damage to the living tissues. ‒ Radon gas is of a great health concern because it occurs naturally in groundwater and is a highly volatile gas, which can be inhaled during the showering process. ‒ For drinking water, there are established standards commonly used for alpha particles, beta particles, photons emitters, radium-226 and -228, and uranium. Hydrology │ 20 Prepared by: Engr. MAAbellera BIOLOGICAL WATER – QUALITY PARAMETERS May cause: ▪ Water-borne diseases ▪ Water contact diseases ▪ Water hygiene problems ▪ Pathogens – biological organisms in water capable of infecting or of transmitting diseases to humans. They are not native to aquatic systems and usually require a HOST for growth and reproduction. Species of pathogens can survive in water and maintain infectious capabilities for significant periods of time. ▪ Water Borne – Pathogens ‒ Those acquired by ingestion of pathogens not only in drinking water but also from water that makes into a person’s mouth from washing food, utensils and hands. ▪ Water-Contact Diseases ‒ Do not require that individuals ingest the water. Example: Schistosomiasis (bilharzias) ‒ common water-contact disease in the world, affecting approximately 200 M people ‒ Is spread by free-swimming larva in water called Cercaria ‒ they attach themselves to human skin, penetrate it and enter the bloodstream. Hydrology │ 21 Prepared by: Engr. MAAbellera ▪ ▪ ▪ Cercaria mature in the liver into worms that lay masses of eggs on the walls of the intestine. When excreted into water, they hatch & find snail hosts in w/c they develop into new Cercaria. From the snails, the Cercaria find human as another host and continue the cycle. Classification of Pathogens (causing water-borne diseases) 1) Bacteria ‒ single-celled microorganisms that can exist either as independent (free-living) organisms or as parasites (dependent on another organism for life) ‒ At low temperatures, bacteria grow and reproduce slowly ‒ As the temperature increases, the rate of growth and reproduction doubles in every additional 10°C (up to the optimum temperature for the species) ▪ Cocci : Spherical bacteria are called cocci (singular coccus). The cells may occur in pairs (diplococci), in groups of four (tetracocci), in bunches (staphylococci), in a beadlike chain(streptococci)or in a cubical arrangement of eight or, more (sarcinae) ▪ Bacilli : Rod-like bacteria are called bacilli (singular bacillus). They generally occur singly, but may occasionally be found in pairs (diplobacilli) or chains (strepto bacilli). ▪ Spirilla : Spiral-shaped bacilli are called spirilla (singular, spirillum). Short incomplete spirals are called vibrios or comma bacteria. There are several distinctions among the various species of bacteria. One distinction depends on how they metabolize their food. ▪ Aerobic bacteria – Bacteria that require oxygen for their metabolism ▪ Anaerobic bacteria – those live only in an oxygen-free environment ▪ Facultative bacteria – can live in either the absence or the presence of oxygen BACTERIA: 1. Escherichia coli (E. coli) ✓ (enteropathogenic) – Gastroenteritis, Diarrhea 2. Leptospira - Leptospirosis ✓ Jaundice, fever (Weil’s disease) 3. Salmonella typhi or Salmonella typhosa ✓ typhoid fever; High fever, diarrhea, ulceration of the intestine 4. Salmonella – Salmonellosis ✓ Food poisoning 5. Vibrio cholerae or Vibrio comma – Cholera ✓ Extremely heavy diarrhea, dehydration 6. Shigella – Shigellosis, Bacillary dysentery 7. Legionella pneumophila – Legionellosis ✓ Acute, Respiratory illness 2) Virus ‒ smallest biological structures which are known to contain all the genetic information necessary for their own reproduction. Hydrology │ 22 Prepared by: Engr. MAAbellera ‒ They can't multiply on their own, so they have to invade a 'host' cell and take over its machinery in order to be able to make more virus particles ‒ They can pass through filters that do not permit the passage of bacteria. ‒ Waterborne viral pathogens are known to cause infectious hepatitis and poliomyelitis 3) Protozoa ‒ lowest form of animal life, they are complete and self contained organisms that can be free – living or parasitic, pathogenic or non – pathogenic ‒ Most protozoa are microscopic in size, and can only be seen under a microscope. However, they do breathe, move and reproduce like multicell animals PROTOZOA: 1. Giardia lamblia – Giardiasis ✓ Mild to severe diarrhea, nausea, indigestion ✓ Also called Beaver disease and backpacker’s disease ✓ Giardia lamblia can be carried by wild animals living in or near natural water systems. 2. Entamoeba histolytica – Amoebiasis ✓ Prolonged diarrhea with bleeding ✓ Epidemic in Chicago, drinking water was contaminated by sewage containing Entamoeba histolytica ✓ over 1400 people were affected, 98 died. 3. Cryptosporidium parvum – Cryptosporidiosis ✓ debilitating w/ diarrhea, vomiting & abdominal pain lasting for several weeks. ✓ Cryptosporidium cannot be disinfected and it can be fatal ✓ Filtration provides the best barrier 4. Balantidium coli - Balantidiasis ✓ Diarrhea, Dysentery 4) Helminths ‒ parasitic worms ‒ The life cycles of helminths often involve 2 or more animal hosts, one of which can be human and contamination may result from human or animal waste that contain helminths. Contaminations could also be via other species such as snails or insects. HELMINTHS: 1. Ascaris lumbricoides ▪ Ascariasis - Roundworm infestation 2. Enterobius vericularis ▪ Enterobiasis - Pinworm 3. Taenia saginata ▪ Taeniasis - Beef tapeworm 4. Taenia solium ▪ Taeniasis - Pork tapeworm 5. Trichuris trichiura ▪ Trichuriasis - Whipworm Hydrology │ 23 Prepared by: Engr. MAAbellera RADIOLOGICAL WATER – QUALITY PARAMETERS ✓ Excessive exposure to radioactive materials is harmful ✓ Unnecessary exposure should be avoided (including drinking water). ✓ Naturally occurring RA compounds include Radon & Radium 226 found in Ground Water. ✓ Strontium – 90 and Tritium are also found in surface water resulting from atmospheric nuclear weapon testing fallout. ✓ The most significant radionuclides associated with drinking water is dissolved radon gas. ✓ Radon is colorless, odorless & tasteless gas occurring naturally in ground water. Additional Terms: • Endemic – refers to a disease prevalent in and confined to a particular population. • Epidemic – is an outbreak of an infectious disease spreading widely in an area. • Pandemic – if the outbreak of an infectious disease is widely spreading worldwide. • Epidemiology – is the study of the causes of a disease spreading in a community. • Microbiology – is the study of microorganisms and their activities. Hydrology │ 24 Prepared by: Engr. MAAbellera EPIDEMIC example Meningococcemia • an acute contagious disease that is caused by Neisseria meningitides bacteria and spread through close contact. It is also known as meningococcal meningitis or cerebrospinal fever. • In the Philippines, the disease became familiarly known as meningo after an outbreak in Baguio during the Christmas season of 2004. • The disease was spotlighted after some cases reported in Baguio and the Cordilleras from the end of 2004 to early 2005 resulting in more than 50 deaths. The crowds that flocked to the area during the Christmas season were considered a main contributing factor to the outbreak. • Efforts to contain the spread of the disease included the distribution of antibiotics and the clean-up of the public marketplace. PANDEMIC example The Black Death • one of the most devastating pandemics in human history, peaking in Europe between 1348 and 1350. • carried by Oriental rat fleas living on the black rats that were regular passengers on merchant ships. It spread throughout the Mediterranean and Europe. • The Black Death is estimated to have killed 30–60 percent of Europe's population[ and reduced the world population from an estimated 450 million to between 350 and 375 million in the 14th century. Hydrology │ 25 Prepared by: Engr. MAAbellera