Water Quality
Content
PURE WATER – is TASTELESS, COLORLESS and ODORLESS liquid made up of hydrogen and nitrogen with a chemical formula of H2O. Water in nature contains dissolved substances. As a result of HYDROLOGIC CYCLE, water contains various other substances as well as gases. These substances are often identified as the IMPURITIES found in water.
CLASSIFICATION OF IMPURITIES
IONIC and DISSOLVED NONIONIC and UNDISSOLVED GASES
MEASURES OF WATER QUALITY
1. DISSOLVED OXYGEN
It is a major parameter in water quality in stream lakes, and other watercourse. It is measured with an oxygen probe and meter.
A high DO in water creates a driving force to get through the membrane, while a low DO would force only limited oxygen through the reaction and thereby create electric current.
2. BIOCHEMICAL OXYGEN DEMAND (BOD)
It is a major parameter indicating the pollution potential of various discharges to watercourse. It is a measure of amount of oxygen required by aerobic bacteria and other microorganisms while stabilizing decomposable matters.
A low rate of oxygen use indicates either the absence of contamination or that the microorganisms are uninterested in consuming the available organic.
SEEDING
A process in which the microorganisms responsible for oxygen uptake are added to BOD bottle with the sample for the oxygen uptake to occur.
3. SOLID
It is the residue on evaporation at 103 degree centigrade. Solid can be divided into two fractions: 1. dissolved solid and 2. suspended solid. Suspended solid can be classified as volatile solid that can be volatized at 600 degree centigrade and fixed solid.
GOOCH CRUCIBLE used to separate SUSPENDED Solid from DISSOLVED solid. It has a holes on the bottom on which the glass fiber filter is placed.
4. NITROGEN It is a useful measure of water quality in streams and lakes. It can be tied up in high energy compounds such as amino acids and amines and this form of nitrogen is known as ORGANIC NITROGEN. One of the intermediate compounds formed during biological metabolisms is AMMONIA NITROGEN.
5. BIOLOGICAL MEASUEMENTS are necessary to determine the potential presence of infectious agent such as pathogenic bacteria and viruses. A number of disease can be transmitted by water. Pathogens are disease causing organisms such as shigella that causes shigellosis, salmonella that causes salmonellosis, etc.
WATER QUALITY STANDARD
1. DRINKING WATER STANDARD - two types of standard are: Primary and Secondary.
Primary Standard relate to human health. Includes physical, chemical and bacteriological standard.
Secondary Standard are for constituents (chloride, copper, hydrogen sulfide, etc.) that make water disagreeable to use.
Turbidity it is the measure of cloudiness of water. It is measured by passing a beam of light through the water and measuring photometrically the light scattered at right angles at the beam.
2. EFFLUENT STANDARD The Environmental Protection Agency (EPA) oversees and states operate programs designed to reduce the flow of pollutants into natural watercourses.
3. SURFACE WATER STANDARD
CATEGORIES OF WATER POLLUTION • Dead organic matter • Pathogens • Organic chemicals • Nutrients • Heavy metals • Acids • Sediments • Heat(thermal pollution) • radioactivity
WATER SUPPLY & TREATMENT
HYDROLOGIC CYCLE Is a continuous circulation of water between the oceans, atmosphere, biosphere and the soils and rocks of the geosphere. Over 1.4 billion cu.km of water exist on earth. The vast majority of this water (96.5%0 is saline(salty) water in oceans. Of the remaining 3.5% that is fresh water, most (59%) is held in long term storage in cold regions as polar ice sheets, glaciers and snow, while 30% lies beneath the earth’s surface as groundwater.
Evaporation – is the process of loss of water from the surface of the earth. Precipitation – is the term applied to all forms of moisture originating in atmosphere and falling to the ground. Transpiration – is the process of loss water from the plants. Condensation – takes place as soon as the air contains more water vapor than it can receive from a free water surface.
Run-Off – is the portion of precipitation on the land that ultimately reaches streams. Percolation – is the movement of water through the soil. Infiltration – is the movement of water from the surface of the soil to soil. Water Table – is the locus point in unconfined material where the hydrostatic pressure is equal to atmospheric pressure.
Meteorological factors that affects evaporation: Air temperature Solar Radiation Wind Speed Humidity Available soil moisture to the plants
Sources of water: 1. Water of the surface of the earth that is exposed to the atmosphere is called SURFACE WATER. 2. Groundwater – water that lies beneath the surface of the earth.
Ground water supply
Zone of aeration – is above the water table where the soil pores is filled with either water and air. Zone of saturation – is below the water table where the soil pores is filled with water.
WATER TREATMENT PROCESS
1. Coagulation – is the chemical alteration of colloidal particles to make them stick together forming a larger particles called flock.
Two mechanisms important in the process of coagulation: a. Charge neutralization – is the mechanism whereby the aluminum ions are used to counter the charge on the colloidal particles.
b. Bridging – involves sticking together of the colloidal particles by virtue of the macromolecules formed by aluminum hydroxide.
2. Flocculation – is a physical process that assists the growth of particles. 3. Settling – simply allow the heavier-than water particles to settle to the bottom. Settling tank is designed to approximate a plug flow reactor.
Variables that influence the movement of particles in settling tank: Particle size Particle shape Particle density Fluid density Fluid viscosity
Factors that cause non-uniform flow in settling: Wind Density Temperature current Inadequate baffling at the tank entrance.
4. Filtration and Backwashing – water from the settling basin enters the filters and seeps through the sand and gravel bed, through the false floor and out into a clear well that stores the finished water. BACKWASHING is the process by which the solids that clogged at the rapid sand filters must be cleaned.
5. Disinfection – following filtration and before storage in the clear well, the water is disinfected to destroy whatever pathogenic organisms might remain.
6. Storage in a clear well
7. Distribution of water – water pumped in the distribution systems usually contains a residual of chlorine to guard any against contamination in the distribution system.
General criteria for water SUSTAINABILITY: Develop water resources in sufficient volume to maintain human health and well-being. Provide sufficient water resources to guarantee the health and maintenance of ecosystem. Ensure minimum standards of water quality for the various users of water resources.
Ensure that actions of humans do not damage or reduce long term renewability of water resources. Promote the use of water efficient technology and practice. Gradually eliminate water pricing policies that subsidize the inefficient use of water.
WASTEWATER TREATMENT
Uses of water: Drinking Recreation Commercial navigation Fish propagation Waste disposal
Types of sewers: Sanitary sewers – carry wastewater through large pipes flowing partially full using gravity feed. Collecting sewers – collect waste water from homes & industrial & converge at a central point. Truck sewers – transport the wastewater from collecting sewers to wastewater treatment plant
Force main – are inverted siphons and pipes from pumping stations, flow under pressure. Storm sewer – carry storm water run-off away from developed area back to environment.
Common contaminants in wastewater: Organic material as measured by BOD Suspended solid Nitrogen Phosphorus Pathogenic organisms
Forms of wastewater Domestic sewage – results from people day to day activities such as bathing, body excretion, food preparation & recreation. Industrial waste Inflow – storm water that seeps into sanitary sewer system through loose manhole covers. Infiltration – occurs when sewer lines are placed below the water table or when rainfall percolates down to the depth of the pipe.
Area of wastewater treatment plant 1. Preliminary treatment – is the removal large particles to prevent damage to the remainder of the unit operation. 2. Primary treatment – is the removal of solid by settling, usually physical process as opposed to biological or chemical. 3. Secondary treatment – is the removal of the demand for oxygen, commonly biological in nature.
4. Tertiary treatment – is the name applied to any number of polishing or clean-up processes, can be physical, biological or chemical. 5. Solid treatment and disposal – is the collection, stabilization and subsequent disposal of solid by other processes.
CLASSIFICATION OF IMPURITIES
IONIC and DISSOLVED NONIONIC and UNDISSOLVED GASES
MEASURES OF WATER QUALITY
1. DISSOLVED OXYGEN
It is a major parameter in water quality in stream lakes, and other watercourse. It is measured with an oxygen probe and meter.
A high DO in water creates a driving force to get through the membrane, while a low DO would force only limited oxygen through the reaction and thereby create electric current.
2. BIOCHEMICAL OXYGEN DEMAND (BOD)
It is a major parameter indicating the pollution potential of various discharges to watercourse. It is a measure of amount of oxygen required by aerobic bacteria and other microorganisms while stabilizing decomposable matters.
A low rate of oxygen use indicates either the absence of contamination or that the microorganisms are uninterested in consuming the available organic.
SEEDING
A process in which the microorganisms responsible for oxygen uptake are added to BOD bottle with the sample for the oxygen uptake to occur.
3. SOLID
It is the residue on evaporation at 103 degree centigrade. Solid can be divided into two fractions: 1. dissolved solid and 2. suspended solid. Suspended solid can be classified as volatile solid that can be volatized at 600 degree centigrade and fixed solid.
GOOCH CRUCIBLE used to separate SUSPENDED Solid from DISSOLVED solid. It has a holes on the bottom on which the glass fiber filter is placed.
4. NITROGEN It is a useful measure of water quality in streams and lakes. It can be tied up in high energy compounds such as amino acids and amines and this form of nitrogen is known as ORGANIC NITROGEN. One of the intermediate compounds formed during biological metabolisms is AMMONIA NITROGEN.
5. BIOLOGICAL MEASUEMENTS are necessary to determine the potential presence of infectious agent such as pathogenic bacteria and viruses. A number of disease can be transmitted by water. Pathogens are disease causing organisms such as shigella that causes shigellosis, salmonella that causes salmonellosis, etc.
WATER QUALITY STANDARD
1. DRINKING WATER STANDARD - two types of standard are: Primary and Secondary.
Primary Standard relate to human health. Includes physical, chemical and bacteriological standard.
Secondary Standard are for constituents (chloride, copper, hydrogen sulfide, etc.) that make water disagreeable to use.
Turbidity it is the measure of cloudiness of water. It is measured by passing a beam of light through the water and measuring photometrically the light scattered at right angles at the beam.
2. EFFLUENT STANDARD The Environmental Protection Agency (EPA) oversees and states operate programs designed to reduce the flow of pollutants into natural watercourses.
3. SURFACE WATER STANDARD
CATEGORIES OF WATER POLLUTION • Dead organic matter • Pathogens • Organic chemicals • Nutrients • Heavy metals • Acids • Sediments • Heat(thermal pollution) • radioactivity
WATER SUPPLY & TREATMENT
HYDROLOGIC CYCLE Is a continuous circulation of water between the oceans, atmosphere, biosphere and the soils and rocks of the geosphere. Over 1.4 billion cu.km of water exist on earth. The vast majority of this water (96.5%0 is saline(salty) water in oceans. Of the remaining 3.5% that is fresh water, most (59%) is held in long term storage in cold regions as polar ice sheets, glaciers and snow, while 30% lies beneath the earth’s surface as groundwater.
Evaporation – is the process of loss of water from the surface of the earth. Precipitation – is the term applied to all forms of moisture originating in atmosphere and falling to the ground. Transpiration – is the process of loss water from the plants. Condensation – takes place as soon as the air contains more water vapor than it can receive from a free water surface.
Run-Off – is the portion of precipitation on the land that ultimately reaches streams. Percolation – is the movement of water through the soil. Infiltration – is the movement of water from the surface of the soil to soil. Water Table – is the locus point in unconfined material where the hydrostatic pressure is equal to atmospheric pressure.
Meteorological factors that affects evaporation: Air temperature Solar Radiation Wind Speed Humidity Available soil moisture to the plants
Sources of water: 1. Water of the surface of the earth that is exposed to the atmosphere is called SURFACE WATER. 2. Groundwater – water that lies beneath the surface of the earth.
Ground water supply
Zone of aeration – is above the water table where the soil pores is filled with either water and air. Zone of saturation – is below the water table where the soil pores is filled with water.
WATER TREATMENT PROCESS
1. Coagulation – is the chemical alteration of colloidal particles to make them stick together forming a larger particles called flock.
Two mechanisms important in the process of coagulation: a. Charge neutralization – is the mechanism whereby the aluminum ions are used to counter the charge on the colloidal particles.
b. Bridging – involves sticking together of the colloidal particles by virtue of the macromolecules formed by aluminum hydroxide.
2. Flocculation – is a physical process that assists the growth of particles. 3. Settling – simply allow the heavier-than water particles to settle to the bottom. Settling tank is designed to approximate a plug flow reactor.
Variables that influence the movement of particles in settling tank: Particle size Particle shape Particle density Fluid density Fluid viscosity
Factors that cause non-uniform flow in settling: Wind Density Temperature current Inadequate baffling at the tank entrance.
4. Filtration and Backwashing – water from the settling basin enters the filters and seeps through the sand and gravel bed, through the false floor and out into a clear well that stores the finished water. BACKWASHING is the process by which the solids that clogged at the rapid sand filters must be cleaned.
5. Disinfection – following filtration and before storage in the clear well, the water is disinfected to destroy whatever pathogenic organisms might remain.
6. Storage in a clear well
7. Distribution of water – water pumped in the distribution systems usually contains a residual of chlorine to guard any against contamination in the distribution system.
General criteria for water SUSTAINABILITY: Develop water resources in sufficient volume to maintain human health and well-being. Provide sufficient water resources to guarantee the health and maintenance of ecosystem. Ensure minimum standards of water quality for the various users of water resources.
Ensure that actions of humans do not damage or reduce long term renewability of water resources. Promote the use of water efficient technology and practice. Gradually eliminate water pricing policies that subsidize the inefficient use of water.
WASTEWATER TREATMENT
Uses of water: Drinking Recreation Commercial navigation Fish propagation Waste disposal
Types of sewers: Sanitary sewers – carry wastewater through large pipes flowing partially full using gravity feed. Collecting sewers – collect waste water from homes & industrial & converge at a central point. Truck sewers – transport the wastewater from collecting sewers to wastewater treatment plant
Force main – are inverted siphons and pipes from pumping stations, flow under pressure. Storm sewer – carry storm water run-off away from developed area back to environment.
Common contaminants in wastewater: Organic material as measured by BOD Suspended solid Nitrogen Phosphorus Pathogenic organisms
Forms of wastewater Domestic sewage – results from people day to day activities such as bathing, body excretion, food preparation & recreation. Industrial waste Inflow – storm water that seeps into sanitary sewer system through loose manhole covers. Infiltration – occurs when sewer lines are placed below the water table or when rainfall percolates down to the depth of the pipe.
Area of wastewater treatment plant 1. Preliminary treatment – is the removal large particles to prevent damage to the remainder of the unit operation. 2. Primary treatment – is the removal of solid by settling, usually physical process as opposed to biological or chemical. 3. Secondary treatment – is the removal of the demand for oxygen, commonly biological in nature.
4. Tertiary treatment – is the name applied to any number of polishing or clean-up processes, can be physical, biological or chemical. 5. Solid treatment and disposal – is the collection, stabilization and subsequent disposal of solid by other processes.
