10 Questions
What are examples of non-point sources of water pollution?
General runoff of sediments, pesticide spraying, and fertilisers from farms
Biodegradable organic matter is a type of water pollutant.
True
What is the maximum dissolved oxygen (DO) at a water temperature of 16°C?
10 mg/L
Fund pollutants are those for which the environment has some _______________ capacity.
absorptive
What is an effect of eutrophic pollutants on aquatic life?
Excessive aquatic plant growth
Stock pollutants include bacteria and viruses.
False
What are the three ways oxygen gets into water?
Diffusion from the surrounding air, aeration (rapid movement), and as a product of photosynthesis.
Match the type of pollutant with its characteristic:
Fund Pollutant = Can be broken down by natural processes Stock Pollutant = Persistent and cannot be removed by natural processes
Water quality analysis often measures the amount of gaseous oxygen (O2) dissolved in an aqueous solution, known as _______________.
dissolved oxygen (DO)
Soaps and detergents are examples of point sources of water pollution.
False
Study Notes
Characteristics of Water
- Physical characteristics: solids, temperature, color, odor, turbidity, oil and grease, conductivity
- Chemical characteristics: organics (proteins, carbohydrates, lipids, surfactants, phenols, pesticides, emerging organics), inorganics (pH, chlorides, alkalinity, nitrogen, phosphorus, heavy metals), gases (oxygen, hydrogen sulfide, methane)
- Aggregate organics: BOD, COD, TOC
- Biological characteristics: pathogens, indicators, viruses, invertebrates
Sources of Water Pollution
- Point sources: single large sources
- Non-point sources: diffuse source of pollution that cannot be attributed to a clearly identifiable, specific physical location or a defined discharge channel
- Measurements: Amm.N., Inorg.N., Kjeldahl N., Org.N
Physico-chemical Characteristics
- Phosphorus: aqueous forms (orthophosphates, polyphosphate, and organic phosphates), importance as nutrient
- Sulphur: aqueous form (sulphate), reduced to sulphide and further to hydrogen sulfide, formation of sulphuric acid and pipe corrosion
- Metallic constituents: priority pollutants (Cd, Cr, Cu, Fe, Pb, Mn, Hg, Ni, and Zn), micronutrients/toxicants, measurable forms (dissolved, suspended, acid extractable)
Wastewater Treatment
- Primary treatment: removes solids, physical operations (screening, sedimentation)
- Secondary treatment: removes organics, biological and chemical operations
- Tertiary treatment: removes nutrients, biological and chemical operations
Typical Unit Operations of a Wastewater Treatment Plant
Primary and Secondary Sewage Treatment (using Suspended Growth process)
Screen
- First unit operation
- Objective: removal of coarse and fine objects, which may get entangled in mechanical equipment (e.g., grit chambers, sedimentation tanks, etc.)
- Examples: general runoff of sediments, pesticide spraying, fertilizers from farms
Point and Non-Point Sources of Water Pollution
Major Water Pollutants and Their Sources
Contaminants Affecting Water Bodies
- Biodegradable organic matter
- Suspended, colloidal, and dissolved solids
- Nutrients
- Pathogens
- Acidic, basic, and ionic species
- Soaps and detergents
- Pesticides
- Colour and odour causing substances
- Volatile organics
- Recalcitrant and refractory organics
- Thermal/Radioactive material
Categories of Pollutants
- Fund pollutants: those for which the environment has some absorptive capacity
- Degradable: organic residuals broken down by bacteria
- Thermal: injection of heat into water source
- Eutrophic: excessive nutrients leading to too much aquatic plant growth
- Persistent pollutants: inorganic/synthetic chemicals partially broken down
- Bacteria, viruses, artificial hormones: from domestic and animal wastes
- Stock pollutants: those for which the environment has little or no absorptive capacity
- Minerals and inorganic/organic chemicals not removed by natural processes (e.g., lead, cadmium, mercury, some agrochemicals, persistent synthetic chemicals, non-biodegradable plastics, and heavy metals)
Nature and Characteristics of Wastewater
Dissolved Oxygen (DO)
- Important measure of water quality
- Oxygen is marginally soluble in water and inversely proportional to temperature
- Maximum DO at water temperature of 16°C is 10 mg/L
- DO analysis measures the amount of gaseous oxygen (O2) dissolved in an aqueous solution
- Oxygen gets into water by diffusion from the surrounding air, by aeration, and as a product of photosynthesis
This quiz covers the physical and chemical characteristics of water, including solids, temperature, colour, and more. Learn about the properties of water and its composition.
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