STUDY GUIDE: EXAM 1
Primary Treatment: Treatment of sewage that only involves the treatment of primary sludge is termed primary sewage treatment. Doesn’t relied on biological BOD.
Steps involved with primary treatment (also known as physical treatment)
∙ Bar Screen (vertical bars; 5 to 10cm apart; trap any trash that would interfere in the treatment of the facility); removal of BOD and suspended solids ∙ Grit Chamber (the velocity of water is decreased to a point where it allows to settle out in the grit chamber (e.g. sand)
∙ Primary Clarifier
Velocity is zero
A mechanical device removes floatable, settable solids
Primary sludge comes from the primary clarifier
*** Removal 3040% of BOD; accomplished because you have remove all solids and organic materials. In addition, we can say that, following primary treatment, BOD removal is <50%***
If you want to learn more check out hum100 class notes
Photosynthesis is the base of primary production to occur
Light Bottle—Dark Bottle Method: Developed by Odom; University of Georgia
• The light bottle displays photosynthesis and respiration and the dark bottle only shows respiration.
• The difference between the measurements of dissolved oxygen (DO) in the initial and dark bottles is an indication of the amount of oxygen that is being consumed by respiration.
• In the bottles exposed to light, the biological processes of photosynthesis and respiration are occurring; therefore, the change over time in dissolved concentration from the initial concentration is a measure of net productivity. We also discuss several other topics like fau minors
• The difference over time between the dissolved concentration in the light bottle and the dark bottle is the total oxygen production and therefore an estimate of gross productivity.
How are photosynthesis and cellular respiration related to each other?
Cellular respiration produces oxygen, while photosynthesis uses oxygen. Photosynthesis releases energy, while cellular respiration stores energy. Photosynthesis used carbon dioxide, while cellular respiration produces carbon dioxide.
Trophic Level are also known as “feeding level”.
• Trophic level 1: Autotrophs produce energy by photosynthesis • Trophic level 2: Herbivores consume plant material
• Trophic level 3: Carnivores consume plant material
• Trophic level 4: Large carnivores or omnivores consume smaller animals
*** Trophic 2, 3, 4 are known to be called Heterotrophs ***
10% Law states that on the average, about 10% of the energy entering a feeding level is transferred to the next level Don't forget about the age old question of o What factors affect contraception availability in the US?
Second Law of Thermodynamics states that each time energy is converted from one for to another some of it is always lost Don't forget about the age old question of wronskian method
∙ This law forces the “shape” of ecosystem
Shape of Ecosystems are (a) Pyramid of numbers (b) Pyramid of dry biomass (c) Pyramid of energy content
Possible in nonsteady state systems for the biomass distribution in two or more trophic levels to become temporarily inverted
***Trophic level biomass increases rather than decreases with increasing trophic level number***
How human activity have affect eutrophication?
Human activities can contribute excess amounts of nitrogen and phosphorous into water. Therefore, human causes eutrophication includes the use of agricultural fertilizers. Other causes include sewage and aquaculture, which is the growing or farming of fish, and aquatic plants.
How chemical contamination can affect the food chain?
It affects the food chain because of scarce food sources and competition; loss of diversity.
Bioaccumulation of toxins
Biomagnification among species
Food Chain Magnification is the increasing concentration of a substance, such as a toxic chemical, in the tissues of organisms at successively higher levels in a food chain. DDT is an example of a substance that biomagnifies; birds accumulate sufficient amounts of DDT from eating fish to cause adverse effects on bird populations. More concentrated at the top of the pyramid.
Euphotic Zone The region of the water column within which plants can photosynthesize. We also discuss several other topics like the genotype of an organism constitutes its observable characteristics.
Depth of euphotic zone depends on the clarity of the water; for photosynthesis to take place
Photosynthesis equals respiration; P=R
If we travel above then photosynthesis is greater than respiration but if we travel downward to the critical depth, then it’ll be respiration. In this case respiration, will be higher than photosynthesis
Littoral Zone: The shell of the water zone; located on the shoreline where you have rooted plants; places like ponds or streamline If you want to learn more check out a is a well developed set of ideas
Pelagic Zone: known as the open water zone
Photic Zone: Also, known as the euphotic zone
Aphotic Zone: Primarily where respiration takes place
Profundal Zone: known as the deepwater zone. The mixed layer is located with the photic zone; associated with thermocline.
Water Turbidity affects photosynthesis. Human activities also affect turbidity. Pollution, waste products on the surface water and runoff with fertilizer are some factors that attributes to water turbidity.
Liebig’s Law of the minimum: states that yield is proportional to the amount of the most limiting nutrient, whichever nutrient it may be.
Shelford’s Law of tolerance: A law stating that the abundance or distribution of an organism can be controlled by certain factors (e.g. the climatic, topographic, and biological) requirement of plants and animals where levels of these exceed the maximum or minimum limits of tolerance of that organism.
• If the arrows are pointed to the right; too high; upper limit of tolerance • If the arrow is pointed to the left; too low: lower limit of tolerance ∙ Optimal Range: Species abundant
***Stress increase from either left or right and that’s the limit of tolerance***
Photic vs. Aphotic Ecosystems
Photic Zone is the upper level of water through which light penetrates Enough light for the occurrence of photosynthesis, so many plants and other photosynthetic organisms live in this zone and food is abundant Bioluminescence (light generated by living things) is the only light seen in this zone
∙ Underlies the photic zone, where light does not reach
∙ Temperature are nearly freezing and decreases with depth
∙ Pressure is extremely high and increases with depth
∙ There virtually no light from the sun (1% or less of sunlight reached this zone), so photosynthesis cannot take place
∙ The only food or energy sources in this zone are from organic matter falling from plants and animals floating down from higher zones and other fish ∙ Animals that inhabits in the aphotic zone are angler fish and ctenophores
Mixed layer is a layer where this turbulence is generated by winds, surface heat fluxes, or processes such as evaporation or sea ice formation which result in an increase in salinity
Denitrification is essentially the conversion of nitrate to nitrogen gas. Denitrification is a natural process carried out by many microorganisms when sufficient oxygen is lacking. Instead if using oxygen as the final electron acceptor in metabolism, nitrate is used.
∙ Nitrogen limitation is relied on denitrification Nitrate is reduced to N2 ∙ Doesn’t form insoluble chemical precipitates
∙ Occurs in a highly productive overlying of water; where oxygen is a more energetically electron acceptor, is depleted, and bacteria respire nitrate as a substitute terminal electron acceptor
∙ Releasing nitrogen back into the water
∙ Takes place under special conditions in both terrestrial and marine ecosystems.
∙ Type of anaerobic respiration
Maximum density at 4 degree in Celsius
4 degree in Celsius and above means warmer water and the density of H2O decreases
4 degree and below means colder temperature and the density of H2O increases
High heat capacity
Water can absorb a lot of heat energy with relatively small change in temperature; temperature change is minimum
Water Column Stability and Overturning
Column of water is resistant to vertical mixing if the density of the water increases with increasing depth
Densest water is found on the bottom
Least dense water is on the top
It must be stratified within these following zones:
Mixed layer or epilimnion (upper layer of water)
Thermocline or metalimnion (transition layer between the mixed layer at the surface and deep water layer) The definitions of these layers are based on temperature
Hypolimnion (lower layer of water in a stratified lake, typically cooler than the water above and relatively stagnant)
Depth is the key issue here
• Lake Erie vs. Lake Washington
∙ The bottom waters in the Central Basin of Lake Erie become anoxic (without oxygen) in the late summer because the productivity of the epilimnion overwhelms the hypolimnion because too many nutrient to metabolize
∙ Lake Washington doesn’t have the same problem because there is no central basin
• Lake Erie is more stressed and the issue is the amount of oxygen that is being stored in epilimnion following spring turnovers. It will disappear when it becomes isothermal; mixed layers’ top to bottom
• Lake Washington; high sufficient oxygen till it turns over. • Seasonal oxygen depletion ONLY if there’s a high epilimnion *** More concerns in the clarity of water***
What does this do to water column?
Shallow waters because the mix layer extends from the surface to the bottom and there is no stratification
At body of water, highly productive depth is a key issue. Most productive: Shallow water. Surface to bottom is mixing
Recycling of nutrients from detritus that has fallen far below the euphotic zone is extremely inefficient
The mixed layer may extend all the way or most if the way to the bottom during much of the year. Recycling of nutrients is highly efficient because there is a little or no part of the system into which the detritus may sink and regenerated nutrients become trapped.
Which is more productive?
Estuaries—semienclosed coastal bodies of water having a free connection with the open ocean. Fresh water and salt water meet. In between you have a buffer zone. Estuaries are naturally eutrophic
∙ Tidal action brings nutrients and food to organisms (complex circulation) ∙ Mixing of sea water with fresh water causes flocculation of particles ∙ Shallow water and mud are heated by the sun at low tide which increases nutrient cycling
∙ Adjacent sea tends to reduce extremes in temperature
Natural Eutrophication is a very slow process, and is somewhat temperature dependent
Cultural Eutrophication happens when the amount of nutrients in the water and/ or the water temperature are changed due to human activity.
∙ Anthropogenic acceleration of eutrophication
∙ Onedirectional nutrient flow
o Nutrientcycling is being altered
o A modification of natural process
o Land to surface water
o Wide variation of oxygen in the water
∙ Problems caused
o Changes in species
o Aquatic pollution
o Bluegreen algae (produce toxins and bad water quality)
Main Sources of Water Pollution in the U.S
Discharges from point sources
Agricultural runoff** (sediments such as soil)
Recognized as major source of nonpoint pollution for many rivers and estuaries
Not very predictable
Concerns with flooding
Prior to 1980
Storm sewer (collects primarily from streets, parking lot, and discharge it); Separated from the municipal sewer
Combined sewer systems
Composition of Urban Runoff
∙ Sediments from erosion
∙ Nutrients from lawn and garden fertilizer
∙ Insecticides and herbicides used on lawns and gardens
∙ Bacteria from fecal wastes of pets
∙ Road slit and other chemicals from surface treatments or spills ∙ Grime and toxic chemicals from settled vehicle exhaust and other air pollution
∙ Oil and grease picked up from road surfaces or disposed of in storm drains ∙ Trash and litter carelessly discard on the ground
Wash load: describing sediments; suspended clay particles. Affect photosynthesis
Bed load: Heavier particles like sand that hover the bottom. Destroy the habitat in the benthic zone
*** Best strategy for control of nonpoint source pollutants is implementing improved land management practices***
∙ Spread of waterborne diseases, such as cholera and typhoid fever ∙ First municipal sewer system not constructed until 1855 in Chicago ∙ First sewage treatment facility not completed until 1886 in New York City
STREAM ECOSYSTEM WITH LOW SEDIMENT BEDLOAD
Manyhiding resting places for small fishes, etc.
Good light penetration supports photosynthesis of attached algae and aquatic plants and abundant food chains
Bacteria, Protozoan, insect larva attached to rocks
SAME STREAM WITH HIGH SEDIMENT BEDLOAD
Clay in suspension prevents light penetration
Hidingresting places buried under sediment
Attached aquatic organism scoured from rocks by sand washing along bottom
Freshwater systemsphosphorus limiting
Marine systemsnitrogen limiting
Why would phosphorus tend to be limiting in freshwater systems?
All essential phosphorus must come from external inputs or from recycling within a lake.
How phosphate enter in aquatic systems?
It precipitates out and fall to the bottom into the sediment. It happens in aphotic zone; lack of oxygen; builds up of CO2; drop in PH. Converting from 3+ to 2+. Ferrous phosphate is more soluble than ferric phosphate.
The city of Seattle voted in 1958 to spend $121 million to develop an effective sewage disposal system for the entire area. Although some of this money was spent to stop discharges of raw sewage into Puget Sound and for other improvements, most the funds were spent to improve the water quality of Lake Washington.