water quality Flashcards
what is wqi?
water quality index, ranges from 1-100
how does the wqi grading scale work?
it is based on various factors that are tested and assigned a q value, these q values are then added up to get a wqi from 0 to 100
91-100 = excellent, 71-90 = good, 51-70 = average, 26-50 = fair, 0-25 = bad
what is biochemical oxygen demand (bod)?
bod is a measure of the oxygen demand in mg by aerobic bacteria per liter of water
bacteria take in oxygen to create energy through aerobic respiration, bod increases or decreases with the number of organisms present in the water and the amount of biodegradable waste
what are phosphates and how do they affect water quality?
phosphates are a form of phosphorus, an essential element for plant growth, it is the limiting term for plant growth
it is usually taken up quickly by algae and other larget aquatic plants
inorganic phosphates are found in laundry detergents
what are blooms?
blooms are excessive growth in one species, usually algae, sign of cultural eutrophication
what is eutrophication and cultural eutrophication?
eutrophication is when a body of water has increased minerals and nutrients, increasing plant growth
cultural eutrophication is man made eutrophication, usually in the form of phosphorus, it makes up most cases of eutrophication
how can increased phosphates and nitrates affect the dissolved oxygen in a body of water?
it decreases the do as it increases algae and bacteria
what is acid rain?
nitric oxide, nitrogen dioxide, and sulfur dioxide from cars and coal convert into nitric acid and sulfuric acid in the atmosphere which falls along with rain into bodies of water as acid rain/snow, causing them to become acidic
how does temperature affect water quality?
warmer water dissolves less oxygen
temp affects photosynthesis
affects metabolic rates of aquatic organisms
affects sensitivity to toxic wastes, parasites, and disease
what is turbidity?
a measure of how clear water is, less clear = lower turbidity = higher suspended solid count
suspend solids may come from soil erosion, waste, urban run off, abundant bottom feeders, or algae growth
how does turbidity affect aquatic life?
higher turbidity blocks photosynthesis
suspended solids can get in gills
reduce growth and disease resistance
prevent egg development
increase temperatures
what is fecal coliform and why is it measured?
fecal coliform bacteria are found in the feces of humans and other animals
they are not dangerous but often carry along pathogenic organisms (e.g. harmful bacteria, viruses, parasites)
pathogens are hard to measure so fecal coliform are measured instead
how do geese and ducks affect wqi?
the waste of geese and duck is high in nitrogen content so it can affect the nitrates in the area
how does the nitrogen cycle work?
blue green algae take atmospheric nitrogen and fix it into ammonia and nitrate, which can be used by plants for growth
this nitrogen can then move up the food chain as animals eat plants and animals eat other animals
after they die, bacteria decompose protein molecules into ammonia by ammonification
this ammonia is then nitrified into nitrates and nitrates, which can be then turned back into atmospheric nitrogen or directly used again by plants
what is waste water?
any water that has been used, can contain human waste, food scraps, etc
