Chemical Cycles in Water Flashcards
Biogeochemistry
The global cycling of chemicals through the biotic and abiotic reservoirs.
Water Cycle
- Water vapor transpires through pores in leaves
- Respiration also produces some water vapor
- Water evaporates from lakes, oceans, and rivers
- Water vapor accumulates in the atmosphere and returns to the land as precipitation.
What Chemicals Cycle Within Ecosystems?
Water, carbon, nitrogen, phosphorus
Carbon Dioxide
Diffuses between water and atmospheric air
Dissolved inorganic carbon (DIC)
Carbon dioxide, carbonic acid, and bicarbonate ion
Dissolved organic carbon (DOC)
Methane (CH4) is simplest form
From decomposition of organic matter
Particulate organic carbon (POC)
All organic matter
Living, dead, waste, etc
Carbon Reservoirs
Rocks, Atmosphere, Oceans, Freshwater, Detritus, Primary producers, Consumers
The formula for creating Carbonic Acid
h2o +co2 >
What is Bicarbonate?
Bicarbonate = carbonic acid
h2co3 >
Titration
Addition of acids until there is a lowering of pH
Buffers
Molecules the prevent pH changes
Primary Sources of Acid Deposition in Aquatic Ecosystems
H2CO3, HNO3, H2SO4
CO3-2, NO3-1, SO4-2
Anesthetic
invertebrates, vertebrates
Lake Nyos
CO2 eruption
Cameroon, 1989
1746 people died
Oxygen gas
Needed for aerobic metabolism
Ozone
Primarily in the upper atmosphere
Inorganic (Oxygen)
Component in many inorganic molecules
Water, Nitrate, phosphate, silicate metal oxides
Organic (Oxygen)
C, H, and O are components of all organic molecules
Oxygen Reservoir
Rocks, Atmosphere, Water
Photosynthesis
essential for life on earth
Water+carbon+Light+plant=glucose and Oxygen
Aerobic Respiration
The process of using glucose and oxygen to produce ATP
Breathing in Water
Adaption to low oxygen, gills, circulatory systems, behavior
Gills
high surface area
keep water moving
Total Phosphorus (TP)
All of the phosphorus in a water sample
10 to 80 ug/L in most lakes
Soluble reaction phosphorus (SRP)
Forms readily available for algae and plants
Total Soluble phosphorus
all phosphorus that can pass through a filter
Orthophosphate
Inorganic form, PO4-3
Nearly insoluble
Dissolved organic phosphorus
from living and/or decomposing organisms
also from detergents and some pesticides
Particulate organic phosphorus
Organic phosphorus in plant and animal bodies and waste
Particulate inorganic phosphorus
orthophosphate bound to particulate matter
electrostatic attraction to clay particles
phosphine gas
PH3 poisons gas produced by anaerobic decomposition of organic matter
Reservoirs of phosphorus
Rock, soil, Guano, atmosphere, oceans, freshwater, primary producers, consumers
Area 226
Experimental lake
Whole lake experiment
David Schindler
First to determine that phosphorus was rate limiting nutrient for algae growth
Total Nitrogen (TN)
All nitrogen in a water sample except nitrogen gas
Nitrogen Gas (N2)
Dissolves easily in water, but inert
Nitrate (NO3) and Nitrite (NO2)
Form from oxides of nitrogen in water
Nitrate is used by many plant, protists and microbes as a N source
Nitrite is toxic
Ammonia
Reduced form of Nitrogen from nitrogen fixation
Waste product of many animals to eliminate N
Easily dissolves in water
Forms ammonium ion (NH4+) in water which can combine with oxygen to form nitrate
Nitrate + nitrite + ammonium = dissolved inorganic nitrogen (DIN)
Organic Nitrogen
Amino acids, nucleotides and excretory products
Reservoirs of Nitrogen
Rocks, atmosphere, oceans, freshwater, primary producers, consumers
Biological processes involving nitrogen in freshwater
Nitrogen fixation, nitrification, denitrification, assimilation, excretion
Nitrogen Fixation
Nitrogen gas to ammonium
Nitrification
ammonium to nitrate or nitrite
Denitrification
Nitrate to nitrogen gas
assimilation
DIN or Organic N incorporation into organic compounds
Excretion
Elimination by animal in ammonium, Urea or Uric acid
Nitrogen-Fixing
bacteria (N2 to NH3)
Symbiotic
Nitrogen relationships with plants
Bacteria gets sugars from plant
plant gets useable forms of nitrogen
Silicon in Water
The element silicon (Si), or silica (SiO2) from aluminosilicate clays
Found in water as the acid, silicic acid (H4SiO4)
Silicate ion (SO4-4) has minor buffering capabilities
Usually at about 13 mg/L in water
Silicate (SO4-3)
Sand.
Critical for diatoms to survive.
Pollution
Any Chemical, physical, of biological change in the environment that harms living organisms
Eutrophication
Excessive nutrients ultimately lead to oxygen-poor water
Trophic level
Describes an organism’s position in the food chain
Primary production
Producers tie up energy
Bioaccumulate or Biomagnify
Fat-soluble chemicals do not readily degrade
Therefore they ascend the food chain
Become more concentrated at higher trophic levels
