Midterm 2 Flashcards
1
Q
Salinity
A
- total quantity of dissolved inorganic solids in water
- ocean’s salinity varies from 33-37‰ (33-37 parts per thousand)
- river water salinity is 0.5 ‰ (0.5 ppt) or less
2
Q
Turbidity
A
how much sunlight gets through water column
3
Q
the process by which water dissolves substances is called
A
hydration?
4
Q
Oxidation state of element is controlled by what environmental factors?
A
water pH and redox potential
5
Q
water pH
A
- hydrogen ion concentration
- acidic, neutral, or alkaline
- measured as negative ten-base logarithm
- pH = – log10 [H+]
- One unit pH change = 10-fold change in (H) ion concentration
- pH for surface water ranges from 4 to 9
6
Q
TDS
A
total dissolved solids
- sum of all dissolved solutes plus silica SiO2 in water
- in rainwater <20 mg/L
- in rivers 50 - 1000 mg/L
- “Mineral water” > 250 mg/L
7
Q
oxidation
A
increase in oxidation state (gain of oxygen, loss of hydrogen, and loss of electrons)
8
Q
reduction
A
loss of oxygen, gain of hydrogen, gain of electrons (oxidation number is reduced)
9
Q
redox potential
A
- Indicates degree to which substance can oxidize or reduce another substance
- positive ORP reading indicates that substance is oxidizing agent
- negative ORP reading indicates that substance is reducing agent
10
Q
Diurnal fluctuations in dissolved oxygen:
A
- Day-time photosynthesis removes CO2 and increases amount of dissolved O2 in water
- However, warmer day-time temperatures decrease amount of dissolved O2 (same in summer)
11
Q
Seasonal fluctuations of dissolved oxygen
A
- In summer, base cations (Ca, Mg) prevail; higher alkalinity
- Groundwater dominates stream flow
- In winter, more acidic soil water and surface runoff dominate
12
Q
chemical weathering
A
- Weathering – mechanical disintegration
and/or chemical decomposition at the lithosphere-atmosphere boundary - Chemical weathering: 80% of all dissolved matter
- Granite and basalt – the most common igneous rocks containing various silicate minerals
- Low susceptibility to weathering
- TDS in catchments draining sedimentary rocks are five times greater than in igneous rock catchments
13
Q
80% of dissolved load in rivers: four solutes
A
calcium Ca, bicarbonate HCO3, sulfate SO4 and silica SiO2
14
Q
Relationship between precipitation and evaporation
A
- In arid and semi-arid climates, solutes become concentrated and start to precipitate
- Calcite CaCO3 and dolomite MgCO3
- As a result, higher concentrations of Na, Cl, and SO4 in the water
15
Q
Rainwater chemistry
A
- <20 mg/L of TDS
- Dissolved CO2 produces H ion
o acidity increases (i.e. pH falls below neutral)
16
Q
Hard water
A
dissolved cations of Ca and Mg (limestones, dolomites)
- “scum line” in bathtubs and kettles; pipe blockage
17
Q
Soft water
A
in silicate rocks (sandstones and igneous rocks)
- Major metal ions are Na, K, Mg, Ca in low concentrations
18
Q
Fund pollutants
A
pollutants for which environment has some absorptive capacity (Ex: carbon dioxide)
19
Q
Stock pollutants
A
pollutants for which environment has little or no absorptive capacity (ex: non-biodegradable litter, heavy metals)
20
Q
Point-source pollution
A
discharged into surface water at specific location through drainage pipe or ditch
- Primary point sources are industries and municipalities
- Point sources are relatively easy to monitor and predict
21
Q
Non-point-source pollution
A
runoff that comes from various sources and includes agricultural and urban runoff
- Nonpoint sources are much harder to control due to unpredictability and uncertainty of sources
22
Q
Eutrophication
A
- accumulation of nitrogen and phosphorous as a result of agricultural runoff and industrial activities
- results: increase in phytoplankton growth, algal blooms, reduced concentrations of dissolved oxygen, deterioration of drinking water quality
23
Q
thermal pollution
A
results from injection of heat into watercourse, usually in form of used industrial water
24
Q
heavy metals
A
lead, cadmium, mercury
- bio-accumulate in food chains and become persistent pollutants
25
acid mine drainage
- outflow of acidic water from metal or coal mines
- occurs when pyrite-bearing rocks (FeS2) exposed to oxygen
- common in abandoned mines (active mines pump out water)
26
acid rain
- atmospheric deposition of acidic substances, such as SO2 and NO2
- when sulfur is release into atmosphere, it combines w/ moisture in chemical reaction to make acid rain
- acid rains have acidity below pH of 4
- sea water pH = 8
27
water acidification
high acidity results in increased solubility of heavy metals (Al, Mn, Pb, Cd, Zn, As)
- at pH <5, Al (aluminum) becomes soluble and leaches into aquatic systems from soils
- fish osmoregulation (ability to control flow of water, salts, and gases in and out) is comprised at Al concentrations
28
Salt water intrusion
saline intrusion b/c of depletion of groundwater reserves in coastal areas
29
The Water Quality Act of 1965
- established ambient water quality standards for interstate watercourses
- states required to file implementation plans
30
The Clean Water Act, 1972
- primary Federal Law that regulates water pollution in US
- amended in 1972 and then again in 1977
- does not cover groundwater contamination
31
The Safe Drinking Water Act of 1974
- administered by EPA
| - primary regulations set maximum allowable concentrations for bacteria, dust, and chemical contaminants
32
Potable water treatment
removing solids (screening, coagulation, filtration, disinfection), membrane treatment, desalination
33
water desalination
- process whereby salt and dissolved solids are removed from water, particularly seawater
- often undertaken to allow otherwise unsuitable water sources to be used for domestic purposes
34
wastewater treatment
- Physical treatment (solid removal)
* Primary settlement tank
- Biological treatment
* Attached growth process using crushed granite or basalt
* Microorganisms attach and build up creating a biofilm
* Oxygen is provided from the atmosphere
- A final settlement tank
* Produced effluent has <10 mg/L of TS (total solids)
* Remaining sludge is rich in energy and nutrients
35
wastewater as energy resource.
- Energy recovery: anaerobic digestion
* Used as part of process to treat organic waste and sewage sludge
* Microorganisms break down biodegradable material in absence of oxygen
* the process produces a biogas (methane)
- In anaerobic conditions, carbon is e-acceptor and can be reduced to methane CH4
C6H12O6 → 3CO2 + 3CH4
- Methane (biogas) is energy-rich: 1 meter3 releases 9.97 kWh of energy when burned
- New option of zero-waste economy operating on renewable energy
36
Net primary productivity (NPP)
total amount of chemical energy stored in plants
37
NPP distribution in aquatic and terrestrial ecosystems
- Highest on land in tropics due to high insolation and precipitation; diminishes poleward and especially in extremely arid or cold areas
- In oceans, productivity is influenced by nutrient content of waters and is highest near areas of upwelling
- chemical energy as carbohydrates consumed by animals or decomposed by microorganisms
38
littoral zone
(close to the shore)-abundant sunlight
39
pelagic (limnetic) photic zone
open to light, the highest lake productivity
40
profundal zone
a deeper zone below the range of light penetration
41
benthic zone
- at the bottom of the lake, transition between water body and sediment
- food web is based around decomposition instead of photosynthesis
42
Biogeochemical cycles
- Hydrologic cycle
- Carbon cycle
- Oxygen cycle
- Nitrogen cycles
43
food pyramid
large number of energy-storing organisms supports smaller number of consumers above
- usually several levels of carnivorous consumers
- largest, most powerful apex predators in the area at top of the pyramid
- Organisms that occupy the same trophic level in food chain consume the same kinds of food
44
Autotrophs
producers/plants; fix carbon through photosynthesis
45
heterotrophs
- primary consumers: plant-eating animals called herbivores
- secondary consumers: herbivores become food for other animals known as carnivores or predators
- omnivores: animals that eat both plants and animals
46
Parasites
live on or in another organism, the host, benefiting at host’s expense
47
Decomposers/detritivores
feed on dead organic matter (bacteria, fungi)
48
Oligotrophic lakes
very low in nutrients
49
Aquatic ecosystem services
regulating, supporting, provisional, and cultural services
50
Regulating services
- flow regulation (wetlands, groundwater, floodplains)
| - sediment transport
51
Supporting services
- primary/secondary production
| - nutrient cycling
52
Effects of high dams
- Blocking migratory fish species from spawning and feeding sites
- Disrupting transport of sediment along river (lower groundwater level, dam sedimentation)
- Changes in water temperature and quality
- Decomposition of organic matter causing fish kills
- Disturbing natural fluctuations of water flow (seasonal floodplains are especially affected)
53
Effects of urbanization
Urban stream syndrome:
- Hydrological change (reduced base flow and increased peak flow)
- Modified thermal regime (change in shading/exposure)
- Runoff from paved areas
- Enhanced nutrients and contaminants
- Transformed channel morphology
* Reduction of biodiversity
54
Biological invasion
Biological invasion
- Invasive species – plant/animal species not native to specific location; has tendency to spread to degree that can cause damage to environment
55
Water-Related Hazards
- Chemical
- Physical
- Biological
56
Measuring Public Health
- The WHO uses a measure of population health called “disability adjusted life year” or DALY
- Illnesses vary from region to region (much higher disease burden in the developing countries), between genders, and age groups
57
Mortality Distribution by Cause of Death
- Group I Communicable diseases (infections) CD
- Group II Non-communicable diseases (cardiovascular, diabetes, etc) NCD
- Group III Injuries (external causes of death)
58
The origin of public health
- Sanitary movement and science of epidemiology emerged in mid-1800s (after industrial revolution)
- Miasma theory - linked foul smells and stagnant air w/ cause of disease
- Germ theory - that presence and actions of microorganisms in body are cause of many diseases
* Dr. John Snow mapped cholera deaths during cholera outbreak in London in 1854
59
Water-borne diseases
infections spread by water
- Cholera
- E-coli
60
Water-carried diseases
infections acquired through ingestion of or being close to contaminated water
- Legionnaires’ disease - Bacteria that thrive in warm aquatic environments
61
Water-washed diseases
infections spread by lack of water and lack of personal hygiene
- Leprosy
- Trachoma – bacterial infection of an eye, can lead to breakdown of cornea and complete blindness
62
Water-based diseases
worm infections spread aquatic invertebrates
| - Schistosomiasis – (snail fever) caused by parasitic flatworms
63
Water-vector diseases
infections spread by insects that require water for their life cycle
- Malaria
- Zika
- yellow fever
- river blindness
- sleeping sickness
64
arsenic poisoning
• Contaminated deep tube-wells
| - Symptoms: skin lesions, dark spots on limbs, swollen limbs and loss of feeling in hands and feet
65
radon contamination
- Radon Rn – radioactive gas - occurs b/c of radioactive decay of uranium in granite and shale rocks
- Continuously produced by radioactive decay of 226Ra present in rocks (produced by radioactive decay of U and Th)
- According to EPA, 2nd leading cause of lung cancer after smoking
66
saltwater intrusions
Sea level rise also increases the risk of saline intrusion, especially in the low-lying coastal areas and deltas
67
algal bloom neurotoxins
- Cyanobacteria produce microcystin toxin
| * liver damage; neurotoxin can result in damage to nervous system
68
Agent Orange
- chemical can damage genes resulting in deformities in children
- environmental damage in Vietnam: ~ 31,000 km2 (11,969 mi2) of forest defoliated
69
dioxin
toxic (cancerogenic) organic compound - byproduct of industrial processes
70
heavy metal contamination
Heavy metals (lead, chromium) are neurotoxins and carcinogens
- Cr – industrial effluent (esp., dye works)
* Maximum Contaminant Level (MCL) in drinking water 0.1 mg/L
- Pb – used in water pipes
* banned in 1970 in Europe, in 1986 in the U.S.
71
EDCs – endocrine disrupting compounds
chemicals that can mimic hormones, inhibit action of hormones, or alter regulatory effects of endocrine system
72
natural hazard vulnerability
```
indicator of how social or ecological system is susceptible to various stressors
• Climate change
• Natural hazards
• Urbanization
• Population growth
• Economic reforms
```
73
Effects of globalization
Globalization ----- industrialization ------- urbanization ------- Slum population growth -------drinking water deficit
