Unit 8: Aquatic and Terrestrial Pollution

Notes

Unit 8: Aquatic + Terrestrial pollution

8.1 - point and nonpoint pollution sources

objective :

• identify differences between point and nonpoint sources of pollution

point sources :

• pollutant that enters environment

• an easily identified and confined place

• you can “point” to it

nonpoint sources :

• epa defines this as many pollutants at once

• e.g. an estuary being polluted bc multiple rivers entering

point sources examples :

• animal waste runoff from a cafos

• emissions from power plants

• bp oil spill (hydrocarbons + benzene)

nonpoint sources examples :

• urban runoff collects multiple pollutants

• pesticides again have multiple different types of chemicals

pollutants :

• specific chemicals or groups of chemicals that come from SPECIFIC sources with specific environmental + human health effects

• on frqs

• memorize lots of pollutant names 

• their sources, environmental + human effects, their mitigation strategies

pollution :

• vague, nondescript term for any substance that’s bad for the environment

• not on frqs

• specific types are okay (e.g. thermal, noise, sediment) bc they have effects

8.2 - human impacts on ecosystems

objective :

• describe the impacts of human activities on aquatic ecosystems

range of tolerance :

• human actions can change it

• e.g. ph, temperature, salinity, sunlight

• also range of tolerance for different pollutants

• pollutants cause limited growth, limited reproduction, difficulty respiring, hormonal disruption, death

• explain specific effects

acid rain :

• ph decreases means that range of tolerance also does

• can cause disrupted blood osmolarity + aluminum toxicity

• indicator species show if ecosystem is acidic or not

• e.g. high crustacean = ph > 6 + high whitemoss = ph < 6

temperature tolerance of reef algae :

• mutualistic relationship between coral + algae

• algae have narrow temperature tolerance and leave the reef when temperature rises

• not only bleaches coral but also algae dies

human impacts on coral reefs :

• ghgs (warm ocean temperature + bleaching coral)

• overfishing + bottom trawling can break coral reef + make water turbid

• sediment pollution = all solid matter in the pollutants

• e.g. sand, gravel + makes water increase turbidity

• toxicants = made by humans

• can be lethal to coral reef ecosystems

• nutrients (e.g. ammonia, cafos) can lead to eutrophication and runoff

oil spills :

• hydrocarbons in crude oil are toxic to marine organisms and can kill them

• decreased visibility + decreased photosynthesis

• oil sticking to bird feathers or sinking to kill bottom-dwellers (toxicity + asphyxiation)

• can also decrease industry (e.g. tourism, fishing, seafood production)

• oil can poison the plants in the estuary meaning that fish cannot reproduce

clean up :

• can happen from underwater well explosion 

• tanker carrying oil can explode

• can use booms to prevent oil from spreading (quickest + immediate)

• physical removal

• synthetic chemicals can be harmful but do get rid of it

• pollution -> more pollution

8.3 - endocrine disruptors

objective :

• describe endocrine disruptors

• describe the effects of endocrine disruptors on ecosystems

definition :

• any compound that can affect hormonal system of animals

• chemicals the mimic hormones (unintentional + intentional)

• they disrupt the normal functioning of the endocrine system

• if it is meant for humans obvi not for humans

• can transfer through sewage

• e.g. atrazine binds to receptors of cells that should convert estrogen into testosterone leading to gender balances

specifics :

• obvi atrazine bc crop runoff and can groundwater

• ddt is an broad-spectrum insecticide that was phased out bc really bad

• still in environment

• phthalates are the plastic compounds

• can enter surface or groundwater through trash, chemical waste

• lead, arsenic, mercury = heavy metals

• human medications should not be used for animals

mercury :

• naturally occurring in coal

• released by coal combustion + trash incineration

• attaches to pm and deposits in soil + water wherever it settles

• endocrine disruptor bc interferes with menstrual cycle

• teratogen can damage fetus brain

• pregnant woman should limit exposure to mercury (no seafood)

arsenic :

• naturally occurring element

• can be exposed by mining and can infiltrate groundwater

• used in rat poison

• anthropogenic sources in pesticides (wood treatment)

• carcinogenic + endocrine disruptor

• can be removed with water filters

lead :

• old paint in homes, water pipes, and pm form coal combustion

• neurotoxicant (inorganic substance the damages cns)

• endocrine disruptor but removed with water filters

coal ash :

• can be a source of mercury, lead, and arsenic

• fly ash = pm carrying the metal that go into ecosystems far away

• bottom ash = bottom of furnace in ash ponds which has a ton off bad stuff temporary but can overflow and go into nearby sources (groundwater)

8.4 - human impacts on wetlands

objective :

• describe the impacts of human activity on wetlands and mangroves

wetlands :

• an area with soil submerged in water for at least part of the year but shallow enough for emergent plants

• wetland plants adapted to living with submerged roots

• ecosystem services = habitats for animal + plant foods, regulating groundwater, sequestration of carbon dioxide, filtering water

• even tourism or research

threats to wetlands :

• pollutants = nutrients (nitrogen, phosphorus), sediment, motor oil, pesticides, endocrine disruptors

• development bc can be changed into other land

• water diversion upstream for flood control

• dam construction reduces the nutrients to the wetlands

• overfishing messes up predatory-prey dynamic

benefits of mangroves :

• provide 800 billion dollars

• can be used for fuel

• protects the coast (more effective than a wall)

• water filtration

• tourist attractions bc of lots of fish there

• sequestration of carbon dioxide

threats :

• logging, agriculture, aquaculture, pollution

• coastal development for like hotels

• climate change can make them extinct

solutions :

• cover crops (crop to stop runoff into water)

• better animal manure management

8.5 - eutrophication

objective :

• explain the environmental effects of excessive use of fertilizers and detergents on aquatic ecosystems

process :

• starts from extra nitrogen + phosphorus bc they fuel algae growth

• algae bloom covers surface of water, blocking sunlight + kills plants below

• algae die-off and bacteria break down algae (aerobic process)

• lowers oxygen levels and kills more animals

• bacteria use up more oxygen 

• creates a positive feedback loop: less o2 -> more dead org. -> more bacterial decomposition -> less o2 -> hypoxia

cultural eutrophication :

• anthropogenic nutrient pollution that leads to eutrophication 

• cultural = human caused

• major sources = discharge from sewage, animal waste from cafos + synthetic fertilizer from agricultural fields + lawns

oligotrophic waterways :

• low nutrient levels, high dissolved oxygen

• can be due to age of water body

• aquatic ecosystems naturally undergo succession

• sediment buildup on bottom (benthic zone) leads to higher nutrient level

• oligotrophic -> mesotrophic -> eutrophic

dissolved oxygen + dead zones :

• decrease in dissolved oxygen (hypoxia) = dad zone

• all aquatic life requires dissolved oxygen for respiration

• fewer do = fewer species

example :

• during the spring sun-heated runoff cuts off contact with oxygen

• nitrogen and phosphorus from soil due eutrophication

• starved of oxygen and cut off means organisms at the bottom die

8.6 - thermal pollution

objective :

• describe the effect of thermal pollution on aquatic ecosystems

solubility of oxygen + temperature :

• solubility = ability of a matter to dissolve into a liquid

• inverse relationship between water temp + oxygen solubility (water temp increase + do decrease)

thermal pollution :

• when heat released into water

• heat increases respiration rate (thermal shock)

• hot water = less o2

• suffocation

sources :

• power plants use cool water from nearby water then return it back hotter

• steel mills, paper mills, use cool water to warm machinery

• urban runoff can be hot bc blacktop + low albedo so then thermal pollution

• nuclear power plants require LOTS of cool water for reactor core (really bad)

cooling towers :

• used to cool steam back into water + to hold warmed water before returning to local surface water

• standard in nuclear power plants so in frqs say increase efficiency of them

8.7 - persistent organic pollutants (pops)
objective :

• describe the effect of persistent organic pollutants on ecosystems

pops :

• persistent (long-lasting) organic (carbon-based) pollutants

• synthetic (human-made) compounds that do not easily breakdown in the environment and accumulate and build up in water + soil

• fat-soluble meaning the also accumulate and persist in animals fat tissue

• can slowly be released from fatty tissue into blood stream which can impact brain + other organs over time (reproductive system)

examples + sources :

• ddt (outdated insecticide)

• even after phaseout still found

• pcbs (plastic/paint additive)

• pbde (fire-proofing)

• bpa (plastic additive)

• dioxins (fertilizer production + combustion of waste + biomass

• byproduct of fertilizer

• 90% of human dioxin exposure comes from animal fats bc fat tissue buildup

• phthalates (plastics)

• perchlorates (rocket/missile fuel, firework)

transport of pops :

• pcbs are released into aquatic ecosystems by industrial wastewater

• toxic to fish (endocrine disruptor)

• reproductive failure = cancer in humans

• human exposure comes through animal products

perchlorates :

• common near military testing sites

• remain in soil and can leach into groundwater or runoff into surface water

travel :

• pops travel long distances through wind + water

• wastewater release from industrial processes, leachate from landfills

• enter soil/water -> eaten by animals -> stored in their fat -> eaten by humans OR taken in by drinking water

8.8 - bioaccumulation and biomagnification

objective :

• describe bioaccumulation + biomagnification

• describe the effects of bioaccumulation and biomagnification

bioaccumulation :

• absorption and concentration of compass (pops) in the cells + fat tissues of organisms

• methylmercury doesn’t dissolve easily in water they  don't enter blood easily + can’ t leave the body

• build up in fat tissue means that they reach higher + higher concentrations in the organisms over time

biomagnification :

• happens bc of bioaccumulation

• increasing concentration of fat-soluble compounds like methylmercury and pops in each level up the trophic pyramid or food web/chain

• begins with pops

• primary consumers take in pops y earring producers

• then secondary consumers have them

• bc of 10% rule organisms at the next trophic level need to eat more food so more pop level

• e.g. salmon, dolphins, whales

biomagnification (ddt) :

• ddt = banned insecticide but still in sediments of water

• taken in by bottom feeders (primary consumer) and goes up each trophic level

• even if extremely low levels they have to eat more so there is more for large predators

• the levels can get high enough to have thinning of eggshells in the birds

methylmercury :

• emitted through coal + volcanoes + is carried by wind then deposited in water where bacteria converts it into toxic methylmercury

• taken in by phytoplankton

• richest higher levels but is a neurotoxicant 

• e.g. tuna, sharks, whales

• human exposure to methylmercury + pops comes from eating large predatory fish

• damages human nervous system + developing fetus

• disrupts reproductive 

8.9 - solid waste disposal

objective :

• describe solid waste disposal methods

• describe the effect of solid waste disposal methods

types + sources :

• msw (municipal solid waste)

• solid waste from cities 

• e.g. trash, litter, garbage, refuse (apes word for trash)

• waste “stream” = flow of solid waste to recycling centers, landfills, or trash incineration facilities

• e-waste = old computers, tvs phones, tablets

• only 2% of msw but have hazardous waste

• can leach endocrine disruptors

• should be disposed of in special facilities

sanitary landfills :

• apes word for developed countries “landfills”

• clay/plastic bottom liner which prevents pollutants from leaking into soil + groundwater

• leachate collection system = system of tubes at bottom to collect leachate (water draining through waste + carrying pollutants) for treatment + disposal

• methane recovery system = tubes to collect methane + can be used for heat

• clay cap = mixture used to cover landfill to keep out animals, keep in smell + allow vegetation to regrow

landfills contents + decomposition :

• low levels of decomposition

• bc low o2, moisture, + organic matter

• since these factors are rarely present together in landfills little decomposition occurs + remain the same size as they started

NO landfill :

• hazardous waste (antifreeze, motor oil, cleaners, electronics, car batteries)

• metals (copper + aluminum)

• old tires can collect water and be breeding ground for mosquitos

YES landfill :

• cardboard/food wrappers + can’t be recycled

• rubber, plastic films

• styrofoam

• food, waste + paper can go into landfills but should be recycled/composted

landfill issues :

• have environmental impacts like groundwater contamination + release of ghgs

• groundwater can be contaminated if leachate leaks

• ghgs come from decomposition -> global warming + climate change

• nimby (not in my back yard) nobody wants a landfill in their backyard

• bc of smell + sight, can attract animals, and contamination of groundwater

• landfills are often placed near low-income or minority communities bc they don’t have resources to advocate against them

waste incineration :

• reduce volume that needs to be landfilled

• can reduce up to 90% but releases air pollutants

• bottom ash may have toxic metals + is stored in ash ponds

• toxic metals can leach out of storage ponds or be released into the atmosphere

• can be burned for electricity bc heat

ocean dumping :

• occurs in some countries 

• usually no environmental regulation

• plastic especially collects into large floating garbage patches

• e.g. great pacific garbage patch

• can suffocate animals

8.10 - waste reduction methods

objective :

• describe changes to current practices that could reduce the amount of generated waste and their associated benefits and drawbacks

reduce, reuse and recycle :

• reducing consumption is the most sustainable bc decreases natural resources harvested + the energy inputs to creating, packaging, and shipping good

• e.g. metal/reusable water bottle, riding bike or walking

• reusing = next best bc it doesn’t add more energy

• e.g. buying second hand clothes, reusing furniture

• recycling = processing + converting solid waste material into new products

• e.g. anna’s recycled shoes

• third r bc least sustainable but better than throwing away

benefits :

• reduces demand for new materials, especially metals + woods

• reduces energy required to ship raw materials + produce new product (less ff)

• reduces landfill volume, obvi conserving space + reducing need for more landfills

drawbacks :

• costly + requires energy

• cities that offer recycling service need to process sort + sell collected materials

• prices change rapidly leading to recycled materials being thrown away often

• when citizens recycle items that shouldn't be it increases the cost for cities to sort + process

composting :

• can be done with organic matter

• decomposition under controlled conditions

• reduces landfill volume + produces rich organic matter

• produces valuable product to sell (compost)

• reduces amt. of methane release by anaerobic decomposition or organic matter

• should be done w/ proper mix of carbon to nitrogen (30:1)

• should also be aerated + mixed to optimize decomposition (bacteria need o2 for decomposition)

• drawbacks = smell, and potential unwanted animals

e-waste :

• waste from electronics (e.g. phones, computers, etc.)

• have heavy metals (e.g. lead, mercury, cadmium)

• can leach these toxic metals

• developed countries sell e-waste to developing countries where workers are exploited which leads to toxic metals in their ecosystems

waste -> energy :

• waste = easily combustible

• can generate electricity

• same process as burning coal, natural gas, biomass

• methane gas produced by decomposition can be collected w/ pipes + burned for electricity

• same process

• reduces landfill volume

• no fracking or mining for ffs

8.11 - sewage treatment

objective :

• describe best practices in sewage treatment

water treatment process :

• primary treatment = physical removal of large debris

• secondary treatment = biological breakdown of organic matter by aerobic decomposition