Exam 1 Material

• strong acid

  weak acid

  pH decreases
• strong base

  weak base

  pH increases
• cholera

  - vibrio cholerae

  - restricted largely to the developing world

  - gram negative, rod shaped proteobacterium

  - contaminated water, shellfish

  - infects small intestine causing fluid loss of up to 20 L per day
• legionella pneumophila

  - opportunistic pathogen

  - form of respiratory pneumonia

  - prefers warm water, such as HVAC cooling towers

  - spreads through inhalation of aerosols
• opportunistic pathogens

  organism that does not normally cause infections and may be ubiquitous but can infect compromised immune system
• giardia

  - only 5 - 10 % of infected people show symptoms but can still spread the cysts

  - resistant to chlorine

  - effectively removed by filtration

  - flagellated protozoan

  - transmitted through wildlife

  - exists as infected cysts
• cryptosporidum parvum

  - forms highly resistant oocysts

  - greatest chlorine tolerance

  - removed by filtration or UV
• norovirus

  - adenovirus

  - viruses aren't alive

  - susceptibility to chlorine disinfection

  - resistant to UV

  - filtration is effective

  - easily transmitted through fecal-oral route involving surface contract
• schistosoma

  - blood fluke

  - complex lifecycle

  - involves snail and mammalian hosts
• what temperature is water most dense

  4 degrees celsius
• protonated equation

  pKa > pH --> protonated
• deprotonated equation

  pKa < pH --> deprotonated
• agriculture water polutanst

  - nitrogen

  - phosphorus

  - salts
• alkalinity

  reflects the water's ability to resist changes in pH due to the presence of buffering compounds
• high alkalinity

  - well buffered

  - useful when we want to have stable chemical properties

  (like during distribution)
• high alkalinity ______ the pH of water bodies and is _________ to ________

  stabilizes the pH of water bodies and is beneficial to aquatic ecosystems
• particle size distribution

  indicates the percentage of particles of a certain size
• turbidity

  - quantifies the amount of suspended solid particles in water

  - measure of light scattering by particles in water
• protons

  based on this number the chemical elements are defined
• electron

  - negatively charged particle

  - determine ions
• neutron

  - particle with no electrical charge

  - determines isotopes
• endocrine disruptors

  - arise primarily from natural sources of contamination

  - can interfere with hormone function

  - can have toxicological effects at low concentration

  - compounds that interfere with the endocrine system
• secondary standards address

  - taste and odor of water

  - color

  - corrosivity

  - hardness

  - fluoride for dental health
• seconday standards

  - not required by EPA

  - suggested limits on contaminants with aesthetic or distribution problems

  - state agencies may make them mandatory
• primary standards

  - mandated for the purpose of protecting public health

  - maximum contaminant level (MCL)

  - treatment technique standard (TT)
• maximum contaminant level (MCL)

  maximum allowable concentration in treated water

  typically upon exit from treatment plant
• treatment technique standard (TT)

  rather than stating a max contaminant level some standard some standards require a specific treatment practice to be used
• coagulation

  - addition of dissolved cations to neutralize negative surface charge on solid particles

  - so they no longer repel each other
• granular media filters

  remove colloidal particles from water by the colloids collide with media particles and stick to them
• flocculation

  formation of loose aggregates of destabilized solids via mixing induced collisions
• sedimentation

  - water fed into clarifier where flocs settle to the bottom to form a sludge later

  - clean water is withdrawn from the top portion vis effluent launders

  - solids continually scraped and collected into a discharge pipe sludge then dewatered
• nonpoint source pollution

  contamination as a result of contaminated rain runoff or snowmelt
• source point pollution

  - discharge from a discrete point like pipe or smokestack

  - easier to regulate treat and control
• covalent bond

  share electrons between two or more atoms
• ionic bond

  atoms bound by electrostatic attraction between ions of opposite charge
• metallic bond

  bonding characterized by a delocalized electron cloud
• hydrogen bond

  electrostatic attraction between partially charged hydrogen atoms and an electronegative atom
• bioaccumulate

  - when a substance becomes concentrated in biological tissues and further concentrated as it moves up food chain

  - mercury
• aromatic compound

  - organic compound

  - 6 carbon atoms with alternating double and singe bonds
• organic compound/moleule

  contains one or more carbon atoms covalently bonded to other atoms