environmental engineering exam 1!!

describe roles played by environmental engineers 

-providing safe, palatable and ample public water supplies

-proper disposal of or recycling wastewater and solid wastes

-control of water, soil, and atmospheric pollution

for solids ppm=

1 mg/kg

for solids ppb=

1 microgram/kg

for water 1 mg/L=

1 mg/kg = 1 ppm

molarity =

mol/L

for air ppmv=

partial pressure for gases, m³ substance/m³ air mixture (mole fraction) x 10^6

assumption to use ppm and ppb

the density must be 1.00 g/mL so it must be FRESH WATER not salt

partial pressure equation

Pn2=Xn2 x Ptotal

aerosol

a tiny droplet of liquid or solid suspended in air (use microgram/m³)

MCL

maximum contaminant level legally enforceable

MCLG

maximum contaminant level goal not legally enforceable

ambient

background levels in air, water, soil (not something coming directly out of a tail pipe)

john snows work

he mapped cases of cholera and was able to determine that it was a waterborne disease, not caused from the air. He saw the clustering of cases around the broad street pump.

collision theory

increase reaction rate by increasing the frequency or velocity of molecular collisions

how to increase reaction rate

-temperature

-changing concentration of reactants

-adding a catalyst

-increasing partial pressure of gaseous reactants

-increasing surface area of reactants

zero order

rate is not affected by concentration

first order

rate is proportionally affected by reactant concentration

define rate of reaction

rate= change in concentration/ change in time (if reactants -concentration)

types of equilibria important

acid/base, air/water(volatilization), water/soil (sorption), dissolved solid (precipitation)

K=

products/reactants (leave out any s or l) exponents if a number is before

what happens at equilibrium?

the equality holds true, if not one direction goes faster until its restored

Kow value?

octanol-water partition coefficent= [ concentration in octanol]/[concentration in water]

characteristics from Kow

it quantifies if a substance dissolves better in very polar water, or mostly non-polar octanol

large Kow value?

-more non-polar

-sticks to soil instead of washing away in water

-bioaccumulates in organisms (especially in fatty tissues)

-biomagnifies in food webs (accumulating in top predators)

autotroph

gets carbon from CO2 or other inorganic C (plants)

heterotroph

gets carbon from eating organic material (humans and animals)

aerobic

uses O2 in metabolism (animals, plants)

anaerobic

doesnt use O2 in metabolism (microbes)

unicellular

one cell (bacteria, archaea)

multicellular

multiple cells (animals, plants)

acellular

no cells, viruses

organic

alive or formally living, C based

inorganic

materials

planktonic

very small organism suspended in water

phyto-

photosynthetic

bioaccumulation

the concentration of POP can reach levels higher than surrounding environment, because it accumulates in the fatty acids of the organisms and aren’t digested

biomagnification

accumulates through food chain, species at the top accumulate more than species at the bottom

POP

persistent organic pollutant, tend to have high Kow values and are resistant to biodegradation (being broken down by living things)