FE Environmental Exam (Copy just incase)

Dose-response toxicity (carcinogen, non-carcinogen)

Carcinogen: any substance that promotes the formation of cancer Risk Assessment

35-acre watershed curve number in precipitation runoff volume:

Civil Engineering-Hydrology-Water Resources NRCS (SCS) Rainfall-Runoff Q = (P - 0.2S)^2 / P + 0.8S S = 1000/CN - 10 Q * area gives volume convert in to ft convert ac to ft^2 43.560 ft^2/ac Water Resources

Break-even (Hand tools option vs Automated System)

Cost for both options (cost per unit * number of units) Annual Savings (cost of hand tools - cost of automated system) Additional Investment (automated system cost - hand tools cost) Payback (additional Investment/annual savings) Engineering Economics

Chemical bonding is represented by the molecules of cyclohexane, cyclohexane and methanol:

Covalent hydrocarbons, polymer molecules, covalent Materials Science

Closed conduits (Darcy-Weisbach, Hazen-Williams, Moody)

Darcy-Weisbach: relates the head loss, or pressure loss, due to friction along a given length of pipe to the average velocity of the guild flow for an incompressible fluid Hazen-Williams: relates the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction Moody: diagram that relates the Darcy-Weisbach friction factor, Reynolds number, and relative roughness for fully developed flow in a circular pipe. Can be used to figure out pressure drop or flow rate down such a pipe Fluid Mechanics

Two open tanks connected by a single pipe water surface elevations up/downstream Pipe length and diameter Darcy friction factor sharp entrance and exit Flow rate in the pipe (cfs):

Energy Equation P1/sp. + z1 + V^2/2g + hm = P2/sp + z2 + V2^2/2g + hl Pressure 1 and 2 are the same Velocity 1 and 2 are the same (no change in Q/A) there is not hm from a pump reduces to: z1 = z2 +hl hl = f (L/D)V^2/2g + Sum k V^2/2g entrance k = 0.5 exit k = 1.0 g = 32.2 ft/sec Fluid Mechanics

Aeration basin for activated sludge facility L=90', W = 30', D=12' MLSS = 4,000 mg/L 1.2 MGD flow BOD5 = 165 mg/L SS = 100 mg/L Organic loading rate (F:M) (lb BOD5/lb SS-day)

F:M = lb BOD5/day to aeration/lb SS in aeration = QoSo/VOlXa Qo = 1.2 MGD So = BOD5 = 165 mg/L Vol = 90 * 30 * 2 converted to gal then Mgal Xa = MLSS = 4,000 mg/L Water and Wastewater

Associated with the corrosion of Sanitary Sewers

H2S Materials Science

60 mL of NaOH solution neutralized 40 mL of 0.5 M H2SO4, the concentration of the NaOH solution is:

H2SO4 + 2 NaOH -> Na2SO4 + 2 H2O 1:2 ration of H's CV NaOH= CV H2SO4 (60 ml)C = (0.5)(40 ml)*2 C = 0.67 M Environmental Science and Chemistry

Which would result in an explosion if mixed

Halogenated organics, alkaline earth metal, and elemental metal Safety Section Hazardous Waste Compatibility Chart Solid and Hazardous Waste

groundwater contains the following cations Na, Ca, Mg Total hardness (mb/L as CaCO3)

Hardness: Ca2+, Mg2+ (not Na+) Ca: Amount * MW ratio = 70 mg/L * 100 mg/mol CaCO3/40 mg/mol Ca Mg: 30 mg/L * 100 mg/mol CaCo3/24.3 mg/mol MG Sum the two OR Ca 2+ : 70 mg/L * mmole/40mg * 2meq/mmole * 50 mg CaCo3/meq Mg2+: 30 mg/L * mmole/24.3 mg * 2meq/mmole * 50 CaCO3/meq Sum the two Water and Wastewater

Multimedia equilibrium partitioning (Henry's law, octagonal partitioning coefficient)

Henry's law: At a constant temperature the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid octagonal partitioning coefficient: Kow is defined as the ratio of a chemical's concentration in the octane phase to its concentration in the aqueous phase of a two-phase octanol/water system Environmental Science and Chemistry

dispersion modeling

How air pollutants disperse in the ambient atmosphere Air Quality

Pressure of a constant mass of an ideal gas is doubled and the absolute temperature is halved, the volume is:

Ideal Gas P1V1/T1 = P2V2/T2 P2/P1 = 2, T2/T1 = 1/2 solve for V2 V2 = T1P1V1/T1P2 V2 = 1/2 * 1/2 * V1 V2 = 1/4 V1 quartered Thermodynamics

2,000 MW energy content 8 kWh/kg ash content 3% thermal efficiency 32% 40% of ash is removed was allowable emission 7020 kg/day min efficiency of removal device:

Input = Power/n = 2000*10^6/.32 = 6250x10^6 Wh 6250x10^6 Wh * 1kg/8x10^3 Wh = 781250 kg/hr 18750000 kg/day 40%, 562500 ash, 225000 removed 337500 x (%) = 330480 find percentage = .9792 Air Quality

1,000 MW steam electric power plant thermal efficiency of 33% coal energy content 11,500 Btu/lb permit emissions of 0.60 lb NOx per million Btu of heat input max allowable rate of emission of NOx (lb/day):

Input = Power/n, convert to Btu (3.413 Btu/hr) Nox is equal to (0.6)(input)(24 hr/day) Air Quality

Intensity-duration rainfall curve 2 in of rainfall in 2 hours annual probability of storm:

Intensity = 2in/2hr = 1 in/hr Frequency = 5 years Probability = 1/5 = 0.2 Water Resources

Stream receives discharge after missing ultimate BOD, 15 DO, 7.0 T at stream temp, Sat DO, 9.2 deoxygenation rate constant (base e) deaeration rate constant (base e) min DO mg/L downstream:

Lo = BOD ultimate = 15mg/L DO = initial deficit = Dsat - Initial = 9.2 - 7.0 DO sat = 9.2 Stream modelling 1. tc days = 1/k2-k1 ln[k2/k1(1-Do((k2-k1)/k1Lo))] 2. D = k1Lo/k2-k1[e^-k1t - e^-kt2] + Doe^-k2t 3. DO = DOsat - D Water and Wastewater

Sanitary Sewer, Manning's roughness, slope, diameter, discharge (m^3/s) when flowing full:

Manning's Equation Q = K/n A Rh^2/3) S^(1/2) -use K = 1 Fluid Mechanics

10' wide rectangular concrete channel grade, Manning's roughness coefficient, depth of flow, Discharge (cfs):

Manning's Equation Q = K/n A Rh^2/3) S^(1/2) Rh = A/P K = 1 (SI unites), and 1.486 (USCS) -use 1.486 Fluid Mechanics

Open channel (Manning)

Manning: applies to uniform flow in open channels and is a function of the channel velocity, flow area and channel slope Fluid Mechanics

Complete mix of an activated sludge system without primary clarification flow rate = 12 MGD 4 clarifiers, diameter = 80', side water depth = 14' aeration basin volume = 3 million gallons SS = 3,000 mg/L residence time = 5 days return flow rate = 10 MGD effluent SS is negligible return sludge SS (mg/L):

Mass Balance (Qo+Qr)Xa = QeXe + QrXw find Xw Q = 12 MGD Qr = 10 MGD Xa = SS = 3,000 mg/L Qe = 12 MGD Xe = 0 Qr = 10 MGD Water and Wastewater

Oxidation of iron in groundwater first-order kinetics, rate constant of 5/hr untreated iron, 1.8 mg/L 90% removal is desired hydraulic residence time (hr) complete mix reactor

Mass Balance 1st order CSTR Quo - QCe - VkCe = 0, V/Q = HRT = Co-Ce/kCe = 1.8 - (.10)(1.8)/5(.10)(1.8) = 1.8 hr Water and Wastewater

room dimensions 50 x 20 x 10m evaporative solvent emissions = 1 kg/hr ventilation rate = 80 air changes per hour no solvent in outside air room solvent concentration (ug/m^3):

Mass Balance at steady state Input - Output + Generation = Accumulation Quo - QC + E = 0 C = QCo +E / Q Q is th e80 air changes/ hr * Volume (50x20x10) Co is 0 E is 1 kg/hr * 10^9 ug Air Quality

Tangential Stress (MPa) inside a tank

Mechanics of Materials Section Cylindrical Vessel - thin-walled, t < do/2 - ot = Pi r/t where r = (ri + ro)/2 where Pi is the pressure (kPa to MPa), r is the radius, and t is the thickness (both in mm) Materials Science

USEPA, preferred strategies for the management of waste materials

Most Desirable to Least Desirable: Pollution Prevention/Waste Minimization Recycle/Reuse Treatment Disposal Ethics and Professional Practice

Roots of F = polynomial (A)/polynomial (B)

Roots occur when F = 0 Divide Polynomials, long division Mathematics Section

Carcinogen in drinking water (mg/L) cancer risk of 30 year old adult (75 kg) given a cancer slope factor of 0.80 [mg/(kg*day)]^-1

Safety Section - Intake Rates Table Ingestion Rate (IR) = 2.3 L/day Chronic Daily Intake = (CW)(IR)(EF)(ED)/(BW)(AT) Chemical concentration in water (CW) Exposure duration (ED) Averaging time (AT) = 365 * 75 Exposure frequency (EF) Body weight (BW) Risk = dose x toxicity = CDI x CSF = Chronic Daily Intake x Cancer Slope Factor Risk Assessment

500 m from equipment, dBA? 100 dBA at a distance of 5m

Safety-Point Source Attenuation dif. SPL (dB) = 1= log10 (r1/r2)^2 =10 log10 (5/500)^2 = -40 @ 500 m = 100 dBA - 40 = 60 dBA Risk Assessment

Activated sludge final clarifiers Number of units in parallel = 2 Unit Diameter = 125' Side water depth = 14' Raw wastewater flow rate = 15MGD Return activated sludge flow rate = 5MGD per MLSS = 3,000 mg/L BOD5 = 200 mg/L SS = 250 mg/L Solids loading rate (lb/(day*ft^2))

Solids loading rate = (Qo + Qr)X/A * 3.34 lb/mgal / mg/L A = 2(pi(125/2)^2) Qo = 15 MGD Qr = 2 * 5 MGD x = 3,000 mg/L Water and Wastewater

To neutralize _g of NaOH dissolved in 1 L of water requires 1 L of:

_ g NaOH * 1 mol/40 g (molecular weight) =_ normal HCl solution Environmental Science and Chemistry

Conventional wastewater treatment processes (activated sludge, decentralized wastewater systems, fixed-film system, disinfection, flow equalization, headworks, lagoons)

activated sludge: decentralized wastewater systems: fixed-film system: disinfection: flow equalization: headworks: lagoons: Water and Wastewater

mole fractions

another way of expressing the concentration of a solution or mixture; equal to the moles of one component divided by the total moles in the solution or mixture Air Quality

Hazardous waste regulations: joint and several liability

any individual responsible party may be required to pay the entire cost of cleanup Ethics and Professional Practice

Population 50,000 municipal solid waste composition paper yard food plastic metals wood glass Other

assume 100 lb of waste apply recycle %s compare 100 to new summation for reduction in mass Solid and Hazardous Waste

Example of an arene

benzene Chemistry Section, Table Environmental Science and Chemistry

Analyses (breakeven, benefit-cost)

breakeven: is the output level at which total revenue is equal to total cost BEP = FC/(SP-VC) BEP, breakeven point FC, fixed costs SP, selling price per unit VC, variable cost per unit benefit-cost: attempts to summarize the overall value of money of a project or proposal Engineering Economics

The primary origin of trihalomethane in potable water supplies

by-products of chlorination from disinfection Water and Wastewater

Facultative bacteria

can use oxygen as a n electron acceptor if available if oxygen is not available, facultative bacteria can use other electron acceptors such as nitrate or organic compounds Environmental Science and Chemistry

Recovery of VOCx can be achieved with

carbon adsorption afterburners and catalytic converters used to control/destory VOCs Air Quality

Bathhouse, air pollution control device for which pollutant streams

carbon black fly ash grains paint pigments page 184. Air pollutants that are particles (carbon monoxide, formaldehyde, Radon in gas phase) Air Quality

Kinetics (chemical, microbiological)

chemical: rates of chemical processes microbiological: vital for the design and control of microbe-based biotechnologies Environmental Science and Chemistry

Conventional water treatment processes (clarification, disinfection, filtration, flocculation, softening, rapid mix)

clarification: disinfection: filtration: flocculation: softening: rapid mix: Water and Wastewater

Alternative treatment process (conservation and reuse, membranes, nutrient removal, ion exchange, activated carbon, air stripping)

conservation and reuse: membranes: nutrient removal: ion exchange: activated carbon: air stripping: Water and Wastewater

A waste is classified as hazardous under RCRA if it exhibits

corrosively, reactivity, toxicity (not radioactivity) Waste that appears on 1 of the 4 hazardous wastes lists (F, K, P, U) or exhibits 1 of the 4 characteristics: ignitability, corrosively, reactivity, toxicity) Solid and Hazardous Waste

disinfection process for potable water 1st order kinetics, rate constant given ideal plug flow reactor hydraulic resident time given expected efficiency

covert time, t to min ln (Cao/Cae) = K(V/A)... Cae/Cao = exp(-K(V/Q, which is t)) and n = (1-Cae/Cao)100% = [1 - expo(-k(V/Q))]100% Water and Wastewater

Particle handling and treatment technologies (bathhouses, cyclones, electrostatic precipitators, settling velocity)

cyclones: method of removing particulates from air, gas, or liquid without using filters but through vortex separation (rotational effects and gravity) electrostatic precipitators: removes suspended dust particles from a gas or exhaust by applying a high voltage electrostatic charge and collecting the particles on charged plates Air Quality

Energy, heat, work

dif. U = q + w Energy: U Heat: q Work: w Thermodynamics

Probability distributions (discrete, continuous, normal, binomial)

discrete = describes the probability of occurrence of each value of a discrete random variable (a discrete random variable is a random variable that has countable values, such as a list of non-negative integers) continuous = area under the curve of its PDF - Probability Density Function (continuous random variable is a random variable with a set of possible values, known as the range, that is infinite and uncountable) normal = mean equal to 0 and variance equal to 1 binomial = probability of x successes out of N trials Probability and Statistics Section

Reactions (equilibrium, acid base, oxidation-reduction, precipitation)

equilibrium: state in which both reactants and products are present in concentrations which have no further tendency to change with time (when the forward reaction proceeds at the same rate as the reverse reaction) acid base: when an acid and a base are placed together, they react to neutralize the acid and base properties, producing a salt oxidation-reduction: involves a transfer of electrons between two species precipitation: formation of an insoluble salt when two solutions containing soluble salts are combined Environmental Science and Chemistry

Expected value (weighted average) in decision making

expected value = average value or mean of a random variable not a probability distribution weighted average = the random variable takes on where the weighting is according to the relative frequency of occurrence of those individual values Probability and Statistics Section

Uncertainty (expected value and risk)

expected value: the difference between expected profits and expected costs risk: the possibility of economic or other loss resulting from the investment decision Engineering Economics

Dermal contact is route of exposure for each of the following environmental media except: groundwater surface water soil food

food, limited to ingestion pathway Risk Assessment

First - order, linear, homogeneous differential equation with constant coefficients

general solution: y' + ay = 0, y = Ce^-at Mathematics Section

A flow enters piepe system A and exits at B and C (same elevation) head loss in Pipe CB:

hL = f (L/D) (V^2/2g) where g=32.2 AB, AC (flow C -> B) hLCB = AB - AC Fluid Mechanics

Glass is said to be an amorphous material, meaning:

has no apparent crystal structure Materials Science

Gas handling and treatment technologies (hoods, ducts, coolers, biofiltration, scrubbers, absorbers, incineration)

hoods: local ventilation device that is designed to limit exposure to hazardous or toxic fumes, vapors, or dusts ducts: conduits or passages used in HVAC to deliver and remove air biofiltration: living material captures and biologically degrades pollutants scrubbers:one of the primary devices that control gaseous emission, especially acid gases incineration: combustion of organic substances contained in waste materials; converts waste into ash, flue gas, and heat Air Quality

toxic non carcinogenic compound 40 hr/wk (ET) conc. 40 ug/m^3 (CA) Inhale Rate 0.9 m^3/hr (IR) Body Mass 70 kg (BW) Chronic Daily Intake: [mg/(kg*day)]

hr/wk -> hr/day ug/m^3 -> mg/m^3 Exposure Table Inhalation of airborne chemicals CDI = (CA)(IR)(ET)/(BW) crossed out (EF)(ED)/(AT) Risk Assessment

Cost (incremental, average, sunk, estimating)

incremental: represents the difference between some type of cost for two alterantives average: is the total cost of an output or activity divided by the total output or activity in units sunk: a past cost that cannot be changed and is therefore irrelevant in engineering economic analysis (estimating: cost analysis) Engineering Economics

Sludge treatment and handling (land application, sludge digestion, sludge dewatering)

land application: sludge digestion: sludge dewatering: Water and Wastewater

Estimation (point, confidence intervals) for a single mean

point = single value of a statistic (ex. the sample mean is a point estimate of the population mean) confidence intervals = defined by two numbers, between which a population parameter is said to lie Probability and Statistics Section

current pop pop 10 yr ago project design life linear growth model population for design:

pop now - pop 10 yr ago / 10 yr = ppl/year now pop + ppl/year*(project design life) = design pop Water Resources

Pumps (power, operating point, parallel and series)

power: qpgh where P is the pump power in Watt p is the fluid density q is the flow rate h is the head different g is the acceleration due to gravity (9.81 m/s^2) operating point: point of maximum discharge, obtained from the intersection between pipe system curve and pump performance curve when the discharge pipe is fully open parallel and series: in series, or connected along a single line, will let you add the head from each together and meet your high head low flow system requirements (the fluid pressure increases as the continuous flow passes through each pump, much like how a multi-stage pump works in parallel, or connected to any number of line branches so that each handles a division of the flow, helps reach low head, high flow operating point that a single pump cannot supply Fluid Mechanics

Licensed professional engineers are obligated to: Model Rules, Section 240.15 Rules of Professional Conduct

practice by performing services only in the areas of their competence and in accordance with the current standards of technical competence Ethics and Professional Practice

Engineer testifying as an expert witness in a product liability case should:

provide a complete and objective analysis within his or her area of competence NCEES Rules of Professional Conduct Section A.4 Ethics and Professional Practice

Ratio of vapor pressure to the saturation of water at a given temperature

relative humidity Thermodynamics

Moody diagram friction factor for a 6 in. cast iron pipe with an absolute roughness of 0.003 ft and an Reynolds number of 10^6

relative roughness = e/D = 0.003/.05 relative roughness, Reynolds Number intersection, go across to friction factor Fluid Mechanics

8 in. diameter duct collects and vents emissions Inlet T, mass flow rate, T is reduced to T2 The mass flow rate of air (lb/min):

same as flow rate (75) Mass is conserved Input mass = output mass Air Quality

Blowers (power, operating point, parallel and series)

same as pump but moves volumes of gas by increasing pressure Fluid Mechanics

pump delivers water from a lake to an elevated storage tank The static head for this pumping application:

static head = z2-z1 z1 = Lake water surface z2 = Water surface in storage tank Fluid Mechanics

lapse rates

the rate at which Earth's atmospheric temperature decreases with an increase in altitude, or increases with the decrease in altitude Air Quality

effluent BOD5 reaction rate constant for BOD exertion (base e) ultimate BOD mg/L

yt = L (1-e^-kt) solve for L, t = 5 Water and Wastewater

bin vehicle capacity 16 tons refuse truck 8 yd^3 at 0.25 ton/yd^3 number of refuse trucks to fill a bin vehicle:

16 tons * yd^3/0.25 ton * 1/8 yd^3 = 8 Solid and Hazardous Waste

2,000 lb paper 65% recovered through recycling weight (tons) recovered

2,000 * 365 days * 0.65 * 1/2000 lbs Solid and Hazardous Waste

Thermodynamic laws (1st, 2nd)

1st: conservation of energy/heat, the total energy of an isolated system is constant; energy can be transformed from one form to another, but can be neither created nor destroyed 2nd: the state of entropy of the entire universe, as an isolated system, will always increase over time (the changes in the entropy in the universe can never be negative) Thermodynamics

50,000 lb/day mass ratio = 3:1, refuse:cover density of fill + cover = 1,000 lb/yd^3 volume (yd^3) of fill (refuse + cover) for 10 years:

(50,000 refuse lb/day + 50,000/3 cover lb/day)* yd^3/1000 lb * 365 day/year * 10 year =243,000 Solid and Hazardous Waste

Equation of a sphere

(x-h)^2 + (y-k)^2 + (z-m)^2 = r^2 Mathematics Section

Reservoir, 300,000 people demand = 100 gal/day/capita fire flow 3,000 gal/min for 8 hours max daily demand peak factor = 1.5 Volume (10^6) of storage:

100 gal/day * 300,000 people + 3000 gal/min * 60 min/1 hr * 8 *1.5 = 46.4 x 10^6 gal Water Resources

equation given the chemical equilibrium constant, K = [C]^2 [D]^2 / [A]^4 [B]

4A + B <-> 2C +2D Chemistry Section, equilibrium constant Environmental Science and Chemistry

lime soda softening plant 5 MGD, 6 filters, A per filter ft^2 design filtration rate (gpm/ft^2) with 1 unit offline

A = 5(A) Overflow rate = Q/A Water and Wastewater

Equivalent uniform annual cost (given initial cost, salvage value after n years, maintenance cost per year, interest rate)

A = Am + P(A/P, i, n) - SV(A/F, i, n) where Am is the maintenance cost per year, P is the initial cost, and SV is the salvage cost Engineering Economics

Community growth in population and water consumption Annual percentage rate of population growth remains equal to the rate in the 1990s Per capita water consumption rate stabilizes projected water demand:

Annual rate of pop. growth = (pop now/pop then)^1/years between pop now * (annual rate of pop growth)^years to future pop * stabilized per capita water consumption = projected water demand Water Resources

discharge to prevent eutrophication would limit:

BOD5, SS, Coliforms, Total N, Total P (not Total K) Water and Wastewater

hydrocarbon combustion process with an increased air to fuel ratio from stoichiometry to slightly above stoichiometric would be expected to increase emissions of:

NOx Co -> CO2 VOC -> CO2 N -> NOx more complete combustion Air Quality

Hot air at 200 d.C. flows across a 50 d.C. surface heat transfer coefficient is 72 W/m^2*C the heat transfer rate (W) over 2 m^2 of the surface:

Newton's Law of Cooling: Convection Heat Transfer Q = hA (Tw - Tinf.) Q = (72)(2)(50-200) Thermodynamics

Aluminum crimp connector is used to connect a copper wire to a battery

Only the aluminum connector will corrode Aluminum is anodic relative to copper and therefore, will corrode to protect the copper Materials Science

rapid sand filter, 4 cells L = 10', W = 10', D = 12' water production rate = 2 MGD take 1 filter offline hydraulic loading rate (gpm/ft^2)

Overflow rate = Q/A, A = 3(LxW) Water and Wastewater

Probability of two conditions with overlap

P(A+B) = PA + PB - P(A,B) P(A,B) = PA * PB Probability and Statistics Section

Probability of independent events A and B (like pulling a marble from 2 different boxes)

P(A,B) = PA * PB Probability and Statistics Section

Find Present Worth (given life span, discount rate, etc.)

PW = -First Cost - Annual Cost (P/A, i, n) + Salvage Value (P/F, i, n) answer is the least negative value Engineering Economics

stability classes

Pas quill atmospheric stability classes, method of categorizing the amount of atmospheric turbulence present Air Quality

Aeration basin for activated sludge facility L, W, D MLSS Flow BOD5 SS primary clarifier, removes 25% BOD5 and 60% SS return activated sludge 0.8 MGD primary sludge solids content = 4% specific gravity = 1 primary sludge volume (ft^3/day)

Primary Sludge Dry Weight Weight = QSon = Flow*SS*0.6 convert to lb/day Wet Weight = Dry Weight/.04 Volume = Wet Weight converted to ft^3/day Water and Wastewater

composite runoff coefficient = 0.65 watershed area extends to 100' on each side of the street centerline capacity of curb inlet is 10 cfs street drainage to accommodate 6.8 in/hr rainfall distance between inlets:

Q = CIA A = Q/CI = 10 / (0.65)(6.8) = 2.26 areas convert to feet * 43,560 ft^2/acre = 98400 ft^2 A = 100 * L L = 98,400 / 100 = 980 ft Water Resources

Intensity - duration rainfall curves 12-acre residential development runoff coefficient C of 0.40 time of concentration 1 hr Rational Method Peak runoff (cfs) from 10-yr storm:

Q = CIA Q = 0.40(1.8 in/hr)12acres 1.8 is from graph, find concentration time, go up to 10 year storm, go across again to get intensity Water Resources

sequence of unit operations and processes for a surface water treatment facility

Rapid mix, flocculation, sedimentation, filtration, disinfection Water and Wastewater

Ecology (Streeter-Phelps, fluviology, limnology, eutrophication)

Streeted-Phelps: describes how dissolved oxygen decreases in a river or stream along a certain distance be degradation of BOD D = k1La/k2-k1 (e^-k1t - e^-k2t) + Dae^-k27 where D is the saturation deficit (D = DOsat - DO), dissolved oxygen concentration at saturation minus the actual dissolved oxygen concentration k1 is the deoxygenation rate k2 is the deaeration rate La is the ultimate BOD Lt is the oxygen demand remaining at time t, Lt = La e^-k1t Da is the initial oxygen deficit t is the elapsed time fluviology: the study of watercourses, rivers limnology: study of inland waters eutrophication: excessive amounts of nutrients stimulates an explosive growth of algae (algal blooms) that depletes the water of oxygen when the algae die and are eaten by bacteria Environmental Science and Chemistry

lime soda softening plant 5 MGD, 2 clarifiers, D=65', tidewater depth = 12' residence time (hr) for parallel:

V = (65/2)^2pi x 12 x 2 ft^3 convert to gal HRT = V/Q = V / 5x10^6 * 24hr/day = hr Water and Wastewater

Value of deposit in savings account after n years

V = initial deposit (F/A, i, n) (F/P, i, n) where F/A is the Uniform Series Compound Amount, to F given A and F/P is the Single Payment Compound Amount, to F given P Engineering Economics

Rapid Mixing Process min hydraulic resident time 45 sec water production rate = 0.3 MGD 2 tanks in parallel, cylindrical liquid depth = radius min liquid depth (ft):

V/Q = HRT V 2= (45sec)(0.3 MGD x 10^6)/(86,400 sec/day)(7.48 gal/ft^3) V = V2/2 Depth = (V/pi)^1/3 Water and Wastewater

Discounted cash flow (life cycle, equivalent, PW, annual worth, FW, rate of return)

life cycle: all the time from the initial conception of an idea to the death of a product (process), cost = sum total of all the costs incurred during the life cycle equivalent: used to compare alternatives PW: Present amount at t = 0 annual worth: uniform amount that repeats at the end of each year for n years FW: equivalent future amount at t = n of any present amount at t = 0 rate of return: is calculated by finding an interest rate that makes the present worth zero Engineering Economics

Coal fired steam electric power plant, control SOx emissions by

lime scrubbing SOx is removed by liquid scrubbing at a high pH Lime may be added to raise the pH Air Quality

Logarithms to base 10

log10 (x) = c where 10^c = x Mathematics Section

Measures of central tendencies and dispersions (e.g. mean, mode, standard deviation)

mean = 1/N Sum xi mode = the number which appears most often in a seat of numbers standard deviation, o(pop) = sqrt [(1/N)Sum(xi - u)^2] where N = number of measurements and u = arithmetic mean Mathematics Section

rectangular homogeneous gate (3x1m), frictionless hinge at the bottom density of fluid on the left 1,600 kg/m^3 magnitude of the force F (kN) to keep the gate closed

mean pressure at the mean height center of pressure is 2/3 of the height from the top Total force of the fluid Ff = pg(H/2)H Ff = (1,600)(9.807)(3/2)(3) F(3) = Ff(1) F = Ff/3 Fluid Mechanics

35,000 people demand is 80 gallons per capita per day (gpcd) 30 days per month reservoir size (millions of gallons)

months less than demand per day (80*35000) subtract what they provide from demand (2.8) multiply by 30 days add together to get total Water Resources

Organic chemistry (nomenclature, functional group reactions)

nomenclature: a root or base indicating a major chain or ring of carbon atoms found in the molecular structure, a suffix or other elements designating functional groups that may be present in the compound, and names of substituent groups, other than hydrogen, that complete the molecular structure functional group reactions: atoms or small groups of atoms that exhibit a characteristic reactivity when treated with certain reagents; a particular functional group will almost always display its characteristic chemical behavior when it is present in a compound Environmental Science and Chemistry

Solution with a pH of 2 using 6 M HCl

pH 2 = [H+] = 10 ^-12 mol/L CV = CV [10^-2][1 L] = 6V V = 1.67 mL Dilute 1.67 mL of HCl to 1 L, using water Environmental Science and Chemistry

Ideal gas equation

pV = nRT Air Quality

Pitot tube Velocity, 2 m/s specific gravity of fluid, 2 reading h (m) on the manometer:

pV^2/2 = gh (p - pair) solve for h h = pV^2/2gh(p - pair) =V^2/2g (assumption that pair is negligible, p's cancel on top and bottom) =2^2/3(9.8) Fluid Mechanics

Agricultural site wo paved parking lot without stormwater dentition facilities would result in: 1. Increase in runoff coefficient 2. Increase in design rainfall intensity 3. Increase in peak discharge rate

pervious to impervious increases C drainage improvements, tc decreases, duration decreases, i increases peak discharge increases, c increases, i increases answer is 1, 2, and 3 Water Resources

emissions of solvent = 100 ug/s at ground level wind speed is 3 m/s neutral stability the ground - level centerline concentration (ug/m^3) 0.1km downwind:

pg. 181 for neutral stability (Class D) and x = 0.1 km gives oy and oz C = 100/(2pi)(wind speed)(oy)(oz) Air Quality

Exposure Routes

the way people or other living organisms come into contact with a hazardous substance (breathing/inhalation, eating or drinking/ingestion, or contact with the skin/dermal contact) Risk Assessment

activated sludge wastewater treatment plant with primary clarification and anaerobic digestion Flow Aeration basin hydraulic residence time aeration basin vol:

time = V/Q Water and Wastewater

Increase reservoir due to pop growth pop then pop now exponential growth future pop:

time between then and now = t1 K = ln Pt - ln Po / t1 then time between now and future = t2 ln Pt = ln Po + Kt2 solve for Pt Water Resources

Mark the diamond that signifies that a material will ignite if moderately heated

top (Position B) Solid and Hazardous Waste

3 wastewater flows combine in a sewer, with flow and BOD given Infiltration (0 BOD) 10% of total flow Resulting BOD

total 1 - 3 flow plus 10% of that find % of each flow % x BOD of each flow Sum BOD Water and Wastewater

Flow measurement (weirs, orifices, flowmeters)

weirs: structure over which water flows in such a way that volumetric flow rates can be calculated orifices: either a volumetric or mass flow rate may be determined; uses Bernoulli's principle - states that there is a relationship between the pressure of the guild and the velocity of the fluid flowmeters: ex. Pitot-tube is a pressure measuring instrument used to measure fluid flow velocity by determining the stagnation pressure and static pressure Fluid Mechanics