Fundamentals of Engineering Exam (FE) Chemistry, Biology and Environmental Engineering Syllabus

How does a catalyst affect a reaction?

A catalyst lowers the activation energy $E_a$ by providing an alternative pathway, speeding both forward and reverse rates equally. It is not consumed and does not change $\Delta G$, $\Delta H$, or the equilibrium position.

Contrast prokaryotic and eukaryotic cells.

Prokaryotes (bacteria, archaea): no membrane-bound nucleus or organelles, circular DNA, smaller. Eukaryotes (plants, animals, fungi, protists): true nucleus, membrane-bound organelles (mitochondria, ER), linear chromosomes, generally larger.

What are the functions of the mitochondria, ribosomes, and cell membrane?

Mitochondria: ATP production via aerobic respiration ('powerhouse'). Ribosomes: protein synthesis (translation). Cell membrane: selectively permeable phospholipid bilayer controlling transport in/out of the cell.

Summarize the central dogma of molecular biology.

$$\text{DNA} \xrightarrow{\text{transcription}} \text{RNA} \xrightarrow{\text{translation}} \text{Protein}$$ DNA stores genetic information, transcribed to mRNA, then translated into proteins by ribosomes. Replication copies DNA.

What are the overall reactions for aerobic respiration and photosynthesis?

Aerobic respiration: $$\ce{C6H12O6 + 6O2 -> 6CO2 + 6H2O} + \text{energy}$$ Photosynthesis (reverse): $$\ce{6CO2 + 6H2O ->[\text{light}] C6H12O6 + 6O2}$$

Name and order the bacterial growth curve phases.

Lag phase (adaptation, no growth), Log/exponential phase (rapid doubling), Stationary phase (growth = death, nutrients limit), and Death/decline phase (cells die exponentially).

Differentiate aerobic, anaerobic, and facultative microorganisms.

Aerobes require $\ce{O2}$. Obligate anaerobes are poisoned by $\ce{O2}$. Facultative organisms use $\ce{O2}$ when available but can switch to fermentation/anaerobic metabolism when it is absent.

Define the bacterial doubling/generation time and give the growth formula.

Generation time is the time for a population to double. Exponential growth: $$N = N_0\,2^{(t/t_d)}$$ where $t_d$ is doubling time. Equivalently $N = N_0 e^{\mu t}$ with specific growth rate $\mu$.

What distinguishes Gram-positive from Gram-negative bacteria?

Gram-positive: thick peptidoglycan cell wall, retains crystal violet (stains purple). Gram-negative: thin peptidoglycan plus an outer lipopolysaccharide membrane, stains pink with safranin counterstain.

Define LD50 and explain its significance in toxicology.

$\text{LD}_{50}$ is the dose lethal to 50% of a test population, usually in mg of substance per kg body weight. A lower $\text{LD}_{50}$ means higher acute toxicity.

Distinguish acute vs chronic toxicity and a carcinogen vs a teratogen.

Acute toxicity: harmful effect from a single/short high exposure. Chronic toxicity: from prolonged low-level exposure. A carcinogen causes cancer; a teratogen causes birth defects in a developing fetus.

What is bioaccumulation versus biomagnification?

Bioaccumulation: buildup of a substance in an individual organism over time (uptake > excretion). Biomagnification: increasing concentration of that substance at successively higher trophic levels of a food chain (e.g. mercury, DDT).

Define BOD and COD and how they differ.

BOD (Biochemical Oxygen Demand): oxygen consumed by microbes degrading organics, typically measured over 5 days ($\text{BOD}_5$). COD (Chemical Oxygen Demand): oxygen equivalent to chemically oxidize all organics. COD $\geq$ BOD because COD includes non-biodegradable matter.

What are the primary indicators of water quality regulated for drinking water?

Turbidity, pH, dissolved oxygen, total dissolved solids (TDS), hardness, coliform/E. coli bacteria, nitrates, and disinfection byproducts. Coliforms indicate possible fecal contamination.

List the conventional steps of a surface-water treatment plant in order.

Coagulation $\to$ Flocculation $\to$ Sedimentation (clarification) $\to$ Filtration $\to$ Disinfection. Coagulation/flocculation aggregate particles; sedimentation/filtration remove them; disinfection (e.g. chlorine) kills pathogens.

What is water hardness and how is it commonly expressed?

Hardness is the concentration of multivalent cations, mainly $\ce{Ca^2+}$ and $\ce{Mg^2+}$, expressed as mg/L equivalent $\ce{CaCO3}$. It causes scale and soap-scum. Removed by lime-soda softening or ion exchange.

Distinguish primary, secondary, and tertiary wastewater treatment.

Primary: physical settling of solids (sedimentation). Secondary: biological removal of dissolved organics (e.g. activated sludge, trickling filter). Tertiary: advanced polishing — nutrient (N, P) removal, filtration, disinfection.

How does the activated sludge process work?

Wastewater is aerated with a microbial floc that metabolizes dissolved organics. The mixed liquor passes to a clarifier where biomass settles; part is recycled (return activated sludge) to maintain the population and the rest is wasted.

Define the food-to-microorganism (F/M) ratio in activated sludge.

$$\frac{F}{M} = \frac{Q\,S_0}{V\,X}$$ where $Q$ is flow, $S_0$ influent BOD, $V$ aeration volume, and $X$ MLSS concentration. It expresses the organic loading per unit biomass and controls sludge performance.

What is the order of the solid waste management hierarchy (most to least preferred)?

Source reduction/prevention $\to$ Reuse $\to$ Recycling/composting $\to$ Energy recovery (incineration with heat capture) $\to$ Treatment/Landfill disposal (least preferred).

What is leachate and why is it a concern at landfills?

Leachate is contaminated liquid that percolates through waste, carrying dissolved and suspended pollutants. It can contaminate groundwater, so modern landfills use liners and leachate collection systems; landfill gas (mostly $\ce{CH4}$ and $\ce{CO2}$) is also collected.

Name the six EPA criteria air pollutants.

Particulate matter ($\text{PM}_{10}/\text{PM}_{2.5}$), ground-level ozone ($\ce{O3}$), carbon monoxide ($\ce{CO}$), sulfur dioxide ($\ce{SO2}$), nitrogen oxides ($\ce{NO_x}$), and lead ($\ce{Pb}$).

What causes acid rain and what is its chemistry?

$\ce{SO2}$ and $\ce{NO_x}$ emissions react with water and oxygen in the atmosphere to form sulfuric and nitric acids: $$\ce{SO2 + H2O -> H2SO3},\quad \ce{2SO2 + O2 + 2H2O -> 2H2SO4}$$ lowering rain pH below ~5.6.

Differentiate primary and secondary air pollutants, and give the ozone example.

Primary pollutants are emitted directly (e.g. $\ce{NO}$, $\ce{SO2}$, $\ce{CO}$). Secondary pollutants form in the atmosphere via reactions; ground-level ozone is secondary, formed photochemically from $\ce{NO_x}$ and VOCs in sunlight.

What air pollution control device is used for particulates versus gaseous pollutants?

Particulates: cyclones, baghouses (fabric filters), electrostatic precipitators (ESPs). Gases: wet/dry scrubbers and absorbers (e.g. flue-gas desulfurization for $\ce{SO2}$), and catalytic converters/SCR for $\ce{NO_x}$.

State the general steady-state mass balance equation.

$$\text{Accumulation} = \text{In} - \text{Out} + \text{Generation} - \text{Consumption}$$ At steady state, accumulation $= 0$, so In $+$ Generation $=$ Out $+$ Consumption.

Write the mass balance for a CSTR (completely mixed reactor) with first-order reaction at steady state.

For $V\frac{dC}{dt}=QC_0 - QC - kVC = 0$: $$C = \frac{C_0}{1 + k\tau}$$ where $\tau = V/Q$ is the hydraulic residence time.

Give the effluent relation for an ideal plug-flow reactor (PFR) with first-order kinetics.

$$\frac{C}{C_0} = e^{-k\tau}$$ where $\tau = V/Q$. For the same conversion of a positive-order reaction, a PFR requires less volume than a CSTR.

What is hydraulic (or detention) retention time and how is it calculated?

Retention time is the average time a fluid parcel stays in a reactor or tank: $$\tau = \frac{V}{Q}$$ where $V$ is volume and $Q$ is volumetric flow rate.

Define a contaminant's half-life for first-order decay and the relationship to the rate constant.

For first-order decay $C = C_0 e^{-kt}$, the half-life is $$t_{1/2} = \frac{\ln 2}{k} = \frac{0.693}{k}$$ the time for the concentration to fall to half its initial value, independent of $C_0$.

What is dilution, and how do you compute a mixed concentration when two streams combine?

By conservation of mass (flow-weighted average): $$C_{mix} = \frac{Q_1 C_1 + Q_2 C_2}{Q_1 + Q_2}$$ where $Q$ are flow rates and $C$ are concentrations of each stream.