Environmental Engineering Test 1

Ecosystem

a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life

Systems Approach

The breaking down of a complex concept into smaller units for purpose of a better understanding of the whole

Regulation

An authoritative rule dealing with details or procedure.

A rule or order issued by an executive authority or regulatory agency of a government and having the force of law.

RCRA (Resource Conservation and Recovery Act)

public law that creates the framework for the proper management of hazardous and non-hazardous solid waste

Ethics

Moral principles that govern a person's behavior or the conducting of an activity

Silent Spring

1962 book by Rachel Carson revolutionized Environmentalism and kick-started the modern environmental movement. Condemned the overuse of pesticides including DDT.

Stoichiometry

the measure of elements

Reactants

A starting material in a chemical reaction

Products

The elements or compounds produced by a chemical reaction.

Chemical Equilibrium

a state in which there is no chemical driving force favoring a change in the system'scomposition

Equilibrium Constant

The rate at which a reaction moves one way or another

Solubility

the maximum quantity (mass) of a substance (solute) that can dissolve in a unit volume of solvent under specified conditions

Acid-Base Equilibria

all inorganic compounds and many organic compounds can be classified as acids, bases, or salts

Henry's Law

the mass of a gas that dissolves in a definite volume of liquid is directly proportional to the pressure of the gas

Reaction Order

Describes how the rate of a chemical reaction depends on reactant concentration.

Concentration Units

Milligrams per Liter (mg/L)

Parts per million (ppm)
Percent (by weight)
Normality (N)

Types of chemical reactions

• Combustion: Reaction with oxygen, producing heat.

• Oxidation-Reduction (Redox): Electron transfer reactions.

Acid-Base Neutralization: Acid + Base → Salt + Water.

Reaction Kinetics

Studies the rate of chemical reactions and factors affecting them (e.g., temperature, catalysts).

Organic Compounds

Carbon-based molecules, including hydrocarbons, alcohols, and amino acids.

Water Chemistry

The study of a polar molecule, which is a good solvent, with pH 7

Historical view of Henry's Law

(1803) proposed at the beginning of the era of modern chemistry, which is surprisingly early, and the law remains very popular. Can be expanded using the first and second law of thermo dynamics.

Great Spheres

Lithosphere,

Biosphere
Atmosphere
Hydrosphere
Cryosphere

Lithosphere

A rigid layer made up of the uppermost part of the mantle and the crust.

biosphere

part of land water and air that contains life.

Atmosphere

A thin layer of gases surrounding Earth

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans

Cryosphere

A term referring to all water that is temporarily frozen in polar ice caps, snow, permafrost, and glaciers

Abiotic

non-living components of an environment

Four main classes of biological compounds

Carbohydrates

Nucleic Acids
Proteins
Lipids

Carbohydrates

major source of energy, the most abundant class of organic compounds found in living organisms

Nucleic Acids

Store and transmit hereditary information that makes up the DNA any organism

Proteins

Called the building blocks of life and found in every organism on Earth. They are the most common molecules found in cells.

Lipids

provide energy for cells, create the cel structure, and provide insulation for the cell.

Viruses

they have genes, they reproduce, and they evolve through natural selection. They do not have cells, they cannot turn food into energy, and without a host they are just inert packets of chemicals Half of human DNA came from these.

Catabolic Pathways

sequence of chemical reactions that break down complex molecules into smaller units and release energy

Energy

all organisms require a constant supply of

Importance of photosynthesis

all life on earth , either directly or indirectly, depends on photosynthesis as a source of food, energy , and O2

Catabolic Pathways

Aerobic Respiration

Anaerobic Respiration
Fermentation

pathogen

is a micro-organism that has the potential to cause disease

infection

is the invasion and multiplication of pathogenic microbes in an individual or population

Disease

is when the infection causes damage to the individual's vital functions or systems

Biological Water treatment

involves the use of different microorganisms; bacteria, viruses, and protozoa

Waterborne diseases

are caused by pathogenic microorganisms that most commonly are transmitted in contaminated fresh water.

cholera and typhoid, are the diseases that are transmitted through drinking water

Water-washed (water-scarce) diseases

diseases where the interruption of the transmission is achieved through proper attention to effective sanitation, washing and personal hygiene

Water-based diseases

diseases transmitted by contact with water, e.g., recreational swimming.

Water-vector diseases

such as malaria, are diseases that are transmitted by a vector, such as the mosquito, which needs water or moisture in order to breed

Law of Conservation of Matter

Matter is not created nor destroyed in any chemical or physical change

Inputs

= outputs + accumulation

Outputs

= inputs - accumulation

Accumulation

= inputs - outputs

Steady State (condition)

when the rate of input and the rate of output are constant and equal, then the mass rate of accumulation is zero

Conservative Substance or Compound

no loss, no formation, mass is conserved - what goes in equals what goes out

decay

(or transformation) is usually time dependent,so a reaction rate is associated

Flowrate

Q given in units (volume/time)

Mixed Systems

Every drop of fluid within the system contains the same concentration of materials and has the same physical properties

Non-conservative

When substance of interest is not conserved

completely mixed batch reactor (CMBR)

Materials are added to a tank, mixed for a sufficiently long period of time for the desired reaction to takeplace, and then discharged as a "batch"

Open system

is one in which both energy and matter can flow across the boundary

Closed system

is one in which energy can flow across the boundary but matter cannot

Specific heat

the amount of energy needed to raise the temperature of a unit mass of a substance by 1 degree

British Thermal Unit (BTU)

The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit

Kilocalorie

energy required to raise 1 kg of water by 1 degree C

Enthalpy

Internal energy of a system plus the product of the pressure and volume of the system

Internal Energy

is equal to the net heat energy entering the system minus the net work done by the system

phase change

When a substance changes phase, energy is absorbed or released without a change in temperature

Heat transfer

Conduction

Convection
Radiation

Conduction

Takes place when there is direct physical contact between objects.Usually associated with solids , where the rate of heat transfer is proportional to the thermal conductivity of the material

Convection

Occurs when a liquid or gas atone temperature comes in contact with a substance at another temperature

Radiation

Can take place even in the absence of any physical medium between objects

Energy Balances

Practice of the first law of thermodynamics

Plug Flow System

theoretically the opposite ofa completely mixed system...an un-mixed system... however the volume for the system under consideration can be considered constant

Plug Flow Reactor (PFR)

Reactions can still take place when non-conservative substances are involved

Step function response

When the concentration of a substance ofi nterest entering a flow-through system changes suddenly, the result of this change of concentration

First Law Thermo

Energy cannot be created or destroyed

Forms of Energy

kinetic energy and potential energy

Producers

organisms that take in and use energy from the Sun or some other source to produce food

Consumers

organisms that take in energy when they feed on producers or other consumers

Decomposers

organisms that take in energy as they break down the remains of organisms

Food Chain

cycle of life with prey and predators

Trophic Levels

producers, primary consumers, secondary consumers, tertiary consumers etc.

Eutrophication

the process by which a body of water becomes enriched in dissolved nutrients that stimulate the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen

Sulfur Cycle

Similar to water, Sulfur is emitted into the air rained down dissolved in water. Sulfur water then enters groundwater where plants and decomposition absorb the sulfur.

ways humans impact ecosystems

Human activities can accelerate the rate at which nutrients enter an ecosystem.

Runoff from agriculture and development, pollutionfrom septic systems and sewers, and other human-related activities increase the flux of both inorganicnutrients and organic substances into terrestrial,aquatic, and coastal marine ecosystems

Bioaccumulation

Contaminate increases in one species over time

Biomagnification

Contaminate increase effect as it goes up the food chain

Nutrient Cycles

Carbon Cycle

Nitrogen Cycle
Phosphorus Cycle
Sulfur Cycle

Population Dynamics

A branch of knowledge concerned with the sizes of populations and the factors involved in their maintenance, decline, or expansion

What is the Systems Approach?

A framework used in engineering and science to break complex systems into smaller parts for better understanding and management. In environmental engineering, it applies to water, air, and solid waste management systems

Issues facing the ecosystem:

• Population growth

• Pollution (air, water, land)

• Climate change

• Deforestation & biodiversity loss

• Waste disposal

• Depletion of natural resources

Why are regulations needed?

Pollution and environmental destruction led to health risks and ecosystem damage. Without regulations, industries did not always self-police. Laws like the Clean Air Act, Clean Water Act, and RCRA help protect resources.

Top 5 Environmental Regulations

#1 - Reorganization Plan No.3 of 1970

#2 Clean Air Act (1970)

#3 - Clean Water Act. (1972) The Federal Water Pollution Control Act of 1948, after

being heavily amended, became the Clean Water Act in 1972

#4 – Endangered Species Act (1973)

#5 – Montreal Protocol. (1987) International treaty signed by the U.S. in 1987. Signed by 197 countries
ablished in 1970