Concepts of Environmental Science and Engineering

Concepts and Principles

• Environment
• Environmental Science
• Environmental Engineering
• Environmental Quality
• Environmental Quality Standards
• Environmental Quality Monitoring

Concept Map of Development, Environment, and Health

• The concept map illustrates the interconnectedness of human health, human activities for development, and the environment.

Environmental Modifications

• Examples of environmental modifications include:
  • Construction of dams and irrigation canals.
  • Irrigated rice fields.
  • Deforestation.
  • Uncontrolled urbanization.
  • Habitat fragmentation.
  • Poor water supply systems.
  • Inadequate garbage and wastewater disposal systems.
  • Lack of shelter.
  • Intensive livestock agriculture.
  • Overcrowded and mixed livestock practices.

Environmental Science vs. Environmental Engineering

• Environmental science studies the natural environment and human impacts on it through scientific methods.
• Environmental engineering focuses on designing solutions to environmental problems through engineering.

Key Environmental Components

• Atmosphere
• Biosphere
• Hydrosphere
• Lithosphere

Environmental Quality

• A measure of the condition of the environment and its impact on humans and other organisms.
• Quality of the environment that is conducive for healthy living.

Environmental Quality Standards

• Allowable levels of pollution for air, water, soil, and noise.
• International Standards (WHO, UNEP).
• European Standards.
• Asian Standards.
• Philippines Standards.

Philippine Standards

• Sanitary Engineering Law (RA 1364).
• Code on Sanitation of the Philippines (PD 856).
• Philippine Clean Air Act of 1999.
• Philippine Clean Water Act of 2004.

Air Quality Index

The Air Quality Index (AQI) is used to communicate air quality. Different AQI levels are associated with different descriptions of air quality and health recommendations.

Water Quality Standards

• Drinking water.
• Water for fish habitats.
• Water for industry.
• Water for recreation (boating, swimming).
• Wastewater.

Why Quality Standards are Needed

• The importance of having quality standards is emphasized.

Steps in Addressing Environmental Problems

• Scientific assessment
• Risk analysis
• Public engagement
• Political considerations
• Long-term environmental management

Ecology Concepts and Principles

• Ecology is the study of the relationships between living organisms, including humans, and their physical environment.
• The term "ecology" comes from the Greek word "oikos," meaning household or house, translated to the Latin word "oeco."

Ecosystem Components

• Biotic: Living things (animals, plants, microorganisms, bacteria, protists, fungus)
• Abiotic: Non-living things (air, light, minerals, soil, water)

Ecological Factors

1. Physical and Chemical:
   • Air/Wind
   • Water/Moisture
   • Energy/Sunlight/Solar Radiation/Heat/Climate
   • Soil/Minerals/Nutrients
2. Biological:
   • Producers
   • Consumers (Herbivores, Carnivores, Omnivores)
   • Decomposers (Microorganisms)

Ecological Processes in an Ecosystem

1. Physical and Chemical:
   • Biogeochemical cycles (Water Cycle, Carbon-Oxygen Cycle, Nitrogen Cycle, Phosphorus Cycle, Sulfur Cycle)
   • Flow and transfer of energy
2. Biological:
   • Growth and reproduction
   • Photosynthesis
   • Respiration/Excretion
   • Decomposition

Levels of Organization

• Individual
• Population
• Community
• Ecosystem
• Biome
• Biosphere

Individual/Organism

• Simplest level of organization; an individual animal, plant, or single-celled life form.
• Habitat - dwelling of organisms
• Niche - role of an organism

Population

• Group of individuals of the same species living and interbreeding within a given area.
• Rely on same resources

Community

• All populations that live in a particular area (consists of different species).
• A group that potentially interacts or lives in the same location.

Ecosystem

• Composed of several communities.
• Combination of abiotic and biotic factors.

Structure of Ecosystem

• Abiotic Factors
• Biotic Factors
  • Producers
  • Consumers
    • Primary (Herbivores)
    • Secondary Carnivores)
    • Tertiary Carnivores)
  • Decomposers

Types of Ecosystem

Natural

• Terrestrial
  • Forest
  • Grassland
  • Desert
• Aquatic
  • Freshwater
    • Lotic (River, stream, or spring)
    • Lentic (Lake, pond, or swamp)
  • Marine

Artificial/Man-Made

Biomes

• Large geographic area with similar climates and ecosystems.
• Can be classified into three types:
  • Terrestrial
  • Freshwater
  • Marine

Types of Biome

The biomes are ordered from hot to cold and from wet to dry.

• Tundra
• Polar Region
• Coniferous Forest (Boreal Forest)
• Subpolar
• Deciduous Forest
• Chaparral
• Grassland
• Desert
• Temperate
• Rainforest
• Tropical Seasonal Forest
• Scrubland
• Savanna
• Desert
• Tropical

Tropical Rainforest

• Temperature ranges from 17^\circ C to 25^\circ C. Located in tropical regions outside the equator.
• Climate remains warm and wet.
• Soils rich in nutrients.
• Tall trees

Temperate Forest

• Temperature ranges from -30^\circ C to 30^\circ C.
• Located in mid-latitude regions, between Artic poles and the tropics.
• Undergo distinct seasonal changes: Spring, Summer, Autumn, Winter
• Includes birch and oaks.

Desert

• Temperature ranges from 45^\circ C to 50^\circ C, cold desert can drop to less than -30^\circ C.
• Located in both sub-tropical and polar regions.
• Vegetation in deserts is sparse.
• Animal biodiversity in deserts is limited.

Tundra

• Temperature ranges from -34^\circ C to 3^\circ C.
• Primarily found in Polar Regions.
• Vegetation mainly comprises low shrubs, herbs, and mosses.
• Animal biodiversity is low.

Taiga

• Temperature ranges from -5^\circ C to 5^\circ C.
• Primarily found in Polar Regions.
• Vegetation: Cone-bearing trees, needle-shaped leaves, scaly-leaved trees.
• Animal: Owls, Moose, Bear.

Biosphere

• Made up of the parts of Earth where life exists - all ecosystems.
• Surface of the earth.

Ecosystem and Human Health

• Ecosystem
  • Biotic
  • Abiotic
• Environmental modifications
• Ecosystem Service
  • Provisioning
  • Regulating
  • Supporting
  • Cultural
• Human Activities
• Human Health

Ecology Concepts and Principles Part 2

Energy Flow

• In an ecosystem, energy comes from the sun.
• Energy flows through Ecosystems from producers to consumers.

Producers

• Make their own food using sunlight
• Autotrophs (plants, algae, etc.)
• Contain chlorophyll
• Can produce its own food supply

Consumers

• Organisms that eat producers or other consumers
• Heterotrophs
• Consumers have to eat to gain energy

Niche of a Producer

• Captures energy and transforms it into organic, stored energy for the use of living organisms
• Can be photoautotrophs (uses light energy such as plant)
• Can be chemoautotrophs (uses chemical energy like nitrosomas “Nitrosomonas and Nitrobacter species are generally used to transform ammonia initially to nitrite and finally to nitrate.”

Photoautotrophs

• Captures energy from the sun by photosynthesis
• Adds oxygen to the atmosphere and removes carbon dioxide from the atmosphere

Chemoautotrophs

• Capture energy from the bonds of inorganic molecules such as Hydrogen Sulfide
• Process is called Chemosynthesis
• Often occurs in deep-sea vents

Types of Consumer

• Herbivores: Eat ONLY Plants
• Carnivores: Eat ONLY other Animals
• Omnivores: Eat Plants and Animals
• Detritivores (Scavengers): Feed on Dead Plant and Animal Remains
• Decomposers: Fungi and Bacteria

Feeding Relationships

Food Chain

• Simple energy path through an ecosystem
• Straight and single pathway for the flow of energy in an ecosystem, through different species of organisms

Food Web

• More realistic path through an ecosystem made of many food chains
• Convoluted or complicated pathway of an ecosystem consist of numerous food chains of the different trophic levels, through which the energy flow

Trophic Levels

• Producers: Always the First Trophic Level - How ENERGY enters the system
• Herbivores: Second Trophic Level
• Carnivores/Omnivores: Make up the remaining trophic levels
• Each level depends on the one below it for energy

Ecological Pyramids

• Graphic representations of the relative amounts of energy or matter at each trophic level
• Energy Pyramid
• Biomass Pyramid
• Pyramid of Numbers

Energy Pyramid

• The energy pyramid illustrates the energy transfer between trophic levels, with energy being "lost" at each transfer.

Interactions and Relationships

• Abiotic and Biotic Interactions

Types of Interactions and Relationships

• Competition (- , -)
• Predation (+ , -)
• Commensalism (0 , +)
• Amensalism (0 , -)
• Parasitism (- , +)
• Mutualism (+, +)

Competition

• Interspecific competition occurs when two or more species compete for a limited resource.
• Intraspecific competition happens when individuals of the same species compete

Predation

• One organism kills and consumes another (beneficial to predator, harmful to prey)
• Predator - organism that does the killing and eating
• Prey - Organism that is being killed and eaten

Commensalism

• One (the commensal organism) benefits from the relationship while the other is unaffected and neither benefits nor is harmed

Amensalism

• The relationship between two organisms, where one is hurt, the other one is unaffected
• Ex: Invasive species

Parasitism

• Relationship between two species of plants or animals in which one benefits at the expense of the other, sometimes without killing the host organism
• Host and Parasite

Mutualism

• Relationship in which both species benefit from each other
• Flower and Bees - Flower need bees for pollination, bees need flowers nectar

Biological Evolution

• Mutation - chemical change in a DNA molecule due to radiation, exposure to toxic, error in DNA
• Natural selection - organisms with better characteristics tend to adapt to environmental challenges and survive several generations
• Migration - movement of an organism or population from one habitat to another

Biological Diversity (Biodiversity)

• Genetic diversity - total number of genetic characteristics of a specific species, subspecies, or group of species
• Species diversity - ecosystem possesses differences in species in terms of genetic variation and distribution
• Habitat diversity - total number of kinds of habitats or ecosystems in a given unit area

Extinction of Species

• The complete disappearance of a species from Earth
• Caused by both natural and unnatural events
• If over an extended period of time, the birth rate of a species is less than the death rate, then extinction will eventually occur
• Species go extinct if it is not able to adapt to changes in its environment, or compete effectively with other organisms

Categories of Extinction of Species

• Extinct - No known individuals remaining
• Extinct in the wild - Known only to survive in captivity, or as a naturalized population outside its historic range
• Critically endangered - Extremely high risk of extinction in the wild
• Endangered - High risk of extinction in the wild
• Vulnerable - High risk of endangerment in the wild
• Near threatened - Likely to become endangered in the near future

Levels of Extinction

• Local Extinction - when a species is no longer found in an area it once inhabited but is still found elsewhere in the world
• Ecological Extinction - where there are so few members of a species left that it can no longer play its ecological roles in the biological communities where it is found
• Biological Extinction - occur when a species is no longer found anywhere on the earth. Biological extinction is FOREVER!

Causes of Extinction

• Natural
  • Climate Change
  • Radiation
  • Disease/epidemics
  • Invasive species
  • Predation/competition
  • Volcanic eruption
  • Asteroid
• Man-made
  • Destruction/Fragmentation of habitat
  • Environmental pollution
  • Poaching/hunting

Ecology Concepts and Principles Part 3

Population Dynamics

• "the study of how populations of organisms change over time, including factors such as birth rates, death rates, and migration"

Characteristics of a Population

• Population - individuals or organisms inhabiting the same area at the same time
• Population Dynamics:
  • Population Size - no. of individual or organisms
  • Population Density - population size in a certain space at a given time
  • Population Dispersion - spatial pattern in habitat
  • Age Structure - proportion of individuals or organisms in each age group in population

Population Size

• Natality (Birth)
  • Number of individuals added through reproduction
  • Crude Birth Rate - Births per 1000
  • Total Fertility Rate - Average number of children/organisms born alive per woman
• Mortality (Death)
  • Number of individuals/organisms removed through death
  • Crude Death Rate - Deaths per 1000

Population Growth

• Population growth depends upon
  • birth rates
  • death rates
  • immigration rates (into area)
  • emigration rates (exit area)
• Pop = Pop_0 + (b + i) - (d + e)
• ZPG (b + i) = (d + e)

Exponential Growth

• J-shaped curve
• Growth is independent of population density
• Assume unlimited resources

Logistic Growth

• S-shaped curve
• Growth is dependent on population density
• Competition of resources

Population Density

• Amount of individuals in a population per unit habitat area
• High density - large number of people or things in a given space
• Low density - small population size and distance from urban areas
• Density depends on social/population structure mating relationships time of year

Classification of Population Dispersion

• Clumped - individuals are lumped together
• Uniform - organisms are regularly spaced in the environment
• Random - organisms randomly dispersed in the environment

Biotic Potential vs. Environmental Resistance

• Biotic potential is the number of offspring of an individual organism that would survive to reproduce age under ideal conditions
• Environmental resistance is the resistance by the environmental conditions to limit a species from growing out of control or to stop them from producing at maximum rate.

Biotic Potential

• Reproductive rate
• Ability to migrate
• Ability to invade new habitats
• Defense mechanism
• Ability to cope with adverse

Environmental Resistance

• Lack of food or nutrients
• Lack of water
• Lack of suitable habitat
• Adverse weather conditions
• Predators
• Disease

Carrying Capacity (K)

• The maximum number of organisms a habitat can support over a given period of time due to environmental resistance
• The maximum population size of the species that the environment can sustain indefinitely

Reproductive Strategies

• Goal of every species is to produce as many offspring as possible
• Each individual has a limited amount of energy to put towards life and reproduction
• This leads to a trade-off of long life or high reproductive rate
• Natural selection has lead to two strategies: r-strategies and k-strategies

K-Strategies vs. R-Strategies

• Surface area to volume ratio
  • K-strategist: Small size, large, surface area to volume ratio
  • r-strategist: Large size, small surface area to volume ratio
• Cell volume
• Growth rate

Bacteria

• Depicts components of bacterial cell anatomy, including the capsule, cell wall, and flagellum

Habitat of Bacteria

• Aerobes: air or oxygen is present
• Anaerobes: air or oxygen is absent
• Facultative: with air or no air
• Mesophiles: areas where the temp. is 37^\circ C
• Extremophiles: extreme environment

Types of Extremophiles

• Halophiles - salty environment
• Acidophiles - acidic as pH 0
• Alkaliphiles - alkiline as pH 10.5
• Psychrophiles - in cold temperature
• Thermophiles - temp up to 75 - 80 C
• Hyperthermophiles - temperatures up to 113 C

Role of Bacteria

• Decomposition (release of nutrients back to the environment)
• Biogeochemical cycle (e.g. nitrogen fixation in nitrogen cycle)
• Precipitation (ice-forming bacteria in the clouds)
• Mineralization (e.g. phosphates to phosphorus)
• Food technology (e.g. cheese manufacturing)
• Industry (e.g. pharmacology, wastewater treatment)

Growth of Microbes

• Increase in the number of cells, not cell size
• One cell becomes a colony of millions of cells
• Control of growth is important for
  • infection control
  • growth of industrial and biotech organisms

Factors of Regulating Growth

• Nutrients
• Environmental conditions
  • Temperature
  • pH
  • Osmotic pressure
• Generation time

Factors of Regulating Growth

• Lag phase - making new enzymes in response to new medium
• Log phase - exponential growth
• Desired for the production of products
• Stationary phase - nutrients becoming limiting or waste products becoming toxic death rate = division rate
• Death phase - death exceeds division

Standard Growth Curve

• Illustrates lag phase, exponential phase, stationary phase, and death phase.

ENVIRONMENTAL CHEMISTRY

Definition of Environmental Chemistry

• Environmental chemistry research focuses on chemical processes that affect the sources, composition, reactions, transport, and fates of chemical species in natural environments (air, water, and soil), the impacts of human activities on these environments, and chemical aspects of pollution prevention and contaminant remediation
• An interdisciplinary science that includes atmospheric, aquatic, and soil chemistry

Environmental Chemistry Coverage

• Heavy metal contamination of land by industry, which can then be transported into water bodies and be taken up by living organisms
• PAHs (polycyclic Aromatic Hydrocarbons) in large bodies of water contaminated by oil spills or leaks. Many of the PAHs are carcinogens and are extremely toxic. They are regulated by concentration (ppb) using environmental chemistry and chromatography laboratory testing
• Nutrients leaching from agricultural land into water courses, which can lead to algal blooms and eutrophication
• Urban runoff of pollutants washing off impervious surfaces (roads, parking lots, and rooftops) during rainstorms. Typical pollutants include gasoline, motor oil and other hydrocarbon compounds, metals, nutrients, and sediment (soil)
• Organometallic compound

Characteristics of Heavy Metals

• Some lighter metals and metalloids are dangerous because of their toxicity and, thus, are termed heavy metals, though some heavy metals, such as gold, typically are not toxic.
• Most heavy metals have a high atomic number and atomic weight, and a specific gravity greater than 5.0.
• Heavy metals include some metalloids, transition metals, basic metals, lanthanides, and actinides.

Examples of Heavy Metals

• Titanium
• Manganese
• Iron
• Cobalt
• Nickel
• Copper
• Zinc
• Gallium
• Arsenic
• Arsenic
• Technetium
• Ruthenium
• Rhodium
• Palladium
• Silver
• Cadmium
• Indium
• Tin

Organometallic Compounds

• The bond between the metal and the carbon atom is often highly covalent in nature.
• Most of the organometallic compounds exist in solid states, especially the compounds in which the hydrocarbon groups are aromatic or have a ring structure.
• The compounds consisting of highly electropositive metals such as sodium or lithium are very volatile and can undergo spontaneous combustion.

Emerging Pollutants

• Chemical or biological contaminants, commonly not regulated
• Can be detected by analytical techniques in low concentrations
• Its long-term adverse effects on health and the environment remain unknown, not well-studied, not fully understood, or with very little information

Group of EPs

• Biological toxins (chloropicrin, microcystins)
• Disinfectants, biocides (triclosan)
• Food additives (sucralose, triacetin)
• Gasoline additives (dialkyl ethers)
• Illicit drugs (morphine, cocaine)
• Pharmaceuticals, antibiotics, veterinary products (Doxycycline, amoxicillin, diazepam)
• Personal care products, cosmetics, sunblockers, B-blockers (metoprolol)
• Pesticides (thiocarbamates)
• Nanomaterials, e-wastes (titanium dioxide)
• Steroids (estradiol, estriol)
• Water disinfection by-products (chloroacetaldehyde)

Top 3 Most Dangerous EPS

• Endocrine-disrupting compounds
• Personal care products
• Residues of pharmaceuticals

Environmental Pathway

• The route that pollutants take through the environment, or the way a person can come into contact with a hazardous substance

Regulated vs. Non-regulated Pollutants

• Regulated pollutant is a substance that is specifically monitored and controlled by environmental laws due to its known harmful effects on human health and the environment
• Non-regulated pollutant is a substance that currently isn't subject to specific regulations potentially because its impacts are less understood or considered less significant at current levels

Regulated Pollutants

• Dioxins (PCDD, PCDF)
• Polyaromatic hydrocarbons (PAHs)
• Polichlorinated Biphenyls (PCBs)
• Chlorinated organic pesticides

Non-Regulated Pollutants

• Bisphenol A
• Steroid sex hormones
• Metal complexes
• Alkylphenol ethoxylates
• Derivatives of phthalates
• Personal care products (PCP’s)
• Brominated Flame Retardants (BFR’s)
• Nonionic surfactants
• Pharmaceuticals’ residues
• Gasoline additives

Effects on Health and Environment

• EFFECTS ON HUMANS: No studies have shown a direct impact on human health. However, the absence of empirical data cannot rule out the possibility of adverse outcomes due to interactions or long- term exposures to these substances.
• EFFECTS ON ENVIRONMENT: While the full effects on the environment are not understood, there is concern about the potential they have for harm because they may act unpredictably when mixed with other chemicals from the environment or concentrate in the food chain.
• EFFECTS ON FISHES: Numerous studies have shown that estrogen and chemicals that behave like it have a feminizing effect on male fish and can alter female-to-male ratios. Other research has uncovered popular antidepressant medication concentrated in the brain of the fishes from water waste treatment plants

Application in Environmental Engineering

• In designing technologies that use chemicals for treating or removing microbial hazards
• In designing technologies that can remove or treat toxic and hazardous chemicals

Measurement of Concentration

Table 2.1 Common Units of Concentration Used in Environmental Measurements

Example 2.1 Concentration in Soil

A 1 kg sample of soil is analyzed for the chemical solvent trichloroethylene (TCE). The analysis indicates that the sample contains 5.0 mg of TCE. What is the TCE concentration in ppm and ppbm?

Solution

[TCE] = \frac{5.0 \text{ mg TCE}}{1.0 \text{ kg soil}} = \frac{0.005 \text{ g TCE}}{10^3 \text{ g soil}} = \frac{5 \times 10^{-6} \text{ g TCE}}{\text{g soil}} \times 10^6 = 5 \text{ ppmm} = 5,000 \text{ ppbm}

Note that in soil and sediments, mg/kg equals ppm, and μg/kg equals ppbm.

Example 2.2 Concentration in Water

One liter of water is analyzed and found to contain 5.0 mg of TCE. What is the TCE concentration in mg/L and ppmm?

Solution

[TCE] = \frac{5.0 \text{ mg TCE}}{1.0 \text{ L H}_2\text{O}} = 5.0 \frac{\text{mg}}{\text{L}}

To convert to ppmm, a mass/mass unit, it is necessary to convert the volume of water to the mass of water. To do this, divide by the density of water, which is approximately 1,000 g/L:

[TCE] = \frac{5.0 \text{ mg TCE}}{1.0 \text{ L H}2\text{O}} \times \frac{1.0 \text{ L H}2\text{O}}{1,000 \text{ g total}} = \frac{5.0 \text{ mg TCE}}{1,000 \text{ g H}_2\text{O}} = \frac{5.0 \times 10^{-6} \text{ g TCE}}{\text{g total}} \times 10^6 \text{ ppmm} = 5.0 \text{ ppmm}

Example 2.3 Concentration in Air

What is the carbon monoxide (CO) concentration expressed in μg/m³ of a 10 L gas mixture that contains 1.0 \times 10^{-3} mole of CO?

Solution

In this case, the measured quantities are presented in units of moles of the chemical per total volume. To convert to mass of the chemical per total volume, convert the moles of chemical to mass of chemical by multiplying moles by CO's molecular weight. The molecular weight of CO (28 g/mole) is equal to 12 (atomic weight of C) plus 16 (atomic weight of O).

[CO] = \frac{1.0 \times 10^{-3} \text{ mole CO}}{10 \text{ L total}} \times \frac{28 \text{ g CO}}{\text{mole CO}} = \frac{28 \times 10^{-3} \text{ g CO}}{10 \text{ L total}} \times \frac{10^6 \mu \text{g}}{g} \times \frac{10^3 \text{ L}}{m^3} = 2,800 \frac{\mu \text{g}}{m^3}

ENVIRONMENTAL MICROBIOLOGY

Definition of Environmental Microbiology

• The study of microbial processes in the environment, microbial communities and microbial interactions
• Also called microbial ecology - the ecology of microorganisms, their relationship with one another and with their environment

Environmental Chemistry Coverage

• Structure and activities of microbial communities
• Microbial interactions and interactions with macroorganisms
• Population biology of microorganisms
• Microbes and surfaces (adhesion and biofilm formation)
• Microbial community genetics and evolutionary processes
• (Global) element cycles and biogeochemical processes
• Microbial life in extreme and unusual little-explored environments

Types of Microorganisms

• Bacteria
• Archaea
• Fungi
• Protozoa
• Viruses

Bacteria

• Bacteria are classified as prokaryotes
• No nucleus
• Cell walls contain peptidoglycan
• Flagella
• Pili

Types of Bacteria

Archaea

• Classified as prokaryotes
• Single-celled microorganisms with structure similar to bacteria
• No nucleus
• Found in extreme environments (e.g. volcanoes)

Fungi

• Classified as eukaryotes
• Except for yeast, most fungi are multicellular creatures
• Can be single- or multi-cellular
• Cell walls contain chitin

Types of Fungi