Biocatalysis & Bioremediation Notes

Bioremediation is the use of biological agents to remove or neutralize pollutants from contaminated soil, water, and air.
Contamination overview, types of contaminants, technologies, and the definition, advantages, and disadvantages of bioremediation will be explored.

Air pollution is the contamination of indoor or outdoor environments by chemical, physical, or biological agents, modifying the atmosphere's natural characteristics.
The World Health Organization (WHO) reports that indoor and outdoor air pollution causes approximately seven million deaths globally each year.
99% of the global population breathes air exceeding WHO guideline limits, containing high levels of pollutants.
Smog: A mixture of smoke and fog.
Soot: Fine black particles from incomplete combustion.

Mobile sources: Cars, buses, planes, trucks, and trains.
Stationary sources: Power plants, oil refineries, industrial facilities, and factories.
Area sources: Agricultural areas, cities, and wood-burning fireplaces.
Natural sources: Wind-blown dust, wildfires, and volcanoes.

PM: Small liquid or solid particles suspended in the air.
O3: Formed from volatile organic compounds (VOCs) and nitrogen oxides (NOx) in sunlight, a major component of smog.
NO2: Produced by combustion, contributes to acid rain.
SO2: Released from burning coal and oil, contributes to acid rain.
CO: Colorless, odorless gas from incomplete combustion.
VOCs: Organic compounds with high vapor pressure and low water solubility, such as aromatic hydrocarbons (benzene, toluene, xylene, ethyl benzene) and halogenated hydrocarbons (chloroethylene and trichloroethylene).

Water pollution is the contamination of water bodies (lakes, rivers, oceans, and groundwater) from industrial waste, agricultural runoff, sewage discharge, and plastic waste.

Oceans (Saltwater): 97.5%
Freshwater: 2.5%
- Ice caps and glaciers: 79%
- Groundwater: 20%
- Other freshwater sources: 1% (lakes, soil, atmosphere, rivers, living organisms)

Global freshwater withdrawals for agriculture, industry, and domestic uses since 1900 have increased significantly.
Projected global water scarcity indicates the world is set to face a 40% water shortage by 2030.

WS: Water scarcity based on quantity only.
WSq: Water scarcity including both water quantity and water quality.
WSqdesal+wwr: Water scarcity based on both water quantity and quality, including desalination and treated wastewater reuse.

Human wastes: Sewage in cities and rural areas.
Industrial wastes: Chemicals, smoke, exhaust, heat pollution.
Chemical run-off: Pesticides and fertilizers from farms, gas, oil, and salt from roads.
Point sources: Discharged to the environment through pipes, sewers, ditches, etc.
Non-point sources: Discharged over large areas (e.g., farms, lawns).

Pesticides, fertilizers, air pollution (smog, smoke, acid rain), chlorine, fluoride, industry, landfills, nitrates, chemical spills, PCBs/Benzene, toxic waste, leaking gas tanks, municipal treatment, copper & lead pipes, septic systems.
Other sources include atmospheric deposition, commercial and animal fertilizer, fodder, mariculture, sludge, surface run-off, sewage treatment facilities, underground aquifers, plants, algae, drains, groundwater, combustion, landfill, urban run-off, septic tanks, industrial sites, residential areas, and underground storage tanks.

Unintentional or accidental introduction of potentially harmful microorganisms such as bacteria, viruses, and fungi.
COVID-19 in wastewater: SARS-CoV-2 excretion into wastewater allows for wastewater surveillance as an early warning system for community spread.

The global number of oil spills from tankers has generally decreased from 1970 to 2021.
The global quantity of oil spilled from tankers has also decreased between 1970 and 2021.

On March 24, 1989, the Exxon Valdez oil tanker struck Bligh Reef in Alaska’s Prince William Sound region.
Approximately $40878 m^3$ of oil were released, affecting over $2092 km$ of shoreline.
Estimated deaths:
- 250,000 seabirds
- 2,800 sea otters
- 300 harbor seals
- 250 bald eagles
- 22 killer whales
- Billions of salmon and herring eggs
Cleanup efforts included skimming oil, applying dispersants, washing beaches with hot water, and rescuing animals.
Oil can penetrate deeply into beach sediments, making surface visibility an unreliable indicator of total contamination.

Trans-Alaska Pipeline System: An 800-mile-long pipeline from Prudhoe Bay to Valdez.
Crosses over 800 rivers and streams, three mountain ranges, and three major active faults.
Three-quarters traverses fragile permafrost.
Built in a zigzag fashion to accommodate temperature changes and potential earthquakes.
Approximately 500 oil spills occur each year in the Prudhoe Bay oil fields and along the $1280 km$ pipeline.
In March 2006, a corroded pipeline leaked up to $1010 m^3$ of oil over five days.
Shut down a plant processing 100,000 barrels of oil per day (over 10% of the pipeline's daily flow).
Cleanup crews recovered more than $72 m^3$ of leaked crude oil.