Green Chemistry: is the creation of greener chemical products and processes that eliminate and reduce harmful wastes in the environment.
Principles of Green Chemistry:
1. Maximize Atom Economy: Synthesize the chemical so that few or no atoms are wasted.
2. Use Safer Solvents and Reaction Conditions: Use solvents that are safe if you have the opportunity.
3. Avoid Chemical Derivatives: Avoid using blocking agents because they can harmful chemical waste.
Presidential Green Chemistry Challenge:
Promotes both the economic and environmental benefits of applying and using Green Chemistry. It awards and recognizes innovators of this new application.
Pollution Prevention Act: In 1990, the EPA passed the PPA to prevent and reduce pollution in the environment. This act opened the door to create new opportunities to clean up and create way to eliminate the pollution that we have generated over the years.
Distribution of Water on Earth:
Saltwater in Oceans and Seas: 97.4%
Ice caps and Glaciers: 1.98%
Soil Moisture: 0.005%
Atmosphere, rivers, plants, animals: 0.001%
Composition of Natural and Seawater:
Aquifers and Groundwater: Ogallala Aquifer > major source
Unusual Properties of Water:
High boiling point > due to hydrogen bonding
High melting point
Density in its solid form is a lot lower than its liquid counterpart, due to the ring shape water makes when it becomes solid
High heat capacity
High heat of vaporization
High surface tension
Water Management and Conservation:
Farmers could avoid their use of water substantially by lining irrigation canals with plastic to reduce loss by seepage and by burying pipes to irrigate from below ground
Toilets waste water with constant flushing but can be replaced by using a much more water-saving model
Can also save water by switching to a water–saving showerhead
Different types of water pollutants:
Disease Causing Agents
Disease outbreaks occur if feces from people infected with pathogens contaminate water supplies.
Diseases that are transmitted when people drink contaminated water include: i. Typhoid fever ii. Cholera iii. Dysentery iv. Infectious hepatitis
v. Polio If coliform bacteria is not found in the water supply, then it can be said there is no feces contamination and no pathogens.
Oxygen-Consuming Waste Dissolved oxygen in lakes and rivers are rapidly depleted if organic waste materials are released into the water
OCW are human and animal feces and industrial wastes from paper mills, tanneries, and food-processing plants.
Aerobic bacteria Eutrophication
Excessive algae growth due to increased amounts of nitrates and phosphates in non-moving water.
Main cause: domestic sewage
Can disrupt the aquatic ecosystem in those waters
If we reduce the amount of phosphates that enter the water then the nitrogen will not cause the sudden algae bloom.
Dissolved Solids and Toxic substances
If water contains over 500 ppm of such slats, the US Public Health Service does not recommend it for drinking
Bioaccumulation: increase concentration in toxic substances in water
Useful measure of toxic pollution in water
Can disrupt the aquatic food chain and cause serious damage
Toxic metals: Cadmium, mercury, lead
Synthetic Organic Chemicals:
Rise in water temperature can seriously affect the surrounding aquatic life by increasing the body temperature of the organisms living in the water.
Can also decrease the solubility of oxygen and decrease the dissolved oxygen content.
1. Primary Treatment:
Screens used to remove large pieces of debris
Sedimentation tank- produces sludge
Calcium hydroxide and aluminum