Environmental Chemistry Flashcards
What is High-Level Waste?
What is Low-Level Waste?
HLW: gives off large amounts of ionizing radiation for a long time (many radioactive nuclei decay each second to produce ionizing radiation), usually contains isotopes with longer half-lives (ionizing radiation given off for a long time)
kept in storage pools (cooling ponds) under water for 9 months, then stored in dry storage casks OR turned into glass (vitrification)
LLW: gives off small amounts of ionizing radiation for a short time
low activity (not many radioactive nuclei decay/second to produce ionizing radiation, isotopes have short half-lives and ionizing radiation is given off for a shorter period of time)
stored on site until it has decayed , disposed as of ordinary waste
How are solvents assessed for use?
toxicity to workers carcinogenic, or other health issues)
safety of the process (flammable, explosive, toxic byproducts)
harm to the environment (contaminate soil/ground water, cause ozone depletion, contribute to greenhouse gas formation when released or burned)
How does anti-bacterial resistance occur?
superbugs: bacteria that carry several resistant genes, cause infections that are extremely difficult to treat
broad-spectrum antibiotics (used against a wide range of bacteria) have enabled infections to thrive
increased exposure to antibiotic kills off competition, increases prevalence of resistant organisms
What is atom economy?
used as a measure of how efficient a particular reaction is in terms of converting as much of the starting materials as possible into useful products
= (molar mass of desired product/total molar mass of all reactants) x 100%
