Liquid and solid waste Flashcards
how are solid hazardous wastes produced
Can be by-products of manufacturing processes or simply discarded commercial products, such as cleaning fluids or pesticides/ from production of goods & products
what does a Listed solid waste mean?
those associated with various manufacturing and industrial processes & with certain commercial chemical products that have been specifically identified by the EPA as consistently posing a hazard to human health and the environment when discarded
what are solid waste characteristics?
ignitability, corrosivity, reactivity, or toxicity, based on test results or the knowledge of the waste generator.
what are the Resource Conservation and Recovery Act (RCRA) regulations on solid waste handling?
cradle to grave managing system, meaning strict standards are set on anyone who generates, recycles transports, treats, stores, or disposes of hazardous waste. From the time its created, transported, treated, stored, and disposed, it is being regulated.
how are nonhazardous wastes produced?
by homeowners, municipal solid waste
how are nonhazardous wastes handled?
municipal waste landfills, recycling
how are liquid wastes produced
households (wastewater from washing clothes, dishes, showering, or human waste) Commercial establishments (fats, oils, grease from cooking), industries (processing/manufacturing such as car shops), biomedical products
what are the three classifications of liquid wastes
degradable, non degradable, persistent chemicals
what are degradable liquid wastes
domestic (most common)
- Can be degraded or stabilized by bacteria - Industrial facilities with food processing, meatpacking, chemical production, etc.
what are non degradable liquid wastes
contain inorganic substances
- inorganic substances such as salt, lead, mercury, etc.
what are persistent liquid waste chemicals
- Synthetic organic chemicals
- Coal products, DDT
- They can be altered by biological & chemical transformation, but it’s an extremely slow process
what are point sources of pollution
Localized and stationary pollution source, industrial/municipal charges
what are non point sources of pollution
less obvious, more widespread sources of pollution
Ex: liquid run-off from agricultural land, water pollution issues
what did the Water Pollution Control Act of 1948 do, what act did it become known as?
- First major U.S. law to address water pollution
- It was amended in 1972 and become known as the Clean Water Act:
- Makes it illegal to discharge pollutant from a point source without a permit:
- Set new standards for industrial wastewater & contamination levels
- Provided funding for sewage treatment plant construction
- Requires all wastewater-treatment plants in the U.S. to provide primary & secondary treatment
what did the Safe Drinking Act of 1974, 1996 do?
- Set standards for protecting groundwater & safety of public drinking water supply to ensure drinking water safety
- Source water protection, operator protection, funding for water system improvements, & public awareness campaigns
what did the Water Quality Act of 1965 do?
- Required states to issue water quality standards for interstate waters, and authorized the newly created Federal Water Pollution Control Administration to set standards where states failed to do so
- To “restore and maintain the chemical, physical, and biological integrity of the nation’s waters”
primary disposal
Permits the solids within the waste to settle and be removed
- All municipal sewage-treatment processes begin with this stage
Involves holding the sewage in a settling tank to permit the removal of solids by sedimentation
Settling tank: allows suspended particles to settle out of wastewater as it flows slowly through the tank, thereby providing some degree of purification. A layer of accumulated solids (sludge) forms at the top & is periodically removed
secondary aka biological disposal
to enhance the application of the biological processes for oxidizing the organic matter in the waste
- Activated sludge process: an aerobic process designed to stabilize the organic material in sewage accomplished by passing the waste through a large open tank where it is held for several hours and its oxygen content maintained by means of air diffusers. Under these conditions, the microorganisms float as suspended particles. The effluent is then sent to a secondary settling tank, where the microorganisms that have settled to the bottom of the secondary tank are pumped back into the aerated tank to maintain an adequate population for microbial growth. The rest of the growth is treated as biosolids and sent to a digester.
- Another method that combines primary & secondary= waste stabilization pond.
tertiary disposal
Involved a variety of processes tailored to the intended uses of the finished products
- Can involve any steps/processes that are applied after primary and secondary treatment
- Disinfecting sewage chemically (chlorine/ UV radiation)
- Disinfecting sewage physically (applying microfiltration prior to its discharge into a bay, lagoon, river, streams)
- Coagulating waste
what is incineration
burning to reduce waste
what is heat treatment
applying heat at moderate temperatures to reduce contaminants
what is solidification
can melt or vaporize contaminated soil and full range of typical wastes and garbage, producing a glass or sand like residue. Through this process, hazardous and toxic chemicals are reduced to their elemental components
what is a land treatment waste disposal
a disposal process in which solid waste, such as sludge from municipal sewage treatment plants, is applied onto or incorporated into the soil surface. Under proper conditions, microbes occurring naturally in the soil break down or immobilize the hazardous constituents.
what is an underground injection well
Steel and concrete encased shafts placed deep in the ground into which wastes are injected under pressure. Although use in the past on a regular basis, this method is being applied in the U.S. only in the case of oil and has wells that are exempted from hazardous waste regulations
impact of improper waste disposal
If there were no formal methods of disposing of wastes, toxic and infectious material will inevitably cause ill health upon humans, increasing injury and infection (Cholera easiest example)
