Hazardous Waste/ BioremediationAP Environmental Science
Hazardous Waste Defined Hazardous waste is a
waste with properties that make it dangerous or potentially harmful to human health or the environment.
Forms of Hazardous Waste Liquids Solids Contained gases Sludges.
The EPA has a list of more than 500 specific hazardous wastes
Characteristics of Hazardous Contains one or more of 39 carcinogenic, mutagenic,
or teratogenic compounds at levels that exceed established limits
Ignitability – Create fires under certain conditions, are spontaneously combustible, or have a flash point less than 60 °C (140 °F). waste oils and used solvents.
Corrosivity – Acids or bases (pH less than or equal to 2, or greater than or equal to 12.5) capable of corroding metal containers. Battery acid is an example.
Continued Reactivity – Unstable under "normal"
conditions, can cause explosions, toxic fumes, gases, or vapors when heated, compressed, or mixed with water. lithium-sulfur batteries and explosives.
Toxicity – Harmful or fatal when ingested or absorbed, this is the issue with leachate
Hazardous Landfill Construction
Hazardous Waste is Listed The F-list (non-specific source wastes). This list
identifies wastes from common manufacturing and industrial processes, such as solvents that have been used in cleaning or degreasing operations. F-listed wastes are known as wastes from non-specific sources.
The K-list (source-specific wastes). This list includes certain wastes from specific industries, such as petroleum refining or pesticide manufacturing. Certain sludges and wastewaters from treatment and production processes in these industries are examples of source-specific wastes.
Listed
The P-list and the U-list (discarded commercial chemical products). These lists include specific commercial chemical products in an unused form. Some pesticides and some pharmaceutical products become hazardous waste when discarded.
BioremediationWhen we have to pull in the little guys to help
2011
Bioremediation the use of microbes to
enhance the elimination of toxic compounds in the environment.
Strategies for bioremediation Using native
(indigenous) microbes Improving microbes
living conditions Adding selected
microbes
Indigenous Microbes There are many naturally occurring microbes
that occur in the environment that will decompose (eat) small amounts of toxin over long periods of time. This works at a very, very slow rate
Improving living condition People can add water
and oxygen to the environment to speed up the growth rate of the microbes. Also by adding additional chemical such as fertilizers.
Adding more and different microbes Adding additional non-
native microbes can help degrade the toxins
Oil Spills
What microbes to use Toxins come in 2 categories
Organic Inorganic
The type of toxin determines how and what microbes can be used
Top 10 contaminants
Lead Trichloroethylene Toulene Benzene PCB’s
Chloroform Phenol Arsenic Cadmium Chromium
Anarerobic tolulene degrader
Azoarcus tolulyticus
(dividing in photo)•Found in a gasoline contaminated aquifer•Tolulene is one of the most toxic components of gasoline•Important find because it is anaerobic and can work in an underground environment.
Biodegradation
Using living organisms to breakdown organic compounds
2,4-D=Weed B Gone--Herbicides
Oil
PCB”s—insulator coolants in electric power plant transformers
DDT—pesticide
Plastic
Detergents
2,4-D
RoundUp,glyphosphate
Three main microbes
Alclegenes eutrohus
Burkholderia cepia
Halomonas
Most widely used herbicide in the US. Between 54-60 million pounds annually
Can be degraded in 2 weeks in agricultural soils
Inorganic Waste
Inorganic wastes contain no Carbon, include heave metals
Although found in nature humans are responsible for accumulating them into abnormally found amounts
Mercury—in batteries
Nitrite—fertilizer runoff
Selenium, Arsenic
Uranium
Acid mine drainage
Bacterial communities
Communities of bacteria can handle even nuclear wasteHighly contaminated waste sites have found bacteria eating the uranium and breaking it down to less water soluble compounds
Acid mine drainage
Using microbial communities to clean the heavy metals
Hazardous waste are creating new fields of study Microbial technology
Limiting factors for critical processes & significant organisms
Identification of key biotic interaction Structure and function of food webs
Environmental biotechnology Cleaning effluents of treatment waste Alternative and ecofriendly processes Alternative and ecofriendly products