4 Risk Management Of Land Contamination Flashcards
What is bioremediation (2)
Adding microorganisms to soil
To remove contaminants
What does bioremediation treat (5)
Oil spills
Chlorinated pesticides
Heavy metals
Diesel
PCBs
What does Pseudomonas Putida treat
Organic solvents
What does Pseudomonas aeruginosa treat
Oil contamination
What does Dehalococcoides ethenogenes treat
Halogenated hydrocarbons
Economic benefits of bioremediation (3)
Clean up time is reduced
Doesn’t require large energy input
Can be carried out in atmospheric conditions
Environmental benefits of bioremediation (compared to traditional methods) (4)
Carried out in situ
Contaminants reduced to almost zero
By products are not toxic
Bacteria used are naturally occurring- no ecosystem damage
Characteristics of traditional treatment of contaminated land (5)
Expensive (energy)
GHG produced
Soil may need treated ex situ : more machinery, labour required
Toxic by products
Soil may need disposed of; landfill
What is the role of / why are GE bacteria used in bioremediation (3)
Decontaminate quicker
Tolerate harsher conditions
Remove toxic materials (that normal bacteria can’t)
Issues with using GE microorganisms (3)
They may;
Affect soil ecology - unknown consequences
Wipe out existing bacteria
Behave differently in field compared to in lab
Explain the use of in situ bioreactor systems to treat small to medium scale amounts of contaminated soil
(Why, How)
Bioreactors are used because they can control the temperature, pH, aeration and stirring conditions
The contents are mixed so pollutants, water, air, nutrients and microorganisms are in permanent contact
Describe how plants can be used to decontaminate industrial pollution of soil
Name the process
Plants called hyperaccumulators (because they can accumulate way more than they need) absorb contaminants from the soil and stores them in the stem and leaves
Phytoremediation
Name pollutants plants can decontaminate (6)
Copper
Cadmium
Strontium
Rubidium
Arsenic
Antimony
Advantages of using alpine penny grass and Indian mustard in decontamination of soil (5)
Hyper accumulator - can hold more nutrient/contaminant than it needs
Stores contaminants in stem or leaves
Can treat more than one pollutant at a time
Materials can be reused
Costs less than traditional methods
Limits of using alpine penny grass and Indian mustard for decontamination of the soil (4)
Takes several crop cycles
Need harvested
Limited to surface area and depth of roots
Contaminated plants are a risk to food chain
