2. Pollution
โข Pollution is the introduction of contaminants
into the natural environment that cause
adverse change.
โข Pollutants, can take the form of chemical
substances or energy, such as noise, heat or
light.
โข Can be either foreign substances/energies or
naturally occurring contaminants.
3. Forms of Pollution
1. Air pollution:- the release of
chemicals and particulates into
the atmosphere. Common
gaseous pollutants; carbon
monoxide, sulfur dioxide,
chlorofluorocarbons (CFCs) and
nitrogen oxides produced by
industry and motor vehicles.
Particulate matter, or fine dust is
characterized by their micrometre
size.
4. Forms of Pollution
2. Light pollution:- includes
light trespass, over-
illumination and
astronomical interference.
3. Littering:- the criminal
throwing of inappropriate
man-made objects,
unremoved, onto public
and private properties.
5. Forms of Pollution
4. Noise pollution:- which encompasses
roadway noise, aircraft noise, industrial noise
as well as high-intensity sonar.
5.Soil contamination occurs when chemicals are
released by spill or underground leakage.
Among the most significant soil contaminants
are hydrocarbons, heavy metals, herbicides,
pesticides etc.
6. Forms of Pollution
6. Radioactive contamination, resulting from 20th
century activities in atomic physics, such as
nuclear power generation and nuclear weapons
research, manufacture and deployment. (See
alpha emitters and actinides in the environment.)
7. Thermal pollution, is a temperature change in
natural water bodies caused by human influence,
such as use of water as coolant in a power plant.
7. Forms of Pollution
8. Visual pollution, which
can refer to the presence
of overhead power lines,
motorway billboards,
scarred landforms (as
from strip mining), open
storage of trash,
municipal solid waste or
space debris.
8. Forms of Pollution
9. Water pollution, by the discharge of
โข wastewater from commercial and industrial waste;
โข Domestic sewage, and
โข Chemical contaminants, such as chlorine, from treated
sewage;
โข Waste and contaminants into surface runoff flowing to
surface waters (including urban runoff and agricultural
runoff, which may contain chemical fertilizers and
pesticides); waste disposal and leaching into
groundwater; eutrophication and littering.
17. Biodegradation
โข Degradation of pollutants by microbes by
using the materials as energy sources.
โข Biodegradable simply means to be consumed
by microorganisms and return to compounds
found in nature.
19. Biodegradation
โข Bioremediation associated with
environmentally friendly products that are
capable of decomposing back into natural
elements.
โข Biosurfactant, an extracellular surfactant
secreted by microorganisms, enhances the
biodegradation process.
20. Biodegradation
โข Some microorganisms have a naturally occurring,
microbial catabolic diversity to degrade,
transform or accumulate a huge range of
compounds.
โข Including hydrocarbons (e.g. oil), polychlorinated
biphenyls (PCBs), polyaromatic hydrocarbons
(PAHs), pharmaceutical substances,
radionuclides, pesticides, and metals.
Decomposition of biodegradable substances may
include both biological and abiotic steps.
21. Bioremediation
โข In situ bioremediation involves treating the
contaminated material at the site, while ex
situ involves the removal of the contaminated
material to be treated elsewhere.
โข Some examples of bioremediation related
technologies are phytoremediation,
bioventing, bioleaching, landfarming,
bioreactor, composting, bioaugmentation,
rhizofiltration, and biostimulation.
22. Bioremediation
โข Bioremediation can occur on its own or can be
spurred on via the addition of fertilizers
(biostimulation) to increase the bioavailability
within the medium.
โข Addition of matched microbe strains to the
medium to enhance the resident microbe
population's ability to break down contaminants.
โข Microorganisms used to perform the function of
bioremediation are known as bioremediators.
23.
24. Bioremediation
โข However, not all contaminants are easily treated
by bioremediation
โข Heavy metals such as cadmium and lead are not
readily absorbed or captured by microorganisms.
โข A recent experiment, however, suggests that fish
bones have some success absorbing lead from
contaminated soil.
โข Bone char has been shown to bioremediate small
amounts of Cadmium, Copper, and Zinc.
โข The assimilation of metals such as mercury into
the food chain may worsen matters.
25. Bioremediation
โข Phytoremediation is useful in these
circumstances because natural plants or
transgenic plants are able to bioaccumulate
these toxins in their above-ground parts,
which are then harvested for removal.
โข The heavy metals in the harvested biomass
may be further concentrated by incineration
or even recycled for industrial use.
26. โข Interest in the microbial biodegradation of pollutants has
intensified in recent years as humanity strives to find
sustainable ways to clean up contaminated environments
โข These bioremediation and biotransformation methods
endeavour to harness the astonishing, naturally occurring
ability of microbial xenobiotic metabolism to degrade,
transform or accumulate a huge range of compounds.
โข Including hydrocarbons (e.g. oil), polychlorinated biphenyls
(PCBs), polyaromatic hydrocarbons (PAHs), heterocyclic
compounds (such as pyridine or quinoline), pharmaceutical
substances, radionuclides and metals
Bioremediation
27. Oil biodegradation
โข Petroleum oil contains aromatic compounds that
are toxic for most life forms. Episodic and chronic
pollution of the environment by oil causes major
ecological perturbations.
โข Marine environments are especially vulnerable
since oil spills of coastal regions and the open sea
are poorly containable and mitigation is difficult.
โข In addition to pollution through human activities,
about 250 million liters of petroleum enter the
marine environment every year from natural
seepages.[9]
28.
29. Oil biodegradation
โข Despite its toxicity, a considerable fraction of
petroleum oil entering marine systems is eliminated by
the hydrocarbon-degrading activities of microbial
communities, in particular by a remarkable recently
discovered group of specialists, the so-called
hydrocarbonoclastic bacteria (HCB).
โข Alcanivorax borkumensis was the first HCB to have its
genome sequenced.[11]
โข Crude oil often contains various heterocyclic
compounds, such as pyridine, which appear to be
degraded by similar, though separate mechanisms than
hydrocarbons.[12]
