The 7 Things I Know About Cyber Security After 25 Years | April 2024
Edsc350 review paper for skype 2
1. THE REMOVAL OF HEAVY METALS BY
MICROORGANISMS: BIOREMEDIATION AT
WORK
A Review Paper submitted by
MARGARET DE GUZMAN
As fulfillment for the requirement in
EDSC 350
(Advance Topics in Biology for Teachers)
4. WASTEWATER TREATMENT
A polluted creek covered with trash in Manila,
Philippines on 01 March 2009. The Department of
Environment and Natural Resources reported in 2008
that the Philippines hosts 50 major polluted rivers,
with a majority of pollutants coming from domestic
waste
6. SOURCES OF HEAVY METALS IN OUR HOMES
HEAVY METAL SOURCES & HOW THEY AFFECT US
7. HEAVY METALS
• chemical elements with a specific
gravity that is at least 5 times the
specific gravity of water. The
specific gravity of water is 1 at
4°C (39°F).
• Some well-known toxic metallic
elements with a specific gravity
that is 5 or more times that of
water are arsenic, 5.7; cadmium,
8.65; iron, 7.9; lead, 11.34; and
mercury, 13.546 (Lide 1992).
8. The main threats to human health from
heavy metals are associated with
exposure to lead, cadmium, mercury
and arsenic (Järup 2003).
Causes and toxicity of heavy metal
contaminants
9. HEAVY METAL TOXICITY IS ONE OF THE MAJOR CURRENT ENVIRONMENT HEALTH
PROBLEMS AND IS POTENTIALLY DANGEROUS BECAUSE OF BIO-ACCUMULATION
THROUGH THE FOOD CHAIN (ASCHNER 2002)
http://www.csuwai.ws/heavymetal/images/
metal_contamination3.jpg
11. EFFECTS OF LEAD POISONING
http://trytostayhealthy.blogspot.com/2011/0
4/lead-poisoning.html
http://healthandenergy.com/air_pollution_h
ealth_effects.htm
15. CONVENTIONAL TECHNOLOGIES USED FOR THE
REMOVAL OF HEAVY METAL IONS
Disadvantages
1. Electro-winning 1. Incomplete metal removal
2. Ion exchange 2. High energy and reagent requirements
3. Lime precipitation 3. Generation of toxic sludge or waste
products
4. Reverse osmosis
5. Electro-dialysis
6. Ultra-filtration
7. Phytoremediation
16. THE POTENTIAL OF MICROORGANISMS TO
REMOVE HEAVY METALS IN CONTAMINATED
SITES
BIOREMEDIATION
17. Bioremediation
• Introduction of microbes
into the environment to Cadmium binding ability of the
restore stability or to
clean up toxic pollutants blue-green alga Hapalosiphon
• oil spills, heavy metals, welwitschii Nägel under
pesticides, chemical
wastes, solid waste
disposal (man-made
controlled conditions
plastics and paper
products)
• water and sewage
treatment; reclamation
of polluted water
Bi 120 Introduction to Microbiology (mlcdg 2010)
18. BIOREMEDIATION
• a process that uses naturally Kinds of bioremediation
occurring or genetically
1. Composting
engineered microorganisms such
as yeasts, fungi and bacteria to 2. Bioaugmentation -introduction of a
transform harmful substances group of natural microbial strain or a
genetically engineered variant so as to
into less or nontoxic compounds. achieve bioremediation.
3. Phytoremediation
• microorganisms break down a
variety of organic compounds in
nature to obtain nutrients,
carbon, and energy for growth
and survival.
19. ADVANTAGES AND DISADVANTAGES OF BIOREMEDIATION
Advantages Disadvantages
1. Eco-friendly, cost-effective, 1. Takes longer compared to
natural method other remedial methods
2. Al technology targeted to
remove heavy metals, 2. The techniques are not yet
radionuclides, xenobiotic refined for sites with mixtures
compounds, organic wastes, of contaminants.
pesticides, etc. using
biological means 3. More research is needed to
3. Used in in-situ conditions perfect this technology.
21. MICROORGANISMS FOR BIOREMEDIATION
Fungi
Bacteria Algae
• Unicellular: yeasts/molds
• Single celled, with
• Unicellular/mul
various shapes • Multicellular: mushrooms
ticellular
• Cellular but have no • Photosynthetic • Saprophytes
nucleus (prokaryote) • Widely
distributed • Widely distributed
• Autotroph/chemotroph
• Stationary/motile
22. MICROORGANISMS THAT CAN TAKE UP AND
ACCUMULATE HEAVY METALS
1. bacteria: Sedum alfredii Hance (Xiong et al. 2008), Stenotrophomonas
maltophilia (Parungao et al. 2007), Bacillus circulans strain EB1 (Yilmaz and
Ensari 2005), and Corynebacterium glutamicum (Choi and Yun 2004)
2. blue-green algae: Nostoc calcicola (Pant 2000), Synechococcus aquatilis
(Reynaud) strain SY 101 (Vallarta, et al. 1998), and Anacystis nidulans
(Singh 1985): and
3. microalgae: Tetraselmis suecica (Perez-Rama et al. 2002) and Chlorella
vulgaris (Carr et al. 1998);
23. HOW DO THEY DO IT?
1. The role of cellular structure, storage polysaccharides, cell wall and
extracellular polysaccharides is evaluated in terms of their potential for
metal sequestration.
2. Binding mechanisms, including the key functional groups involved and the
ion-exchange process. Quantification of metal-biomass interactions is
fundamental to the evaluation of potential implementation strategies, hence
sorption isotherms, ion-exchange constants, as well as models used to
characterize algal biosorption . The sorption behavior (i.e., capacity, affinity)
of brown algae with various heavy metals is summarized and their relative
performance is evaluated
24. BIOSORPTION
• Biosorption technology is based on extensive research work which resulted
in the discovery of potent metal-binding biomass types.
• This technology is capable of effectively and economically removing heavy
metals from industrial aqueous solutions and wastewaters.
• The metals of sufficiently high values can be recovered and resold.
• These unique biosorbent materials are derived from specific types of
microbial biomass by a simple process which makes them applicable
in large-scale sorption processes.
25. DIRECTIONS OF RESEARCH
• The bioremediation technology most suitable for a specific site is determined by
several factors, such as site conditions, indigenous microorganism population,
and the type, quantity, and toxicity of contaminant chemicals present.
• Some treatment technologies involve the addition of nutrients to stimulate or
accelerate the activity of indigenous microbes.
• Optimizing environmental conditions enhance the growth of microorganisms and
increase microbial population resulting in improved degradation of hazardous
substances.
• However, if the biological activity needed to degrade a particular contaminant is
not present at the site, suitable microbes from other locations, called exogenous
microorganisms, can be introduced and nurtured.
• Other technologies being demonstrated are phytoremediation, or the use of
plants to clean up contaminated soils and ground water, and fungal remediation,
which employs white-rot fungus to degrade contaminants.
