Transcript STANDAR LABORATORIUM UNTUK UJI MIKROBIOLOGI PADA …

Phytoremediation
Dr. Tini Surtiningsih, Ir., DEA
Phytoremediation
 Phytoremediation is the use of plants, trees
and herbaceous species to eliminate or
degrade contaminants or reduce their
bioavailability in both water and soil.
 Many chemical species that can be treated
with phytoremediation techniques, which
comprise
 heavy metals
 organic compounds such as pesticides,
solvents, and other persistent pollutants
(PCB´s)
Phytoremediation can be applied as long as
the concentration of the pollutant is within
an appropriate concentration range, which
shall not be too high, since it may cause
phytotoxicity to the plant
Phytoremediation can be performed
following different methods:
 Phytoextraction: Uptake and
concentration of pollutants from the
environment into the plant biomass.
 Phytostabilization: Reduction of the
mobility of the contaminants in the
environment.
 Phytotransformation: Chemical
modification of the environmental
substances as a direct result of the
plant metabolism.
Phytostimulation: Enhancement
of the native soil microbial activity
for the degradation of
contaminants.
Phytovolatilization: Removal of
substances from soil or water with
release into the air.
Rhizofiltration: Filtering water
through a mass of roots to remove
toxic substances or excess
nutrients.
 Regarding the rhizosphere, there are other
techniques besides the rhizofiltration.
 The roots can be used as stimulator of the
micro-organisms living there due to the
exudates that plants expulse in this
medium.
 This can increase the amount of organisms
in 2 or 3 orders of magnitude.
 Within remediation, one of the most important
factors to take into account is the tolerance of the
plant.
 The same chemical species may produce different
effects at the same concentration in different
plants.
 For this reason, it is important to know about the
background levels in the polluted area:
 Sites with natural high concentration of some
pollutant may lead to an increased presence of
tolerant species.
 These species are of big interest for
phytoremediation and hence many are used for
remediation purposes.
 These plants are able to accumulate due to
different detoxifying mechanisms such as the
chelation of heavy metals or the storage of the
contaminants in vacuoles or the cellular wall
 Plants which are able to accumulate extremely
high concentrations in their tissues are considered
hiperaccumulator species. Although their ability of
accumulating high concentrations of metals is
highly interesting, these species normally only
show low growth rates and hence are not suitable
for extracting high amounts of pollutants from the
soil.
 However there are plants which are able to
accumulate lower concentrations of metal
but present higher growth rates. For this
reason, these species showed to be more
suitable for phytoextraction processes.
 The low accumulation capacity of these
species may be highly improved by the
addition of synthetic chelates, which
increase the solubility of metal in the soil,
making them more bioavailable for the
plant and hence increasing the uptake rate
of metals by the plant
 . Examples of
chelating agents are EDTA,
NTA or weak organic acids, such as citric
acid. Chelates, however, have to be used
with caution, since they may increase the
mobility of pollutants, posing a risk of
contamination of underlying groundwaters
 They may also provoke negative effects for
the native microbial community of the soil.
In particular, EDTA has recently been
banned as a chelating agent, due to its
toxicity for the soil microbiota and its high
persistence.
 These plants are able to accumulate due to
different detoxifying mechanisms such as the
chelation of heavy metals or the storage of the
contaminants in vacuoles or the cellular wall
 Plants which are able to accumulate extremely
high concentrations in their tissues are considered
hiperaccumulator species. Although their ability of
accumulating high concentrations of metals is
highly interesting, these species normally only
show low growth rates and hence are not suitable
for extracting high amounts of pollutants from the
soil.
 However there are plants which are able to
accumulate lower concentrations of metal
but present higher growth rates. For this
reason, these species showed to be more
suitable for phytoextraction processes.
 The low accumulation capacity of these
species may be highly improved by the
addition of synthetic chelates, which
increase the solubility of metal in the soil,
making them more bioavailable for the
plant and hence increasing the uptake rate
of metals by the plant
 Examples of chelating agents are EDTA,
NTA or weak organic acids, such as citric
acid. Chelates, however, have to be used
with caution, since they may increase the
mobility of pollutants, posing a risk of
contamination of underlying groundwaters
 They may also provoke negative effects for
the native microbial community of the soil.
In particular, EDTA has recently been
banned as a chelating agent, due to its
toxicity for the soil microbiota and its high
persistence.
 To improve the effectiveness of these
technologies, genetic manipulation of some
organisms can be used.
 For example, tobacco plant was inoculated
with bacterial genes encoding a
nitroreductase enzyme.
 Genetically engineered tobacco plant
showed a significantly faster degradation of
TNT and an enhanced resistance to the toxic
effect of the explosive.
 Regarding the economical aspects of these
technologies, some studies suggest that
when a phytoremediation process is used
instead the conventional processes,
 the costs may be reduced up to 50-60%.
 However, the effectiveness of the process has to be taken
into account.
 Although the price is significantly lower,
 the time needed for the remediation may be much
longer.
 No specific regulatory standards have been developed
for phytoremediation processes, so that installations
must be approved on a case by case basis. There are
several regulatory issues which will need to be
addressed on most sites
 Several methods exist for the disposal of the harvested
pollutant-rich crop after a phytoextraction process:
Pre-treatment processes aim to reduce the volume of
biomass to be treated, by strongly reducing its water
content. Composting, compactation and pyrolisis are
the most important ones. After the pre-treatments, the
final disposal of vegetal material takes places.
 Although the only technique used in praxis is the
incineration (in combination with filtering
mechanisms to clean the gas effluent), other
techniques exist, such as the direct disposal in a
deponie.
 Other techniques also are being developed at a
laboratory scale, such as the ashing or the liquid
extraction techniques. However they still lack the
required technology for its on-field application
 Phytoremediation is an emerging and
promising technology which permits a low
cost alternative to other remediation
processes.
 However, the mechanisms behind the
remediation process still need to be better
understood, so that the best speciespollutant combination can be chosen.
 Other problems such as contaminant
migration need to be focused in further
studies to minimize the drawback of this
new technology.
TERIMA KASIH ATAS PERHATIANNYA
Wassalamu’alaikum Wr. Wb.
Fitoremediasi
 Fitoekstraksi/fitoakumulasi
 Rhizofiltrasi
 Fitostabilisasi, mobilisasi logam
 Fitodegradasi/fitotransformasi,
menguraikan/menghancurkan log berat
 Fitovolatilasi
 Rhizodegradasi, mikroba rhizosfir
Kelebihan fitoremediasi
 Memanfaatkan cahaya matahari
 Biaya murah
 Mudah diterima masyarakat
 Bioremediasi EXSITU, mahal
 Bioremediasi INSITU, lebih murah
Keterbatasan fitoremediasi
 Terbatas pada air dan tanah
 Cara kerja lambat
 Meracuni tnaman
 Potensi racun masuk makanan
 Racun sulit diketahui jenisnya
 Hanya untuk lingkungan tanah dan air
Jenis tanaman fitoremediasi
 Bunga matahari/ Heliantus anuus : mendegradasi
Uranium
 Populas trichocarpa, P.deltaritas Famili sacnaceae :
mendegradasi TCE (Trichloroethylene)
 Najar graminae (tumbuhan air) : menyerap Co, Pb,Ni
 Vetiver grass (Vetiveria zizonaides), akar wangi :
mendegradasi Pb, Zn
Tanaman air fitoremediasi
 Menyerap/mengakumulasi logam berat pada semua
jaringan
 Kangkung air
 Teratai
 Eceng gondok
 Dengan 2 cara
Bioremediasi
dengan mikroba
 Oxidasi, bersamaan pertumbuhan mikroba
 Reduksi, elektron akseptor
 Akumulasi logam pada dinding sel
 Akumulasi logam dalam vakuola sel
 Menghasilkan enzim pendegradasi logam,
eksoenzim diluar sel, endoenzim dalam sel
Mikroba
bioremediasi
logam
 Bakteri mentransformasi
Fe : Thiobacillus,
Leptothrix, Crenothrix,Sulfolobus, Gallionela
 Bakteri mentransformasi Mn :
 Arthrobacter, Leptothrix, Sphaerotillus
 Hg : Pseudomonas, Bacillus