Post on 01-Nov-2014
Handout:BIOREMEDIASI
SENYAWA PENCEMAR
Bahan Kuliah
SudrajatFMIPA UnmulSamarinda
APA SAJA SENYAWA-SENYAWA PENCEMAR LINGKUNGAN?
Pencemar Senyawa-senyawa yang
secara alami ditemukan di alam tetapi jumlahnya (konsentrasinya) sangat tinggi tidak alami.
Contoh: Minyak mentah,
minyak hasil penyulingan
Fosfat Logam berat
Senyawa xenobiotik Senyawa kimia hasil
rekayasa manusia yang sebelumnya tidak pernah ditemukan di alam.
Contoh: Pestisida Herbisida Plastik Serat sintetis
REMEDIASI LINGKUNGAN
• Remediasi: Proses perbaikan.
• Proses perbaikan lingkungan yang tercemar.
• Pendekatan-pendekatan yang dilakukan untuk menghilangkan pencemar dari lingkungan.
TEKNOLOGI YANG UMUM DIGUNAKAN UNTUK MENGHILANGKAN SENYAWA
PENCEMAR
Ekstraksi uap tanah Tekanan udara Serapan panas Pencucian tanah Dehalogenasi kimiawi Ekstraksi tanah Penggelontoran tanah in situ Bioremediasi
BIOREMEDIASI SENYAWA ORGANIK:
Proses mengubah senyawa pencemar organik yang berbahaya menjadi senyawa lain yang lebih aman dengan memanfaatkan organisme.
Melibatkan proses degradasi molekular melalui aktifitas biologis.
Campur tangan manusia untuk mempercepat degradasi senyawa pencemar yang berbahaya agar turun konsentrasinya atau menjadi senyawa lain yang lebih tidak berbahaya melalui rekayasa proses alami atau proses mikrobiologis dalam tanah, air dan udara.
KEUNGGULAN BIOREMEDIASI SENYAWA ORGANIK
Proses alami. Mengubah molekul senyawa pencemar
organik, bukan hanya memindahkan. Beaya paling murah dibandingkan cara
yang lain. Hasil akhir degradasi adalah gas karbon
dioksida, air, dan senyawa-senyawa sederhana yang ramah lingkungan.
ALASAN PENGGUNAAN PERLAKUAN BIOLOGIS
Murah, karena: Dapat digunakan in-situ sehingga
mengurangi beaya pengangkutan dan gangguan lingkungan.
Mikroba alami dapat digunakan.
PELAKU UTAMA:
• Mikroorganisme :
Bakteria, Sianobakteria, dan fungi > Remediasi oleh mikrobia
• Tanaman > Fitoremediasi
• Mikroorganisme dan tanaman
PENERAPAN BIOREMEDIASI
Situs-situs yang sulit dijangkau Lingkungan di bawah permukaan
tanah Air berminyak Limbah Nuklir
BIDANG ILMU YANG DIBUTUHKAN UNTUK KEBERHASILAN BIOREMEDIASI
Ilmu tanah Geokimia organik
dan anorganik Geofisika Hidrologi
Rekayasa bioproses
Modeling komputer Mikrobiologi
dan/atau botani
KEUNTUNGAN MENGGUNAKAN MIKROBIA UNTUK MENDEGRADASI SENYAWA PENCEMAR ORGANIK:
Jumlahnya banyak dan ada dimana-mana Jalur metabolisme dalam aktivitas
hidupnya dapat dimanfaatkan untuk mendegradasi senyawa pencemar organik dan mengubahnya menjadi senyawa yang lebih tidak berbahaya
PERTIMBANGAN KIMIA DAN MIKROBIOLOGIS YANG PERLU
DIPERTIMBANGKAN:
• Apakah kontaminannya dapat terdegradasi secara biologis?– hidrokarbon minyak bumi sederhana– hidrokarbon aromatik (hingga 3 cincin)– amina sederhana– ester– keton– eter
SENYAWA PENCEMAR ORGANIK YANG SECARA POTENSIAL DAPAT
DIBIOREMEDIASIMudah didegradasi
____________
Sedikit terdegradasi
_____________
Sulit terdegradasi_____________
Umumnya tidak terdegradasi
_____________BBM,Minyak tanah
kreosot, tars batubara
Pelarut terkorinasi (TCE)
Dioxins
keton danalkohol
Pentakoro-fenol (PCP)
Beberapa pestisida dan herbisida
Bifenil terpoliklorinasi (PCB)
Aromatikmonosiklik
Aromatikbisiklik
(naftalena)
BIOREMEDIASI SENYAWA ORGANIK PADA SKALA
MIKROSKOPIS
Nutrien pembatas
Sumber karbon/energibagi bakteria
Pengolahan lahan tercemar senyawa organik dapat dikelompokkan ke dalam:
Ex situ – pengolahan dilakukan di tempat lain sehingga perlu pemindahan.
In situ – pengolahan dilakukan di tempat pencemaran tanpa pemindahan.
PENGOLAHAN BIOLOGIS LAHAN TERCEMAR SENYAWA ORGANIK
BIOREMEDIASI EX-SITUTanah terkontaminasi diangkat ke dan diperlakukan di permukaan
CONTOH PENGOLAHAN TANAH TERCEMAR SENYAWA ORGANIK
SECARA EX SITU (1)
1.Slurry Phase : Bejana besar digunakan sebagai “bio-reactor” yang mengandung tanah, air, nutrisi dan udara untuk membuat mikroba aktif mendegradasi senyawa pencemar.
BIOREAKTOR
Cairan terkontaminasi
Tanah terkontaminasi
Saluran keluar tanah
Pengatur suhu
PengadukUap keluar
Udara masuk
Nutrien
Saluran keluar cairan
CONTOH PENGOLAHAN TANAH TERCEMAR SENYAWA ORGANIK
SECARA EX SITU (2)
2.Composting: Limbah dicampur dengan jerami atau bahan lain untuk mempermudah masuknya air, udara, dan nutrisi.
Tiga tipe pengomposan:
* Dalam Lubang
* Mechanically agitated in-vessel
* Tumpukan
CONTOH PENGOLAHAN TANAH TERCEMAR SENYAWA ORGANIK
SECARA EX SITU (3)
3.Biopile: tanah tercemar tidak dipindahkan namun diangkat ke permukaan, ditumpuk, dan diberi perlakuan penambahan air, udara, dan nutrien.
BIOFILES
Nutrien/airLapisan
Gravel
Penampungan Leachate
Lapisan Kedap Air
Tanah terkontaminasi
CONTOH PENGOLAHAN TANAH TERCEMAR SENYAWA ORGANIK
SECARA EX SITU (4)
4.Landfarming: Tanah terkontaminasi dipindahkan dan disebar di permukaan lapangan kemudian diperlakukan dengan penambahan bakteri, air, udara, dan nutrisi. Cara ini yang paling sering digunakan.
LANDFARMING
Tangki
Saringan/PompaUdara
Lapisan Gravel
Tanah terkontaminasi
CONTOH PENGOLAHAN TANAH TERCEMAR SENYAWA ORGANIK IN
SITU (1)
Bio-venting: pemompaan udara dan nutrisi melalui
sumur injeksi.
Air Sparging: pemompaan udara untuk meningkatkan
aktifitas degradasi oleh mikroba.
2.1.Biostimulation
Biosparging
AIR SPARGING
CONTOH PENGOLAHAN TANAH TERCEMAR SENYAWA ORGANIK IN
SITU (2)
Injeksi Hidrogen Peroksida : menggunakan sprinkler atau pemipaan.
Sumur Ekstraksi : Untuk mengeluarkan air tanah yang kemudian ditambah nutrisi dan oksigen dan dimasukkan kembali ke dalam tanah melalui sumur injeksi.
Zona terkontaminasi
Permukaan air tanah
yang lama
Permukaan air tanah yang
baru
Pengolahan Air
Penambahan Nutrien/ Oksigen
Sumur Recovery
Sumur Injeksi
3.KOMBINASI BIOREMEDIASI EX-SITU DAN IN-SITU
Unsaturatedzone
Dalam cara ini aktifitas mikrobia penghuni tanah ditingkatkan
Aquifer
OPTIMASI BIOREMEDIASI LAHAN TERCEMAR SENYAWA ORGANIK (1)
Untuk mengoptimalkan dan mempercepat biodegradasi senyawa pencemar yang ada di dalam air dan tanah dapat digunakan mikroba yang telah beradaptasi dan digabungkan dengan: Menjamin ketersediaan air (kadar air
antara 30-80%). Menambahkan nutrisi (nitrogen,
fosfor, sulfur).
OPTIMASI BIOREMEDIASI LAHAN TERCEMAR SENYAWA ORGANIK (2)
Menjamin ketersediaan oksigen.
(jika tipe degradasi aerobik) 2-3 kg oksigen per kg hidrokarbon yang didegradasi.
Menjamin pH moderat – Tidak terlalu masam maupun basa, antara 6-9.
Menjamin suhu yang moderat - 10o to 40oC.
OPTIMASI BIOREMEDIASI LAHAN TERCEMAR SENYAWA ORGANIK (3)
Penambahan enzim, katalis kimia untuk mendegradasi senyawa-senyawa limbah.
Penambahan surfaktan (detergen).
KELEMAHAN PERLAKUAN BIOLOGIS
Kadang-kadang tidak efektif di beberapa lokasi karena toksisitas pencemar: Logam Senyawa organik berkhlor Garam-garam anorganik
WAKTU YANG DIPERLUKAN
in situ perlu waktu bervariasi antara 1 - 6 tahun.
ex situ antara 1-7 bulan.
REMEDIASI LAHAN TERCEMAR SENYAWA ANORGANIK (LOGAM)
INTERAKSI LOGAM-MIKROBIA
LOGAM BERAT YANG DAPAT DIPERLAKUKAN
Logam beracun• Uranium• Kromium• Selenium• Timbal (Pb)• Teknetium• Raksa
Logam lainnya• Vanadium• Molibdenum• Tembaga• Emas• Perak
BIOLEACHING
Mekanisme mobilisasi logam Produksi asam organik atau asam sulfat yang
dapat membentuk khelat logam Mikrobia heterotropik = asam organik Thiobacillus spp. = asam sulfat
Meleaching logam dari padatan limbah kota Zn, Cu, Cr, Pb, Ni, Al
Ada hubungan antara efisiensi penghilangan dengan pH
BIOSORPSI
Biosorpsi merupakan salah satu mekanisme imobilisasi logam
Logam terserap di permukaan sel oleh interaksi anion-kation
OVERVIEW FITOREMEDIASI
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.
FITOEKSTRAKSI
Absorpsi logam berat oleh akar tanaman dan translokasinya dalam tanaman
FITOSTABILISASI
Imobilisasi logam dalam tanah oleh penjerapan, pengendapan dan kompleksasi.
• 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.
RHIZOFILTRASI
Penghilangan logam dari lingkungan perairan
• 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 species-pollutant 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.
FITOREMEDIASI
Phyto-extraction
Rhizo-filtration
Phyto-stabilization
Rhizo-degradation
Phyto-degradation
FITOREMEDIASI
Phyto-volatilization
HydraulicControl
Vegetative Cover
Riparian Corridors
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
Bioremediasi dengan mikroba• Dengan 2 cara
– 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
Phytoremediation
• ≈350 plant species naturally take up toxic materials– Sunflowers used to remove radioactive cesium
and strontium from Chrenobyl site– Water hyacinths used to remove arsenic from
water supplies in Bangladesh, India
Phytoremediation
• Drawbacks– Only surface soil (root zone) can be treated– Cleanup takes several years
Transgenic plants
Royal DemolitioneXplosive
Stimulates plant growth!
Gene from bacterium moved to plant genome
Careers in Bioremediation
• Outdoor inspection • Lab testing• Administration
Company employeeGovernment
EmployeeRegulatory oversight
Summary
• Many factors control biodegradability of a contaminant in the environment
• Before attempting to employ bioremediation technology, one needs to conduct a thorough characterization of the environment where the contaminant exists, including the microbiology, geochemistry, mineralogy, geophysics, and hydrology of the system