kul_bioremediasis2

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


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


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



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


2.INSITU BIOREMEDIATION

http://www.envirotools.org/factsheets/images/bioremediation2.gif

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).


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.


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