Handout: BIOREMEDIASI SENYAWA PENCEMAR Bahan Kuliah Sudrajat FMIPA Unmul Samarinda

APA SAJA SENYAWA-SENYAWA PENCEMAR LINGKUNGAN? 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 DIBIOREMEDIASI Mudah didegradasi ____________ Sedikit terdegradasi _____________ Sulit terdegradasi Umumnya tidak terdegradasi BBM, Minyak tanah kreosot, tars batubara Pelarut terkorinasi (TCE) Dioxins keton dan alkohol Pentakoro-fenol (PCP) Beberapa pestisida dan herbisida Bifenil terpoliklorinasi (PCB) Aromatik monosiklik bisiklik (naftalena)

BIOREMEDIASI SENYAWA ORGANIK PADA SKALA MIKROSKOPIS Nutrien pembatas Sumber karbon/energi bagi bakteria

PENGOLAHAN BIOLOGIS LAHAN TERCEMAR SENYAWA ORGANIK 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.

BIOREMEDIASI EX-SITU Tanah 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.

Cairan terkontaminasi BIOREAKTOR Cairan terkontaminasi Tanah terkontaminasi Saluran keluar tanah Pengatur suhu Pengaduk Uap 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 Tanah terkontaminasi Nutrien/ air Lapisan Gravel Lapisan Kedap Air Penampungan Leachate

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 Tanah terkontaminasi Saringan/ Pompa Udara Lapisan Gravel

2.INSITU BIOREMEDIATION

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.

Sumur Injeksi Sumur Recovery Penambahan Nutrien/ Oksigen Pengolahan Air Permukaan air tanah yang baru Zona terkontaminasi Permukaan air tanah yang lama

3.KOMBINASI BIOREMEDIASI EX-SITU DAN IN-SITU Unsaturated zone Aquifer Dalam cara ini aktifitas mikrobia penghuni tanah ditingkatkan

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

Phyto-volatilization FITOREMEDIASI Phyto-volatilization Hydraulic Control 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 Demolition eXplosive Gene from bacterium moved to plant genome Stimulates plant growth!

Careers in Bioremediation Outdoor inspection Lab testing Administration Government Employee Regulatory oversight Company employee

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