xi

DAFTAR ISI Halaman

HALAMAN JUDUL............................................................ i LEMBAR PERSETUJUAN ............................................. ii LEMBAR PENGESAHAN .............................................. iii HALAMAN RIWAYAT HIDUP........................................ .. iv HALAMAN PERUNTUKAN............................................ .. v KENYATAAN KEASLIAN TUGAS AKHIR.................... .. vi RINGKASAN .................................................................. vii SUMARY........................................................................ . . viii KATA PENGANTAR...................................................... .. ix DAFTAR ISI .................................................................... xi DAFTAR TABEL ............................................................ xiii DAFTAR GAMBAR ......................................................... xiv DAFTAR LAMPIRAN ..................................................... xv I. PENDAHULUAN ......................................................... . 1

1.1 Latar Belakang ................................................... . 1 1.2 Rumusan Masalah ............................................. . 3 1.3 Tujuan Penelitian ................................................. 3 1.4 Manfaat Penelitian ................................................ 4 1.5 Batasan Masalah .................................................. 4

II. TINJAUAN PUSTAKA ................................................ 5 2.1 Mikroalga ......................................................... ..... 5 2.2 Klasifikasi Mikroalga........................................ ...... 5 2.2.1 Cyanobactteria (Alga Biru)........................... ...... 5 2.2.2 Chlorophyta (Alga Hijau)............................... ..... 6 2.2.3 Chrysophyta (Alga Coklat Emas).................. ..... 6 2.3 Manfaat Mikroalga.......................................... ....... 6 2.3.1 Penyerapan Emisi Gas CO2......................................... ........ 6 2.3.2 Bahan Bakar Alternatif (Biofuel).................. ....... 6 2.3.3 Sebagai Pakan Alami ........................................ 7 2.3.4 Sebagai Pengolah Limbah Logam............. ........ 7 2.3.5 Kesehatan.................................................... ...... 8 2.4 Mikroalga Penghasil Lipid............................. ........ 8 2.5 Karakteristik dan Morfologi Mikroalga............ ....... 10 2.5.1 Nannochloropsis sp.................................... ........ 10

xii

2.5.2 Botryococcus braunii...................................... .... 13 2.6 Pertumbuhan Mikroalga ................................... .... 14 2.7 Faktor yang Mempengaruhi

Pertumbuhan Mikroalga ........................................ 16 2.7.1 Nutrien...................................................... .......... 17 2.7.2 pH (Derajat Keasaman)............................ ......... 17 2.7.3 Suhu .................................................................. 17 2.7.4 Intensitas Cahaya .............................................. 18 2.7.5 Salinitas.............................................................. 18 2.8 Biogas ........................................ .......................... 19 2.9 Limbah Cair Biogas......................................... ...... 20 III. METODE PENELITIAN ................................ ........ 22 3.1 Tempat dan Waktu Penelitian ........... ........ ........... 22 3.2 Alat dan Bahan Penelitian........ ............................. 22 3.2.1 Bahan...............................................……………. 22 3.2.2 Alat…………………………………..………………. 22 3.3 Variabel Penelitian ................................. ............. 22 3.3.1 Variabel Bebas .................................................. 22 3.3.2 Variabel Terikat ................................................. 23 3.3.3 Variabel Kontrol ................................................. 23 3.4 Metode Penelitian …………………………………… 23 3.5 Prosedur Penelitian.............................................. 24 22 3.5.1 Persiapan Peralatan dan Bahan Penelitian........ 24 3.5.2 Persiapan Slurry Sebagai Nutrisi Pada

Pertumbuhan Mikroalga..................................... 25 3.5.3 Analisa Kualitas Air Slurry ............................…. 25 3.5.4 Kultivasi Mikroalga Dengan Perlakuan

Variasi Konsentrasi Slurry................................... 25 3.6 Parameter Pengamatan .................................... .. 26 3.6.1 Laju pertumbuhan Nannochloropsis sp dan Botryococcus braunii.................................... 26 3.6.2 Kadar Lipid Nannochloropsis sp dan

Botryococcus braunii ..................................... 27 3.6.3 Kualitas Air........................................................ 27

3.7 Analisis Data........................................................ 29

xiii

IV. HASIL dan PEMBAHASAN ............................ .. .. 30 4.1 Kondisi Lingkungan Kultur Mikroalga................... . 30 4.2 Pengaruh Slurry Biogas Terhadap Kelimpahan

Sel Mikroalga .................................................... .. 32 4.3 Pengaruh Slurry Biogas Terhadap Laju

Pertumbuhan Sel Mikroalga.................................. 36 4.4 Pengaruh Slurry Biogas Terhadap Kandungan

Lipid Mikroalga....................................................... 39 V. KESIMPULAN dan SARAN .............................. .. 42 5.1 Kesimpulan ...................................................... .. 42 5.2 Saran ............................................................... .. 42 DAFTAR PUSTAKA ................................................... 43 LAMPIRAN .................................................................. 50

xiv

DAFTAR TABEL

Nomor Judul Tabel Halaman

Tabel 2.1 Profil kandungan asam lemak pada beberapa spesies mikroalga.................................................. 9

Tabel 2.2 Komposisi kandungan minyak pada beberapa spesies mikoalga................................................... 10

Tabel 3.1 Tabel Rancangan Penelitian…………………...... 24 Tabel 4.1 Kondisi Lingkungan Kultur Mikroalga B. Braunii.. 31 Tabel 4.2 Kondisi Lingkungan Kultur Mikroalga

Nannochloropsis sp............................................... 32 Tabel 4.3 Analisis Ragam Kelimpahan Sel Botryococcus

braunii…............................................................... 34 Tabel 4.4 Analisis Ragam Kelimpahan Sel Nannochloropsis

sp…....................................................................... 35

Tabel4.5 Kadar Lipid Mikroalga………………………….…... 39

xv

DAFTAR GAMBAR

Nomor Judul Tabel Halaman

Gambar 2.1 Koloni Nannochloropsis sp....................... 11 Gambar 2.2 Morfologi Sel Nannochloropsis sp............ 12 Gambar 2.3 A. Koloni Botryococcus braunii................. 14 Gambar 2.3 B. Morfologi sel Botryococcus braunii....... 14 Gambar 2.4. Fase Pertumbuhan Mikroalga.................. 15 Gambar 2.5 Sketsa Digester (reactor biogas) Anaerob.. 19 Gambar 3.1 Skema penelitian 24 Gambar 3.3 Diagram Alir Kultivasi Mikroalga…………... 26 Gambar 4.1 Grafik Pertumbuhan B. braunii…………….. 33 Gambar 4.2 Grafik pertumbuhan sel Nannochloropsis.. 36 Gambar 4.3 Grafik Laju pertumbuhan B.braunii……….. 37 Gambar 4.4 Grafik Laju Pertumbuhan Nannochloropsis sp........................................................... 38

xvi

DAFTAR LAMPIRAN

Lampiran Judul Lampiran Halaman

Lampiran 1. Persiapan Slurry........................................... 51 Lampiran 2. Perhitungan Tabel Satu Arah Nannochloropsis

sp...................................................................... 52 Lampiran 3. Perhitungan Tabel dua arah nannochloropsis

sp..................................................................... 54 Lampiran 4. analisa keragaman nannochloropsis sp ....... 55 Lampiran 5. laju pertumbuhan nannochloropsis sp ......... 57 Lampiran 6. perhitungan tabel satu arah b braunii .......... 59 Lampiran 7. perhitungan tabel dua arah b braunii............ 60 Lampiran 8. Analisa keragaman B braunii ...................... 61 Lampiran 9. laju pertumbuhan b braunii ......................... 63 Lampiran 10. uji anova ph nannochloropsis

sp……………………………………................... 64 Lampiran 11. uji anova ph b braunii.................................. 68 Lampiran 12. uji anova do nannochloropsis sp ............... 72 Lampiran 13. uji anova do b braunii................................. 76 Lampiran 14. uji anova suhu nannochloropsis sp............ 80 Lampiran 15. uji anova suhu B braunii ............................ 83 Lampiran 16. analisa metode zeleni nannochloropsis sp.. 86 Lampiran 17. analisa metode zeleni b braunii.................. 87 Lampiran 18. kandungan air limbah biogas...................... 88 Lampiran 19. dokumentasi penelitian ............................... 89