Presentasi sedang didownload. Silahkan tunggu

Presentasi sedang didownload. Silahkan tunggu

Sigid Hariyadi DO – BOD – COD Dept. Manajemen Sumberdaya Perairan - IPB.

Presentasi serupa


Presentasi berjudul: "Sigid Hariyadi DO – BOD – COD Dept. Manajemen Sumberdaya Perairan - IPB."— Transcript presentasi:

1 Sigid Hariyadi DO – BOD – COD Dept. Manajemen Sumberdaya Perairan - IPB

2 TINGKAT JENUH (SATURASI) OKSIGEN TERLARUT: Dissolved Oxygen (DO)

3 ages/50_composition_of_the_earth.gif

4  Efek ketinggian (altitude) : ketinggian bertambah,  tekanan parsial gas menurun,  kelarutan gas berkurang ketinggian tingkat berkurangnya kelarutan  m4 % per 300 m  m3 % per 300 m  m2,5 % per 300 m  Efek temperatur : temperatur meningkat -- kelarutan berkurang  Efek salinitas : adanya berbagai mineral terlarut -- menurunkan kelarutan gas.  tk. kejenuhan gas dalam air laut, % lebih rendah daripada dalam akuades. FAKTOR KELARUTAN / TINGKAT SATURASI OKSIGEN:

5 S % o = 0, ,805 Cl (% o ) S ( ppm ) = ,805 Cl ( ppm ) atau Kandungan chloride (Cl) dihitung berdasarkan nilai salinitas : TINGKAT SATURASI O 2 DI PERAIRAN LAUT

6

7 Dissolved Oxygen (DO) Oksigen adalah gas terlarut dalam air bila sampel terekspose ke udara  DO bisa berkurang atau bertambah dari seharusnya pengambilan sampel utk titrasi  perlu alat khusus DISTRIBUSI VERTIKAL O 2 dipengaruhi oleh:  kondisi kelarutan  hidrodinamika -- pergerakan air  input fotosintesis  penggunaan oleh biota & proses-proses kimia Bottle train sampler Sigid Hariyadi – 2005/2008

8 Prinsip penentuan DO (metode Winkler/Iodometri): endapan coklat  bila tidak ada Oksigen: endapan putih  proporsional dg jumlah O 2 yang ada penambahan asam  indikator biru tak berwarna Sigid Hariyadi – 2005/2008

9 Modifikasi metode Winkler/Iodometri:  Flokulasi alum : 10% K 2 SO 4 Al 2 (SO 4 ) 3 & 35% NaOH  bila air keruh Sulfamic acid : NH 2 SO 2 OH  bila kadar nitrit tinggi azide alsterberg : NaN 3  bila kadar nitrit & bhn organik tinggi   Pomeroy – Kirscman – Alsterberg : penggunaan Na I (6 N) dan NaOH (10N) sbg pengganti NaOH + K I  bila kadar oksigen lewat jenuh (over saturated)  Sigid Hariyadi – 2005/2008

10 Pengukuran dgn DO-meter: 1.Warming up (on & biarkan bbrp menit) 2.Kalibrasi alat pada angka nol (zero adjustment) 3.Kalibrasi alat pada “red line” (red line adjusment) 4.Kalibrasi alat thd kadar O 2 udara pada temperatur dan tekanan udara (atau ketinggian tempat)  Standardisasi dgn metode Winkler pd sampel yg sama ( scr periodik ) Prinsip Pengukuran: Tekanan O 2 dlm air Sensor/ membran arus Jarum penunjuk skala / digital Sigid Hariyadi – 2005/2008

11 Botol BOD Sigid Hariyadi – 2005/2008

12 probe DO-meter

13 BOD (Biochemical Oxygen Demand): (Biological) ( DO i - DO 5 ) mg/L  Inkubasi sampel dlm botol BOD pada 20 o C selama 5 hari  shg O 2 terlarut pd hari ke-5 masih ada & terukur  Perlu pengenceran yg cermat & aerasi Botol gelap Inkubasi 20 o C 5 hari DO 5 DO i Sigid Hariyadi – 2005/2007

14  Bahan beracun: Hg, Cr 6+, Cl 2  Kurangnya nutrien  Kurangnya mikroorganisme/bakteri  pH 8½  Senyawa pengganggu: Sigid Hariyadi – 2005/2007

15 Sigid Hariyadi – 2005/2008

16 BOD decomposition rates vary widely DO Consumed (mg/l) Decaying phytoplanton biomass Black water organic matter Municipal, industrial BOD loads Time 5 days BOD 5 Sigid Hariyadi – 2005/2008

17 BOD decomposition rates vary widely Time 50 days 5 days Black water organic matter Municipal, industrial BOD loads DO Consumed (mg/l) Decaying phytoplanton biomass Sigid Hariyadi – 2005/2008

18

19 Pre – treatment: Penambahan Nutrien & Pengenceran Sigid Hariyadi – 2005/2008

20 BOD (Biochemical Oxygen Demand): BOD 3  inkubasi pada 30 o C selama 3 hari  Jenis dan jumlah bahan organik terlarut & tersuspensi (koloid)  Jenis dan jumlah (komposisi) mikroorganisme pengurai  kecukupan oksigen Nilai BOD :  upayakan nilai DO 5(end) sekitar 1 mg/L  sebaiknya selisih DO berkisar 5 – 7 mg/L  mengubah pH, seluruh aktivitas ionik  mengubah aktivitas organik  mengubah salinitas lingkungan fisik- kimia- biologi air sampel Pengenceran: Sigid Hariyadi – 2005/2007 (Tropik)

21 From: DHV Consultants BV & DELFT HYDRAULICS, Training module # WQ - 15 Understanding biochemical oxygen demand test. Hydrology Project Technical Assistance. New Delhi

22 COD (Chemical Oxygen Demand):  Bhn organik  dioksidasi dg K 2 Cr 2 O 7 pada kondisi asam & panas  Kelebihan K 2 Cr 2 O 7  dititrasi dg FAS (back titration) dg indikator feroin potassium dichromate Ferrous Ammonium Sulfate  perlu larutan blanko  senyawa pengganggu: Cl (air laut), NO 2 - sulfamic acid + HgSO4 (200 mg/L per 1000 mg/L chloride) S % o = 0, ,805 Cl (% o ) S ( ppm ) = ,805 Cl ( ppm ) atau S= 30 % o = ppm  Cl = 16603,88 ppm  3,321 g HgSO4 per liter sampel Contoh : Sigid Hariyadi – 2005/2008

23 Reflux, untuk penentuan COD Sigid Hariyadi – 2005/2008

24 Wastewater typeBOD 5 (mg/L)COD (mg/L) Tomato processing , ,300 Corn processing1, ,7003, ,100 Cherry processing ,9001, ,800 Poultry plant processing , ,200 Milk plant processing ,7901, ,800 Becker, University of Maryland

25 Perairan-peruntukan BOD (mg/L)COD (mg/L) Air tawar – Kelas I210 Air tawar – Kelas II325 Air tawar – Kelas III650 Air tawar – Kelas IV12100 Air laut - Biota20- Air laut - Wisata10- Air laut - Pelabuhan-- → rekreasi air → budidaya ikan, ternak → air baku minum → irigasi pertanian Sigid Hariyadi 25

26  COD menggambarkan jumlah bahan organik total, baik yang mudah urai maupun yang sulit urai Berdasarkan prinsip analisisnya, maka dapat dikatakan bahwa:  BOD menggambarkan bahan organik mudah urai  Nilai permanganat (TOM-total organic matter) TIDAK pernah lebih besar daripada nilai COD, karena oksidator yang digunakan pada analisis COD lebih kuat  TVS (total volatile solids) juga menggambarkan bahan organik berdasarkan prinsip analisis pembakaran residu organik sampel pada suhu tinggi (550 o C) dan gravimetri  Parameter bahan organik lainnya adalah TOC (total organic carbon) Sigid Hariyadi 26

27 BOD COD / rasio antara bahan organik mudah urai dgn bahan organik total/sulit urai COD ≥ BOD COD ≥ TOM Total Organic Matter oxidator: KMnO 4 TVS Total Volatile Solid TOC Total Organic Carbon  bahan organik dibakar  tidak mengukur Oksigen ekuivalensi  dapat dihubungkan dgn BOD COD BOD TOM Sigid Hariyadi 27

28 Total Carbon (TC) – all the carbon in the sample, including both inorganic and organic carbon Total Inorganic Carbon (TIC) – often referred to as inorganic carbon (IC), carbonate, bicarbonate, and dissolved carbon dioxide (CO2); a material derived from non-living sources. Total Organic Carbon (TOC) – material derived from decaying vegetation, bacterial growth, and metabolic activities of living organisms or chemicals. Non-Purgeable Organic Carbon (NPOC) – commonly referred to as TOC; organic carbon remaining in an acidified sample after purging the sample with gas. Purgeable (volatile) Organic Carbon (POC) – organic carbon that has been removed from a neutral, or acidified sample by purging with an inert gas. These are the same compounds referred to as Volatile Organic Compounds (VOC) and usually determined by Purge and Trap Gas Chromatography. Dissolved Organic Carbon (DOC) – organic carbon remaining in a sample after filtering the sample, typically using a 0.45 micrometer filter. Suspended Organic Carbon – also called particulate organic carbon (PtOC); the carbon in particulate form that is too large to pass through a filter. TOC:

29 1.Acidification 2.Oxidation 3.Detection and Quantification Analysis of TOC: Acidification : The removal and venting of IC and POC gases from the liquid sample by acidification and sparging occurs in the following manner. Oxidation : The second stage is the oxidation of the carbon in the remaining sample in the form of carbon dioxide (CO2) and other gases. Modern TOC analyzers perform this oxidation step by several processes: 1.High Temperature Combustion 2.High temperature catalytic (HTCO) oxidation 3.Photo-oxidation alone 4.Thermo-chemical oxidation 5.Photo-chemical oxidation 6.Electrolytic Oxidation High temperature combustion: Prepared samples are combusted at 1,350o C in an oxygen-rich atmosphere. All carbon present converts to carbon dioxide, flows through scrubber tubes to remove interferences such as chlorine gas, and water vapor, and the carbon dioxide is measured either by absorption into a strong base then weighed, or using an Infrared Detector.[3] Most modern analyzers use non-dispersive infrared (NDIR) for detection of the carbon dioxide. Detection and quantification: Accurate detection and quantification are the most vital components of the TOC analysis process. Conductivity and non-dispersive infrared (NDIR) are the two common detection methods used in modern TOC analyzers. TOC:

30

31


Download ppt "Sigid Hariyadi DO – BOD – COD Dept. Manajemen Sumberdaya Perairan - IPB."

Presentasi serupa


Iklan oleh Google