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NUTRIEN : NITROGEN. SIGID HARIYADI. Dep. Manajemen Sumberdaya Perairan Fakultas Perikanan dan Ilmu Kelautan - IPB. ESSENTIAL NUTRIENT. Tucker, MR. 1999. Essential Plant Nutrients : their presence in North Carolina soils and role in plant nutrition. C.
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NUTRIEN:NITROGEN SIGID HARIYADI Dep. ManajemenSumberdayaPerairan FakultasPerikanandanIlmuKelautan - IPB
ESSENTIAL NUTRIENT Tucker, MR. 1999. Essential Plant Nutrients: their presence in North Carolina soils and role in plant nutrition
C • biomass-limiting nutrients: membatasiproduksi biomass • rate-limiting nutrients: membatasilajuproduktivitas primer
Siklus Nitrogen di perairan NH4+ NO3 N2 • bakteritertentu • blue-green algae
nitrogen also plays important roles in other water quality processes and may constitute a problem: The oxidation of NH4to NO3during the nitrification process consumes oxygen and may contribute significantly to the oxygen depletion of a waterbody. High concentrations of un-ionized NH3can be toxic to aquatic life. The common form of nitrogen in water is NO3, which itself is not toxic. However, bacteria in the intestinal tract of infants can convert nitrates to highly reactive NO2, which may cause the so-called “ blue baby ” syndrome and death from suffocation. There are strict regulations governing the amount of nitrate that can be present in drinking water. nitrogen is not as often limiting to plant growth as phosphorus in many natural waters, especially in freshwaters. Thus, most of the eutrophica-tionmanagement efforts are focused on phosphorus control.
4. NH3 + H2O NH4OHNH4+ + OH- NITROGEN (N) Nitrogen di perairanterdapatdalamberbagaibentukseperti: NO3- (Nitrat) NO2- (Nitrit) gas N2 terlarut NH3 (Ammonia) – gas terlarut NH4+(ion Ammonium), dan N organikkompleks– dlmjumlahbesar (org N) 1. N2 (g) + O2 (g)2 NO (g) 2. 2 NO (g) + O2 (g) ----> 2 NO2 (g) 3. 3 NO2 + H2O ----> 2 H+ + 2 NO3- + NO Reaksi kesetimbangan amonia dan amonium:
Nitrosomonas • Nitrobacter Nitrifikasi: melibatkanbakterinitrifikasi 2NH4+ + 3O22NO2-+ 4H+ + 2H2O 2 NO2-+ O22 NO3- RespirasiNitrat (denitrifikasi):
Total Nitrogen (TN): N-organik Total Kjeldhal Nitrogen (TKN): Total Amonia Nitrogen (TAN) atau TA: total amonia [ ] = konsentrasi (mol/L atau mg/L)
Ammonia - N • metodaIndophenol (=metodaphenate) ( Utksampel air dgnkesadahan < 400 mg/L danberkadar NO2-N < 5 mg/L) Phenol dan hypochlorite (chlorox) bereaksi dalam kondisi larutan basa membentuk phenylquinone-monoimine yang selanjutnya akan bereaksi dengan ammonia membentuk indophenol yang berwarna biru. Kepekatan warna biru sebanding dengan kadar ammonia yang ada. Phenol + Hypochlorite ⇨ phenylquinone-monoimine + NH3 ⇨Indophenol (biru) Semua amonia (NH3& NH4+) NH3 kondisi alkalin/basa Phenol + NH3 + 3ClO- ‑‑‑‑> Indophenol + 2H2O + OH- + 3Cl- (Hypochlorite) (biru) setiap set penentuan ammonia, harus selalu disertai denganpenentuan standar ammonia dan blanko • Kadar ammonia yang terukurpadametodainiadalahammonia total yaituterdiridari NH3dan NH4-, karenapadalarutanbersuasanabasa kuatsemua ammonia beradadlmbentuk NH3 TAN SigidHariyadi
Total Ammonia Nitrogen Prosentase NH3 thd ammonia total (TAN) sangat dipengaruhi oleh: • pH • temperatur • salinitas air payau & air laut SigidHariyadi Sumber: Trussel (1972) in Boyd (1979)
100 1 +antilog (pKa – pH) % NH3 = % un-ionized ammonia: pKa = -log (Ka) Ka : konstanta ionisasi
AmoniadanAmonium: [ ] = konsentrasi (mol/L) KonstantakesetimbanganamoniaKedipengaruhiolehtemperatur (T): TdalamC pada 25 C
Proporsiamoniumthd total amonia (TA): Proporsiamoniathd total amonia (TA): total amonia
Siklus Nitrogen SigidHariyadi – 2011
Siklus N SigidHariyadi – 2011
Distribusivertikalamoniadannitrat di danauter-stratifikasi
Konsep N-P ratio: Di dalamsampel plankton, rasio atom = 106 C : 16 N : 1 P Redfield ratio (1963) N-P ratio • sediaan nutrien bagi perkembangan algae Normalnya ⇨ 16 atom N : 1 atom P 7.2 mg/LN:1 mg/LP Bila N-P ratio < 7 ⇨ Npotensialsbgfaktorpembatas Bila N-P ratio > 8 ⇨ Ppotensialsbgfaktorpembatas “Biologically available” N = nitrat + nitrit + ammonia “Bio-available” P = orthophosphate • konsentrasidarimasing-masingNdanPtetapperludiketahui
Referensi: ① ② ③