Permodelan reaktor sharon dengan umpan urea-amonia

SHARON (Single reactor High activity Ammonia Removal Over Nitrite)-Anammox (Anaerobic Ammonium Oxidation) has never been used for treating wastewater with high urea content. Three prior researches have been done to examine the performance of SHARON process with urea-ammonia feed but the results are still unable to explain its performance. To explain these results, a model of SHARON process is needed to be built. Based on material balances of SHARON process in a stirred tank reactor, a model was built. The model is nonlinear differential equation system and was solved using Least Square Method with the help of MATLAB. The simulation result shows that nitrate was always occurred in the effluent of the SHARON process. Based on this research, equimolar nitrite to ammonia ratio can be obtained only if the feed is equimolar in urea and bicarbonate composition. Optimized kinetic parameter obtained are μmaxamm = 1,16E-05 s-1, μmaxnit = 3,998E-05 s-1, KNH3amm = 3,346E-02 mol mL-3, Kl,HNO2amm = 1,45E-02 mol mL-3, Kl,HNO2amm = 6,14E-03 mol mL-3. This result show that there are inhibition in oxidizing ammonium in the reactor and inhibition on growth of the nitrite oxidizer. Keywords : modelling, SHARON, urea-ammonia, kinetic parameter Abstrak Proses SHARON (Single reactor High activity Ammonia Removal Over Nitrite)-Anammox (Anaerobic Ammonium Oxidation) belum pernah digunakan untuk mengolah air limbah dengan konsentrasi urea tinggi. Data-data yang diperoleh dari percobaan pendahuluan belum dapat menjelaskan unjuk kerja reaktor SHARON dengan umpan berupa urea-amonia. Oleh karena itu, perlu disusun pemodelan matematika untuk menentukkan parameter kinetika pertumbuhan mikroba dan parameter stoikiometrik reaksi yang terjadi pada reaktor SHARON. Penyusunan model dilakukan berdasarkan neraca massa reaktor tangka reaktor kontinyu berpengaduk. Model yang dihasilkan berupa system model menunjukkan bahwa konsentrasi nitrat sama dengan nol pada keluaran reaktor SHARON dengan umpan urea-amonia tidak dapat dicapai. Untuk mendapatkan nisbah nitrit terhadap nitrat yang ekuimolar, diperlukan umpan dengan komposisi urea dan bikarbonat yang ekuimolar. Parameter kinetic yang diperoleh dari hasil optimasi model adalah μmaxamm = 1,16E-05 s-1, μmaxnit = 3,998E-05 s-1, KNH3amm = 3,346E-02 mol mL-3, Kl,HNO2amm = 1,45E-02 mol mL-3, Kl,HNO2amm = 6,14E-03 mol mL-3. Kata Kunci : pemodelan, SHARON, urea-amonia, parameter kinetik

The SHARON process in the treatment of landfill leachate

The purpose of this paper was to study the partial nitrification of the nitrogen present in a landfill leachate applying the SHARON process in order to obtain a suitable effluent to the ANAMMOX process. As a first step, the SHARON reactor was fed anaerobically pre-treated leachate at an ammonium concentration of 2,000 mg N/L (1.1 kg N/m3 d). In such conditions, the average ammonium and nitrite concentrations in the effluent were 775 mg N/L and 1,225 mg N/L, respectively. During this period the COD removal was very low since most of the biodegradable organic matter was removed in the anaerobic pre-treatment. Afterwards, the SHARON reactor was fed leachate without a previous treatment and the efficiency of the partial nitritation diminished. As well, the COD removal increased, achieving a percentage around 28%.

Controlling the nitrite:ammonium ratio in a SHARON reactor in view of its coupling with an Anammox process

The combined SHARON–Anammox process for treating wastewater streams with high ammonia load is the focus of this paper. In particular, partial nitritation in the SHARON reactor should be performed to such an extent that a nitrite:ammonium ratio is generated which is optimal for full conversion in an Anammox process. In the simulation studies performed in this contribution, the nitrite:ammonium ratio produced in a SHARON process with fixed volume, as well as its effect on the subsequent Anammox process, is examined for realistic influent conditions and considering both direct and indirect pH effects on the SHARON process. Several possible operating modes for the SHARON reactor, differing in control strategies for O2, pH and the produced nitrite:ammonium ratio and based on regulating the air flow rate and/or acid/base addition, are systematically evaluated. The results are quantified through an operating cost index. Best results are obtained by means of cascade feedback control of the SHARON effluent nitrite:ammonium ratio through setting an O2 set-point that is tracked by adjusting the air flow rate, combined with single loop pH control through acid/base addition.