scholarly journals Determination of rate parameter for kinetics of nitrification

2018 ◽  
Vol 4 (2) ◽  
pp. 234
Author(s):  
S R Juliastuti ◽  
J Baeyens ◽  
C Creemers ◽  
J Degreve
Keyword(s):  
Oxygen Uptake ◽  
Organic Compounds ◽  
Total Nitrogen ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Inhibitory Effect ◽  
Rate Parameter ◽  
Autotrophic Biomass ◽  
Kinetics Of

Determination of rate parameter for kinetics of nitrification The nitrification process is the bottleneck step in the total nitrogen removal. The formation of nitrate is considered as the rate limiting step in the whole process and its kinetics determine the design of the nitrification reactor. Heavy metals (Zn2+ and Cu2+) and different organic compounds are used as micropollutants. These kinetics were experimentally measured by respirometry. In line with the aim of the paper, the experimental investigation are conducted to develop design equations to describe kinetic rate relationships under optimum conditions, study the parameter influence such as pH and inhibition by reaction intermediates and inhibition by external pollutants. Results demonstrate that the maximum value of the specific growth rate of autotrophic biomass() is 1.02 day at pH=7 and decreases at pH 7.5; inhibition occurs at substrate (NH4) concentrations in excess of 15 mg N/l; inhibition occurs at increasing concentrations of NO –N and Cu2+ has more pronounced inhibitory effect than Zn2+. The inhibitory effect of organic compounds are listed as the Chlorobenzene > Trichloroethylene> Phenol> Ethyl benzene; the experimental oxygen uptake rate (OUR)-test results the autotrophic kinetic parameter values, which can be used in design equations. Keywords: Respirometry,  Autotrophic Biomass,  Nitrification, Oxygen Uptake Rate Abstrak Proses nitrifikasi merupakan langkah penting pada penurunan kadar total nitrogen. Pembentukan nitrat dianggap sebagai tahap pembatas kecepatan reaksi pada keseluruhan proses dan kinetikanya menentukan perancangan dari bagian proses nitrifikasi. Logam berat (Zn2+ dan Cu2+) dan berbagai jenis komponen organik digunakan sebagai mikropolutan. Kinetika ini secara eksperimental diukur menggunakan respirometer. Tujuan penelitian adalah mengembangkan persamaan perancangan yang menggambarkan hubungan laju kinetika pada kondisi optimum, studi pengaruh parameter seperti pH, inhibisi karena reaksi intermediat, dan inhibisi oleh polutan dari luar. Hasil penelitian ditunjukkan sebagai berikut: harga laju pertumbuhan  biomasa autotrof maksimum spesifik  adalah 1,02 hari-1 pada pH=7 dan menurun pada pH 7,5; inhibisi terjadi pada konsentrasi substrat (NH4+) lebih besar dari 15 mg N/l; inhibisi terjadi pada peningkatan  konsentrasi NO -N ;Cu2+  lebih dikenal sebagai penyebab  inhibisi  daripada Zn2+. Efek inhibisi dari komponen organik di daftar mulai dari Chlorobenzene sampai Ethylbenzen. Tes OUR menghasilkan harga parameter kinetika yang dapat dipakai pad apersamaan perencanaan  lumpur aktif nitrifikasi. Kata Kunci: Respirometer, BiomasaAutotrof, Nitrifikasi, Laju Kenaikan Oksigen

A New Approach to Quantify Spatial Distribution of Biofilm Kinetic Parameters by In Situ Determination of Oxygen Uptake Rate (OUR)

2009 ◽  
Vol 43 (3) ◽  
pp. 757-763 ◽  
Author(s):  
Xiao-Hong Zhou ◽  
Yu-Qin Qiu ◽  
Han-Chang Shi ◽  
Tong Yu ◽  
Miao He ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Oxygen Uptake ◽  
Kinetic Parameters ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
New Approach

scholarly journals Application of a modified OxiTop® respirometer for laboratory composting studies

2016 ◽  
Vol 42 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Krystyna Malińska
Keyword(s):  
Oxygen Uptake ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Fixed Ratio ◽  
Apple Pomace ◽  
Glass Vessel ◽  
Moisture Contents ◽  
Wide Mouth ◽  
Closed Steel

Abstract This study applied a modified OxiTop® system to determine the oxygen uptake rate during a 2-day respiration test of selected composting materials at different moisture contents, air-filled porosities and composition of composting mixtures. The modification of the OxiTop® respirometer included replacement and adjustment of a glass vessel (i.e. a 1.9-L glass vessel with wide mouth was used instead of a standard 1-L glass bottle, additionally the twist-off vessel lid was adjusted to attach the measuring head) and application of a closed steel mesh cylinder of 5 cm in diameter and 10 cm in height with the open surface area of the mesh of approximately 56.2%. This modification allowed obtaining different bulk densities (and thus air-porosities) of the investigated composting materials in laboratory composting studies. The test was performed for apple pomace and composting mixtures of apple pomace with wood chips at ratios of 1:0.5, 1:1, 1:1.5 (d.w), moisture contents of 60%, 65% and 75% and air-filled porosities ranging from 46% to 1%. Due to diverse biodegradability of the investigated apple pomace and composting mixtures this test allows for the determination of the effects of different air-porosities (due to compaction in a pile) on the oxygen uptake rate for mixtures with a fixed ratio of a bulking agent. The described method allows for laboratory determination of the effects of moisture content and compaction on biodegradation dynamics during composting.

scholarly journals Aktivitas Mikroba Lumpur Aktif Konsentrasi Tinggi Pada Sistem Lumpur Aktif- Membran

REAKTOR ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 27
Author(s):  
Budiyono Budiyono ◽  
T. Setiadi ◽  
I. G. Wenten
Keyword(s):  
Oxygen Uptake ◽  
Retention Time ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Suspended Solid ◽  
Rate Parameter ◽  
Solid Retention Time ◽  
Mixed Liquor Suspended Solid ◽  
Mixed Liquor ◽  
Specific Oxygen Uptake Rate

Pengolahan air limbah dengan sistem kombinasi proses lumpur aktif dengan membrane telah banyak dimanfaatkan di beberapa negara maju. Sistem ini diketahui mampu beroperasi dengan konsentrasi lumpur aktif (MLSS, Mixed Liquor Suspended Solid) sangat tinggi sehingga menghasilkan sistem yang  kompak dengan efisiensi pengolahan tinggi. Penelitian ini mengkaji aktifitas mikroba yang terlibat dalam sistem. Aktifitas yang dikaji antara lain laju pemanfaatan oksigen spesifik (SOUR, specific oxygen uptake rate), parameter kinetika, serta laju pemanfaatan nitrogen dan fosfor.Proses pengolahan berjalan pada konsentrasi MLSS jauh di atas proses lumpur aktif konvensional, yaitu berturut-turut 18.400, 22.900, 24.300, dan 25.500 mg/l. Untuk mendapatkan konsentrasi MLSS tersebut, proses pengolahan beroperasi pada waktu tinggal cairan (HRT, hydraulic retention yime) 24 jam dan waktu tinggal sel (SRT, solid retention time) 8, 16, 24, dan 32 hari. Hasil penelitian menunjukkan bahwa mikroorganisme yang terlibat pada proses ini ditandai oleh mikroorganisme yang mempunyai laju pertumbuhan sangat lambat. Parameter kinetika yang diperoleh sebagai berikut: laju pertumbuhan maksimum spesifik (μmax) 0,024 jam-1, koefisien perolehan sel (Y)  0,515 (mg sel/ mg COD), konstanta setengah jenuh (Ks) 589 mg/l, dan laju kematian spesifik (b) 0,010 jam-1. Dengan semakin tinggi konsentrasi lumpur aktif, maka aktifitas mikroba akan semakin kecil.  SOUR yang diperoleh untuk SRT  8,16,2 dan 32 hari berturut-turut  sebesar 0,612; 0,357; 0,279; 0,207 gO2 / (gMLSS.hari). bila ditinjau dari segi operasionalisasi unit pengolahan limbah, maka proses pengolahan lumpur aktif – membran jauh lebih menghemat kebutuhan nitrogen dan fosfor untuk nutrient.Kata kunci : aktifitas mikroba, sistem lumpur aktif-membran, SOUR

Exposure to degraded coral habitat depresses oxygen uptake rate during exercise of a juvenile reef fish

Coral Reefs ◽  
2021 ◽  
Author(s):  
Adam T. Downie ◽  
Caroline M. Phelps ◽  
Rhondda Jones ◽  
Jodie L. Rummer ◽  
Douglas P. Chivers ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Reef Fish ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Juvenile Reef Fish

Mass transfer impacts in flocculent and granular biomass from SBR systems

2004 ◽  
Vol 50 (10) ◽  
pp. 203-212 ◽  
Author(s):  
D. Gapes ◽  
B.-M. Wilén ◽  
J. Keller
Keyword(s):  
Mass Transfer ◽  
Particle Size ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Batch Reactor ◽  
Average Particle Size ◽  
Gas Analysis ◽  
Average Particle

An experimental study was conducted to describe mass transfer impacts within nitrifying aggregates sourced from sequencing batch reactor (SBR) activated sludge systems. Flocculent and granular sludge with high nitrification activity was obtained in two laboratory SBR systems, supplied with a synthetic, ammonium-based feed. The flocculent biomass was fractionated using a sieving procedure, in order to obtain biomass fractions with different particle size distributions. The oxygen uptake rate (OUR) response to changes in dissolved oxygen concentration was measured under highly controlled conditions in a titrimetric and off-gas analysis (TOGA) sensor, and the results used to assess mass transfer effects. As the average particle size of the biomass increased, mass transfer limitations were found to increase significantly. Empirically fitted, apparent KS,O2 values were demonstrated to be highly dependent on particle size, and reflect the mass transfer limitations occurring in the aggregates within a given system. Such parameters thus have little to do with the actual biokinetic parameter from which they are derived. The results obtained from the TOGA sensor study were consistent with those obtained from a microelectrode study on the same nitrifying granules. Together, these studies add considerable weight to the conclusion that consideration of external and internal mass transfer limitations is vital to the accurate description of activated sludge treatment processes, particularly those with a high oxygen uptake rate.

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