Chlorophenol Degradation under Oxic and Anoxic Conditions

1992 ◽  
Vol 25 (1) ◽  
pp. 147-152 ◽  
Author(s):  
Jaakko A. Puhakka ◽  
Wen K. Shieh ◽  
Kimmo Järvinen ◽  
Esa Melin
Keyword(s):  
Steady State ◽  
Fluidized Bed ◽  
Electron Donor ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Potassium Nitrate ◽  
Fluidized Bed Reactors ◽  
Reactor Operation ◽  
Feed Concentration ◽  
Effective Removal

The degradation of 2,4,6,-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetra-chlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP) was evaluated in oxic fluidized-bed reactors. The pseudo-steady-state reactor operation at a hydraulic retention time of 5 hours and feed concentrations of 54 mg/l of 2,4,6-TCP and 64 mg/l of 2,3,4,6-TeCP resulted in stable and effective removal performances on these compounds. GC/MS results indicated over 99 % removal of both 2,4,6-TCP and 2,3,4,6-TeCP. However, PCP degradation at 74 mg/l feed concentration was neglible under these conditions. Further, a denitrifying biofilm was developed which was able to use 4-chlorophenol (4-CP) as the sole electron donor in denitrification reactions. No anoxie biofilm able to degrade 2,4-dichlorophenol (2,4-DCP) or PCP degradation in the presence of potassium nitrate could be developed.

Effects of hydraulic retention time, co-substrate and nitrogen source on laundry wastewater anionic surfactant degradation in fluidized bed reactors

2017 ◽  
Vol 224 ◽  
pp. 246-254 ◽  
Author(s):  
Marcus Vinicius Freire Andrade ◽  
Isabel Kimiko Sakamoto ◽  
Juliano José Corbi ◽  
Edson Luiz Silva ◽  
Maria Bernadete Amâncio Varesche
Keyword(s):  
Nitrogen Source ◽  
Fluidized Bed ◽  
Anionic Surfactant ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Fluidized Bed Reactors ◽  
Surfactant Degradation

Biohydrogen production in anaerobic fluidized bed reactors: Effect of support material and hydraulic retention time

2010 ◽  
Vol 35 (8) ◽  
pp. 3379-3388 ◽  
Author(s):  
Aruana Rocha Barros ◽  
Eduardo Lucena Cavalcante de Amorim ◽  
Cristiane Marques Reis ◽  
Gessia Momoe Shida ◽  
Edson Luiz Silva
Keyword(s):  
Fluidized Bed ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Biohydrogen Production ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Effect Of Support

Longitudinal dispersion and biomass hold-up of anaerobic fluidized bed reactors

1996 ◽  
Vol 34 (5-6) ◽  
pp. 461-468 ◽  
Author(s):  
M. Turan ◽  
I. Öztürk
Keyword(s):  
Fluidized Bed ◽  
Retention Time ◽  
Fluidized Beds ◽  
Hydraulic Retention Time ◽  
Biomass Concentration ◽  
Pulse Response ◽  
Longitudinal Dispersion ◽  
Fluidized Bed Reactors ◽  
Biofilm Growth ◽  
Biological Growth

Longitudinal dispersion in fluidized bed reactors was studied using pulse-response techniques for both clean and anaerobic-biofilm coated media. A large number of experimental data on the longitudinal dispersion and biofilm growth in the anaerobic fluidized bed reactors (AFBRs) were investigated. Some correlations applicable to fluidized beds were obtained for both the hydraulic retention time and the biomass concentration versus the ratio Pe/Re. The biomass concentration tends to zero for a critical retention time in AFBRs. The biological growth in the bed causes an increase of Pe number.

The effects of hydraulic retention time and feed COD concentration on the rate of hydrolysis of primary sewage sludge under methanogenic conditions

2006 ◽  
Vol 54 (5) ◽  
pp. 91-100 ◽  
Author(s):  
N.E. Ristow ◽  
S.W. Sötemann ◽  
M.C. Wentzel ◽  
R.E. Loewenthal ◽  
G.A. Ekama
Keyword(s):  
Steady State ◽  
Sewage Sludge ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Mean Value ◽  
Operating Conditions ◽  
Hydrolysis Rate ◽  
Feed Concentration ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

A series of completely mixed methanogenic anaerobic digesters have been operated to determine the rate of hydrolysis of primary sewage sludge. The hydraulic retention time was reduced from 60 d to when the system failed (∼5 d), while the feed COD concentration was 40, 25, 13 and 2 gCOD/L. A steady state model based on first order kinetics was developed to simulate the hydrolysis rate at each retention time and feed concentration. With the mean value for the hydrolysis rate constant (0.992±0.492 d−1), this model was able to accurately predict the effluent COD for all steady state operating conditions. However, the effluent COD concentration was relatively insensitive to the exact value for this constant. The model provides a framework for analysis of anaerobic digestion experimental data, to enable meaningful comparisons.

scholarly journals Evaluasi Hydraulic Retention Time (Hrt) Terhadap Removal Chemical Demand (Cod) Dalam Pengolahan Air Lindi Menggunakan Aerobic Fluidized Bed Reactor (AFBR)

2018 ◽  
Vol 2 (2) ◽  
pp. 28
Author(s):  
Elli Prasetyo
Keyword(s):  
Steady State ◽  
Chemical Oxygen Demand ◽  
Fluidized Bed ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Fluidized Bed Reactor ◽  
Start Up

Sampah merupakan masalah utama disetiap kota besar di indonesia. Tumpukan sampah menghasilkan air lindi dengan kandungan organik yang tinggi. Beban organik yang tinggi dan meningkatnya laju alir lindi memerlukan kolam aerasi yang luas untuk mengolah lindi. Salah satu metode pengolahan air lindi yang tepat dan efisien dengan menggunakan proses anaerobik. Anaerobic Fludized Bed Reaktor (AFBR) merupakan salah satu reactor anaerobic dengan efisiensi tinggi. Zeolit digunakan sebagai media imobilisasi bakteri untuk meningkatkan efisiensi pengolahan secara anaerobic pada reactor AFBR. Penyesuaian model kinetika dilakukan pada tahap awal menggunakan data reactor fase batch untuk diaplikasikan pada AFBR fase continyu. Model kinetika untuk mengevaluasi pengaruh Hydraulic Retention Time (HRT) terhadap removal Chemical Oxygen Demand (COD) AFBR dengan zeolit sebagai media imobilisasi. Eksperimen dilakukan dalam tiga fase, yaitu fase batch, fase start-up, dan fase steady state. Fase batch bertujuan untuk menentukan konstanta model kinetika. Fase start-up bertujuan untuk memverifikasi konstanta model yang ditentukan dengan data batch pada AFBR saat masa start up. Fase steady state bertujuan untuk mengevaluasi pengaruh HRT selama reactor beroperasi. Reaktor AFBR mencapai kondisi steady state tercepat pada HRT 10 dengan removal COD 73,40%. Hal ini membuktikan bahwa mikroorganisme tidak mengalami washout bahkan pada laju beban organik yang lebih tinggi sehingga mikroorganisme dapat menstabilkan populasinya. Data menunjukkan bahwa sCOD effluen (SCODeff) lindi TPA Piyungan mencapai nilai terendah pada kisaran 2.000 – 2.500 mg/L, Produksi biogas mengikuti fluktuasi nilai sCODeff. Pada kondisi steady state, nilai ini tidak dipengaruhi oleh HRT.

Effect of hydraulic retention time on metal precipitation in sulfate reducing inverse fluidized bed reactors

2014 ◽  
Vol 90 (1) ◽  
pp. 120-129 ◽  
Author(s):  
Denys Kristalia Villa Gomez ◽  
Anne Marie Enright ◽  
Eki Listya Rini ◽  
Audrey Buttice ◽  
Herman Kramer ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Fluidized Bed Reactors ◽  
Sulfate Reducing ◽  
Metal Precipitation ◽  
Inverse Fluidized Bed

Anaerobic/aerobic biodegradation of pentachlorophenol using GAC fluidized bed reactors: optimization of the empty bed contact time

1997 ◽  
Vol 36 (6-7) ◽  
pp. 107-115 ◽  
Author(s):  
Gregory J. Wilson ◽  
Amid P. Khodadoust ◽  
Makram T. Suidan ◽  
Richard C. Brenner
Keyword(s):  
Fluidized Bed ◽  
Oxygen Demand ◽  
Aerobic Biodegradation ◽  
Fluidized Bed Reactors ◽  
Reactor Performance ◽  
Reactor Operation ◽  
Significant Cost ◽  
Second Stage ◽  
Primary Substrate ◽  
Chlorinated Phenolic Compounds

An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to predominately equimolar concentrations (>99%) of monochlorophenol (MCP) in two GAC fluidized bed reactors at Empty Bed Contact Times (EBCTs) ranging from 18.6 to 1.15 hours. However, at lower EBCTs, MCP concentrations decreased to less than 10% of the influent PCP concentration suggesting mineralization. The optimal EBCT was determined to be 2.3 hours based on PCP conversion to MCPs and stable reactor operation. Decreasing the EBCT fourfold did not inhibit degradation of PCP and its intermediates, thus allowing removal of PCP at much lower detention time and resulting in a significant cost advantage. Analytical grade PCP was fed via syringe pumps into two fluidized bed reactors at influent concentrations of 100 mg/l and 200 mg/l, respectively. Acting as the primary substrate, ethanol was also fed into the reactors at concentrations of 697 and 1388 mg/l. Effluent PCP and chlorinated phenolic compounds were analyzed weekly to evaluate reactor performance. Biodegradation pathways were also identified. 3-chlorophenol (CP) was the predominant MCP and varied simultaneously with 3,5-dichlorophenol (DCP) concentrations. Likewise, 4-CP concentrations varied simultaneously with 3,4-DCP concentrations. A second stage aerobic GAC fluidized bed reactor was added after the anaerobic reactor to completely mineralize the remaining MCP and phenols. Data show no presence of phenol and MCP in the effluent or on the GAC. Overall, the chemical oxygen demand (COD) fed to the system was reduced from 75 g/d in the influent to less than 1.5 g/d in the effluent.

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