Biological denitrification of a textile effluent in a dynamic sand filter

1998 ◽  
Vol 38 (1) ◽  
pp. 123-132 ◽  
Author(s):  
R. Canziani ◽  
L. Bonomo
Keyword(s):  
Removal Rate ◽  
Plug Flow ◽  
Pilot Scale ◽  
Zero Order ◽  
Biofilm Reactor ◽  
Textile Effluent ◽  
Order Kinetic ◽  
Sand Filter ◽  
Loading Rates ◽  
Nitrogen Bubbles

Post-denitrification of a pre-treated textile effluent was tested in a pilot-scale dynamic up-flow sand filter, which has been used as a biofilm reactor, together with filtration of suspended solids (SS) and decolorization. The potential application of the reactor as a three-in-one unit (decolorization, filtration and denitrification) has been successfully tested. Biomass growth and the sloughing of biological film did not prevent the removal of high concentrations of influent SS. Both pilot- and bench-scale tests confirmed that the intrinsic denitrification kinetics was zero-order, corresponding to a half-order removal rate if nitrate concentration is lower than 10 mgN l−1. Zero-order and half-order kinetic constants have also been calculated. At low nitrate loading rates (up to 2 kgN m−3 d−1) the filter followed the ideal plug-flow hydrodynamic model. In the lower part of the filter, zero-order kinetics fitted denitrification removal rates, while in the upper part of the filter denitrification followed half-order kinetics. At nitrate loading rates higher than 2.5 kgN m−3 d−1, nitrogen bubbles developed and partially mixed the reactor. Consequently, flatter concentration profiles were detected in the reactor and denitrification followed half-order kinetics along the entire filter.

Sludge production characteristics of small-scale wastewater treatment facilities using anaerobic/aerobic biofilm reactors

1996 ◽  
Vol 34 (3-4) ◽  
pp. 379-387 ◽  
Author(s):  
Yuhei Inamori ◽  
Tomotake Takai ◽  
Yasuhiro Yamamoto ◽  
Nobuyoshi Katagai ◽  
Toshihiro Sankai ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Plug Flow ◽  
Biofilm Reactor ◽  
Small Scale ◽  
Constant Flow Rate ◽  
Loading Rates ◽  
Circulation Ratio ◽  
Treatment Facilities ◽  
Production Characteristics ◽  
Sludge Production

Sludge production characteristics were investigated in many on-site small-scale wastewater treatment facilities used to treat domestic wastewater of about 1.25m3/day. Two popular types have been used in experiments for several years; one was an anaerobic bed reactor with constant flow-rate control system followed by aerobic bio-filtration reactor CFR type facility), and the other was an aerobic bed reactor with plug-flow stream followed by aerobic biofilm reactor (PFS type facility). Circulation ratio was set at 0 and 4. From the results obtained, lower sludge production rates were observed in CFR type facilities. Furthermore, it was suggested that a promotion of sludge decrease occurred in facilities with high denitrification activity at circulation ratio of 4. The results from experiments with different SS loading rates in laboratory-scale reactors suggested that at higher loading rates, the produced sludge was greater on account of the decrease of nitrification activity even on a circulating operation.

High biofilm activity under increased oxygen concentrations in a pressurised biofilm system

2005 ◽  
Vol 52 (7) ◽  
pp. 69-75 ◽  
Author(s):  
K.F. Janning ◽  
S.N. Bak ◽  
M. Andersen ◽  
G.H. Kristensen
Keyword(s):  
Liquid Film ◽  
Reaction Rate ◽  
Removal Rate ◽  
Fold Increase ◽  
Order Rate Constant ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Synthetic Wastewater ◽  
Film Diffusion ◽  
Zero Order Reaction

A new pressurised biofilm reactor (PBR) process with a patented disc system that enables constant biofilm control has been developed to treat concentrated wastewater with respect to easily degradable organic matter under pressures of up to 6 bar. The pressurisation enables a six-fold increase of the O2 saturation level and aeration capacity, which potentially increases the reaction rate of COD as long as O2 is limiting the reaction rate. Experiments performed in a pilot-scale PBR-reactor fed by synthetic wastewater were conducted to verify the potential and kinetics of heterotrophic conversion of O2 and acetate. Under O2-limited conditions the maximum removal rate of O2 and CODf was measured to rA,O2=60 g O2/m2/d and rA,CODf=150 g CODf/m2/d at 70 mg O2/l. Experiments verified that half-order kinetics could be applied but liquid film diffusion apparently influenced the reaction rate considerably. The observed half-order rate constant was experimentally determined to K½A,O2=7.0 (g O2)1/2m−1/2d−1 but this value is underestimated by 15% due to the observed liquid film diffusion. Based on this the intrinsic zero-order reaction rate was estimated at k0f,O2=190 kg O2/m3 biofilm/d when both liquid film and biofilm diffusion were taken into account.

scholarly journals Polishing of Chemical Oxygen Demand (COD) Using Moving Bed Bio-Reactor

2015 ◽  
Vol 773-774 ◽  
pp. 1281-1285
Author(s):  
Jamal Ali Kawan ◽  
Rakmi Abd-Rahman ◽  
Othman bin Jaafar ◽  
Fatihah Suja
Keyword(s):  
Chemical Oxygen Demand ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Research Work ◽  
Real Life ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Moving Bed ◽  
Building Engineering

The pilot-scale experiment in moving bed biofilm reactor (MBBR) with a capacity of 433 L was carried out for this study with real life situations, it was decided that the complete research work must be done under as realistic conditions as possible,i.e.with real municipal wastewater, chemical free and with local commercially available products such as carriers for biofilm reactor. The reactor was start-up in 30/9/2013 up to date, Effluent from clarifier of STP used as influence of MBBR for polishing. MBBR is using continues down flow to polish effluent municipal wastewater from a faculty of new building engineering community in UKM to get the water free from main pollutant parameters, for reuse in the irrigation or discharge to the river. Laboratory experiments will conduct with different hydraulic retention time (HRT), filling ratio of plastic (Enviro Multi Media) in the MBBR about 5%. Aerobic reactors used the majority of the decaying organic material. An average removal rate of 41.75%, 32.85%, 24.80% and 35.77% of initial chemical oxygen demand (COD) were achieved under a HRT of 24hr, 12hr, 6hr and 2hr, respectively. The model simulated results showed good agreements with experimental results. The model could be employed in the design of a full-scale MBBR process for simultaneous removal of organic carbon from effluent STP.

Pesticide removal by GAC preloaded with natural organic matter

2002 ◽  
Vol 2 (1) ◽  
pp. 147-154 ◽  
Author(s):  
Y. Matsui ◽  
K. Iwaki ◽  
M. Uematsu ◽  
A. Yuasa
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Natural Organic Matter ◽  
Membrane Filtration ◽  
Removal Rate ◽  
Free Water ◽  
Pilot Scale ◽  
Order Kinetic ◽  
Pesticide Concentration ◽  
Pesticide Removal

The removal of hydrophobic and hydrophilic pesticides (simazine and asulum) by granular activated carbon (GAC) adsorbers preloaded with natural organic matter (NOM) was studied through experiments using pilot scale columns and microcolumns. The pesticide concentration increased with time after the pesticide application, and it reached a pseudo-steady-state plateau. Less than 8% of the adsorbed simazine desorbed back into the column effluent by 15 days after the influent was switched to simazine-free water. The simazine desorbed from the upper part of the bed was re-adsorbed in the lower part, keeping the effluent concentration at a low level. In the pseudo-steady-state, the removal rate was described by a first order kinetic reaction for the pesticide concentration. The evaluation of removal rate modulus value revealed the profile of loaded pesticide-competitive NOM with depth. The pesticide-competitive NOMs were different for each pesticide. The percentage of the simazine-competitive NOM to the whole NOM increased after UF membrane filtration (molecular weight cutoff 1K), but not for the asulum-competitive NOM.

Dairy washwater treatment using a horizontal flow biofilm system

2008 ◽  
Vol 58 (9) ◽  
pp. 1879-1888 ◽  
Author(s):  
E. Clifford ◽  
M. Rodgers ◽  
D. de Paor
Keyword(s):  
Loading Rate ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Dairy Farm ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Nitrate Contamination ◽  
Horizontal Flow ◽  
Ambient Temperatures ◽  
Economical Alternative

In Ireland, land-spreading is the most widely used method for treating dairy wastewaters. This can be labour intensive and can cause, in some cases, nitrate contamination of groundwater. In this study a simple pilot-scale horizontal flow biofilm reactor (HFBR) with a step-feed was developed and tested at a dairy farm site in County Offaly, Ireland for partial remediation of this soiled water prior to landspreading. During the 122-day study, the top surface plan area (TSPA) hydraulic loading rate was 50 L/m2/day. Influent concentrations averaged: 2904.2 mg total chemical oxygen demand (COD)/L, 950 mg 5-day biochemical oxygen demand (BOD5)/L and 177.9 mg total nitrogen (TN)/L. Between Days 1 and 45 frequent ambient temperatures below 4°C inhibited the build-up of biomass resulting in low removals. From Day 45 the HFBR unit removed 74.9% total COD and 69.6% BOD5, equivalent to TSPA removals of 108.8 g COD/m2/day and 33.1 g BOD5/m2/day. On Sheet 29, by the end of the study, the NH4–N had reduced from 123.1 mg/L in the influent to 37.0 mg/L. TN removal in the reactor averaged 56.0% equating to a TSPA removal rate of 5.0 g TN/m2/day. The HFBR does not require any mechanical aeration, was simple and inexpensive to construct and can provide a robust and economical alternative for the remediation of agricultural soiled water before landspreading.

Comparative study of domestic wastewater treatment efficiencies between facultative pond and water spinach pond

1995 ◽  
Vol 32 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Seni Karnchanawong ◽  
Jaras Sanjitt
Keyword(s):  
Growth Rates ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Organic Content ◽  
Water Spinach ◽  
Removal Rates ◽  
Mass Removal ◽  
Loading Rates ◽  
Tropical Conditions ◽  
Average Water

Two pilot-scale studies were comparatively conducted under tropical conditions during December 1992 to September 1993. One study involved facultative ponds(FP) and the others water spinach ponds(SP). Four rectangular concrete ponds, 0.8 m × 2.4 m × 1.1 m (width × length × depth), were employed to treat the Chiang Mai University campus wastewater. Water spinach (Ipomoea aquatica) was planted in two of the ponds. The influent characteristics noted showed a low organic content, i.e. BOD 25.4-29.9 mg/l, with BOD:N ratio around 1:1. The investigations were conducted using the following hydraulic retention times (HRT): 1.6, 2, 2.7, 4, 8 and 16 d. The results showed that the BOD, COD and SS mass removal rates increased as the mass loading rates increased and the SP was significantly more effective in reducing the organic content than the FP. No relationship was found between TN mass removal and the loading rates. However, the TP mass removal rates in the SP and the FP were rather low and were considered to be insignificant. It was observed that SS accumulated in the water spinach root systems which tended to act as a strainer. This process led to plant growth inhibition and finally die-off. The average water spinach growth rates varied from 37 to 107 g wet wt./(m2.d) and no relationship was established between the growth rates and the HRT.

Anaerobic Thermophilic (55°C) Treatment of TMP Whitewater in Reactors Based on Biomass Attachment and Entrapment

1999 ◽  
Vol 40 (11-12) ◽  
pp. 67-75 ◽  
Author(s):  
Sigrun J. Jahren ◽  
Jukka A. Rintala ◽  
Hallvard Ødegaard
Keyword(s):  
Granular Sludge ◽  
Biofilm Reactor ◽  
Upflow Anaerobic Sludge Blanket ◽  
Hybrid Reactor ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Anaerobic Reactors ◽  
Multi Stage ◽  
Degradation Rates ◽  
Thermomechanical Pulping

Thermomechanical pulping (TMP) whitewater was treated in thermophilic (55°C) anaerobic laboratory-scale reactors using three different reactor configurations. In all reactors up to 70% COD removals were achieved. The anaerobic hybrid reactor, composed of an upflow anaerobic sludge blanket (UASB) and a filter, gave degradation rates up to 10 kg COD/m3d at loading rates of 15 kg COD/m3d and hydraulic retention time (HRT) of 3.1 hours. The anaerobic multi-stage reactor, consisting of three compartments, each packed with granular sludge and carrier elements, gave degradation rates up to 9 kg COD/m3d at loading rates of 15-16 kg COD/m3d, and HRT down to 2.6 hours. Clogging and short circuiting eventually became a problem in the multi-stage reactor, probably caused by too high packing of the carriers. The anaerobic moving bed biofilm reactor performed similar to the other reactors at loading rates below 1.4 kg COD/m3d, which was the highest loading rate applied. The use of carriers in the anaerobic reactors allowed short HRT with good treatment efficiencies for TMP whitewater.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

Use of a sequencing batch biofilter for degradation of azo dyes (acids and bases)

2000 ◽  
Vol 42 (5-6) ◽  
pp. 329-336 ◽  
Author(s):  
M. Quezada ◽  
I. Linares ◽  
G. Buitrón
Keyword(s):  
Azo Dyes ◽  
Azo Dye ◽  
Degradation Rate ◽  
Removal Rate ◽  
Textile Effluent ◽  
Colour Removal ◽  
Substrate Degradation ◽  
Acids And Bases ◽  
Removal Efficiencies ◽  
Basic Red 46

The degradation of azo dyes in an aerobic biofilter operated in an SBR system was studied. The azo dyes studied were Acid Red 151 and a textile effluent containing basic dyes (Basic Blue 41, Basic Red 46 and 16 and Basic Yellow 28 and 19). In the case of Acid Red 151 a maximal substrate degradation rate of 288 mg AR 151/lliquid·d was obtained and degradation efficiencies were between 60 and 99%. Mineralization studies showed that 73% (as carbon) of the initial azo dye was transformed to CO2 by the consortia. The textile effluent was efficiently biodegraded by the reactor. A maximal removal rate of 2.3 kg COD/lliquid·d was obtained with removal efficiencies (as COD) varying from 76 to 97%. In all the cycles the system presented 80% of colour removal.

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