Nitrogen removal in a submerged filter with no effluent recirculation

2000 ◽  
Vol 42 (3-4) ◽  
pp. 51-58 ◽  
Author(s):  
P.C. Chui ◽  
Y. Terashima ◽  
J.H. Tay ◽  
H. Ozaki ◽  
S. Jeyaseelan
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Industrial Effluents ◽  
Anaerobic Treatment ◽  
Anoxic Zone ◽  
Influent Concentration ◽  
Test Conditions ◽  
Effluent Recirculation ◽  
Effluent Recycling

The performance of a partly aerated submerged filter in treating high nitrogenous wastewaters such as industrial effluents after anaerobic treatment was investigated in this study. The filter was operated without effluent recycling and its response to various test conditions of aeration rates, hydraulic loads, COD/N ratios and hydraulic retention times was evaluated. Results indicated that for an influent concentration of 250 mg N/L and for a loading rate of 0.7 kg N/m3.d, 60% of the nitrogen can be removed. For a reduced loading rate of 0.25 kg N/m3.d, nitrogen removal efficiency could reach 86%. Denitrification was hypothesized to have taken place inside the support media in the aerated zone of the filter where oxygen was lacking as well as at locations immediately below the air diffuser where an anoxic zone was formed with the back-flowing nitrified substrate.

scholarly journals Stuydy on sequencing batch moving bed membrane bioreactor technology (SBMBMBR) for the removal of organic and total nitrogen in tannery wastewater

2014 ◽  
Vol 17 (2) ◽  
pp. 69-79
Author(s):  
Linh Van Tran ◽  
Phuoc Van Nguyen ◽  
Phuong Thi Thanh Nguyen
Keyword(s):  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Loading Rate ◽  
Nitrogen Loading ◽  
Cod Removal ◽  
Tannery Wastewater ◽  
Moving Bed ◽  
Cod Removal Efficiency

The SBMBMBR technology (sequencing batch moving bed membrane bioreactor), a combiantion of membrane filtration MF process in activated sludge with sequencing batch (SBR) moving bed using Anox Kaldnes K2 (MBBR), has been studied for the removal of organic and total nitrogen in tannery wastewater. After 170 days, reasearch results showed that the COD removal efficiency was ranged from 89,2±0,6 to 95,9±0,3% when the organic loading rate changed from 0,564±0,019 to 1.207±99 kgCOD/m3/day. The total nitrogen removal efficiency reached 30,0±4,9 to 65,9±13,3. The highest COD removal efficiency was 0,72±0,02 kgCOD/m3/day. The lowest nitrogen removal efficiency was 10,8±5,4% at 0,327±0,020 kgTN/m3/day of nitrogen loading rate. During the research, the adhensional tension of microorganism was insignificant. The biomass remained unchanged with 6.808±226 mg/L of Mixed liquor suspended solids (MLSS). When the salinity went up from 3.500 to 8.000 mgCl/l, the COD and nitrogen removal efficiency decreased. However, the conversion of nitrogen was improved and the recovery of biomass following the changed loading rate was quite fast.

Nitrogen removal from reject water with primary sludge as denitrification carbon source

2010 ◽  
Vol 61 (12) ◽  
pp. 2965-2972 ◽  
Author(s):  
L. Zhang ◽  
S. J. Zhang ◽  
J. Zhou ◽  
S. Y. Wang ◽  
Y. P. Gan ◽  
...  
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Suspended Solid ◽  
Nitrogen Loading ◽  
Solid Retention Time ◽  
Primary Sludge ◽  
Reject Water ◽  
Denitrification Reactor

A novel system was used for nitrogen removal from reject water. This system includes one anoxic/oxic reactor for nitrification and a special reactor for denitrification in which primary sludge was added intermittently as electron donor. In denitrification reactor, sludge fermentation and denitrification reaction took place simultaneously and promoted each other. It was found that effluent recycle could improve nitrogen removal efficiency due to reclaiming of alkalinity. Under steady state conditions, the average solid retention time (SRT) in denitrification reactor was 12–15 d, a total nitrogen loading rate was 0.2 kg N/(m3 day) and TN removal efficiency was more than 90% without extra carbon source addition. Primary sludge was degraded so that volatile suspended solid (VSS) decreased by 50%. Further investigation showed that ORP could be taken as a control parameter for sludge addition.

APLIKASI PROSES BIOLOGI ANAEROBIK PADA PENGOLAHAN AIR LIMBAH ORGANIK BERKONSENTRASI GARAM TINGGI “STUDI KASUS INDUSTRI UME BOSHI”

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Ikbal Mahmud
Keyword(s):  
Fluidized Bed ◽  
Removal Efficiency ◽  
Loading Rate ◽  
Salt Content ◽  
Fluidized Bed Reactor ◽  
Anaerobic Treatment ◽  
Evolved Gas ◽  
Toc Removal ◽  
Anaerobic Fluidized Bed Reactor ◽  
Organic Carbon Loading

Anaerobic treatment of wastewater with high organic and salt content but low pH (TOC, 14 g/l; salt, 150 g/l; pH,2.7) generated during an “ume boshi” manufacturing process was investigated. Five-fold-diluted “ume boshi” effluent was treated by a draw-and-fill method at a volumetric TOC (total organic carbon) loading rate of 3.0  g/l/d with a TOC removal efficiency of 75%. Five-fold-diluted “ome boshi” effluent was also treated in an anaerobic fluidized-bed reactor (AFBR) at a maximum volumetric TOC loading rate of 3.0 g/l/d, which gave almost the same results as the draw-and-fill method. However, ten-fold-diluted “ome boshi” effluent could be treated in the AFBR at a maximum volumetric TOC loading rate of 11 g/l/d with a TOC removal efficiency of 85%. The methane content in the evolved gas was high, being 70%. The red pigment in the “ome boshi” effluent was completely decolorized by the anaerobic treatment.  Key words :, Anaerobic fluidized-bed reactor, “Ume boshi”Co2+ and Ni2+ ions, decolorization

Simultaneous Nitrification and Denitrification in Biofilm-Electrode Reactor

2013 ◽  
Vol 652-654 ◽  
pp. 1633-1636 ◽  
Author(s):  
Xiao Liu ◽  
Mei Yang ◽  
Xian Huai Huang
Keyword(s):  
Dissolved Oxygen ◽  
Electric Current ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Simultaneous Nitrification And Denitrification ◽  
Autotrophic Denitrification ◽  
Effluent Recirculation ◽  
Removal Efficiencies ◽  
Nitrification And Denitrification ◽  
Limited Oxygen

To study the nitrification and denitrification in compartmented biofilm-electrode reactor (C-BER) under limited oxygen, influence of mild electrolysis on nitrogen removal was investigated under low C/N (mole ratios) with dissolved oxygen about 1mg/ L. It was found that nitrogen removal was mainly through simultaneous nitrification and denitrification (SND). C/N ratio was 1, average total nitrogen (TN) removal efficiencies were 33% and 45% for electric current of 5 and 15mA. C/N was 0.5, electric current was 25mA and effluent was recirculated, TN removal efficiency increased to 60%, within which autotrophic denitrification accounted for about 51%. There was about 50% NH3-N reduced under 15mA when C/N ratio was 1, this increased to 70% for 25mA when C/N ratio was 0.5. Nevertheless, TN reduced between anode and cathodes accounted for 64% in all. The experimental results show that both higher electric current and effluent recirculation are good for SND process under oxygen-limited condition, nitrogen removal can be activated by mild electrolysis.

scholarly journals Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 876 ◽  
Author(s):  
Kangmao He ◽  
Huapeng Qin ◽  
Fan Wang ◽  
Wei Ding ◽  
Yixiang Yin
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Early Stage ◽  
Nitrogen Concentration ◽  
Rainfall Amount ◽  
Dry Period ◽  
Upward Trend ◽  
Influent Concentration ◽  
Bioretention System ◽  
Exponential Decline

Adding a submerged zone (SZ) is deemed to promote denitrification during dry periods and thus improve NO3− removal efficiency of a bioretention system. However, few studies had investigated the variation of nitrogen concentration in the SZ during dry periods and evaluated the effect of the variation on nitrogen removal of the bioretention system. Based on the experiment in a mesocosm bioretetion system with SZ, this study investigated the variation of nitrogen concentration of the system under 17 consecutive cycles of wet and dry alternation with varied rainfall amount, influent nitrogen concentration and antecedent dry periods (ADP). The results indicated that (1) during the dry periods, NH4+ concentrations in SZ showed an exponential decline trend, decreasing by 50% in 12.9 ± 7.3 h; while NO3− concentrations showed an inverse S-shape declining trend, decreasing by 50% in 18.8 ± 6.4 h; (2) during the wet periods, NO3− concentration in the effluent showed an S-shape upward trend; and at the early stage of the wet periods, the concentration was relatively low and significantly correlated with ADP, while the corresponding volume of the effluent was significantly correlated with the SZ depth; (3) in the whole experiment, the contribution of nitrogen decrease in SZ during dry periods to NH4+ and NO3− removal accounted for 12% and 92%, respectively; and the decrease of NO3− in SZ during the dry period was correlated with the influent concentration in the wet period and the length of the dry period.

scholarly journals TREATMENT CHARACTERISTICS AND OPERATIONAL PARAMETERS OF A NEWLY DEVELOPED REACTOR WITH SLUDGE SEPARATION FILTER AND AIRLIFT PUMP FOR CARBON AND NITROGEN REMOVAL

2015 ◽  
pp. 136-141
Author(s):  
Fumitake Nishimura
Keyword(s):  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Loading Rate ◽  
Middle Part ◽  
Operational Parameters ◽  
Anoxic Zone ◽  
Treatment Characteristics ◽  
Airlift Pump ◽  
N Loading ◽  
Aerobic Zone

Nutrient removal from sewage is one of the most urgently required issues from the viewpoint of prevention of eutrophication and preservation of water quality for water supply system. Among several nutrient removal methods, biological treatment, which is a modified activated sludge system is widely applied. However, biological nitrogen removal process, which consists of nitrification and denitrification steps, needs opposite operations at several stages such as necessity of oxygen and requirement of electron donor of organic compounds. In this study, treatment characteristics of a reactor with both sludge separation filter and airlift pump are investigated. This reactor has sludge separation filter in the middle part and airlift pump that supplies oxygen and circulate liquid from aerobic zone to anoxic zone in order to cut down the required energy. From laboratory scale experiments, design and operational parameters are investigated and it is shown that NH4-N loading rate of 35 mgN/(L-media･hr) at aerobic zone and DO loading rate of less than 0.15 kgDO/(kgMLSS･d) to anoxic zone are required for stable treatment.

Performance of a partly aerated biofilter in the removal of nitrogen

1996 ◽  
Vol 34 (1-2) ◽  
pp. 187-194 ◽  
Author(s):  
P. C. Chui ◽  
Y. Terashima ◽  
J. H. Tay ◽  
H. Ozaki
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Nitrogen Concentration ◽  
Fixed Bed ◽  
Bulk Liquid ◽  
Carbon Oxidation ◽  
High Nitrogen ◽  
Volumetric Loading ◽  
High Nitrogen Concentration

The removal efficiency of nitrogen and organic matter in an anoxic/aerobic upflow fixed bed filter was studied. Tests were carried out on the effects of aeration, hydraulic loading rate, and COD/N ratio on nitrogen removal and carbon oxidation. A synthetic high nitrogen concentration wastewater was used as substrate feed in the study. At an influent concentration of 250 mg N/L, and for volumetric loadings of up to 1 kg N/m3.day, between 41% and 86% of the nitrogen was removed. This was achieved without the recycling of effluent for denitrification. Nitrogen removal was possible when simultaneous denitrification took place inside the support media where oxygen was lacking. COD removal efficiency was consistently above 95% even at a high volumetric loading of 5 kg COD/m3.day and a bulk liquid dissolved oxygen level as low as 1.1 mg/L.

Treatment of landfill leachate by a pilot-scale modified Ludzack-Ettinger and sulfur-utilizing denitrification process

2004 ◽  
Vol 50 (6) ◽  
pp. 141-148
Author(s):  
J.-H. Bae ◽  
I.-S. Lee ◽  
M.-S. Jang ◽  
K.-H. Ahn ◽  
S.-H. Lee
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Landfill Leachate ◽  
Loading Rate ◽  
Removal Rate ◽  
Packed Bed ◽  
Pilot Scale ◽  
Packed Bed Reactor ◽  
Treatment System ◽  
Flow Mode

Nitrogen removal efficiency of a pilot-scale system consisted of Modified Ludzack-Ettinger (MLE) followed by sulfur-utilizing denitrification (SUDNR) process was evaluated with a landfill leachate. For SUDNR, a down-flow mode sulfur packed bed reactor (SPBR) filled with sulfur and limestone particles was used. Although total nitrogen removal efficiency of the MLE process was about 80% at the recycle ratio of 4, effluent contained 350-450 mg/L NO3--N. Up to a loading rate of 1.2 kg NO3--N/m3-day, the SPBR could achieve complete removal of nitrate, and nitrate removal rate was kept to that level even at higher loading rate. When a COD/N ratio of MLE process was maintained at 2 instead of 4, more organics with molecular weight less than 500 were utilized for heterotrophic denitrification although denitrification was not complete with the lack of electron donors. Clogging in the SPBR, mainly by the accumulation of nitrogen gas in the pores, could easily be removed by introducing the effluent in an upward direction for 1 min at 1 hr intervals. The proposed treatment system could achieve nitrate free effluent with a slight increase in chemical cost. Furthermore, depending on further COD removal requirement after biological treatment, the proposed treatment system can be an economical solution.

Vacuum Operation for Overloaded Anaerobic Treatment Systems

1989 ◽  
Vol 21 (4-5) ◽  
pp. 87-95
Author(s):  
J. De Santis ◽  
A. A. Friedman
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Anaerobic Treatment ◽  
Optimum Operating ◽  
Operating Pressure ◽  
Simple Modification ◽  
Anaerobic Reactors ◽  
Fixed Film ◽  
Solids Retention ◽  
High Concentrations

Overloaded anaerobic treatment systems are characterized by high concentrations of volatile fatty acids and molecular hydrogen and poor conversion of primary substrates to methane. Previous experiments with fixed–film reactors indicated that operation with reduced headspace pressures enhanced anaerobic treatment. For these studies, four suspended culture, anaerobic reactors were operated with headspace pressures maintained between 0.5 and 1.0 atm and a solids retention time of 15 days. For lightly loaded systems (0.4 g SCOD/g VSS-day) vacuum operation provided minor treatment improvements. For shock organic loads, vacuum operation proved to be more stable and to support quicker recovery from upset conditions. Based on these studies and a companion set of bioassay tests, it was concluded that: (a) a loading rate of about 1.0 g SCOD/g VSS-day represents a practical loading limit for successful anaerobic treatment, (b) a headspace pressure of approximately 0.75 atm appears to be an optimum operating pressure for anaerobic systems and (c) simple modification to existing systems may provide relief for organically overloaded systems.

Enhancement of nitrogen removal in subsurface flow constructed wetlands employing a 2-stage configuration, an unsaturated zone, and recirculation

1995 ◽  
Vol 32 (3) ◽  
pp. 59-67 ◽  
Author(s):  
Kevin D. White
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Great Promise ◽  
Effluent Recirculation ◽  
Wetland Treatment ◽  
Subsurface Flow Constructed Wetlands ◽  
Inlet Zone ◽  
Bod Removal

Constructed wetland technology is currently evolving into an acceptable, economically competitive alternative for many wastewater treatment applications. Although showing great promise for removing carbonaceous materials from wastewater, wetland systems have not been as successful at nitrification. This is primarily due to oxygen limitations. Nitrification does occur in conventional wetland treatment systems, but typically requires long hydraulic retention times. This paper describes a study that first evaluated the capability of subsurface flow constructed wetlands to treat a high strength seafood processor wastewater and then evaluated passive aeration configurations and effluent recirculation with respect to nitrogen treatment efficiency. The first stage of a 2-stage wetland treatment system exhibited a relatively short hydraulic retention time and was designed for BOD removal only. The second stage wetland employed an unsaturated inlet zone and effluent recirculation to enhance nitrification. Results indicate that organic loading, and thus BOD removal, in the first stage wetland is key to optimal nitrification. Passive aeration through an unsaturated inlet zone and recirculation achieved up to 65-70 per cent ammonia nitrogen removal at hydraulic retention times of about 3.5 days. Inlet zone configuration and effluent recirculation is shown to enhance the nitrogen removal capability of constructed wetland treatment systems.

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