Effect of internal recycle rate on the high-strength nitrogen wastewater treatment in the combined UBF/MBR system

2005 ◽  
Vol 51 (10) ◽  
pp. 241-247 ◽  
Author(s):  
Y.T. Ahn ◽  
S.T. Kang ◽  
S.R. Chae ◽  
J.L. Lim ◽  
S.H. Lee ◽  
...  
Keyword(s):  
Surface Charge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Synthetic Wastewater ◽  
High Concentration ◽  
Combined System ◽  
Recycle Rate ◽  
Influent Flow

An anaerobic/aerobic system combining an anaerobic upflow-sludge bed filter (UBF) and an aerobic membrane bioreactor (MBR) was operated to enhance organic and nitrogen removal efficiency. The internal recycle rate, which is one of the most important operation factors that affects overall removal efficiency, was varied from 100% to 300% of the influent flow. Under these conditions, the overall removal efficiencies of organic and nitrogen and characteristics of membrane fouling in the combined system treating the synthetic wastewater including high concentration of organics and nutrients were studied. As a result, nitrogen removal efficiency was increased to 67% when the internal recycle rate was 300% of influent flow rate. As the internal recycle ratio increased from 100% to 200%, protein content decreased by 17% and carbohydrate content increased by 12%. However, there was no remarkable difference in total extracellular polymeric substances (EPS) content. At the high recycle rate of 300%, the surface charge of sludge was decreased while hydrophobicity (specific ultraviolet absorbance, SUVA) was increased. The differences in SUVA and surface charge were 11% and 1%, respectively. It is concluded that SUVA and EPS composition were important parameters affecting membrane fouling in the combined system.

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

scholarly journals Micro-pressure swirl reactor (MPSR) for efficient COD and nitrogen removal of high-concentration wastewater

2020 ◽  
Vol 82 (9) ◽  
pp. 1795-1807 ◽  
Author(s):  
Dejun Bian ◽  
Zebing Nie ◽  
Fan Wang ◽  
Shengshu Ai ◽  
Suiyi Zhu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Lower Cost ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Swirl Flow ◽  
High Concentration ◽  
Internal Circulation ◽  
Carbon And Nitrogen ◽  
Pressure Swirl

Abstract A micro-pressure swirl reactor (MPSR) was developed for carbon and nitrogen removal of wastewater, in which dissolved oxygen (DO) gradient and internal circulation could be created by setting the aerators along one side of the reactor, and micro-pressure could be realized by sealing most of the top cap and increasing the outlet water level. In this study, velocity and DO distribution in the reactor was measured, removal performance treating high-concentration wastewater was investigated, and the main functional microorganisms were analyzed. The experiment results indicated that there was stable swirl flow and spatial DO gradient in MPSR. Operated in sequencing batch reactor mode, distinct biological environments spatially and temporally were created. Under the average influent condition of chemical oxygen demand (COD) concentration of 2,884 mg/L and total nitrogen (TN) of 184 mg/L, COD removal efficiency and removal loading was 98% and 1.8 kgCOD/(m3·d) respectively, and TN removal efficiency and removal loading reached up to 90% and 0.11 kgTN/(m3·d) respectively. With efficient utilization of DO and simpler configuration for simultaneous nitrification and denitrification, the MPSR has the potential of treating high-concentration wastewater at lower cost.

Effect of continuously dosing Cu(II) on pollutant removal and soluble microbial products in a sequencing batch reactor

2015 ◽  
Vol 72 (9) ◽  
pp. 1653-1661 ◽  
Author(s):  
YangWei Yan ◽  
YuWen Wang ◽  
Yan Liu ◽  
Xiang Liu ◽  
ChenChao Yao ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Pollutant Removal ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Soluble Microbial Products ◽  
Cod Removal Efficiency ◽  
Microbial Products

The effects of synthetic wastewater that contained 20 mg/L Cu(II) on the removal of organic pollutants in a sequencing batch reactor were investigated. Results of continuous 20 mg/L Cu(II) exposure for 120 days demonstrated that the chemical oxygen demand (COD) removal efficiency decreased to 42% initially, followed by a subsequent gradual recovery, which peaked at 78% by day 97. Effluent volatile fatty acid (VFA) concentration contributed 67 to 89% of the influent COD in the experimental reactor, which indicated that the degradation of the organic substances ceased at the VFA production step. Meanwhile, the varieties of soluble microbial products (SMP) content and main components (protein, polysaccharide, and DNA) were discussed to reveal the response of activated sludge to the toxicity of 20 mg/L Cu(II). The determination of Cu(II) concentrations in extracellular polymeric substances (EPS) and SMP throughout the experiment indicated an inverse relationship between extracellular Cu(II) concentration and COD removal efficiency.

Influence of extracellular polymeric substances on nitrogen removal in an intermittently-aerated membrane bioreactor

2005 ◽  
Vol 51 (11) ◽  
pp. 151-158 ◽  
Author(s):  
H. Nagaoka ◽  
H. Nemoto
Keyword(s):  
Molecular Weight ◽  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Removal Rate ◽  
Membrane Surface ◽  
Synthetic Wastewater ◽  
Nitrifying Bacteria ◽  
Gel Chromatography ◽  
Bacterial Cells ◽  
Intermittent Aeration

Influence of EPS on fouling of intermittent aeration MBR reactor (denitrification MBR) was investigated changing intermittent aeration cycle (10 minute-cycle and 120 minute-cycle) in laboratory-scale reactors using synthetic wastewater. EPS were extracted from bacterial cells using cation resin method and molecular weight fractioning of EPS was conducted using gel chromatography. In both of the reactors, nitrogen removal rate was almost 100% after 50th day although DO concentration was not very high during the aerated phase because of accumulation of nitrifying bacteria in the reactors. In the 120 minutes-cycle reactor, trans-membrane pressure increased more rapidly than in the 10 minutes-cycle reactor. The reason might be that EPS of more than 1000 kDa, which are the main fouling substances, are produced more rapidly in the 120 minute-cycle condition. It was also found that three peaks at around 100 kDa, 500 kDa and 2000 kDa are prominent in EPS in intermittent-aeration MBR irrespective of cycle and higher molecular weight EPS are decomposed to smaller molecular weight EPS on membrane surface.

On-line control of a SBR system for nitrogen removal from industrial wastewater

2001 ◽  
Vol 43 (3) ◽  
pp. 93-100 ◽  
Author(s):  
G. Andreottola ◽  
P. Foladori ◽  
M. Ragazzi
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Low Cost ◽  
Ammonia Removal ◽  
High Concentration ◽  
Plywood Industry ◽  
On Line ◽  
Pre Treatment ◽  
Study Laboratory ◽  
System Operating

In this study, laboratory-scale experiments were conducted applying the SBR activated sludge process to a wastewater from a wood factory operating on plywood production. Due to the fact that the wastewater is characterised with a high concentration of ammonia, the aim was to evaluate the nitrogen removal process with SBR system operating with a on-line control of ORP, pH and DO. The complete ammonia removal corresponded exactly to the “Ammonia Valley” in the pH versus time graphic. The ammonia removal efficiency in SBR was 99% at 20°C. The denitrification reaction was completed when in the ORP versus time graphic appeared the “Nitrate Knee”. From the experimental results the optimisation of the SBR cycle allowed the doubling of the applied load with respect to a not optimised cycle (performed in the same volume reactor), without a decrease in the removal efficiency. Moreover, the possibility of stopping the aeration just after the appearance of the Ammonia Valley allows an energy saving. The easy operation and the low cost make the SBR system an interesting option for the biological pre-treatment of plywood industry to be discharged into surface water.

scholarly journals Denitrification performance of Pseudomonas fluorescens Z03 immobilized by graphene oxide-modified polyvinyl-alcohol and sodium alginate gel beads at low temperature

2020 ◽  
Vol 7 (3) ◽  
pp. 191542 ◽  
Author(s):  
Meizhen Tang ◽  
Jie Jiang ◽  
Qilin Lv ◽  
Bin Yang ◽  
Mingna Zheng ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Low Temperature ◽  
Polyvinyl Alcohol ◽  
Pseudomonas Fluorescens ◽  
Sodium Alginate ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Aerobic Denitrification ◽  
Gel Beads

Improving the effect of microbial denitrification under low-temperature conditions has been a popular focus of research in recent years. In this study, graphene oxide (GO)-modified polyvinyl-alcohol (PVA) and sodium alginate (SA) (GO/PVA–SA) gel beads were used as a heterotrophic nitrification–aerobic denitrification (HN–AD) bacteria ( Pseudomonas fluorescens Z03) carrier to enhance nitrogen removal efficiency levels at low temperatures (6–8°C). The removal efficiency of N H 4     + -N and N O 3       − -N and the variations in concentrations of extracellular polymeric substances (EPS) under different GO doses (0.03–0.15 g l −1 ) were studied. The results indicated that the addition of GO can improve the efficiency of nitrogen removal, and the highest removal efficiency level and highest carbohydrate, protein, and total EPS content levels (50.28 mg, 132.78 mg and 183.06 mg (g GO/PVA–SA gel) −1 , respectively) were obtained with 0.15 g l −1 GO. The simplified Monod model accurately predicted the nitrogen removal efficiency level. These findings suggested that the application of GO serves as an effective means to enhance nitrogen removal by stimulating the activity of HN–AD bacteria.

Effects of poly aluminum chloride dosing positions on the performance of a pilot scale anoxic/oxic-membrane bioreactor (A/O-MBR)

2015 ◽  
Vol 72 (5) ◽  
pp. 689-695 ◽  
Author(s):  
Shaodong Guo ◽  
Fangshu Qu ◽  
An Ding ◽  
Langming Bai ◽  
Guibai Li ◽  
...  
Keyword(s):  
Phase I ◽  
Removal Efficiency ◽  
Phase Ii ◽  
Nitrogen Removal ◽  
Aluminum Chloride ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Pilot Scale ◽  
Phase Iii ◽  
Removal Efficiencies

The effects of poly aluminum chloride (PACl) dosing positions on the performance of a pilot scale anoxic/oxic membrane bioreactor were investigated. PACl dosage was optimized at 19.5 mg Al2O3/L by jar test. Nutrients removal efficiencies and sludge properties were systematically investigated during periods with no PACl dosing (phase I), with PACl dosing in oxic tank (phase II) and then in anoxic tank (phase III). The results showed that total phosphorus removal efficiency increased from 18 to 88% in phase II and 85% in phase III with less than 0.5 mg P/L in effluent. Ammonia nitrogen removal efficiencies reached 99% in all phases and chemical oxygen demand removal efficiencies reached 92%, 91% and 90% in the three phases, respectively. Total nitrogen removal efficiency decreased from 59% in phase I to 49% in phases II and III. Dosing PACl in the oxic tank resulted in smaller sludge particle size, higher zeta potential, better sludge settleability and lower membrane fouling rate in comparison with dosing PACl in the anoxic tank.

Removal of Ammonia Nitrogen from Landfill Leachate by Ultrasound/Ultraviolet Process

2013 ◽  
Vol 448-453 ◽  
pp. 536-539
Author(s):  
Bin Liu ◽  
Xu Ya Peng ◽  
Qi Tian ◽  
Hua Zhao
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Landfill Leachate ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Aeration Rate ◽  
Ammonia Removal ◽  
Ultrasonic Power ◽  
High Concentration ◽  
Leachate Treatment

Landfill leachate treatment is a major problem to be solved in the field of environmental protection, and ammonia nitrogen is one of the major pollutants in landfill leachate, whose processing technology needs further improvement. In this paper, ultrasound/ultraviolet co-oxidation technology was directly applied to the treatment of high concentration landfill leachate without the pretreatment operations of dilution, filter, and adjusting the pH conditions. The results showed that: ultrasonic and ultraviolet had certain effects on the ammonia nitrogen removal, and the ammonia nitrogen removing effects became better when the ultrasonic power was greater, or the ultraviolet wavelength was shorter. When the ultrasonic power was 100 W, the ammonia nitrogen removal efficiency was 25.2%, and the UV of 254 nm could decompose 20.2% of the ammonia nitrogen in landfill leathate. In the condition of aeration, ultrasonic and ultraviolet had good synergistic effect on leachate ammonia nitrogen treatment. When the ultrasonic power was 100 W, UV wavelength was 254 nm, and the aeration rate was 150 L/h, the ammonia removal efficiency of high concentration leachate (ammonia nitrogen concentration of 1800 mg/L) reached 98.5% after 6 hours. The paper's research results provide a useful reference for the removal of landfill leachate ammonia nitrogen.

Effect of Suspended Carriers on Extracellular Polymeric Substances in MBR

2014 ◽  
Vol 955-959 ◽  
pp. 1939-1943
Author(s):  
Chun Hua Zhang ◽  
Xiao Xia Ou ◽  
Feng Jie Zhang
Keyword(s):  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Aeration Rate ◽  
Woven Fabric ◽  
Membrane Model ◽  
Synthetic Wastewater ◽  
Model Surface ◽  
Submerged Membrane Bioreactor

Suspended carriers were added into a submerged membrane bioreactor (SMBR) using polypropylene non-woven fabric (PP NWF) as membrane model to treat synthetic wastewater. The changes of EPSSEPSB and EPS in activated sludge mixing liquid of MBR and in sludge on membrane model surface were researched at different aeration rate. The results showed that adding suspended carriers in MBR can increase the concentration of EPSS and EPSB in activated sludge mixing liquid, but the effect on EPSS and EPSB in the sludge on membrane model surface is related to aeration rate. Adding suspended carriers can increase the concentration of EPSS and EPSB in the sludge on membrane model surface at 0.10m3/h of aeration rate; the concentration of EPSS and EPSB in the sludge with suspended carriers is reduced when aeration rate is increased to 0.25m3/h. The study on the effect of aeration rate on EPS in sludge mixing liquid of MBR and in sludge on membrane model surface showed that an optimized aeration rate exists if suspended carriers are added to control MBR membrane fouling. At the optimized aeration rate, membrane fouling can be mitigated and controled effectively.

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