COD removal efficiency and mechanism of HMBR in high volumetric loading for ship domestic sewage treatment

2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.

2008 ◽  
Vol 57 (7) ◽  
pp. 1047-1052 ◽  
Author(s):  
U. Durán ◽  
O. Monroy ◽  
J. Gómez ◽  
F. Ramírez

The biological elimination of polymeric resins compounds (PRC) such as acrylic acid and their esters, vinyl acetate and styrene under methanogenic and oxygen-limited methanogenesis conditions was evaluated. Two UASB reactors (A and B) were used and the removal of the organic matter was studied in four stages. Reactor A was used as methanogenic control during the study. Initially both reactors were operated under methanogenic conditions. From the second stage reactor B was fed with 0.6 and 1 mg/L·d of oxygen (O2). Reactor A had diminution in chemical oxygen demand (COD) removal efficiency from 75±4% to 37±5%, by the increase of PRC loading rate from 750 to 1125 mg COD/L·d. In this reactor there was no styrene elimination. In reactor B the COD removal efficiency was between 73±5% and 80±2%, even with the addition of O2 and increase of the PRC loading rate, owing to oxygen being used in the partial oxidation of these compounds. In this reactor the yields were modified from 0.56 to 0.40 for CH4 and from 0.31 to 0.60 for CO2. The O2 in low concentrations increased 40.7% the consumption rates of acrylic acid, methyl acrylate and vinyl acetate, allowing styrene consumption with a rate of 0.103 g/L·d. Batch cultures demonstrated that under methanogenic and oxygen-limited methanogenesis conditions, the glucose was not used as an electron acceptor in the elimination of PRC.


2010 ◽  
Vol 37 (3) ◽  
pp. 496-501 ◽  
Author(s):  
K.N. Njau ◽  
M. Renalda

A horizontal subsurface flow constructed wetland (HSSFCW) was employed to remove tannins from the effluent of a tannins extracting company. Two HSSFCW cells with hydraulic retention time (HRT) of 9 d and packed with limestone were used. One cell without macrophytes was used as a control, while the second cell was planted with Phragmites mauritianus . Results indicated that HSSFCW was capable of treating tannin wastewater that has been seeded with primary facultative pond sludge. Tannins and chemical oxygen demand (COD) removal efficiency of 95.9% and 90.6% with outlet concentration of 27 mg/L and 86 mg/L, respectively, were obtained in the planted cell; while the tannins and COD removal efficiency of 91.1% and 89.5% with outlet concentration of 57 mg/L and 96 mg/L, respectively, were obtained in the control cell.


2020 ◽  
Vol 167 ◽  
pp. 01009
Author(s):  
Qin Cai ◽  
Hui-qiang Li ◽  
Ping Yang

A continuous flow chemical reactor was constructed to study the dephosphorization effect on the effluent of the oxygen-limited internal-loop fluidized membrane bioreactor (IF-MBR) for domestic sewage treatment. Removal effect of total phosphorus (TP) by four coagulants of AlCl3, FeCl3, polyaluminum ferric chloride (PAFC) and polyaluminium chloride (PAC) was evaluated. Results showed that when the ratio of coagulants to TP was 5 (coagulants in terms of Fe and Al), the removal efficiency of TP by FeCl3 was 92.5% and the addition of FeCl3 resulted in an increase in the chromaticity of the effluent. PAC and PAFC had good removal of TP, and the removal percentage achieved 96.2 and 97.4, respectively. However, the flocs they produced were small and light, and the performance in settlement was poor. AlCl3 performed well as a phosphorus removal agent, the removal rate of TP reached 97.4%, and the flocs were large and dense. Based on this, AlCl3 was the best choice for IF-MBR and then the experiment further optimized the Al/P ratio. Results showed that when the Al/P ratio was above 1:1, the effluent TP concentration was lower than 1mg/L; when the ratio was higher than 2.5:1, the effluent TP was lower than 0.5mg/L.


2002 ◽  
Vol 45 (10) ◽  
pp. 243-248 ◽  
Author(s):  
L. Seghezzo ◽  
R.G. Guerra ◽  
S.M. González ◽  
A.P. Trupiano ◽  
M.E. Figueroa ◽  
...  

The performance of a sewage treatment system consisting of a settler followed by an Upflow Anaerobic Sludge Bed (UASB) reactor is described. Mean ambient and sewage temperature were 16.5 and 21.6°C, respectively. Total Chemical Oxygen Demand (CODt) concentration averaged 224.2 and 152.6 mg/L, for raw and settled sewage, respectively. The effluent concentration was 68.5 mgCODt/L. Total and suspended COD removal efficiencies of approximately 70 and 80%, respectively, have been observed in the system at a mean Hydraulic Retention Time (HRT) of 2 + 5 h. Maximum COD removal efficiency was achieved in the UASB reactor when upflow velocity (Vup) was 0.43 m/h (HRT = 6 h). Mean Specific Methanogenic Activity (SMA) and Volatile Suspended Solids (VSS) concentration in the granular sludge bed were 0.11 gCOD-CH4/gVSS.d and 30.0 gVSS/Lsludge, respectively. SMA was inversely related to VSS concentration, and both parameters varied along the sludge bed height. The Solids Retention Time (SRT) in the reactor was 450 days. Sludge characteristics have not been affected by changes of up to one month in Vup in the range 0.28–0.85 m/h (HRT 3–9 h). This system or two UASB reactors in series could be an alternative for sewage treatment under moderate temperature conditions.


2021 ◽  
Vol 18 (4) ◽  
pp. 135-140
Author(s):  
Sanju Sreedharan

Zero energy technologies and sustainable energy production are the two major concerns of present day researches. Microbial fuel cells (MFCs) are bioreactors that extract chemical energy stored in organic compounds, into electric potential, through bio-degradation. The core reason for the high strength of effluent generated from slaughterhouses is animal blood. The current study evaluates the potential of MFC technology to reduce the pollution strength of cattle blood in terms of chemical oxygen demand (COD). The current study was piloted in three stages using lab scale two chambered MFC: The first stage was to determine the best oxidising agent as compared to natural aeration from three accessible options, KMnO4, diffused aeration and tape grass aquatic plant. KMnO4 was found to be the superlative with a 30% reduction in COD in 100 hrs batch reactor and a maximum power of 0.97 mW using 125 mL livestock blood. The second stage of the study optimised the concentration of KMnO4. At 500 mg/L KMnO4 concentration, 50% COD removal efficiency was acquired in a batch reactor of 60 hrs with an average energy output of 1.3 mW. In the final stage on the addition of coconut shell activated carbon with an Anolyte at a rate of 40 mL/125 mL of substrate COD removal efficiency increased to 74.9%.


2001 ◽  
Vol 44 (4) ◽  
pp. 167-174 ◽  
Author(s):  
R. M.L. Bolaños ◽  
M. B.A. Varesche ◽  
M. Zaiat ◽  
E. Foresti

A bench-scale horizontal-flow anaerobic immobilized biomass (HAIB) reactor was assayed aiming to verify its potential use for phenol degradation. The HAIB reactor consisted of a bore-silicate tube (100 cm long; 5.04 cm diameter) filled with polyurethane foam matrices containing immobilized anaerobic sludge. Before being subjected to phenol, the reactor was fed with synthetic substrate at the influent chemical oxygen demand (COD) of 1,028 mg.l−1 achieving 98% of COD removal efficiency. Thereafter, phenol as the sole carbon source was added under step-increasing concentrations from 50 to 1,200 mg.l−1. Phenol degradation was evaluated by gas chromatographic analysis of influent and effluent samples. Process monitoring included determinations of pH, volatile acids, alkalinity and COD. The HAIB reactor was operated at a constant hydraulic detention time (HDT) of 12 hours. After 33 days with 50 mg/l of phenol in the influent, the reactor achieved 98% of COD removal efficiency. Successful phenol degradation (efficiency removal of 99%) occurred for influent concentrations of 100, 300, 600, 900 and 1,200 mg.l−1 after 148, 58, 47, 29 and 7 days, respectively. The predominance of Methanosaeta-like, rods and methanogenic cocci could be observed in all the operating conditions, besides the presence of phenol oxidizing microorganisms as irregular rods. The results indicate that phenol degradation at very high rates can be accomplished in HAIB reactors containing acclimatized biomass.


2012 ◽  
Vol 610-613 ◽  
pp. 1691-1695
Author(s):  
Chun Juan Dong ◽  
Qing Ye Pan

Treatment of actual domestic wastewater at ambient temperature, even low temperature is considered to be difficult by traditional systems. The present study is related to treatment of actual domestic wastewater in an EGSB reactor. The study showed the effectiveness of biological treatment of actual domestic wastewater involving appropriate microorganism and granules in an EGSB reactor. At 26°C, the reactor was operated at 18.7kg COD.m−3.d−1 of average organic loading and 83% high COD removal efficiency, and even at the highest loading rate of 57.12kgCOD.m−3.d−1, the COD removal efficiency still could attain to 68%. Varied influent flow need to supply varied optimal and thus to ensure the optimal removal effect. Low temperature would cause pollutant removal rate decrease. However, enhancing could optimize the contact of sludge and wastewater and thus strengthen the performance effect. Modified Stover–Kincannon model was applied to data obtained from experimental studies in EGSB reactor. Treatment efficiencies of the reactor were investigated at different hydraulic retention times (0.5-1.3h) and different operation temperature (15°C, 26°C). The modified Stover–Kincannon model was best fitted to the EGSB reactor, and the substrate utilization rate( ), saturation constant value( ), and actual pollutant removal rate( ) were found to be , , and for 26°C, , , and for 15°C( before increasing ), and , , and for 15°C(after increasing ). Low temperature could cause decrease and thus cause distinct decreasing of COD removal efficiency. However, increasing could increase and accordingly increase COD removal efficiency.


2012 ◽  
Vol 178-181 ◽  
pp. 376-379
Author(s):  
Fang Li ◽  
Zeng Lu Qi

This paper adopted a 3-stage rotating biological contactor (RBC), while the operating parameters could be controlled properly, this kind of RBC can obtain better removal effect in domestic sewage treatment. At 25oC, when hydraulic retention time (HRT) is 4h ,6h,8h,10h and 12h ,removal rate of COD is 65.14%,86.10%,89.82%,85.93% and 78.58%.HRT fixes on 8h, removal rate of NH3 –N is 75% after adjusting alkalinity. When rotating rate of RBC is 4,6,8,10,12 and 14 r/min, the removal rate of TN is 53.88%,56.78%,60.03%,58.49%,55.32% and 54.87%.RBC also has a good removal efficiency of TP and obtains the removal rate of TP 45%.There is good prospect in domestic sewage treatment with RBC.


2013 ◽  
Vol 67 (11) ◽  
pp. 2549-2559 ◽  
Author(s):  
S. Wang ◽  
J. Hovland ◽  
R. Bakke

The anaerobic biodegradation of reclaimer MEA (monoethanolamine) waste (MEAw) with easily degradable co-substrates was investigated in a laboratory-scale bioreactor at room temperature during a 160 d experimental run. The reactor that was constructed with three phases to facilitate attached biofilm and suspended biomass retention for degradation of the complex and challenging MEAw performed well. A feed strategy of step-wise increasing organic loading rate (OLR) by either increasing feed MEAw concentration or the hydraulic loading rate was applied. The system performance was evaluated by chemical oxygen demand (COD) removal efficiency, methane yield, MEA removal, and the accumulation of ammonia and volatile fatty acid (VFA). The total COD removal efficiency initially was 93% when the feed was mainly easily degradable co-substrate. The total removal dropped to 75% at the end when MEAw constituted 60% of the feed COD. Ion chromatography results show that the MEA and some unidentified feed chemicals were almost completely consumed. The main products of MEAw degradation were ammonia, VFAs and biogas. The ammonia nitrogen concentration reached about 2.0 g/L, which may explain the observed inhibition of acetoclastic methanogenesis leading to acetate accumulation. Methane accounted for up to 80% of the biogas generated. The highest methane yield was 0.34 L/g-COD while the yield was 0.16 L/g-COD at the highest load. This study shows that more than 80% reclaimer MEAw COD degradation with a co-substrate can be maintained in a hybrid anaerobic bioreactor operated in a wide loading range.


2016 ◽  
Vol 74 (9) ◽  
pp. 2202-2210
Author(s):  
Jia Liu ◽  
Wei Zuo ◽  
Yu Tian ◽  
Jun Zhang ◽  
Hui Li ◽  
...  

A membrane bioreactor (MBR) coupled with a worm reactor (SSBWR) was designed as SSBWR-MBR for sewage treatment and excess sludge reduction. However, total phosphorus (TP) release caused by worm predation in the SSBWR could increase the effluent TP concentration in the SSBWR-MBR. To decrease the amount of TP excreted, chemical treatment reactor was connected after the SSBWR-MBR to remove the excess phosphorus (P). The effects of chemical treatment at different time intervals on the performance of the SSBWR-MBR were assessed. The results showed that a maximum TP removal efficiency of 21.5 ± 1.0% was achieved in the SSBWR-MBR after chemical treatment. More importantly, a higher sulfate concentration induced by chemical treatment could promote TP release in the SSBWR, which provided further TP removal from the SSBWR-MBR. Additionally, chemical oxygen demand (COD) removal efficiency of the SSBWR-MBR was increased by 1.3% after effective chemical treatment. In the SSBWR-MBR, the chemical treatment had little effects on NH3-N removal and sludge production. Eventually, chemical treatment also alleviated the membrane fouling in the SSBWR-MBR. In this work, the improvement on TP, COD removal and membrane fouling alleviation was achieved in the SSBWR-MBR using additional chemical treatment.


Sign in / Sign up

Export Citation Format

Share Document