scholarly journals Submerged anaerobic membrane bioreactor (SAnMBR) performance on sewage treatment: removal efficiencies, biogas production and membrane fouling

2017 ◽  
Vol 76 (6) ◽  
pp. 1308-1317 ◽  
Author(s):  
Rong Chen ◽  
Yulun Nie ◽  
Jiayuan Ji ◽  
Tetsuya Utashiro ◽  
Qian Li ◽  
...  
Keyword(s):  
Methane Production ◽  
Membrane Fouling ◽  
Comprehensive Evaluation ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Nitrogen And Phosphorus ◽  
Batch Tests ◽  
Cake Layer ◽  
Biomass Yields

A submerged anaerobic membrane reactor (SAnMBR) was employed for comprehensive evaluation of sewage treatment at 25 °C and its performance in removal efficiency, biogas production and membrane fouling. Average 89% methanogenic degradation efficiency as well as 90%, 94% and 96% removal of total chemical oxygen demand (TCOD), biochemical oxygen demand (BOD) and nonionic surfactant were obtained, while nitrogen and phosphorus were only subjected to small removals. Results suggest that SAnMBRs can effectively decouple organic degradation and nutrients disposal, and reserve all the nitrogen and phosphorus in the effluent for further possible recovery. Small biomass yields of 0.11 g mixed liquor volatile suspended solids (MLVSS)/gCOD were achieved, coupled to excellent methane production efficiencies of 0.338 NLCH4/gCOD, making SAnMBR an attractive technology characterized by low excess sludge production and high bioenergy recovery. Batch tests revealed the SAnMBR appeared to have the potential to bear a high food-to-microorganism ratio (F/M) of 1.54 gCOD/gMLVSS without any inhibition effect, and maximum methane production rate occurred at F/M 0.7 gCOD/gMLVSS. Pore blocking dominated the membrane fouling behaviour at a relative long hydraulic retention time (HRT), i.e. >12 hours, while cake layer dominated significantly at shorter HRTs, i.e. <8 hours.

Membrane fouling and performance evaluation of conventional membrane bioreactor (MBR), moving biofilm MBR and oxic/anoxic MBR

2014 ◽  
Vol 69 (7) ◽  
pp. 1403-1409 ◽  
Author(s):  
Sher Jamal Khan ◽  
Aman Ahmad ◽  
Muhammad Saqib Nawaz ◽  
Nicholas P. Hankins
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Water Flux ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Membrane Bioreactors ◽  
Nitrogen And Phosphorus ◽  
Biofilm Carrier ◽  
Cake Layer ◽  
And Performance

In this study, three laboratory scale submerged membrane bioreactors (MBRs) comprising a conventional MBR (C-MBR), moving bed MBR (MB-MBR) and anoxic-oxic MBR (A/O-MBR) were continuously operated with synthesized domestic wastewater (chemical oxygen demand, COD = 500 mg/L) for 150 days under similar operational and environmental conditions. Kaldnes® plastic media with 20% dry volume was used as a biofilm carrier in the MB-MBR and A/O-MBR. The treatment performance and fouling propensity of the MBRs were evaluated. The effect of cake layer formation in all three MBRs was almost the same. However, pore blocking caused a major difference in the resultant water flux. The A/O-MBR showed the highest total nitrogen and phosphorus (PO4-P) removal efficiencies of 83.2 and 69.7%, respectively. Due to the high removal of nitrogen, fewer protein contents were found in the soluble and bound extracellular polymeric substances (EPS) of the A/O-MBR. Fouling trends of the MBRs showed 12, 14 and 20 days filtration cycles for C-MBR, MB-MBR and A/O-MBR, respectively. A 25% reduction of the soluble EPS and a 37% reduction of the bound EPS concentrations in A/O-MBR compared with C-MBR was a major contributing factor for fouling retardation and the enhanced filtration capacity of the A/O-MBR.

Pollutant removal and membrane fouling in an anaerobic submerged membrane bioreactor for real sewage treatment

2014 ◽  
Vol 69 (8) ◽  
pp. 1712-1719 ◽  
Author(s):  
Fangyuan Wang ◽  
Jianrong Chen ◽  
Huachang Hong ◽  
Aijun Wang ◽  
Hongjun Lin
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Submerged Membrane Bioreactor ◽  
Membrane Flux ◽  
Cake Layer

Real sewage was continuously treated by a laboratory-scale anaerobic submerged membrane bioreactor (AnSMBR) for over 160 days. Results showed that around 90% of chemical oxygen demand, and 99% of turbidity and total suspended solids in the sewage could be removed by the AnSMBR system. Membrane flux sustained at 11 L/(m2 h) was realized with biogas sparging. Small flocs from sludge deflocculation in the early operational period caused a high membrane fouling rate, and the high specific filtration resistance of the cake layer appeared mostly attributable to the osmotic pressure effect. The performance results were also compared with those in the literature for upflow anaerobic sludge blanket reactors and aerobic membrane bioreactors for sewage treatment, demonstrating that AnSMBR could provide a desirable alternative for sewage treatment.

scholarly journals Assessment of phytoremediation potencial of Allium cepa L. in raw sewage treatment

2020 ◽  
Vol 80 (2) ◽  
pp. 431-436 ◽  
Author(s):  
A. S. Bertan ◽  
F. P. Baumbach ◽  
I. B. Tonial ◽  
T. S. Pokrywiecki ◽  
E. Düsman
Keyword(s):  
Allium Cepa ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Mitotic Cell ◽  
Artemia Salina ◽  
Cytotoxicity Test ◽  
Nitrogen And Phosphorus ◽  
Toxic Activity ◽  
Allium Cepa L ◽  
Physicochemical Data

Abstract Whereas the effects of the substances found in domestic sewage on live organisms is important to evaluate the use of plants to remove pollutants from the environment. The objective of this study was to assess the phytoremediation activity of Allium cepa L. (onion) roots exposed to raw sewage, as well as the acute toxic activity of this effluent for the bioindicators A. cepa, through a cytotoxicity test, and Artemia salina L., through a mortality/immobility test. The physicochemical assessments of the sewage were conducted in two scenarios: immediately after collection and after being in contact with onion roots (phytoremediation) for 24 hours. The physicochemical data indicate there was a reduction in nitrogen and phosphorus levels and in biochemical oxygen demand in sewage treated. The results from the cytotoxicity test with A. cepa indicated a reduction in the mitotic cell divisions of the onions treated with the raw sewage. The mortality/immobility test with A. salina indicated that the concentrations with 50 and 100% of raw sewage induced the mortality of the nauplii. Thus, the data suggest new studies that seek greater efficiency, efficacy and viability of onion phytoremediation.

scholarly journals Enhancement anaerobic digestion and methane production from kitchen waste by thermal and thermo-chemical pretreatments in batch  leach bed reactor with down flow

2018 ◽  
Vol 64 (No. 3) ◽  
pp. 128-135 ◽  
Author(s):  
Radmard Seyed Abbas ◽  
Alizadeh Hossein Haji Agha ◽  
Seifi Rahman
Keyword(s):  
Anaerobic Digestion ◽  
Microwave Irradiation ◽  
Methane Production ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Lag Phase ◽  
Kitchen Waste ◽  
Gompertz Equation ◽  
Chemical Pretreatments ◽  
Pretreatment Conditions

The effects of thermal (autoclave and microwave irradiation (MW)) and thermo-chemical (autoclave and microwave irradiation – assisted NaOH 5N) pretreatments on the chemical oxygen demand (COD) solubilisation, biogas and methane production of anaerobic digestion kitchen waste (KW) were investigated in this study. The modified Gompertz equation was fitted to accurately assess and compare the biogas and methane production from KW under the different pretreatment conditions and to attain representative simulations and predictions. In present study, COD solubilisation was demonstrated as an effective effect of pretreatment. Thermo-chemical pretreatments could improve biogas and methane production yields from KW. A comprehensive evaluation indicated that the thermo-chemical pretreatments (microwave irradiation and autoclave- assisted NaOH 5N, respectively) provided the best conditions to increase biogas and methane production from KW. The most effective enhancement of biogas and methane production (68.37 and 36.92 l, respectively) was observed from MW pretreated KW along with NaOH 5N, with the shortest lag phase of 1.79  day, the max. rate of 2.38 l·day<sup>–1</sup> and ultimate biogas production of 69.8 l as the modified Gompertz equation predicted.

Performance of a pilot-scale constructed wetland for stormwater runoff and domestic sewage treatment on the banks of a polluted urban river

2014 ◽  
Vol 69 (7) ◽  
pp. 1410-1418 ◽  
Author(s):  
Weijie Guo ◽  
Zhu Li ◽  
Shuiping Cheng ◽  
Wei Liang ◽  
Feng He ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Sewage Treatment ◽  
Stormwater Runoff ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Domestic Sewage ◽  
Nitrogen And Phosphorus ◽  
Effective Technique ◽  
Integrated Constructed Wetland ◽  
One Year

To examine the performance of a constructed wetland system on stormwater runoff and domestic sewage (SRS) treatment in central east China, two parallel pilot-scale integrated constructed wetland (ICW) systems were operated for one year. Each ICW consisted of a down-flow bed, an up-flow bed and a horizontal subsurface flow bed. The average removal rates of chemical oxygen demand (CODCr), total suspended solids (TSS), ammonia (NH4+-N), total nitrogen (TN) and total phosphorus (TP) were 63.6, 91.9, 38.7, 43.0 and 70.0%, respectively, and the corresponding amounts of pollutant retention were approximately 368.3, 284.9, 23.2, 44.6 and 5.9 g m−2 yr−1, respectively. High hydraulic loading rate (HLR) of 200 mm/d and low water temperatures (&lt;15 °C) resulted in significant decrease in removals for TP and NH4+-N, but had no significant effects on removals of COD and TSS. These results indicated that the operation of this ICW at higher HLR (200 mm/d) might be effective and feasible for TSS and COD removal, but for acceptable removal efficiencies of nitrogen and phosphorus it should be operated at lower HLR (100 mm/d). This kind of ICW could be employed as an effective technique for SRS treatment.

scholarly journals Bacterial community shift and effects of the inclusion of a mixed psychrotrophic bacteria strain for sewage treatment in constructed wetland in winter seasons

2021 ◽  
Author(s):  
xiaoyan xu ◽  
Jie Jiang ◽  
Zhinan Guo ◽  
Lianglun Sun ◽  
Meizhen Tang
Keyword(s):  
Low Temperature ◽  
Constructed Wetlands ◽  
High Throughput Sequencing ◽  
Sewage Treatment ◽  
High Capacity ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Degradation Kinetic ◽  
Psychrotrophic Bacteria

Abstract The mechanism of wastewater treatment based on psychrophilic strains to improve the denitrification efficiency of constructed wetlands at low temperatures has already become a new hotspot. In this study, three mixed psychrophilic strains (Psychrobacter TM-1, Sphingobacterium TM-2 and Pseudomonas TM-3) with high capacity of denitrification were added into a vertical-flow constructed wetlands (CWs), and the effect of the mixed strains on CWs sewage treatment was evaluated. The removal efficiency of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN) and total phosphorus (TP) was quantified to establish the degradation kinetic model and determine the best dosage of the mixed strains. The effect mechanism of the mixed strains on indigenous microbial community and the change of sewage treatment performance in low temperature constructed wetlands was clarified by high-throughput sequencing technology. The results showed that the mixed strains can effectively remove the organic pollutants (nitrogen and phosphorus) and the optimum dosage of the mixed strain was 2.5%,with average removal rates of 1.52, 2.12, 2.07 and 1.29 times than those of the control. Meanwhile, the dominant strains in the CWs were Proteobacteria (31.23–44.34%), Chloroflexi (12.04–19.05%), Actinobacteria (10.6-20.62%), Acidobacteria (8.23–11.65%), Firmicutes (2.23–15.95%) and Bacteroidetes (4.01–18.9%). These findings provide a basis for the removal of pollutants in constructed wetlands at low temperature.

An operational survey of a natural lagoon treatment plant combining macrophytes and microphytes basins

1995 ◽  
Vol 32 (3) ◽  
pp. 79-86
Author(s):  
Louis Vandevenne
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Quality Standard ◽  
Biological Mechanisms ◽  
Nitrogen And Phosphorus ◽  
Artificial Wetlands ◽  
In Series ◽  
Better Than

The sewage treatment plant studied, located in a rural area, is designed to treat the wastewater for a population of 650. The station functions in accordance with the principle of natural lagoons via artificial wetlands combining macrophytes and microphytes lagoons arranged in series. The overall surface area including the primary lagoon gives rise to a specific load of 6 m2/inhabitant. Both the primary and secondary treatments produce a very good water quality in accordance with the conventional parameters (SS, Suspended Solids; BOD5, the Biological Oxygen Demand over a 5 day period; COD, the Chemical Oxygen Demand). The tertiary purification of the nitrogen and phosphorus does not give as good results as expected, respectively 42% and 35% removal; very little better than those of a conventional installation. The tertiary quality standard appears not to be attainable since the successive biological mechanisms carrying out the elimination process are followed by a release of the pollutants and an insufficient elimination (plant exportation) by the macrophytes. The design and management of the macrophytes basins is relatively tricky, particularly with respect to the removal of weeds and the regulation of the water level in the macrophytes basins.

Laboratory-scale membrane up-concentration and co-anaerobic digestion for energy recovery from sewage and kitchen waste

2015 ◽  
Vol 73 (3) ◽  
pp. 597-606 ◽  
Author(s):  
Nguyen Thi Tuyet ◽  
Nguyen Phuoc Dan ◽  
Nguyen Cong Vu ◽  
Nguyen Le Hoang Trung ◽  
Bui Xuan Thanh ◽  
...  
Keyword(s):  
Energy Recovery ◽  
Membrane Filtration ◽  
Waste Treatment ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Integrated System ◽  
Total Carbon ◽  
Organic Loading Rate ◽  
Kitchen Waste

This study assessed an alternative concept for co-treatment of sewage and organic kitchen waste in Vietnam. The goal was to apply direct membrane filtration for sewage treatment to generate a permeate that is suitable for discharge. The obtained chemical oxygen demand (COD) concentrations in the permeate of ultrafiltration tests were indeed under the limit value (50 mg/L) of the local municipal discharge standards. The COD of the concentrate was 5.4 times higher than that of the initial feed. These concentrated organics were then co-digested with organic kitchen wastes at an organic loading rate of 2.0 kg VS/m3.d. The volumetric biogas production of the digester was 1.94 ± 0.34 m3/m3.d. The recovered carbon, in terms of methane gas, accounted for 50% of the total carbon input of the integrated system. Consequently, an electrical production of 64 Wh/capita/d can be obtained when applying the proposed technology with the current wastes generated in Ho Chi Minh City. Thus, it is an approach with great potential in terms of energy recovery and waste treatment.

Improvement of an integrated system of membrane bioreactor and worm reactor by phosphorus removal using additional post-chemical treatment

2016 ◽  
Vol 74 (9) ◽  
pp. 2202-2210
Author(s):  
Jia Liu ◽  
Wei Zuo ◽  
Yu Tian ◽  
Jun Zhang ◽  
Hui Li ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Chemical Treatment ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Integrated System ◽  
Cod Removal ◽  
N Removal ◽  
Excess Sludge Reduction

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.

scholarly journals Inter-stage thermophilic aerobic digestion may increase organic matter removal from wastewater sludge without decreasing biogas production

2017 ◽  
Vol 77 (3) ◽  
pp. 721-726
Author(s):  
Sasha D. Hafner ◽  
Johan T. Madsen ◽  
Johanna M. Pedersen ◽  
Charlotte Rennuit
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Aerobic Digestion ◽  
Anaerobic Digesters ◽  
Stage System ◽  
Thermophilic Aerobic Digestion ◽  
Pre Treatment

Abstract Combining aerobic and anaerobic digestion in a two-stage system can improve the degradation of wastewater sludge over the use of either technology alone. But use of aerobic digestion as a pre-treatment before anaerobic digestion generally reduces methane production due to loss of substrate through oxidation. An inter-stage configuration may avoid this reduction in methane production. Here, we evaluated the use of thermophilic aerobic digestion (TAD) as an inter-stage treatment for wastewater sludge using laboratory-scale semi-continuous reactors. A single anaerobic digester was compared to an inter-stage system, where a thermophilic aerobic digester (55 °C) was used between two mesophilic anaerobic digesters (37 °C). Both systems had retention times of approximately 30 days, and the comparison was based on measurements made over 97 days. Results showed that the inter-stage system provided better sludge destruction (52% volatile solids (VS) removal vs. 40% for the single-stage system, 44% chemical oxygen demand (COD) removal vs. 34%) without a decrease in total biogas production (methane yield per g VS added was 0.22–0.24 L g−1 for both systems).

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