scholarly journals Removal of Contaminants of Emerging Concern (CECs) Using a Membrane Bioreactor (MBR): a short review

2019 ◽  
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Membrane Bioreactor ◽  
Emerging Contaminants ◽  
Synergistic Effects ◽  
Aquatic Organisms ◽  
Endocrine Disrupting Compounds ◽  
Short Review ◽  
Contaminants Of Emerging Concern ◽  
Operational Conditions

<p>Contaminants of emerging concern (CECs), such as pharmaceuticals and personal care products (PPCPs) and as endocrine disrupting compounds, have recently recognized as the next set of pollutants due to their toxic effects on human health and aquatic organisms at very low concentrations. One of effective methods to remove these emerging contaminants present in the aquatic environment is a membrane bioreactor (MBR). In this review, 27 CECs belonged to diverse categories of PPCPs were surveyed from the point of view of the removal efficiency by several types of MBR modules with various operational conditions, such as a type of MBR, hydraulic retention time and sludge retention time. As a result, this review provided the overall ranges in the removal efficiency of 27 CECs by different MBR filtrations and modules. Certain categories of PPCPs such as analgesics/anti-inflammatory drugs (acetaminophen and ibuprofen), steroids/hormones (estriol and testosterone) and stimulant (caffeine) have relatively higher removal rates, while antimicrobial agent (TCEP) is rarely removed in the different MBRs. For further implementation of CEC removal by a MBR system, physical characteristics/biological fate of a wide variety of CECs, individual/synergistic effects which may occur during MBR operation, and application of advanced MBR technologies should be studied.</p>

scholarly journals Research trends on emerging environment pollutants – a review

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
I. Rykowska ◽  
W. Wasiak
Keyword(s):  
Natural Environment ◽  
Emerging Contaminants ◽  
Aquatic Organisms ◽  
Endocrine Disrupting Compounds ◽  
Research Trends ◽  
Multicomponent Mixtures ◽  
Groundwater Contaminants ◽  
Hormonal Imbalance ◽  
Endocrine Disrupting

AbstractConcern for the natural environment increasingly devotes more attention to growing potential hazards resulting from the release of various substances. Currently, one of the main problems associated with environmental pollution is the derivation of organic compounds from wastewater. Substances derived from sewage leaks into the environment in the form of a multicomponent mixtures often enhances the toxic effects caused by these compounds. While analyzing the reports in the literature of the last two decades it can be seen that substantial efforts are devoted to the determination of selected trace contaminants present in wastewater. Among the most marked there are endocrine disrupting compounds, residues of pharmaceuticals and personal care products, plastics and sunscreens. Recently, a new group of compounds joined the aforementioned contaminants, namely drugs, whose legality and availability is increasing every year. Exposure to these type of compounds, named in the literature as emerging contaminants (ECs), involves, among others, such effects as hormonal imbalance, reduction of the survivability of aquatic organisms and reproductive problems. This paper provides a review of the types of emerging organic groundwater contaminants (EGCs) which are beginning to be found in the natural environment in many countries all around the world.

A submerged tubular ceramic membrane bioreactor for high strength wastewater treatment

2003 ◽  
Vol 47 (1) ◽  
pp. 105-111 ◽  
Author(s):  
D.D. Sun ◽  
J.L. Zeng ◽  
J.H. Tay
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Retention Time ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Treatment Plant ◽  
High Strength ◽  
Cod Removal ◽  
Utilization Rate ◽  
Cod Removal Efficiency

A 4 L submerged tubular ceramic membrane bioreactor (MBR) was applied in laboratory scale to treat 2,400 mg-COD/L high strength wastewater. A prolonged sludge retention time (SRT) of 200 day, in contrast to the conventional SRT of 5 to 15 days, was explored in this study, aiming to reduce substantially the amount of disposed sludge. The MBR system was operated for a period of 142 days in four runs, differentiated by specific oxygen utilization rate (SOUR) and hydraulic retention time (HRT). It was found that the MBR system produced more than 99% of suspended solid reduction. Mixed liquor suspended solids (MLSS) was found to be adversely proportional to HRT, and in general higher than the value from a conventional wastewater treatment plant. A chemical oxygen demand (COD) removal efficiency was achieved as high as 98% in Run 1, when SOUR was in the range of 100-200 mg-O/g-MLVSS/hr. Unexpectedly, the COD removal efficiency in Run 2 to 4 was higher than 92%, on average, where higher HRT and abnormally low SOUR of 20-30 mg-O/g-MLVSS/hr prevailed. It was noted that the ceramic membrane presented a significant soluble nutrient rejection when the microbial metabolism of biological treatment broke down.

scholarly journals Improving the Imazapyr Degradation by Photocatalytic Ozonation: A Comparative Study with Different Oxidative Chemical Processes

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1446
Author(s):  
Salma Bougarrani ◽  
Zakarya Baicha ◽  
Lahbib Latrach ◽  
Mohammed El Mahi ◽  
Francisco José Hernandez Fernandez
Keyword(s):  
Removal Efficiency ◽  
Ozone Concentration ◽  
Organic Contaminants ◽  
Synergistic Effects ◽  
Heterogeneous Photocatalysis ◽  
Operational Conditions ◽  
Oxidation Processes ◽  
First Order ◽  
Photocatalytic Ozonation ◽  
Constant Rate

The degradation of imazapyr (C13H15N3O3), an active element in the aqueous solution of commercial herbicide, was investigated. This study was the first to evaluate in a comprehensive manner the efficiency of advanced oxidation processes for imazapyr degradation. Results showed that Imazapyr degradation is significantly affected by operational conditions such as TiO2 concentration, ozone concentration, initial concentration of imazapyr and pH. The kinetics of Imazapyr consumption was the first order with respect to Imazapyr concentration and zero order with respect to ozone concentration with a constant rate of 0.247 min−1 and 0.128 min−1 for photocatalytic ozonation and heterogeneous photocatalysis, while it was the first order with respect to Imazapyr and the first order with respect to ozone concentrations when only ozone was used with a constant rate of 0.053 mol L−1 min−1 at pH 7. The results revealed that more than 90 percent of the removal efficiency representing the elimination of imazapyr was held up to 7 μM. Further increase in the concentration of imazapyr leads to a drop in the removal efficiency, however the total imazapyr degradation was reached in 20 min utilizing photocatalytic ozonation for 5 μM of Imazapyr in the presence of 100 mg L−1 of TiO2, 10 mg L−1 of ozone at pH 7. Photocatalytic ozonation and heterogeneous photocatalysis utilizing TiO2 as a semiconductor process appeared possible and well suited for the treatment of organic contaminants such as imazapyr herbicides, although at certain dosages of pH and common time for wastewater treatment, imazapyr was not degraded with ozonation on its own. The association of two oxidation processes, ozonation and photocatalysis, has improved oxidation efficiencies for water treatment under optimal conditions, leading to the development of non-selective hydroxyl and more reactive radicals in the oxidation medium, as well as the resulting synergistic effects between photocatalysis and ozonation that react more rapidly with imazapyr herbicide.

scholarly journals Dynamics of Archaeal and Bacterial Communities in Response to Variations of Hydraulic Retention Time in an Integrated Anaerobic Fluidized-Bed Membrane Bioreactor Treating Benzothiazole Wastewater

Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yue Li ◽  
Qi Hu ◽  
Da-Wen Gao
Keyword(s):  
Fluidized Bed ◽  
Removal Efficiency ◽  
Retention Time ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
High Strength ◽  
Service Period ◽  
Miseq Platform

An integrated anaerobic fluidized-bed membrane bioreactor (IAFMBR) was investigated to treat synthetic high-strength benzothiazole wastewater (50 mg/L) at a hydraulic retention time (HRT) of 24, 18, and 12 h. The chemical oxygen demand (COD) removal efficiency (from 93.6% to 90.9%), the methane percentage (from 70.9% to 69.27%), and the methane yield (from 0.309 m3 CH4/kg·CODremoved to 0.316 m3 CH4/kg·CODremoved) were not affected by decreasing HRTs. However, it had an adverse effect on membrane fouling (decreasing service period from 5.3 d to 3.2 d) and benzothiazole removal efficiency (reducing it from 97.5% to 82.3%). Three sludge samples that were collected on day 185, day 240, and day 297 were analyzed using an Illumina® MiSeq platform. It is striking that the dominant genus of archaea was always Methanosaeta despite of HRTs. The proportions of Methanosaeta were 80.6% (HRT 24), 91.9% (HRT 18), and 91.2% (HRT 12). The dominant bacterial genera were Clostridium in proportions of 23.9% (HRT 24), 16.4% (HRT 18), and 15.3% (HRT 12), respectively.

Removal of endocrine disrupting chemicals in a large scale membrane bioreactor plant combined with anaerobic-anoxic-oxic process for municipal wastewater reclamation

2011 ◽  
Vol 64 (7) ◽  
pp. 1511-1518 ◽  
Author(s):  
Chunying Wu ◽  
Wenchao Xue ◽  
Haidong Zhou ◽  
Xia Huang ◽  
Xianghua Wen
Keyword(s):  
Removal Efficiency ◽  
Large Scale ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Estrogenic Activity ◽  
Endocrine Disrupting Compounds ◽  
Gas Chromatography Mass Spectrometry ◽  
Wastewater Reclamation ◽  
Kd Values ◽  
Endocrine Disrupting

The removal of eight typical endocrine disrupting compounds (EDCs) in a full scale membrane bioreactor combined with anaerobic-anoxic-oxic process (A2/O-MBR) for municipal wastewater reclamation located in Beijing was investigated. These EDCs, including 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), bisphenol A (BPA), estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), estriol (E3) and 17α-ethinylestradiol (EE2), were simultaneously analyzed by gas chromatography/mass spectrometry after derivatization. The concentrations of eight EDCs were also measured in sludge of anaerobic, anoxic, oxic and membrane tanks to measure sludge-water distribution coefficients (Kd values) as the indicator of adsorption propensity of target compound to sludge. The removal efficiencies of EDCs reached above 97%, except for 4-n-NP removal efficiency of 72%, 4-OP removal efficiency of 75% and EE2 removal efficiency of 87% in the A2/O-MBR process. The high Kd values indicated that the sludge had a large adsorption capacity for these EDCs, and significantly contributed to removal of EDCs. Yeast estrogen screen assay was performed on samples to assess the total estrogenic activity by measuring the 17β-E2 equivalent quantity (EEQ), expressed in ng-EEQ/L. The measured EEQ value was markedly reduced from 72.1 ng-EEQ/L in the influent to 4.9 ng-EEQ/L in the effluent. Anoxic tank and anaerobic tank contributed to 80% and 37% in total EEQ removal, respectively.

Calculation methods to perform mass balance of endocrine disrupting compounds in a submerged membrane bioreactor: fate and distribution of estrogens during the biological treatment

2011 ◽  
Vol 64 (11) ◽  
pp. 2158-2168 ◽  
Author(s):  
E. B. Estrada-Arriaga ◽  
P. Mijaylova
Keyword(s):  
Mass Balance ◽  
Water Distribution ◽  
Membrane Bioreactor ◽  
Dry Weight ◽  
Endocrine Disrupting Compounds ◽  
Distribution Coefficients ◽  
Operational Conditions ◽  
Submerged Membrane Bioreactor ◽  
Endocrine Disrupting ◽  
Adsorption Processes

The purpose of this paper is to report the study of the fate and distribution of three endocrine disrupting compounds (estrogens); Estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) in a laboratory scale submerged membrane bioreactor (SMBR). For this matter, both aqueous and solids phases were analyzed for the presence of E1, E2 and EE2. The outcome of this study was that three SMBRs showed enhanced elimination of estrogens in different operational conditions; the estrogen removal was close to 100% in SMBR. Additionally, E1, E2 and EE2 were detected in SMBR sludge at concentrations of up to 41.2, 37.3 and 36.9 ng g−1 dry weight, respectively. The estrogen removal in the SMBRs was directly influenced by a combination of simultaneous biodegradation–adsorption processes, indicating that the main removal mechanism of the estrogens in the SMBRs is the biodegradation process. The E1, E2 and EE2 were biologically degraded in the SMBR (87–100%). The sorption of estrogens onto activated sludge was from 2%. Therefore, a high potential for estrogen removal by biodegradation in the SMBR was observed, allowing less estrogen concentration in the dissolved phase available for the adsorption of these compounds onto biological flocs. Two different methods were carried out for mass balance calculations of estrogens in SMBR. For the first method, the measured data was used in both liquid and solid phases, whereas for the second one, it was in aqueous phase and solid–water distribution coefficients (Kd) value of E1, E2 and EE2. The purpose of these methodologies is to make easier the identification of the main mechanisms involved in the removal of E1, E2 and EE2 in a SMBR. Both methods can be applied in order to determine the mechanism, fate and distribution of estrogens in a SMBR.

scholarly journals Performance of a membrane bioreactor in extreme concentrations of bisphenol A

2018 ◽  
Vol 77 (6) ◽  
pp. 1505-1513 ◽  
Author(s):  
Yassine Ouarda ◽  
Mehdi Zolfaghari ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Gerardo Buelna ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Removal Efficiency ◽  
Retention Time ◽  
Membrane Bioreactor ◽  
Heterotrophic Bacteria ◽  
Oxygen Demand ◽  
Ammonia Removal ◽  
Biodegradation Rate ◽  
Solid Retention Time ◽  
Submerged Membrane Bioreactor

Abstract In this study, a submerged membrane bioreactor was used to study the effect of low and high bisphenol A (BPA) concentration on the sludge biological activity. The pilot was operated over 540 days with hydraulic retention time and solid retention time of 5.5 hours and 140 days, respectively. As a hydrophobic compound, BPA was highly adsorbed by activated sludge. In lower concentrations, the biodegradation rate remained low, since the BPA concentration in the sludge was lower than 0.5 mg/g TS; yet, at an influent concentration up to 15 mg/L, the biodegradation rate was increasing, resulting in 99% BPA removal efficiency. The result for chemical oxygen demand removal showed that BPA concentration has no effect on the heterotrophic bacteria that were responsible for the organic carbon degradation. In higher concentrations, up to 16 mg of BPA was used for each gram of sludge as a source of carbon. However, the activity of autotrophic bacteria, including nitrifiers, was completely halted in the presence of 20 mg/L of BPA or more. Although nitrification was stopped after day 400, ammonia removal remained higher than 70% due to air stripping. Assimilation by bacteria was the only removal pathway for phosphorus, which resulted in an average 35% of P-PO4 removal efficiency.

scholarly journals Laboratory- and full-scale studies on the removal of pharmaceuticals in an aerated constructed wetland: effects of aeration and hydraulic retention time on the removal efficiency and assessment of the aquatic risk

2017 ◽  
Vol 76 (6) ◽  
pp. 1457-1465 ◽  
Author(s):  
Hannele Auvinen ◽  
Wilhelm Gebhardt ◽  
Volker Linnemann ◽  
Gijs Du Laing ◽  
Diederik P. L. Rousseau
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Retention Time ◽  
Rural Areas ◽  
Hydraulic Retention Time ◽  
Aquatic Organisms ◽  
Healthcare Facility ◽  
Surface Flow ◽  
Full Scale ◽  
Small Water

Pharmaceutical residues in wastewater pose a challenge to wastewater treatment technologies. Constructed wetlands (CWs) are common wastewater treatment systems in rural areas and they discharge often in small water courses in which the ecology can be adversely affected by the discharged pharmaceuticals. Hence, there is a need for studies aiming to improve the removal of pharmaceuticals in CWs. In this study, the performance of a full-scale aerated sub-surface flow hybrid CW treating wastewater from a healthcare facility was studied in terms of common water parameters and pharmaceutical removal. In addition, a preliminary aquatic risk assessment based on hazard quotients was performed to estimate the likelihood of adverse effects on aquatic organisms in the forest creek where this CW discharges. The (combined) effect of aeration and hydraulic retention time (HRT) was evaluated in a laboratory-scale batch experiment. Excellent removal of the targeted pharmaceuticals was obtained in the full-scale CW (&gt;90%) and, as a result, the aquatic risk was estimated low. The removal efficiency of only a few of the targeted pharmaceuticals was found to be dependent on the applied aeration (namely gabapentin, metformin and sotalol). Longer and the HRT increased the removal of carbamazepine, diclofenac and tramadol.

The effect of aeration and non-aeration time on simultaneous organic, nitrogen and phosphorus removal using an intermittent aeration membrane bioreactor

2002 ◽  
Vol 46 (9) ◽  
pp. 193-200 ◽  
Author(s):  
Z. Ujang ◽  
M.R. Salim ◽  
S.L. Khor
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Phosphorus Removal ◽  
Organic Nitrogen ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Intermittent Aeration ◽  
Nitrogen And Phosphorus ◽  
Solid Retention Time ◽  
Aeration Time

A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 mm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.

Evaluation of a tropical single-cell waste stabilization pond system for irrigation

1995 ◽  
Vol 31 (12) ◽  
pp. 267-273 ◽  
Author(s):  
B. S. O. Ceballos ◽  
A. Konig ◽  
B. Lomans ◽  
A. B. Athayde ◽  
H. W. Pearson
Keyword(s):  
Single Cell ◽  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Full Scale ◽  
Waste Stabilization Pond ◽  
North East ◽  
Helminth Eggs ◽  
Waste Stabilization ◽  
Better Than

A single full-scale primary facultative pond in Sapé, north-east Brazil was monitored for performance and efficiency. The pond had a hydraulic retention time of 61 days and achieved a 95% BOD5 removal efficiency and had no helminth eggs in the effluent. The effluent failed to meet the WHO faecal coliform guideline for unrestricted irrigation. The pond was dominated by the cyanobacterium Microcystis and gave better than predicted orthophosphate removal. Details of how the system could be simply upgraded utilizing the same land are discussed.

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