Membrane filtration for particles removal after ozonation-biofiltration

2007 ◽  
Vol 56 (10) ◽  
pp. 101-108 ◽  
Author(s):  
S. Osterhus ◽  
K. Azrague ◽  
T. Leiknes ◽  
H. Odegaard
Keyword(s):  
Membrane Reactor ◽  
Membrane Filtration ◽  
Submicron Particles ◽  
Plate Count ◽  
Uv Absorbance ◽  
Heterotrophic Plate Count ◽  
Operational Factors ◽  
Process Combination ◽  
By Products ◽  
Very High

With the process combination Ozonation-Biofiltration-Membranefiltration (the OBM-process) an average removal of 63% for UV-absorbance (UV254), 79% for color, and 28% for DOC was obtained treating NOM containing surface water. In this paper, focus has been made on the removal of particles after the ozonation and biofiltration treatment steps, using a submerged hollow fiber ultrafiltration membrane reactor. For this purpose the membrane performed adequately. The ultrafiltration step did not have a significant impact on the removal of color, UV254, and DOC. However, the SS and the heterotrophic plate count (HPC) was almost completely removed, and the turbidity was reduced by 65% by the membrane filtration, even at very high fluxes. Fouling occurred during operation, and operational factors of both the ozonation/biofiltration and the membrane reactor were important for controlling this. The experiments at pH 6.5 gave a higher permanent fouling than at pH 8.5, which was caused by the different oxidation pathways and consequently by the change in size and hydrophobicity of the by-products. On the other hand, the reversible fouling was less important at low pH. The mechanical cleaning was efficient, however, it seemed that the air scouring participated to the formation of submicron particles which favored the fouling.

scholarly journals Comparison of the ColiPlate™ Kit with Two Common E. coli Enumeration Methods for Water

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1804
Author(s):  
Cassi J. Gibson ◽  
Abraham K. Maritim ◽  
Jason W. Marion
Keyword(s):  
High Risk ◽  
Natural Water ◽  
Membrane Filtration ◽  
Fecal Contamination ◽  
Reference Method ◽  
World Health ◽  
Risk Levels ◽  
E Coli ◽  
Field Samples ◽  
Very High

Quantitatively assessing fecal indicator bacteria in drinking water from limited resource settings (e.g., disasters, remote areas) can inform public health strategies for reducing waterborne illnesses. This study aimed to compare two common approaches for quantifying Escherichia coli (E. coli) density in natural water versus the ColiPlate™ kit approach. For comparing methods, 41 field samples from natural water sources in Kentucky (USA) were collected. E. coli densities were then determined by (1) membrane filtration in conjunction with modified membrane-thermotolerant E. coli (mTEC) agar, (2) Idexx Quanti-Tray® 2000 with the Colilert® substrate, and (3) the Bluewater Biosciences ColiPlate kit. Significant correlations were observed between E. coli density data for all three methods (p < 0.001). Paired t-test results showed no difference in E. coli densities determined by all the methods (p > 0.05). Upon assigning modified mTEC as the reference method for determining the World Health Organization-assigned “very high-risk” levels of fecal contamination (> 100 E. coli CFU/100 mL), both ColiPlate and Colilert exhibited excellent discrimination for screening very high-risk levels according to the area under the receiver operating characteristic curve (~89%). These data suggest ColiPlate continues to be an effective monitoring tool for quantifying E. coli density and characterizing fecal contamination risks from water.

scholarly journals Biofilm reduction potential of 0.02% polyhexanide irrigation solution in several types of urethral catheters

BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Florian H. H. Brill ◽  
Julia Hambach ◽  
Christian Utpatel ◽  
Diana C. Mogrovejo ◽  
Henrik Gabriel ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Saline Solution ◽  
Bacterial Biofilm ◽  
Plate Count ◽  
Vitro Assay ◽  
Significant Difference ◽  
Irrigation Solution ◽  
Clinically Relevant Bacteria

Abstract Background Long-term use of urethral catheters is associated with high risk of urinary tract infection (UTI) and blockage. Microbial biofilms are a common cause of catheter blockage, reducing their lifetime and significantly increasing morbidity of UTIs. A 0.02% polyhexanide irrigation solution developed for routine mechanical rinsing shows potential for bacterial decolonization of urethral catheters and has the potential to reduce or prevent biofilm formation. Methods Using an in vitro assay with standard market-leading types of catheters artificially contaminated with clinically relevant bacteria, assays were carried out to evaluate the biofilm reduction and prevention potential of a 0.02% polyhexanide solution versus no intervention (standard approach) and irrigation with saline solution (NaCl 0.9%). The efficiency of decolonization was measured through microbial plate count and membrane filtration. Results Irrigation using a 0.02% polyhexanide solution is suitable for the decolonization of a variety of transurethral catheters. The effect observed is significant compared to irrigation with 0.9% saline solution (p = 0.002) or no treatment (p = 0.011). No significant difference was found between irrigation with 0.9% saline solution and no treatment (p = 0.74). Conclusions A 0.02% polyhexanide solution is able to reduce bacterial biofilm from catheters artificially contaminated with clinically relevant bacteria in vitro. The data shows a reduction of the viability of thick bacterial biofilms in a variety of commercially available urinary catheters made from silicone, latex-free silicone, hydrogel-coated silicone and PVC. Further research is required to evaluate the long-term tolerability and efficacy of polyhexanide in clinical practice.

scholarly journals Effect of different heterotrophic plate count methods on the estimation of the composition of the culturable microbial community

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e862 ◽  
Author(s):  
Eva Theres Gensberger ◽  
Eva-Maria Gössl ◽  
Livio Antonielli ◽  
Angela Sessitsch ◽  
Tanja Kostić
Keyword(s):  
Microbial Community ◽  
Plate Count ◽  
Heterotrophic Plate Count

Lignin distribution in waterlogged archaeological Picea abies (L.) Karst degraded by erosion bacteria

Holzforschung ◽  
2014 ◽  
Vol 68 (7) ◽  
pp. 791-798 ◽  
Author(s):  
Nanna Bjerregaard Pedersen ◽  
Uwe Schmitt ◽  
Gerald Koch ◽  
Claus Felby ◽  
Lisbeth Garbrecht Thygesen
Keyword(s):  
Picea Abies ◽  
Lignin Content ◽  
Middle Lamella ◽  
Uv Absorbance ◽  
Tem Analysis ◽  
Lignin Distribution ◽  
Transmission Electron ◽  
Residual Material ◽  
Ray Parenchyma Cells ◽  
Very High

Abstract The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV-microspectrophotometry (UMSP). Lignin rich cell wall compartments such as cell corner (CC), compound middle lamella (CML), torus, initial pit border and mild compression wood (CW) appeared morphologically well preserved together with S1 and S3 layers and epithelial and ray parenchyma cells. Residual material (RM) from degraded S2 showed a varied lignin distribution as evidenced by the different local UV-absorbance intensities. However, evaluation of UV-absorbance line spectra of RM revealed no change in conjugation of the aromatic ring system. Presence of RM with both very low and very high lignin absorbances showed evidence for disassembly of lignin during degradation combined with aggregation of lignin fragments and physical movement of these fractions. In contrast to TEM analysis, locally decreasing lignin content was found by UMSP in CML regions.

scholarly journals Progress in Reactors for High-Temperature Fischer–Tropsch Process: Determination Place of Intensifier Reactor Perspective

2014 ◽  
Vol 12 (1) ◽  
pp. 639-664 ◽  
Author(s):  
Samrand Saeidi ◽  
Masoud Talebi Amiri ◽  
Nor Aishah Saidina Amin ◽  
Mohammad Reza Rahimpour
Keyword(s):  
High Temperature ◽  
Process Parameters ◽  
Membrane Reactor ◽  
Product Distribution ◽  
Production Yield ◽  
Fischer Tropsch ◽  
By Products

Abstract High-temperature Fischer–Tropsch (HTFT) process aims to produce lighter cuts such as gasoline and diesel. For many years there have been studies and improvements on HTFT process to make the existing reactors more efficient. Recent studies proposed new configurations such as dual-type membrane reactor and coupling configurations reactor, which improved the performances of this process. This achievement persuades us to update the existing knowledge about the available reactors for HTFT process. In this article, features and performances overview of two classes of reactors are reviewed. The first class consists of the reactors which are based on older studies, and the second one includes recent studies which are called product intensifier reactors. Finally, it is shown that the product intensifier reactors have higher CO conversions and lower selectivity of undesired by-products which results in higher production yield of gasoline. Furthermore, the place of product intensifier reactor among common reactors with regard to the influence of the process parameters on the product distribution has been estimated.

scholarly journals Effect of variations in heterotrophic plate count methods on bacterial estimation in some sachet water in Calabar Metropolis

2019 ◽  
Vol 1 (2) ◽  
pp. 018-027
Author(s):  
Augusta Oluchi Mmuoegbulam ◽  
Augustine Agorye Unimke ◽  
Iniobong Ebenge Andy ◽  
Ogemdi Chinwendu Anika ◽  
Rachael Teniola Macaulay
Keyword(s):  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Sachet Water

scholarly journals Review on antibiotics treatment by electrochemical membrane reactor

2021 ◽  
Vol 233 ◽  
pp. 01042
Author(s):  
Lei Chao ◽  
Feilong Chen ◽  
Yi Han ◽  
Yafeng Li
Keyword(s):  
Membrane Reactor ◽  
Membrane Filtration ◽  
Electrode Materials ◽  
Degradation Mechanism ◽  
Membrane Reactors ◽  
Membrane Electrode ◽  
Actual Application ◽  
Electrochemical Membrane Reactor ◽  
Antibiotic Degradation ◽  
The Impact

Lower consumption, higher efficiency, environmental protection, and reliability are the development trends for the treatment of antibiotic wastewater in future. To accomplish this, the electrochemical membrane reactor (ECMR) is developed by combining membrane filtration and electrochemical advanced oxidation technology. The device configuration and working mode of the electrochemical membrane reactor are introduced and compared. Besides, the principles of the removal of antibiotics by the reactor are explained with emphasis. Furthermore, the commonly used cathode and anode materials of the reactor in the current research are summarized, and the electrode materials are discussed. The effects of selection and modification on the elimination of antibiotics in the reactor and the impact are analysed. To address the limitations of electrochemical membrane reactors, this review proposes that more research should be done in the aspects of antibiotic degradation mechanism, reduction of membrane electrode R&D costs, and actual application of amplification devices.

Other heterotrophic plate count bacteria

2004 ◽  
pp. 125-143
Author(s):  
Steven Percival ◽  
Rachel Chalmers ◽  
Martha Embrey ◽  
Paul Hunter ◽  
Jane Sellwood ◽  
...  
Keyword(s):  
Plate Count ◽  
Heterotrophic Plate Count
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