The antifouling, antimicrobial, elution behavior, skin irritant, and cytotoxicity properties of water-soluble phosphate glass on stainless steel were evaluated. Water-soluble phosphate glass samples with 35% Cu (mol/mol) were prepared by altering the network modifier (Na2O, K2O) and network former (P2O5, B2O3) compositions. The materials were melted at temperatures within the range of 850-950 °C. The melt was then quenched and ground into fine particles using a twin roll mill. The resulting water-soluble glasses were prepared as glass frit (size < 100 μm) using a sieve. The amorphous phase was determined by X-ray diffraction and differential thermal analysis. Water-soluble glasses with a reduced Cu ion elution rate of 1.2 ppm per week were formed because the chemical resistances of the formulated glasses improved as the P2O5 content decreased and the B2O3 content increased. To test its antifouling properties, the glass frit was mixed with paint and coated onto a STS316L sheet. The surface roughness was increased markedly from 1.4 to 19.2 nm, increasing the specific surface area for antimicrobial activity. It was demonstrated that the proposed method was able to form noncytotoxic, nonirritant, water-soluble glasses with 99.9% antimicrobial activity against Staphylococcus aureus. These results suggest that water-soluble phosphate glass on STS316L sheets could be useful in filtration plants.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- bioznečištění prevence a kontrola MeSH
- čištění vody přístrojové vybavení MeSH
- difrakce rentgenového záření MeSH
- filtrace přístrojové vybavení MeSH
- fosfáty chemie farmakologie MeSH
- králíci MeSH
- kůže účinky léků MeSH
- sklo chemie MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The scope of the study was to apply Phenotype Biolog MicroArray (PM) technology to test the antibiotic sensitivity of the bacterial strains isolated from on-site wastewater treatment facilities. In the first step of the study, the percentage values of resistant bacteria from total heterotrophic bacteria growing on solid media supplemented with various antibiotics were determined. In the untreated wastewater, the average shares of kanamycin-, streptomycin-, and tetracycline-resistant bacteria were 53, 56, and 42%, respectively. Meanwhile, the shares of kanamycin-, streptomycin-, and tetracycline-resistant bacteria in the treated wastewater were 39, 33, and 29%, respectively. To evaluate the antibiotic susceptibility of the bacteria present in the wastewater, using the phenotype microarrays (PMs), the most common isolates from the treated wastewater were chosen: Serratia marcescens ss marcescens, Pseudomonas fluorescens, Stenotrophomonas maltophilia, Stenotrophomonas rhizophila, Microbacterium flavescens, Alcaligenes faecalis ss faecalis, Flavobacterium hydatis, Variovorax paradoxus, Acinetobacter johnsonii, and Aeromonas bestiarum. The strains were classified as multi-antibiotic-resistant bacteria. Most of them were resistant to more than 30 antibiotics from various chemical classes. Phenotype microarrays could be successfully used as an additional tool for evaluation of the multi-antibiotic resistance of environmental bacteria and in preliminary determination of the range of inhibition concentration.
- MeSH
- antibakteriální látky farmakologie MeSH
- Bacteria klasifikace účinky léků genetika izolace a purifikace MeSH
- bakteriální léková rezistence MeSH
- čištění vody přístrojové vybavení MeSH
- mikročipová analýza metody MeSH
- odpadní voda chemie mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
Nontuberculous mycobacteria (NTM) are ubiquitous organisms in all natural ecosystems, including water environments. Several of these species are potential pathogens which affect human health. NTM most commonly cause pulmonary, skin or soft tissue infections. Primary sludge obtained from the water treatment plants of four drinking water reservoirs were subjected to analysis for mycobacteria. Five decontamination methods (5% oxalic acid, modified Petroff, HCl-NaOH, N-acetyl-L-cysteine-sodium hydroxide and 0.05% cetylpyridinium chloride), three growth media (Herrold's egg yolk medium with and without the antibiotic cocktail PANTA and Löwenstein-Jensen medium with sodium pyruvate) and three incubation temperatures (25, 30 and 37 °C) for isolation of mycobacteria were compared in the analysis of 18 sludge samples. To evaluate examined methods, the overall positive, negative, and contamination rate, and these rates in respect to localities are taken into account. Statistical analysis demonstrated that the best combination for the recovery of mycobacteria with the minimum number of contaminating microorganisms is 5% oxalic acid decontamination cultured on Herrold's egg yolk medium with the antibiotic cocktail PANTA at 25 °C. The least suitable is N-acetyl-L-cysteine-sodium hydroxide decontamination cultured on Löwenstein-Jensen medium with sodium pyruvate at 25 °C. From 18 sludge samples we isolated 27 mycobacterial species or groups; Mycobacterium algericum, M. arabiense, M. heraklionense, M. minnesotense, M. moriokaense, M. salmoniphilum and M. vulneris were isolated from the natural water environment for the first time. Because the natural water environment is the main source of potentially pathogenic mycobacteria for humans, it is important to direct particular focus to newly described mycobacterial species.
- MeSH
- bakteriologické techniky metody MeSH
- čištění vody přístrojové vybavení metody MeSH
- dekontaminace metody MeSH
- kultivační média analýza metabolismus MeSH
- Mycobacterium genetika růst a vývoj izolace a purifikace MeSH
- odpadní vody mikrobiologie MeSH
- sladká voda mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Ion-exchange tap water demineralization for process water preparation results in a saline regeneration wastewater (20-100 mS cm(-1)) that is increasingly problematic in view of discharge. A coupled nanofiltration-membrane distillation (NF-MD) process is evaluated for the recovery of water and sodium chloride from this wastewater. NF-MD treatment of mixed regeneration wastewater is compared to NF-MD treatment of separate anion- and cation-regenerate fractions. NF on mixed regeneration wastewater results in a higher flux (30 L m(-2) h(-1) at 7 bar) compared to NF on the separate fractions (6-9 L m(-2) h(-1) at 30 bar). NF permeate recovery is strongly limited by scaling (50% for separate and 60% for mixed, respectively). Physical signs of scaling were found during MD treatment of the NF permeates but did not result in flux decline for mixed regeneration wastewater. Final salt composition is expected to qualify as a road de-icing salt. NF-MD is an economically viable alternative compared to external disposal of wastewater for larger-scale installations (1.4 versus 2.5 euro m(-3) produced demineralized water for a 10 m3 regenerate per day plant). The cost benefits of water re-use and salt recuperation are small when compared to total treatment costs for mixed regenerate wastewater.
- MeSH
- chlorid sodný chemie izolace a purifikace MeSH
- čištění vody přístrojové vybavení metody MeSH
- destilace přístrojové vybavení metody MeSH
- filtrace přístrojové vybavení metody MeSH
- membrány umělé MeSH
- odpadní produkty analýza MeSH
- odpadní voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
The aim of this study was to investigate the suitability of a novel electrospun polyurethane nanofibre material for water-treatment purposes. Bacterial removal efficiency was tested in the laboratory by filtering artificial water spiked with Escherichia coli through a 0.25 µm nanofibre membrane. The results were compared with those obtained using a commercial microfiltration material (MV020T) with a similar pore size (0.20 µm). Alongside the laboratory experiments, we also determined filtration efficiency with semi-pilot scale experiments using actual wastewater from the secondary sedimentation tank of a wastewater treatment plant. The laboratory experiments indicated very high log10 removal efficiency, ranging from 5.8 to 6.8 CFU (colony-forming units)/ml. These results were better than those of the commercial membrane (3.8-4.6 CFU/ml). The semi-pilot scale experiment confirmed the membrane's suitability for microbial filtration, with both E. coli and total culturable microorganisms (cultured at both 22 and 36 °C) showing a significant decline compared to the non-filtered control (wastewater from the secondary outlet).
- MeSH
- čištění vody přístrojové vybavení MeSH
- Escherichia coli MeSH
- filtrace přístrojové vybavení MeSH
- membrány umělé * MeSH
- nanovlákna * MeSH
- pilotní projekty MeSH
- polyurethany chemická syntéza MeSH
- povidon MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge.
- MeSH
- anaerobní bakterie fyziologie MeSH
- analýza selhání vybavení MeSH
- bioreaktory mikrobiologie MeSH
- chemické látky znečišťující vodu izolace a purifikace metabolismus MeSH
- čištění vody přístrojové vybavení MeSH
- design vybavení MeSH
- methan metabolismus MeSH
- odpadní voda mikrobiologie MeSH
- odpadní vody mikrobiologie MeSH
- sulfan izolace a purifikace metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- aqua purificata,
- MeSH
- čištění vody * metody normy přístrojové vybavení MeSH
- kvalita vody normy MeSH
- laboratoře * MeSH
- řízení kvality MeSH
- voda MeSH
Many articles have been published on coagulant dosing in membrane bioreactors, though few have been long-term studies examining the treatment of real wastewater. This study summarises the results of a membrane bioreactor pilot-plant (flat sheet membrane, nominal pore size 0.03 μm) that treated real municipal wastewater for two-years. Both influence of phosphorus precipitation by ferric sulphate on membrane permeability (flux decrease) and soluble microbial product concentration (especially on carbohydrates and proteins) were monitored. Flux decrease over work cycles lasting several months without phosphorus precipitation were compared to two periods with precipitation. X-ray elemental diffractometry of the filtration cake showed differences in the main contributors to inorganic fouling, with decreases in Ca and Si during operation with coagulant addition, and an increase in Fe.
- MeSH
- anaerobní bakterie metabolismus MeSH
- analýza selhání vybavení MeSH
- bioreaktory mikrobiologie MeSH
- chemické látky znečišťující vodu izolace a purifikace metabolismus MeSH
- čištění vody přístrojové vybavení MeSH
- design vybavení MeSH
- fosfor MeSH
- frakční precipitace MeSH
- membrány umělé * MeSH
- rozpustnost MeSH
- ultrafiltrace přístrojové vybavení MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This paper evaluates the results from a 12-month study of a single-household wastewater treatment plant with submerged membrane module (household MBR plant) that was monitored from winter to winter season. The samples were collected at least twice a week (an intensive research study at real conditions). The household MBR (membrane bioreactor) plant was linked to a family house with 4 residents. In this study the treatment plant was fed by real domestic wastewater. In contrast to most other experiments with small-scale WWTPs (wastewater treatment plants) carried out in laboratories and facilities of large municipal WWTPs (polygons) which guarantee stable and flexible operation but the characteristics of wastewater and activated sludge in these studies usually differ from those that occur in real small-scale/single-household WWTPs. One of the main goals of this research was to test the response of membrane and activated sludge to different conditions during real operation of the household MBR plant, such as a long period of zero influent/load, or vice versa the presence of a large amount of concentrated wastewater (e.g. during the weekend), very low winter temperatures (water temperature below 5-6 degrees C), high pH values, and the presence of domestic detergents.
- MeSH
- bioreaktory MeSH
- charakteristiky rodiny MeSH
- čištění vody přístrojové vybavení metody MeSH
- design vybavení MeSH
- látky znečišťující životní prostředí analýza MeSH
- lidé MeSH
- odpad tekutý - odstraňování přístrojové vybavení metody MeSH
- odpadní vody MeSH
- pilotní projekty MeSH
- rodina MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
