scholarly journals Reusable and pH-Stable Luminescent Sensors for Highly Selective Detection of Phosphate

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 190
Author(s):  
Do Yeob Kim ◽  
Dong Gyu Kim ◽  
Bongjin Jeong ◽  
Young Il Kim ◽  
Jungseok Heo ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Specific Binding ◽  
Tap Water ◽  
Water Environment ◽  
Polymer Particle ◽  
Repeated Measurements ◽  
Practical Application ◽  
Luminescent Sensors ◽  
Ph Range ◽  
Average Size

Phosphate sensors have been actively studied owing to their importance in water environment monitoring because phosphate is one of the nutrients that result in algal blooms. As with other nutrients, seamless monitoring of phosphate is important for understanding and evaluating eutrophication. However, field-deployable phosphate sensors have not been well developed yet due to the chemical characteristics of phosphate. In this paper, we report on a luminescent coordination polymer particle (CPP) that can respond selectively and sensitively to a phosphate ion against other ions in an aquatic ecosystem. The CPPs with an average size of 88.1 ± 12.2 nm are embedded into membranes for reusable purpose. Due to the specific binding of phosphates to europium ions, the luminescence quenching behavior of CPPs embedded into membranes shows a linear relationship with phosphate concentrations (3–500 μM) and detection limit of 1.52 μM. Consistent luminescence signals were also observed during repeated measurements in the pH range of 3–10. Moreover, the practical application was confirmed by sensing phosphate in actual environmental samples such as tap water and lake water.

Phosphorus transport in saturated slag columns: experiments and mathematical models

1996 ◽  
Vol 34 (1-2) ◽  
pp. 153-160 ◽  
Author(s):  
S. H. Lee ◽  
S. Vigneswaran ◽  
K. Bajracharya
Keyword(s):  
Mathematical Models ◽  
Sorption Capacity ◽  
Algal Blooms ◽  
Sandy Loam ◽  
Dynamic Condition ◽  
Water Environment ◽  
Breakthrough Curves ◽  
Column Experiments ◽  
Phosphorus Transport ◽  
Waste Products

Excessive phosphorus (P as orthophosphate) is one of the major pollutants in natural water that are responsible for algal blooms and eutrophication. P removal by slag is an attractive solution if the P sorption capacity of slag is significant. To design an efficient land treatment facility, basic information on the behaviour of P in the media-water environment is required. In this study, detailed column experiments were conducted to study the P transport under dynamic condition, and mathematical models were developed to describe this process. The column experiments conducted with dust and cake waste products (slag) from a steel industry as adsorbing indicated that they had higher sorption capacity of P than that of a sandy loam soil from North Sydney, Australia. P transport in the dust and cake columns exhibited characteristic S-shaped or curvilinear breakthrough curves. The simulated results from a dynamic physical nonequilibrium sorption model (DPNSM) and Freundlich isotherm constants satisfactorily matched the corresponding experimental breakthrough data. The mobility of P is restricted by the adsorbents and it is proportional to the sorption capacity of them.

scholarly journals Adsorption of As(V) by the Novel and Efficient Adsorbent Cerium-Manganese Modified Biochar

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2720
Author(s):  
Ting Liang ◽  
Lianfang Li ◽  
Changxiong Zhu ◽  
Xue Liu ◽  
Hongna Li ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Photoelectron Spectroscopy ◽  
Water Environment ◽  
Polluted Water ◽  
X Ray ◽  
Modified Biochar ◽  
Wide Ph Range ◽  
Infrared Spectrometer ◽  
Pseudo Second Order ◽  
Ph Range

Arsenic has become a global concern in water environment, and it is essential to develop efficient remediation methods. In this study, a novel adsorbent by loading cerium and manganese oxide onto wheat straw-modified biochar (MBC) was manufactured successfully aiming to remove arsenic from polluted water. Through scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FT-IR), and other techniques, it was found the loading of cerium and manganese oxide on MBC played a significant role in As(V) adsorption. The results of the batch test showed that the adsorption of MBC followed the pseudo-second order kinetics and Langmuir equation. The adsorption capacity of MBC was 108.88 mg As(V)/g at pH = 5.0 (C0 = 100 mg/L, dosage = 0.5 g/L, T = 298 K) with considerable improvement compared to the original biochar. Moreover, MBC exhibited excellent performance over a wide pH range (2.0~11.0). Thermodynamics of the sorption reaction showed that the entropy (ΔS), changes of enthalpy (ΔH) and Gibbs free energy (ΔG), respectively, were 85.88 J/(moL·K), 22.54 kJ/mol and −1.33 to −5.20 kJ/mol at T = 278~323 K. During the adsorption, the formation of multiple complexes under the influence of its abundant surface M-OH (M represents the Ce/Mn) groups involving multiple mechanisms that included electrostatic interaction forces, surface adsorption, redox reaction, and surface complexation. This study indicated that MBC is a promising adsorbent to remove As(V) from polluted water and has great potential in remediating of arsenic contaminated environment.

scholarly journals Poly-3-Hydroxybutyrate in Legionella pneumophila, an Energy Source for Survival in Low-Nutrient Environments

1999 ◽  
Vol 65 (2) ◽  
pp. 822-827 ◽  
Author(s):  
Brian W. James ◽  
W. Stuart Mauchline ◽  
P. Julian Dennis ◽  
C. William Keevil ◽  
Robin Wait
Keyword(s):  
Legionella Pneumophila ◽  
Tap Water ◽  
Water Environment ◽  
Nile Red ◽  
Dry Weight ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Term Survival ◽  
Reliable Determination ◽  
Nonculturable Cells

ABSTRACT Chloroform-soluble material was extracted from two strains ofL. pneumophila serogroup 1 following growth in continuous culture. The purified material was identified as poly-3-hydroxybutyrate (PHB) by nuclear magnetic resonance spectroscopy and by gas chromatography-mass spectrometry. PHB yields of up to 16% of cell dry weight were extracted from culture samples. The PHB was located in electron-dense intracellular inclusions, which fluoresced bright yellow when stained with the lipophilic dye Nile red. A Nile red spectrofluorometric assay provided a more accurate and reliable determination of the PHB content. PHB accumulation increased threefold during iron-limited culture and was inversely related to the concentration of iron metabolized. Chemostat-grown cells survived in a culturable state for at least 600 days when incubated at 24°C in a low-nutrient tap water environment. Nile red spectrofluorometry and flow cytometry demonstrated that PHB reserves were utilized during starvation. PHB utilization, as revealed by the decline in mean cellular fluorescence and cell complexity, correlated with loss of culturability. Fluorescence microscopy provided visual evidence of PHB utilization, with a marked reduction in the number of Nile red-stained granules during starvation. Heat shock treatment failed to resuscitate nonculturable cells. This study demonstrates that L. pneumophila accumulates significant intracellular reserves of PHB, which promote its long-term survival under conditions of starvation.

Inactivation of algal blooms in eutrophic waterof drinking water supplies with the photocatalysisof TiO2 thin film on hollow glass beads

2005 ◽  
Vol 52 (9) ◽  
pp. 145-152 ◽  
Author(s):  
S.-C. Kim ◽  
D.-K. Lee
Keyword(s):  
Thin Film ◽  
Algal Blooms ◽  
Tio2 Thin Film ◽  
Photosynthetic Activity ◽  
Uv Light ◽  
Glass Beads ◽  
Practical Application ◽  
Hollow Glass ◽  
Photocatalytic Inactivation ◽  
Inactivation Efficiency

Photocatalytic inactivation of algae, Anabaena, Microcystis, and Melosira, was carried out with TiO2-coated Pyrex hollow glass beads under the illumination of UV light (370nm wavelength). After being irradiated with UV light in the presence of the TiO2-coated Pyrex glass beads, Anabaena and Microcystis, known as typical cyanobacteria, lost their photosynthetic activity, and the string of Anabaena cells and the colonies of Microcystis cells were completely separated into individual spherical ones. In the case of Melosira, which is a typical diatom, however, somewhat lower photocatalytic inactivation efficiency was obtained, which was believed to be due to the presence of the inorganic siliceous wall surrounding the cells of Melosira. The TiO2-coated hollow glass beads could successfully be employed for the practical application in a eutrophicated river under sunlight. More than 50% of the chlorophyll-a concentration could be reduced by the action of TiO2 photocatalysis.

scholarly journals New Electropositive Filter for Concentrating Enteroviruses and Noroviruses from Large Volumes of Water

2009 ◽  
Vol 75 (8) ◽  
pp. 2393-2399 ◽  
Author(s):  
Mohammad R. Karim ◽  
Eric R. Rhodes ◽  
Nichole Brinkman ◽  
Larry Wymer ◽  
G. Shay Fout
Keyword(s):  
River Water ◽  
Tap Water ◽  
Water Flow Rate ◽  
Cost Effective ◽  
Ohio River ◽  
Norwalk Virus ◽  
Significant Difference ◽  
Flow Rate Range ◽  
Ph Range ◽  
Virus Recovery

ABSTRACT The U.S. Environmental Protection Agency's information collection rule requires the use of 1MDS electropositive filters for concentrating enteric viruses from water, but unfortunately, these filters are not cost-effective for routine viral monitoring. In this study, an inexpensive electropositive cartridge filter, the NanoCeram filter, was evaluated for its ability to concentrate enteroviruses and noroviruses from large volumes of water. Seeded viruses were concentrated using the adsorption-elution procedure. The mean percent retention of seeded polioviruses by NanoCeram filters was 84%. To optimize the elution procedure, six protocols, each comprising two successive elutions with various lengths of filter immersion, were evaluated. The highest virus recovery (77%) was obtained by immersing the filters in beef extract for 1 minute during the first elution and for 15 min during the second elution. The recovery efficiencies of poliovirus, coxsackievirus B5, and echovirus 7 from 100-liter samples of seeded tap water were 54%, 27%, and 32%, respectively. There was no significant difference in virus recovery from tap water with a pH range of 6 to 9.5 and a water flow rate range of 5.5 liters/min to 20 liters/min. Finally, poliovirus and Norwalk virus recoveries by NanoCeram filters were compared to those by 1MDS filters, using tap water and Ohio River water. Poliovirus and Norwalk virus recoveries by NanoCeram filters from tap and river water were similar to or higher than those by the 1MDS filters. These data suggest that NanoCeram filters can be used as an inexpensive alternative to 1MDS filters for routine viral monitoring of water.

scholarly journals Sport i rekreacja przy wybranych akwenach objętych zakwitami alg i sinic na przykładzie wybranych zbiorników Polski

2015 ◽  
Vol 13 (3) ◽  
pp. 105-117
Author(s):  
Justyna Pacelt ◽  
Wojciech Szeligiewicz
Keyword(s):  
Algal Blooms ◽  
Water Contamination ◽  
Human Life ◽  
Water Environment ◽  
Recreational Activity ◽  
Basic Resource ◽  
Holiday Season ◽  
Water Conditions ◽  
Toxic Blooms ◽  
Financial Losses

The water environment constitutes a basic resource for not only human life but also recreational activity during the holiday season. In reservoirs with high trophic level caused mainly by water contamination, algal blooms occur. This phenomenon is especially intensive in spring and than in summer and affects the use of water reservoirs and coastal areas by people. One type, toxic blooms, is very dangerous for human health. If people who use the reservoir for recreational and professional purposes are unaware of the occurrence of this type of bloom, it may cause serious health problems and financial losses. To avoid this situation, cooperation among institutions which monitor water conditions on each reservoir must be established.

scholarly journals SIZE EFFECT OF COPPER NANOPARTICALS ON MICROCYSTIS AERUGINOSA

2018 ◽  
Vol 16 (2) ◽  
pp. 361-367
Author(s):  
Nguyen Trung Kien ◽  
Tran Thi Thu Huong ◽  
Nguyen Hoai Chau ◽  
Dang Dinh Kim ◽  
Duong Thi Thuy
Keyword(s):  
Particle Size ◽  
Microcystis Aeruginosa ◽  
Copper Nanoparticles ◽  
Algal Blooms ◽  
Water Environment ◽  
Freshwater Ecosystems ◽  
Particle Sizes ◽  
Toxic Cyanobacteria ◽  
The Stability ◽  
Effect Of Copper

Cyanobacterial and toxins produced in cyanobacterial water blooms cause serious environmental problems which effects on freshwater ecosystems. The use of nanomaterials to control algal blooms is a new potential way for practical application due to its antibacterial as well as distinct physicochemical properties of nanomaterials. The particle size is one of the most determinant characteristics creating the different between nanomaterials and their larger bulk counterparts. However, size-dependent toxicity of nanoparticles has remained largely unknown. This study aimed to evaluate effect of three different nanoparticle sizes (d ≤ 10 nm; 30 nm ≤ d ≤ 40 nm and d ≥ 50 nm) on toxic cyanobacteria Microcystis aeruginosa. The copper nanoparticles were synthesized by electrochemical method and coated with chitosan to enhance the stability of materials in the water environment. The copper nanoparticle concentrations selected for toxic test were range from 0 (control); 0,01ppm; 0,05ppm; 0,1 ppm; 1ppm and 5 ppm. After ten days of experiment, the growth of M. aeruginosa was mainly affected at concentrations of 1 ppm and 5 ppm and there are no differences in inhibition between the particle sizes with efficiency of more than 80% in comparison to control. The highest toxicity of copper nanoparticles in M. aeruginosa was observed at particle size of 30 nm ≤ d ≤ 40 nm with EC50 = 0,73 ppm, which was respectively three to seven times less than the particle sizes of d ≥ 50 nm (EC50 = 2,62 ppm) and d ≤ 10nm (EC50 = 5,02 ppm) at the same time.

scholarly journals Spectrophotometric determination of active chlorine by the color of indophenolic compounds

2019 ◽  
Vol 57 (3) ◽  
pp. 93-98
Author(s):  
Svetlana E. Pratskova ◽  
◽  
Oksana E. Sirenko ◽  
Keyword(s):  
Sodium Nitroprusside ◽  
Natural Waters ◽  
Tap Water ◽  
Active Chlorine ◽  
Molar Ratios ◽  
Spectrophotometric Methods ◽  
Organic Impurities ◽  
Ph Range ◽  
Fold Excess

Chlorination is a method of disinfection and oxidation of organic impurities in water. Chlorine is present in aqueous solutions in various forms, which are formed as a result of the chlorination of water. Spectrophotometric methods are very important for determining small amounts of chlorine and its compounds. The article presents a modification of the classical indophenolic method. Determination of active chlorine should be carried out at room temperature, maintaining the solutions for 50 minutes, the pH range is 11.9 ± 0.1. The optimal concentration of reagents: 33-fold excess of N-phenanthranilic acid, 2-fold excess of sodium nitroprusside, and the concentration of ammonium chloride should be 4 to 7 times less than the concentration of active chlorine. The following interaction scheme was proposed: oxidation of ammonia to chloramine with hypochlorite, amination of N-phenanthanilate with the formation of sodium 4-amino-N-phenylanthranilate, oxidation of 4-amino-N-phenylanthranilate with sodium hypochlorite to an indamin compound, followed by complexation with sodium nitroprusside. The linearity range of the calibration curve is 1-23 mg/l, the convergence is 2.3%, the relative error is 1%. The molar ratios of ions and oxidizing agents present in natural waters that do not interfere with the determination of active chlorine are investigated. The optimal concentrations of reagents, sequential variation of the concentration of solutions and fixing the change in light absorption were established. The ratio of the stoichiometric coefficients according to the reaction equation was: ammonium: N-phenanthranilic acid: sodium nitroprusside: hypochloride was 1: 2: 1: 1. It is proposed to use this method to determine the active chlorine in tap water. It is recommended to use the calibration schedule to determine the preliminary content, and to establish a more accurate concentration, use the method of additives.

scholarly journals Studies on Target-specificity and Biological Activity of Streptococcus Serum Antibody and Sulfate Amikacin Conjugates

2019 ◽  
pp. 1-10
Author(s):  
Lingxiao Yi ◽  
Xiang Li ◽  
Wei Dong
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activity ◽  
Acute Toxicity ◽  
Specific Binding ◽  
Serum Antibody ◽  
Target Specificity ◽  
Practical Application ◽  
Response Sensitivity ◽  
Polyethylene Glycol 6000 ◽  
And Staphylococcus Aureus

To investigate the target-specificity and biological activity of Streptococcus serum antibody and sulfate amikacin conjugates. The recent used polyethylene glycol 6000 (PEG6000) as the coupling agent to produce Coupled complexes of Streptococcus serum antibody and sulfate amikacin. Then, analyzed the antibody being in conjugates specificity which against Streptococcus, and the antibody being in conjugates immunogenicity. Besides, we also detected the acute toxicity, antimicrobial activity and bioavailability of sulfate amikacin being in conjugates. As a result, the antibody specific binding to Streptococcus, instead of Escherichia coil, Pasteurella and Staphylococcus aureus. Biological activity results showed that coupling decreased Streptococcus serum antibody immunogenicity, increased Streptococcus serum antibody response sensitivity. Simultaneously, the results indicated that coupling reduced the acute toxicity of sulfate amikacin, improved sulfate amikacin bioavailability and antimicrobial activity of sulfate amikacin. The combination effect on the antibacterial activity of drug and the biological activity of serum antibody is helpful for the practical application of targeted drugs.

An Examination of Trapped Bubbles for Viscous Drag Reduction on Submerged Surfaces

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Kelly A. Stephani ◽  
David B. Goldstein
Keyword(s):  
Drag Reduction ◽  
Flat Plate ◽  
Tap Water ◽  
Water Environment ◽  
Film Coating ◽  
Force Balance ◽  
Viscous Drag ◽  
Vertical Orientation ◽  
Drag Forces ◽  
Horizontal Orientation

Viscous drag reduction on a submerged surface can be obtained both in the limit of an unbroken gas film coating the solid and in the nanobubble or perhaps microbubble coating regime when an air layer is created with superhydrophobic coatings. We examine an intermediate bubble size regime with a trapped-bubble array (TBA) formed in a tap water environment using electrolysis to grow and maintain bubbles in thousands of millimeter-sized holes on a solid surface. We show that even though surface tension is sufficient to stabilize bubbles in a TBA against hydrostatic and shear forces beneath a turbulent boundary layer, no drag reduction is obtained. Drag measurements were acquired over Reynolds numbers based on plate length ranging from 7.2×104<ReL<3.1×105 using either a force balance for plates mounted in a vertical orientation, or by performing a momentum integral balance using a wake survey for a flat plate mounted in either vertical or horizontal orientation. In that the drag forces were small, emphasis was placed on minimizing experimental uncertainty. For comparison, the flow over a flat plate covered on one side by a large uninterrupted gas film was examined and found to produce large drag reductions of up to 32%.

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