scholarly journals Impact of kaolinite clay particles on the filtration of Cryptosporidium-sized microspheres

2013 ◽  
Vol 13 (6) ◽  
pp. 1583-1592 ◽  
Author(s):  
Isabelle Papineau ◽  
Nathalie Tufenkji ◽  
Benoit Barbeau
Keyword(s):  
Microbial Contamination ◽  
Source Water ◽  
Kaolinite Clay ◽  
Clay Particles ◽  
Zeta Potentials ◽  
Filter Performance ◽  
Key Barrier ◽  
The Impact ◽  
Granular Filtration ◽  
Blocking Mechanism

Granular filtration remains a key barrier for Cryptosporidium removal in water treatment plants without UV irradiation. To assess the impact of clay particles in source water on Cryptosporidium removal efficiency by granular filtration, this study investigated the co-transport of Cryptosporidium-sized microspheres and kaolinite particles in sand columns. To investigate the influence of clay load on microsphere transport and deposition, varying influent kaolinite concentrations (0–106particles/mL) and microsphere concentrations (102–106microspheres/mL) were tested. The spatial distribution of retained microspheres was examined subsequent to experiments via filter coring. Results demonstrate that increasing the influent microsphere concentration impaired filter performance due to a blocking mechanism whereby previously retained particles repel incoming particles. In contrast, when the particulate load was dominated by kaolinite (for an equivalent particulate load), filter performance improved as a result of filter ripening whereby previously deposited particles act as additional collectors. Thus, microsphere-kaolinite interactions proved to be favorable although both particles possessed negative zeta potentials in the tested conditions. This study demonstrates that granular filter performance is vulnerable to peak events of microbial contamination. Conversely, Cryptosporidium-sized microsphere removal by granular filtration is enhanced in the presence of kaolinite in source water.

Depressed filtration ripening enhances removal of Cryptosporidium parvum

2002 ◽  
Vol 2 (3) ◽  
pp. 159-168 ◽  
Author(s):  
V. Gitis ◽  
R.C. Haught ◽  
R.M. Clark ◽  
E. Radha Krishnan
Keyword(s):  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Pilot Scale ◽  
Kaolin Clay ◽  
Clay Particles ◽  
Physico Chemical ◽  
Cryptosporidium Parvum Oocysts ◽  
Granular Filtration ◽  
Electrostatic Adhesion ◽  
Innovative Concept

Pilot-scale experiments were conducted to investigate removal of Cryptosporidium parvum by contact granular filtration. The research demonstrated enhanced removal of Cryptosporidium parvum in the presence of kaolin particles. This is believed to be due electrostatic adhesion of Cryptosporidium parvum oocysts to the kaolin clay particles. The elementary physico-chemical interactions between filter granules and suspension particles will be discussed. This innovative concept was successfully implemented to reduce the ripening sequence of subsequent filtration experimental test runs by the addition of large surface area particles to slurry of kaolin and Cryptosporidium parvum in surface water.

scholarly journals Influence of monometallic and bimetallic phytonanoparticles on physiological status of mezquite

2019 ◽  
Vol 14 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Daniel Gonzalez-Mendoza ◽  
Benjamín Valdez-Salas ◽  
Erick Bernardo-Mazariegos ◽  
Olivia Tzintzun-Camacho ◽  
Federico Gutiérrez-Miceli ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Positive Impact ◽  
Photochemical Efficiency ◽  
Localized Surface Plasmon ◽  
Physiological Status ◽  
Ag Nps ◽  
Zeta Potentials ◽  
Minimum Particle Size ◽  
Ag Particles ◽  
The Impact

AbstractThe present study was conducted to evaluate the impact of monometallic and bimetallic nanoparticles (NPs) of copper (Cu) and silver (Ag) from Justicia spicigera on the photochemical efficiency and phenol pattern of Prosopis glandulosa. In this study, the existence of localized surface plasmon resonance absorption associated with the nano-sized nature of Ag, Cu and Cu/Ag particles was confirmed by the presence of a single peak around 487, 585, and 487/580 nm respectively. Zeta potential and electrophoretic mobility were found to be 0.2 mV and 0.02 μmcm/(Vs) for synthesized NPs indicating less stability and thus tendency to agglomerate, and broad distribution of particles. Cu-NPs and Cu/Ag-NPs demonstrate that the dispersed phase is stable and has a minimum particle size at zeta potentials above –30 mV. Changes in phenolic compounds, total chlorophyll, and photochemical efficiency in leaves exposed to Ag, Cu and Cu/Ag phyto-nanoparticles were evaluated up to 72 hours. The results revealed that Ag-NP and Cu-NP from J. spicigera at 100 mg/L showed significant reduction in chlorophyll, epidermal polyphenol content and photochemical efficiency of P. glandulosa. In contrast, the application of bimetallic Cu/Ag-NP from J. spicigera showed a positive impact on physiological parameters of P. glandulosa after 72 h of exposure.

scholarly journals EXPLORATION OF INTERCALATED KAOLINITE CLAY FOR THE UPTAKE OF BASIC DYE BY ADSORPTION − EQUILIBRIUM, KINETICS AND THERMODYNAMIC STUDIES

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
C. E. Chigbundu ◽  
K. O. Adebowale
Keyword(s):  
Experimental Data ◽  
Linear Regression ◽  
Goodness Of Fit ◽  
Linear Regression Analysis ◽  
Dye Adsorption ◽  
Batch Adsorption ◽  
Sem Images ◽  
Kaolinite Clay ◽  
Non Linear ◽  
The Impact

Dyes are complex and sensitive organic chemicals which exposes microbial populations, aquatic lives and other living organisms to its toxic effects if their presence in water bodies or industrial effluents are not properly handled. This work therefore, comparatively studied the adsorption efficiencies of natural raw kaolinite (NRK) clay adsorbent and dimethyl sulphoxide (DMSO) faciley intercalated kaolinite clay (DIK) adsorbent for batch adsorption of Basis Red 2 (BR2) dye. The impact of varying the contact time, temperature and other operating variables on adsorption was also considered. The two adsorbents were characterized using SEM images, FTIR and XRD patterns. Linear and non-linear regression analysis of different isotherm and kinetic models were used to describe the appropriate fits to the experimental data. Error analysis equations were also used to measure the goodness-of-fit. Langmuir isotherm model best described the adsorption as being monolayer on homogenous surfaces while Kinetic studies showed that Elovich model provides the best fit to experimental data. The adsorption capacities of NRK and DIK adsorbents for the uptake of BR2 were 16.30 mg/g and 32.81 mg/g, respectively (linear regression) and 19.30 mg/g and 30.81 mg/g, respectively (non-linear regression). The thermodynamic parameter, ∆G showed that BR2 dye adsorption onto the adsorbents were spontaneous. DIK adsorbent was twice efficient compared with NRK for the uptake of BR2 dye.

scholarly journals Modelling the impact of microbial contamination of fuel filtration efficiency

2017 ◽  
Vol 169 (2) ◽  
pp. 133-136
Author(s):  
Rafał KRAKOWSKI
Keyword(s):  
Numerical Model ◽  
Microbial Contamination ◽  
Petroleum Products ◽  
Filtration Efficiency ◽  
The Other ◽  
Entire System ◽  
Factors Influencing ◽  
Three Stages ◽  
The Impact ◽  
Growth Of Bacteria

In this paper the concept of filtration and the problem of microbial contamination occurring in the fuels and oils was presented. Then the factors influencing the growth of bacteria in petroleum products were described in detail. In the next part of the article modeling of the impact of fuel microbial contamination on filtration efficiency was performed. The modeling presented in the article is an example showing how undesirable phenomenon is the microbial contamination and how pollution affects the other elements of the entire system. As part of the modeling, numerical model of filtration with the solution was presented. Then analysis results on the basis of the impurities concentration characteristics in the fuel as a function of the fouling thickness in the partition of the filter is performed. The development of impurities was divided into three stages. In the article for one case the trend line was presented. The article was completed conclusions.

scholarly journals Aeration of premises by means of protection against respiratory infections on the basis of natural fitoncydes in the complex of prevention of influenza and SARS in the conditions of the collectives of preschool and school heats concerns

2019 ◽  
pp. 67-73
Author(s):  
I. V. Sergeeva ◽  
A. S. Yamshchikov ◽  
Т. A. Debelova
Keyword(s):  
Side Effects ◽  
Environmental Factors ◽  
Microbial Contamination ◽  
Respiratory Infections ◽  
Heating Season ◽  
Dry Air ◽  
Rising Incidence ◽  
The Impact ◽  
Positive Results ◽  
At Home

The article presents the results obtained from the use of aeration with large forms of bactericidal spray (cedar) in preschool and school institutions in Krasnoyarsk in conjunction with individual aeration of small forms of bactericidal spray (cedar) at home in the season of rising incidence of influenza and ARVI. Due to a decrease in the total microbial contamination of the air environment and surface when using the harmless bactericidal spray (cedar), there is a decrease in the incidence of ARVI among children who regularly receive aeration for 4 weeks, and there is a lighter course of ARVI and the absence of complicated forms in 2 times in the observed children in comparison with the group where aeration was not applied. The positive results obtained during the 4-week observation, and the absence of any side effects from the spraying of bactericidal spray (cedar) allows us to recommend it for the prevention of influenza and ARVI during the period of epidemic or seasonal increase in morbidity in organized groups of preschool and school institutions. Considering that since the beginning of the heating season, dry air is installed in the premises, the use of aeration of bactericidal spray reduces the impact of harmful environmental factors on the child’s body, which is facilitated by the ionization and moistening of the air with phytoncide spray components.

scholarly journals The influence of dielectric decrement on electrokinetics

2013 ◽  
Vol 724 ◽  
pp. 69-94 ◽  
Author(s):  
Hui Zhao ◽  
Shengjie Zhai
Keyword(s):  
Asymptotic Analysis ◽  
Double Layer ◽  
Debye Length ◽  
Charged Surface ◽  
Ion Specificity ◽  
Zeta Potentials ◽  
Condensed Layer ◽  
The Impact ◽  
Surface Conduction ◽  
Electro Osmotic Flow

AbstractWe treat the dielectric decrement induced by excess ion polarization as a source of ion specificity and explore its impact on electrokinetics. We employ a modified Poisson–Nernst–Planck (PNP) model accounting for the dielectric decrement. The dielectric decrement is determined by the excess-ion-polarization parameter $\alpha $ and when $\alpha = 0$ the standard PNP model is recovered. Our model shows that ions saturate at large zeta potentials $(\zeta )$. Because of ion saturation, a condensed counterion layer forms adjacent to the charged surface, introducing a new length scale, the thickness of the condensed layer $({l}_{c} )$. For the electro-osmotic mobility, the dielectric decrement weakens the electro-osmotic flow owing to the decrease of the dielectric permittivity. At large $\zeta $, when $\alpha \not = 0$, the electro-osmotic mobility is found to be proportional to $\zeta / 2$, in contrast to $\zeta $ as predicted by the standard PNP model. This is attributed to ion saturation at large $\zeta $. In terms of the electrophoretic mobility ${M}_{e} $, we carry out both an asymptotic analysis in the thin-double-layer limit and solve the full modified PNP model to compute ${M}_{e} $. Our analysis reveals that the impact of the dielectric decrement is intriguing. At small and moderate $\zeta ~({\lt }6kT/ e)$, the dielectric decrement decreases ${M}_{e} $ with increasing $\alpha $. At large $\zeta $, it is known that the surface conduction becomes significant and plays an important role in determining ${M}_{e} $. It is observed that the dielectric decrement effectively reduces the surface conduction. Hence in stark contrast, ${M}_{e} $ increases as $\alpha $ increases. Our predictions of the contrast dependence of the mobility on $\alpha $ at different zeta potentials qualitatively agree with experimental results on the dependence of the mobility among ions and provide a possible explanation for such ion specificity. Finally, the comparisons between the thin-double-layer asymptotic analysis and the full simulations of the modified PNP model suggest that at large $\zeta $ the validity of the thin-double-layer approximation is determined by ${l}_{c} $ rather than the traditional Debye length.

METAPHYLAXIS OF APPLICATION OF VETERINARY PREPARATIONS «MULTIOMYCIN 1%» AND «YUBERIN ORAL»

2021 ◽  
pp. 41-47
Author(s):  
E. V. Romanova
Keyword(s):  
Microbial Contamination ◽  
Veterinary Drug ◽  
Production Test ◽  
Combined Use ◽  
Negative Effect ◽  
The Impact ◽  
Daily Gain ◽  
Positive Effect ◽  
Experimental Group

We studied the effect of the antimicrobial drug «Multiomycin 1 %» on the hematological and biochemical pa-rameters of blood, the activity of digestive enzymes (amylase, alkaline phosphatase, protease), the structure of the mi-crobiocenosis of the small and large intestines, and the quality of the products. Based on the results of preclinical stud-ies, a production test was carried out in conjunction with the veterinary drug «Yuberin oral», as well as an assessment of the impact on the productivity of poultry was given. «Multiomycin 1 %» did not adversely affect the chickens. The drug had a positive effect on the activity of the digestive processes, increased their activity. Contributed to a decrease in the total microbial contamination in the contents of the small and large intestines and an increase in the content of bifidobacteria and lactobacilli. Combined use with yuberin contributed to an increase in safety, an increase in the aver-age daily gain, as well as a decrease in the incidence of gastroenteritis. The weight gain at the end of the experiment in the chickens of the experimental group was 3,74 % higher than in the control. The use of the veterinary drug «Multiomycin 1 %» did not have a negative effect on the quality of the products.

scholarly journals A particle filter scheme for multivariate data assimilation into a point-scale snowpack model in an Alpine environment

2018 ◽  
Vol 12 (7) ◽  
pp. 2287-2306 ◽  
Author(s):  
Gaia Piazzi ◽  
Guillaume Thirel ◽  
Lorenzo Campo ◽  
Simone Gabellani
Keyword(s):  
Data Assimilation ◽  
Particle Filter ◽  
Multivariate Data ◽  
Model Parameters ◽  
Parameter Perturbation ◽  
Point Scale ◽  
Meteorological Forcing ◽  
System Sensitivity ◽  
Filter Performance ◽  
The Impact

Abstract. The accuracy of hydrological predictions in snow-dominated regions deeply depends on the quality of the snowpack simulations, with dynamics that strongly affect the local hydrological regime, especially during the melting period. With the aim of reducing the modelling uncertainty, data assimilation techniques are increasingly being implemented for operational purposes. This study aims to investigate the performance of a multivariate sequential importance resampling – particle filter scheme, designed to jointly assimilate several ground-based snow observations. The system, which relies on a multilayer energy-balance snow model, has been tested at three Alpine sites: Col de Porte (France), Torgnon (Italy), and Weissfluhjoch (Switzerland). The implementation of a multivariate data assimilation scheme faces several challenging issues, which are here addressed and extensively discussed: (1) the effectiveness of the perturbation of the meteorological forcing data in preventing the sample impoverishment; (2) the impact of the parameter perturbation on the filter updating of the snowpack state; the system sensitivity to (3) the frequency of the assimilated observations, and (4) the ensemble size.The perturbation of the meteorological forcing data generally turns out to be insufficient for preventing the sample impoverishment of the particle sample, which is highly limited when jointly perturbating key model parameters. However, the parameter perturbation sharpens the system sensitivity to the frequency of the assimilated observations, which can be successfully relaxed by introducing indirectly estimated information on snow-mass-related variables. The ensemble size is found not to greatly impact the filter performance in this point-scale application.

Source water impact model (SWIM) - a watershed guided approach as a new planing tool for indirect potable water reuse

2001 ◽  
Vol 43 (10) ◽  
pp. 267-275 ◽  
Author(s):  
J. E. Drewes ◽  
P. Fox
Keyword(s):  
Water Quality ◽  
Water Reuse ◽  
Reclaimed Water ◽  
Water Sources ◽  
Distribution Data ◽  
Source Water ◽  
Impact Model ◽  
Water Impact ◽  
Potable Reuse ◽  
The Impact

The scope of this study was to develop a model to assess the impact of source water quality on reclaimed water used for indirect potable reuse. The source water impact model (SWIM) considered source water qualities, water supply distribution data, water use and the impact of wastewater treatment to calculate reclaimed water quality. It was applied for sulfate, chloride, and dissolved organic carbon (DOC) at four water reuse sites in Arizona and California. SWIM was able to differentiate between the amount of salts derived by drinking water sources and the amount added by consumers. At all sites, the magnitude of organic residuals in reclaimed water was strongly effected by the concentration of organics in corresponding water sources and effluent-derived organic matter. SWIM can be used as a tool to predict reclaimed water quality in existing or planned water reuse systems.

Sign in / Sign up

Export Citation Format

Share Document