scholarly journals Análisis de interferencia de parámetros físicos del agua, en desinfección por radiación UV

2016 ◽  
Vol 14 (2) ◽  
Author(s):  
Pedro Mauricio Acosta Castellanos ◽  
Carlos Andrés Caro Camargo ◽  
Néstor Rafael Perico Granados
Keyword(s):  
Escherichia Coli ◽  
Ultraviolet Radiation ◽  
Environmental Conditions ◽  
Water Samples ◽  
Evaluation Research ◽  
Uv Disinfection ◽  
Physical Parameters ◽  
Physical Factors ◽  
Static Test ◽  
Microbiological Parameters

<p>Este artículo presenta los resultados de investigación de la evaluación en la eficacia de la remoción de parámetros microbiológicos del agua por medio de radiación ultravioleta. Se hizo mediante ensayos estáticos en un banco de pruebas donde se irradiaron nueve muestras de agua, en las que se variaron las condiciones del medio y del agua. Los parámetros microbiológicos analizados fueron echerichia coli, coliformes totales y mesófilos.</p><p>Se analizaron las muestras de agua, a partir de variar de manera controlada sus parámetros físicos, los que influyen en la inactivación, como turbiedad, tiempo de exposición y volumen de agua tratada y concentración microbiológica. Se infirió cuáles son los factores físicos que más tienen influencia en la inactivación y se comprobó la importancia de tratamientos primarios previos a la desinfección por radiación ultravioleta.</p><p>Se construyeron las curvas dosis-respuesta de cada uno de los parámetros microbiológicos y su relación con el parámetro físico analizado. A partir de éstas se determinó la dosificación necesaria para la inactivación. Las muestras de agua fueron analizadas mediante los métodos de número más probable, sustrato definido y recuento en placa.</p><p>Abstract<br />This paper presents the results of evaluation research on the effectiveness of the removal of microbiological parameters water by ultraviolet radiation. It was made by a static test where nine water samples, in which environmental conditions and water were varied irradiated trials. The microbiological parameters analyzed were Escherichia coli, total coliforms and mesophilic.<br />Water samples were analyzed from controllably vary its physical parameters, which influence the inactivation, as turbidity, exposure time and volume of treated water and microbiological concentration. Inferred what physical factors that influence the importance of inactivation and prior to UV disinfection are primary treatments was tested.</p>

Occurrence and Removal of Cryptosporidium spp. Oocysts and Giardia spp. Cysts in Kenyan Waste Stabilisation Ponds

1993 ◽  
Vol 27 (3-4) ◽  
pp. 97-104 ◽  
Author(s):  
A. M. Grimason ◽  
H. V. Smith ◽  
W. N. Thitai ◽  
P. G. Smith ◽  
M. H. Jackson ◽  
...  
Keyword(s):  
Waste Water ◽  
Water Samples ◽  
Laboratory Experiments ◽  
Municipal Waste ◽  
Retention Period ◽  
Waste Stabilisation Ponds ◽  
Cryptosporidium Spp ◽  
Physico Chemical ◽  
Microbiological Parameters ◽  
Final Effluent

This study was designed to determine tlie occurrence and removal of Cryptosporidium spp. oocysts and Giardia spp. cysts, in municipal waste-water by waste stabilisation ponds in tlie Republic of Kenya. Eleven waste stabilisation pond systems located in towns across Kenya were included. A total of 66 waste-water samples were examined for the presence of oocysts and cysts, comprising 11 raw waste-water and 55 pond effluent samples over a two month period. Cryptosporidium spp. oocysts were detected in 6 and Giardia spp. cysts in 9 of the designated pond systems analysed demonstrating their ubiquitous nature throughout Kenya. Oocyst levels detected in raw waste-water samples ranged from 12.5 - 72.97 oocysts/l and various pond effluents between 2.25 - 50 oocysts/l. Cyst levels detected in raw waste-water samples ranged from 212.5 to 6212.5 cysts/l and in various pond effluents from 3.125 to 230.7 cysts/l. No Cryptosporidium spp. oocysts were detected in the final effluent from any pond systems studied (11/11). Whereas no Giardia spp. cysts were detected in the final effluent from 10 of 11 waste stabilisation pond systems studied, one pond system was found to be consistently discharging cysts in the final effluent at concentrations ranging from 40 to 50 cysts/l. The minimum retention period for the removal of Cryptosporidium spp. oocysts and Giardia spp. cysts was 37.3 days. Laboratory experiments were performed to assess physico-chemical and microbiological parameters to express relationships between pond performance and protozoa removal.

An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay

1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Membrane Filtration ◽  
Faecal Coliforms ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Wide Range ◽  
Pure Cultures ◽  
Glucuronidase Assay

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.

Emerging investigator series: interacting effects of environmental factors on Daphnia magna removal of Escherichia coli from wastewater

2021 ◽  
Vol 7 (4) ◽  
pp. 726-738
Author(s):  
Seyyed M. H. Abtahi ◽  
Ojaswi Aryal ◽  
Niveen S. Ismail
Keyword(s):  
Escherichia Coli ◽  
Environmental Factors ◽  
Daphnia Magna ◽  
Environmental Conditions ◽  
E Coli

Zooplankton can significantly impact E. coli inactivation in wastewater, but inactivation rates are dependent on environmental conditions.

UV inactivation and characteristics after photoreactivation of Escherichia coli with plasmid: Health safety concern about UV disinfection

2012 ◽  
Vol 46 (13) ◽  
pp. 4031-4036 ◽  
Author(s):  
Meiting Guo ◽  
Jingjing Huang ◽  
Hongying Hu ◽  
Wenjun Liu ◽  
Jian Yang
Keyword(s):  
Escherichia Coli ◽  
Safety Concern ◽  
Uv Disinfection ◽  
Health Safety

Simulation of Thrombus Formation Process Using Lattice Boltzmann Method With Consideration of Adhesion Force to Wall

2010 ◽  
Author(s):  
Masaaki Tamagawa
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Adhesion Force ◽  
Thrombus Formation ◽  
Artificial Organs ◽  
Physical Parameters ◽  
Physical Factors ◽  
Blood Pumps ◽  
Boltzmann Method ◽  
Rotary Blood Pumps

Recently artificial organs, especially rotary blood pumps, have been developed in the worldwide, but in this development, thrombus occurs in the pumps. In general, the main physical factors of thrombus formation are considered to be shear rate, wall properties for blood’s adhesion. But, there are no proper CFD codes for predicting thrombus formations using physical parameters in shear flows. In this paper, new model for predicting thrombus formation by considering aggregation and adhesion force to the wall by lattice Boltzmann method is proposed, and the trend of thrombus’s adhesion to the wall can be simulated more adequately than that of previous one.

Model of disharmonic succession of dystrophic lakes based on aquatic beetle fauna (Coleoptera)

2019 ◽  
Vol 70 (2) ◽  
pp. 195 ◽  
Author(s):  
J. Pakulnicka ◽  
A. Zawal
Keyword(s):  
Environmental Conditions ◽  
Physical Parameters ◽  
Humic Lakes ◽  
Ecological Value ◽  
Water Ph ◽  
Rare And Endangered ◽  
Successional Stages ◽  
The One ◽  
Aquatic Beetle

Directional changes in environmental conditions during individual stages of the succession of lakes should determine the character of the aquatic beetle fauna inhabiting them. Can changes in environmental conditions lead to degradation of fauna and to a deterioration of the ecological quality of lakes? We analysed this problem in 40 lakes. The fauna of the lakes proved to be rich and diverse in terms of species. Deterioration of species richness along successional stages was not observed, but distinct changes were noted in faunal composition. The eurytopic component proved stable, whereas changes in specialised components (i.e. lake and river species and tyrphophiles) were of key importance. The formation of beetle communities in the lakes was influenced to a greater extent by environmental factors, namely substrate, macrophyte structure and Sphagnum mat cover, than by the physical parameters of the water (pH, saturation or conductivity). The lakes proved to be of considerable ecological value. Regardless of the stage of succession, they are a habitat for numerous species, including rare and endangered ones. Hence, on the one hand humic lakes play an important role in local biodiversity, whereas on the other hand they may be perceived as refuges for species in environments that could be restored as a result of beneficial measures.

scholarly journals Quality of water sources in Southwestern Uganda using the compartment bag test (CBT): a cross-sectional descriptive study

2019 ◽  
Vol 9 (4) ◽  
pp. 683-693
Author(s):  
Richard Onyuthi Apecu ◽  
Lucas Ampaire ◽  
Edgar Mugema Mulogo ◽  
Fred Norman Bagenda ◽  
Afsatou Traore ◽  
...  
Keyword(s):  
Water Samples ◽  
Water Sources ◽  
World Health ◽  
Most Probable Number ◽  
Physical Parameters ◽  
Probable Number ◽  
Gravitational Flow ◽  
Quality Of Water ◽  
Compartment Bag Test

Abstract The aim of this study was to assess the bacteriological quality of water sources in the two rural areas of Uganda using the compartment bag test (CBT). In total, 200 water samples were collected from 69 different water sources and processed within 6 h of collection. Positive and negative controls were processed each day together with water samples. Physical parameters were measured in situ. Descriptive statistics were used to generate mean, minimum, maximum, standard deviations and percentages. The results indicated that 29% of the water sources met the National Standards and World Health Organization (WHO) Guidelines for drinking water. Sixty percent of the borehole, 44% of gravitational flow taps and 14% of roof rain water met the required standards. Of the open water sources, 75% of the rivers, 50% of open channels and 43% of unprotected dug wells plus 25% of protected springs and 9% of gravitational flow schemes had most probable number counts &gt;100 Escherichia coli/100 mL of water. Most of the water sources in the study areas were not fit for human consumption without prior treatment. The CBT was found to be robust and easy to use in all field situations. The mean physical parameters of water sources were within the acceptable limits.

scholarly journals Horizontal Transfer of Antimicrobial Resistance by Extended-Spectrum β Lactamase-Producing Enterobacteriaceae

2011 ◽  
Vol 3 (01) ◽  
pp. 037-042 ◽  
Author(s):  
Varsha K Vaidya
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Environmental Conditions ◽  
Horizontal Transfer ◽  
Hospital Setting ◽  
Alkaline Lysis ◽  
Antibiotic Resistant ◽  
Extended Spectrum ◽  
Synergy Test

ABSTRACT Background: The purpose of this work was to study the acquisition of new antibiotic-resistant genes carried by extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae via horizontal transfer to understand their rampant spread in the hospitals and in the community. Materials and Methods: A retrospective analysis of 120 ESBL screen-positive isolates of Escherichia coli and Klebsiella pneumoniae, which were subjected to antimicrobial susceptibility testing, was carried out. The Double Disc Synergy Test (DDST) and Inhibitor-Potentiation Disc Diffusion Test (IPDD) were employed for confirmation of ESBL activity. The transferability of the associated antibiotic resistance for amoxicillin, amikacin, gentamicin, cefotaxime and ceftriaxone was elucidated by intra- and intergenus conjugation in Escherichia coli under laboratory as well as under simulated environmental conditions. Transformation experiments using plasmids isolated by alkaline lysis method were performed to study the transferability of resistance genes in Klebsiella pneumoniae isolates. Results : ESBL production was indicated in 20% each of the Escherichia coli and Klebsiella pneumoniae isolates. All the ESBL isolates showed co- resistance to various other groups of antibiotics, including 3GC antibiotics, though all the isolates were sensitive to both the carbapenems tested. Conjugation-mediated transfer of resistance under laboratory as well as environmental conditions at a frequency of 3-4 x 10-5 , and transformation-mediated dissemination of cefotaxime and gentamicin resistance shed light on the propensity of ESBL producers for horizontal transfer. Conclusions: The transfer of resistant markers indicated availability of a large pool of resistance genes in the hospital setting as well as in the environment, facilitating long-term persistence of organisms.

scholarly journals Environmental Pollution Around Dhaka EPZ and its Impact on Surface and Groundwater

1970 ◽  
Vol 46 (2) ◽  
pp. 153-162 ◽  
Author(s):  
MKA Khan ◽  
M Alam ◽  
MS Islam ◽  
MQ Hassan ◽  
MA Al-Mansur
Keyword(s):  
Waste Water ◽  
Water Samples ◽  
Industrial Effluent ◽  
Industrial Effluents ◽  
Industrial Sector ◽  
Background Concentration ◽  
Physical Parameters ◽  
Clay Layer ◽  
Surrounding Area ◽  
Surface And Groundwater

Industrial sector is gradually playing a more important role in Bangladesh economy and EPZs have provided a good platform of industrial establishment. Dhaka EPZ since its establishment has altered the fragile environment of the surrounding area. Huge amount of effluents discharged from Dhaka EPZ has been polluting the surface and groundwater. Surface water contamination by industrial effluents released from Dhaka Export Processing Zone (DEPZ) and the ramification to groundwater have been estimated. The study involves analyzing physicochemical properties along with major Anionic contaminants in waste water samples. Conversely their potential transmission into groundwater has been evaluated by analyzing HTW water samples from the surrounding area. Some important physical parameters were measured while collecting the sample in field condition. The suite of 6 major anions (F-, Cl-, NO2-, NO3-, SO4-2 and HCO3-) have been measured in ppm level of concentration by analyzing with chemically suppressed Ion Chromatograph while HCO3- content was determined by Titration method. Analysis reveals pH maximum 9.55, DO maximum 2.40 mg/L, TDS maximum 1280 mg/L, Bi-carbonate maximum 891 mg/L, Sulfate maximum 452 mg/L, Chloride maximum 179 mg/L, Nitrate maximum 44 mg/L and Fluoride not above detection limit. Higher concentration of Cl-, SO4-2, NO3- in waste water samples compared to the standard by DOE (Department of Environment) as well as background concentration from uncontaminated water can be correlated with industrial effluent discharge. On the other hand low level of concentration found in groundwater samples indicates that groundwater is still safe. This phenomenon is explained by the presence of impervious clay layer. Key words: Dhaka EPZ; Effluent; Madhupur Tract; Contaminants; DOE; Environment; Clay layer DOI: http://dx.doi.org/10.3329/bjsir.v46i2.8181 Bangladesh J. Sci. Ind. Res. 46(2), 153-162, 2011

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