scholarly journals Survival of Kanagawa-positive strains ofVibrio parahaemolyticusin a brackish-water area

1985 ◽  
Vol 95 (2) ◽  
pp. 299-307 ◽  
Author(s):  
N. H. Kumazawa ◽  
E. Kato
Keyword(s):  
Brackish Water ◽  
Water Samples ◽  
Vibrio Parahaemolyticus ◽  
Water Area ◽  
The Other ◽  
Gastropod Mollusc ◽  
Corbicula Japonica

SUMMARYVibrio parahaemolyticuswas observed to overwinter in sediments and to be present in considerable numbers in sediments andClithon retropictus(gastropod mollusc) during summer months at a brackish-water area along Hashizu Creek in Japan. The highest level of the organisms was 97·3 × 106and 2·3 × 107/100 g in sediments andC. retropictusrespectively.Production of Kanagawa haemolysin was detected in approximately 12% and 20% of strains isolated from sediments andC. retropictusrespectively at two stations in Hashizu Creek but were not detected at the other three stations. Two haemolysin-producing strains were isolated from water samples but none were isolated fromCorbicula japonica(bivalve molluse). These findings suggest that haemolysin producers are preserved principally in sediments and some shellfish in the brackish-water areas with restricted salinity conditions.

Temporal variability of disinfection by-products concentration in urban public water system

2013 ◽  
Vol 14 (4) ◽  
pp. 393-398
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Temporal Variability ◽  
Water System ◽  
The Other ◽  
Major Constituent ◽  
System P ◽  
Public Water System ◽  
Drinking Water Samples ◽  
By Products

The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban water supply network of Karachi city that served more than 18 million people. Drinking water samples were collected from 58 locations in summer (May-August) and winter (November-February) seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer (93.07%), while the other THMs determined at lower concentrations. Summer and winter concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO (100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median concentration (2.5%-23.06%) of THMs compared to winter.

Changes in Nutrient Levels of Lake Water Stored at 4 °C

1984 ◽  
Vol 41 (6) ◽  
pp. 985-988 ◽  
Author(s):  
A. H. El-Shaarawi ◽  
M. A. Neilson
Keyword(s):  
Statistical Analysis ◽  
Lake Water ◽  
Water Samples ◽  
Soluble Reactive Phosphorus ◽  
Lake Ontario ◽  
The Other ◽  
Nutrient Levels ◽  
Glass Bottles ◽  
Reactive Phosphorus

Water samples were collected on Lake Ontario during April and November, filtered (0.45 μm), and immediately analyzed onboard ship for the nutrients soluble reactive phosphorus, nitrate-plus-nitrite, and ammonia. Replicates were stored in glass bottles at 4 °C and reanalyzed within 8 d. Statistical analysis showed that soluble reactive phosphorus decreased by 11 and 13% and nitrate-plus-nitrite by 7 and 6%, whereas ammonia increased by 75% on one cruise and decreased by 37% on the other.

scholarly journals Hydrochemical Characteristics of the Surgut Reservoir Water Area Littoral Sections

2018 ◽  
Author(s):  
Keyword(s):  
Spatial Distribution ◽  
Power Plants ◽  
Thermal Power ◽  
Water Area ◽  
The Other ◽  
Anthropogenic Pressure ◽  
Taiga Zone ◽  
Thermal Power Plants ◽  
Reservoir Water ◽  
First Time

Cooling reservoirs of thermal power plants represent the special class of natural/ engineering systems with, on the one hand, natural geo/systems as one subsystem and, on the other hand, production/technological units as the other subsystem. Studying of these ecosystems’ functioning regularities seems to be helpful for water quality management and rational organization of water use. Besides, it is topical due to the low level of the relevant knowledge in the North of the Western Siberia. The authors for the first time in the Middle Ob Region have carried out a two-year session of monitoring of hydro/chemical indicators and temperature regime of the thermal power plants cooling reservoirs in the riparian stripe of water area. All previous investigations were done only by industrial water users within the frameworks of production monitoring in terms of three indicators in three points of the cooling reservoir water area downstream the power plant dam. Spatial distribution of concentrations of biogenic ions, salt composition, pH, organic matter, and metals in specific natural/technological system of the Surgut hthermal power plants’ reservoirs has been analyzed for the first time for the conditions of the Western Siberian taiga zone. Sources of anthropogenic pressure upon a water body have been identified. According the results of the indicators’ spatial distribution analysis three sections of the Surgut reservoir water area have been separated: a background section of the Chernaya River; a section upstream the dam with predominantly recreational character of the anthropogenic pressure; and a sectio0n downstream the dam with anthropogenic pressure of technological origin. According the outcomes of the correlation analysis indicators of the anthropogenic pressure character have been reveald.

scholarly journals Quantitative assessment of ionic status of pond water for irrigation and aquaculture usage in the selected sites of Mymensingh areas, Bangladesh

2019 ◽  
Vol 6 (2) ◽  
pp. 301-313
Author(s):  
Taslima Akter ◽  
Shampa Rani Ghosh ◽  
Sitesh Chandra Sarker ◽  
Md Mokhlesur Rahman ◽  
KM Eadun Nabi
Keyword(s):  
Water Samples ◽  
Quantitative Assessment ◽  
Ph Value ◽  
Pond Water ◽  
The Other ◽  
Acceptable Limit ◽  
Legal Limit ◽  
Other Hand ◽  
Agricultural Chemistry ◽  
Inorganic Components

Ponds are considered to be self-contained, land lock ecosystem which is often teeming with rich vegetation and diverse organismal life. The pond water contains different organic and inorganic components. The experiment was carried out in laboratory, Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh through collection of pond water from Gouripur and Muktagacha under Mymensingh division for assessment of major ionic status and suitability parameters for irrigation and aquaculture usage in quantitative way. Around 30 samples were collected from different location. On the basis of HCO3 ion, all water samples except 3 samples were not suitable for irrigation because this anion exceeded the acceptable limit (1.5 meL-1). On the other hand, HCO3 ion was not treated as problematic in all samples except 2 samples for aquaculture usages. The concentrations of Ca, Mg, Na, K, PO4 and SO4 were far below the recommended limit. Considering aquaculture usage, Cl ion was considered as hazardous in all the pond water samples because this anion was above the legal limit (<0.003mgL-1). pH value of pond ranged from 7.02 to 7.87 indicating alkaline in nature and were not problematic for irrigation and aquaculture usage. Among the major ionic constituents, the remarkable significant correlations existed between Ca vs Mg, Ca vs K, Mg vs SO4, K vs Na, Na vs SO4. Res. Agric., Livest. Fish.6(2): 301-313, August 2019

scholarly journals Evaluation of the microbial community structure of potable water samples from occupied and unoccupied buildings using16S rRNA amplicon sequencing

2020 ◽  
Author(s):  
Kimothy L Smith ◽  
Howard A Shuman ◽  
Douglas Findeisen
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
Water Samples ◽  
Ad Hoc ◽  
Microbial Community Composition ◽  
Amplicon Sequencing ◽  
The Other ◽  
Water Usage ◽  
16S Rrna Amplicon Sequencing ◽  
Oxford Nanopore

AbstractWe conducted two studies of water samples from buildings with normal occupancy and water usage compared to water from buildings that were unoccupied with little or no water usage due to the COVID-19 shutdown. Study 1 had 52 water samples obtained ad hoc from buildings in four metropolitan locations in different states in the US and a range of building types. Study 2 had 36 water samples obtained from two buildings in one metropolitan location with matched water sample types. One of the buildings had been continuously occupied, and the other substantially vacant for approximately 3 months. All water samples were analyzed using 16S rRNA amplicon sequencing with a MinION from Oxford Nanopore Technologies. More than 127 genera of bacteria were identified, including genera with members that are known to include more than 50 putative frank and opportunistic pathogens. While specific results varied among sample locations, 16S rRNA amplicon abundance and the diversity of bacteria were higher in water samples from unoccupied buildings than normally occupied buildings as was the abundance of sequenced amplicons of genera known to include pathogenic bacterial members. In both studies Legionella amplicon abundance was relatively small compared to the abundance of the other bacteria in the samples. Indeed, when present, the relative abundance of Legionella amplicons was lower in samples from unoccupied buildings. Legionella did not predominate in any of the water samples and were found, on average, in 9.6% of samples in Study 1 and 8.3% of samples in Study 2.SynopsisComparison of microbial community composition in the plumbing of occupied and unoccupied buildings during the COVID-19 pandemic shutdown.

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