A new method for analysis of osmium isotopes and concentrations in surface and subsurface water samples

2009 ◽  
Vol 258 (3-4) ◽  
pp. 136-144 ◽  
Author(s):  
M. Paul ◽  
L. Reisberg ◽  
N. Vigier
Keyword(s):  
Water Samples ◽  
New Method ◽  
Subsurface Water ◽  
Osmium Isotopes

scholarly journals A new method for determination of bicarbonate ion in a small amount of environmental water samples

2009 ◽  
Vol 38 (4) ◽  
pp. 157-168 ◽  
Author(s):  
Taketoshi MISHIMA ◽  
Shinji OHSAWA ◽  
Makoto YAMADA ◽  
Koichi KITAOKA
Keyword(s):  
Water Samples ◽  
Environmental Water ◽  
New Method ◽  
Environmental Water Samples

scholarly journals Surface and subsurface water quality assessment in semi-arid region: a case study from Quetta and Sorange Intermontane Valleys, Pakistan

2014 ◽  
Vol 16 (5) ◽  
pp. 938-954 ◽  
Keyword(s):  
Water Samples ◽  
Central Valley ◽  
Water Quality Assessment ◽  
Hydrochemical Facies ◽  
Subsurface Water ◽  
Rock Types ◽  
Sodium Percent ◽  
Semi Arid Region ◽  
Siwalik Group ◽  
Quetta Valley

<div> <p>Present investigation is an exertion to explore safe means of water for the community in the water scare region. In order to accomplish such goal origin of springs as well as chemical analyses of groundwater samples from different locations were carried out. Four zones are discovered on the basis of nature of water points, rock types and water chemistry. These zones are Hard Rocks Springs (HRS), Valley Springs (VS), Recharge Areas Aquifers (RAA) and Central Valley Aquifers (CVA). HRS are originated from thick successions of limestone (Kirthar Limestone) and thick packages of channelized sandstone and conglomerates of the Siwalik Group. It is recommended that Chiltan, Parh, Kirthar, Dhok Pathan and Soan formations may be focused for future needs of safe water supply in the Quetta valley. This study includes the analysis of different physico-chemical parameters such as Total dissolved solids (TDS), pH, turbidity, Electrical conductivity (EC), hydrochemical facies, Sodium Adsorption Ration (SAR), Sodium Percent (Na%), Kelleys Index (KI), Permeability Index (PI), major cation and anions to assess the quality of groundwater sources. The outcomes of groundwater analyses were equated with various drinking water standards e.g., NSDWQ-Pak, USEPA, and EU. The results are plotted for determination of lateral variations and to empathize the reasons of these variations. The affects of rock types, geological structures as well as anthropogenic causes on origin and results are discussed systematically. The hydrochemical facies identified show that the alkaline earth exceeds alkalies, strong acids exceeds weak acids, mixed type (no cation, anion exceeds 50%), no dominant cation and anion types but water of VS is calcium chloride and sulfate type. The water is classified as C2-S1 (HRS), C3-S1 (CVA &amp; RAA) and C3-S2 (VS) based on SAR and EC values, which intend that most water samples can be used for irrigation safely except water samples collected from VS. Based on the Na% the water samples are categorized as excellent to good and good to permissible limits. The water is suitable for irrigation as all samples bear KI less than 1. The PI values in the water samples studied (less than 40) also contemplate that the water is desirable for irrigation use, although caution is needed of VS water.</p> </div> <p>&nbsp;</p>

An improved method for recovering and preconcentrating mercury in natural water samples for stable isotope analysis

2019 ◽  
Vol 34 (11) ◽  
pp. 2303-2313 ◽  
Author(s):  
Kai Li ◽  
Che-Jen Lin ◽  
Wei Yuan ◽  
Guangyi Sun ◽  
Xuewu Fu ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotopic Composition ◽  
Stable Isotope Analysis ◽  
Natural Water ◽  
Water Samples ◽  
Isotope Analysis ◽  
New Method ◽  
Improved Method ◽  
Natural Water Samples

A new method is developed to meet the criteria for precise and efficient measurements of mercury isotopic composition in various water samples.

Microfluidic paper-based analytical device using gold nanoparticles modified with N,N′-bis(2-hydroxyethyl)dithiooxamide for detection of Hg(ii) in air, fish and water samples

2020 ◽  
Vol 44 (43) ◽  
pp. 18662-18667
Author(s):  
Sattar Shariati ◽  
Gholamreza Khayatian
Keyword(s):  
Gold Nanoparticles ◽  
Water Samples ◽  
Visual Detection ◽  
Color Change ◽  
Digital Camera ◽  
New Method ◽  
Naked Eye ◽  
Analytical Device

A new method for visual detection of mercury by color change is developed that can detect Hg2+ by the naked eye or a digital camera.

A method for recovering enterovirus from infected samples by adsorption onto shaken suspended cells

1971 ◽  
Vol 17 (10) ◽  
pp. 1279-1282 ◽  
Author(s):  
Jack Konowalchuk ◽  
Joan I. Speirs
Keyword(s):  
Conventional Method ◽  
Water Samples ◽  
Comparative Studies ◽  
Vero Cells ◽  
New Method ◽  
Liquid Sample ◽  
Culture Dish ◽  
Plaque Development ◽  
Suspended Cells ◽  
Stationary Period

A method is described whereby enterovirus present in a 5-ml liquid sample may be efficiently recovered for plaque enumeration on a single 60 × 15 mm culture dish. Adsorption is accomplished by constant agitation of the sample with suspended cells followed by a stationary period to allow monolayer formation for plaque development. Comparative studies with the use of coxsackievirus B5 and poliovirus 1, on HEp-2 and Vero cells respectively, indicated that the conventional method of adsorption onto stationary monolayers would require 50 times as many dishes and cells for an equal efficiency. The new method might be useful for the recovery of small numbers of viruses from food or water samples providing they are nontoxic to cells and contain no bacteria.

scholarly journals Phytotoxicological assessment and its relationship with environmental variables of Rio Grande Reservoir waters (São Paulo State, Brazil)

2020 ◽  
Vol 24 ◽  
pp. e15
Author(s):  
Thais De Araujo Goya Peduto ◽  
Tatiane Araujo de Jesus ◽  
Lucia Helena Gomes Coelho ◽  
Werner Siegfried Hanisch ◽  
Mercia Regina Domingues Moretto ◽  
...  
Keyword(s):  
Water Samples ◽  
Environmental Variables ◽  
Bottom Water ◽  
Rio Grande ◽  
Sao Paulo ◽  
Metropolitan Region ◽  
Subsurface Water ◽  
Lepidium Sativum ◽  
São Paulo ◽  
Rio Grande Reservoir

Environmental monitoring indicators guide the decision-making process of public policies. Bioassays using seeds are a potential tool to evaluate water quality indicators, since their results can be expressed in a phytotoxicity scale, the tests are quite simple, relatively fast, and low cost. In this context, the objectives of this study were to evaluate the phytotoxicity of Rio Grande reservoir waters and its relationship with environmental variables. In Brazil, this reservoir is an important water source for the public supply of the Metropolitan Region of São Paulo. In 2018, subsurface and bottom water were collected in four sampling campaigns. The environmental variables were measured both in field and at the laboratory. In field, it was used a multiprobe of ammonium (N-NH4+), electrical conductivity (EC), nitrate (N-NO3-), pH, dissolved oxygen (DO) and water temperature (T); and, at the laboratory, of total nitrogen (TN) and total phosphorus (TP). Bioassays using seeds of cucumber (Cucumis sativus), garden cress (Lepidium sativum), and mustard (Sinapis alba) were performed (n = 6). The bioassays consisted of incubating the seeds and the water samples on Petri dishes at (20º ± 2 ºC) in the absence of light for 3 days, in case of S. alba, and for 4 days, in case of C. sativus and L. sativum. ISO water was used as a control. Afterward, the number of germinated seeds and the roots' length were determined to calculate the Germination Index (GI). Statistical analyses were performed, such as the Shapiro-Wilk test, the analysis of variance (ANOVA) and the Tukey test, to verify the differences between the seeds' responses to the environmental variables. The Principal Component Analysis (PCA) was applied to the environmental variables and the GI to identify the most representative variables. This study indicated that, in May of 2018, the subsurface water was moderately phytotoxic to L. sativum (GI = 61.3 ± 8.2%); and the bottom water was very phytotoxic to L. sativum (GI = 23.6 ± 14.5%) and S. alba (26.2 ± 12.0%). In all other sampling campaigns, the water samples potentiated seed germination, which can be related to nutrients concentrations The L. sativum proved to be more sensitive, due to the lower degrees of data dispersion and the higher degrees of toxicity when compared to the other analysed seeds.

Factors affecting the occurrence of Escherichia coli O157 contamination in irrigation ponds on produce farms in the Suwannee River Watershed

2013 ◽  
Vol 59 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Ganyu Gu ◽  
Zhiyao Luo ◽  
Juan M. Cevallos-Cevallos ◽  
Paige Adams ◽  
George Vellidis ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Environmental Factors ◽  
Water Samples ◽  
Fecal Coliforms ◽  
Subsurface Water ◽  
Escherichia Coli O157 ◽  
Culturable Bacteria ◽  
River Watershed ◽  
E Coli ◽  
Suwannee River

Outbreaks of enteritis caused by Escherichia coli O157 associated with fresh produce have resulted in questions about the safety of irrigation water; however, associated risks have not been systematically evaluated. In this study, the occurrence and distribution of the human pathogen E. coli O157 from vegetable irrigation ponds within the Suwannee River Watershed in Georgia were investigated, and the relationship to environmental factors was analyzed. Surface and subsurface water samples were collected monthly from 10 vegetable irrigation ponds from March 2011 to February 2012. Escherichia coli O157 was isolated from enriched filtrates on CHROMagar and sorbitol MacConkey agar media and confirmed by an agglutination test. Presence of virulence genes stx1, stx2 , and eae was tested by polymerase chain reaction. In addition, 27 environmental variables of the sampled ponds were measured. Denaturing gradient gel electrophoresis was conducted for the analysis of bacterial communities in the water samples. Biserial correlation coefficients were calculated to evaluate the log10 colony-forming unit per millilitre correlations between the environmental factors and the occurrence of E. coli O157. Stepwise and canonical discriminant analyses were used to determine the factors that were associated with the presence and absence of E. coli O157 in water samples. All 10 ponds were positive for E. coli O157 some of the time, mainly in summer and fall of 2011. The temporal distribution of this bacterium differed among the 10 ponds. Temperature, rainfall, populations of fecal coliform, and culturable bacteria were positively correlated with the occurrence of E. coli O157 (P < 0.05), while the total nitrogen concentration, oxidation–reduction potential, and dissolved oxygen concentration were negatively correlated with the occurrence of this pathogen (P < 0.05). Temperature and rainfall were the most important factors contributing to the discrimination between samples with and without E. coli O157, followed by bacterial diversity and culturable bacteria population density. Bacterial numbers and diversity, including fecal coliforms and E. coli O157, increased after rainfall (and possibly runoff from pond margins) in periods with relatively high temperatures, suggesting that prevention of runoff may be important to minimize the risk of enteric pathogens in irrigation ponds.

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