scholarly journals Research and Prospect of Numerical Simulation of River Water Environment

2021 ◽  
Vol 692 (3) ◽  
pp. 032007
Author(s):  
Yan Li ◽  
Yuhu Luo
Keyword(s):  
Numerical Simulation ◽  
River Water ◽  
Water Environment

scholarly journals Numerical Simulation of the Effects on Low Temperature Drainage from LNG on the Ocean Water Environment

2017 ◽  
Vol 05 (03) ◽  
pp. 71-80
Author(s):  
Mingyuan Sun ◽  
Yi Zhang ◽  
Longxi Han ◽  
Bo Chen ◽  
Tiantian Liu
Keyword(s):  
Numerical Simulation ◽  
Low Temperature ◽  
Water Environment ◽  
Ocean Water

Numerical simulation of optimal deconvolution in a shallow-water environment

2001 ◽  
Vol 110 (1) ◽  
pp. 170-185 ◽  
Author(s):  
Ben S. Cazzolato ◽  
Philip Nelson ◽  
Phillip Joseph ◽  
Richard J. Brind
Keyword(s):  
Numerical Simulation ◽  
Shallow Water ◽  
Water Environment ◽  
Shallow Water Environment

scholarly journals Detection and Genetic Analysis of Human Sapoviruses in River Water in Japan

2010 ◽  
Vol 76 (8) ◽  
pp. 2461-2467 ◽  
Author(s):  
Masaaki Kitajima ◽  
Tomoichiro Oka ◽  
Eiji Haramoto ◽  
Hiroyuki Katayama ◽  
Naokazu Takeda ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Real Time ◽  
River Water ◽  
Water Samples ◽  
Detection Efficiency ◽  
Water Environment ◽  
Filter Method ◽  
Rt Pcr ◽  
Pcr Assay ◽  
River Water Samples

ABSTRACT We investigated the prevalence of sapoviruses (SaVs) in the Tamagawa River in Japan from April 2003 to March 2004 and performed genetic analysis of the SaV genes identified in river water. A total of 60 river water samples were collected from five sites along the river, and 500 ml was concentrated using the cation-coated filter method. By use of a real-time reverse transcription (RT)-PCR assay, 12 (20%) of the 60 samples were positive for SaV. SaV sequences were obtained from 15 (25%) samples, and a total of 30 SaV strains were identified using six RT-PCR assays followed by cloning and sequence analysis. A newly developed nested RT-PCR assay utilizing a broadly reactive forward primer showed the highest detection efficiency and amplified more diverse SaV genomes in the samples. SaV sequences were frequently detected from November to March, whereas none were obtained in April, July, September, or October. No SaV sequences were detected in the upstream portion of the river, whereas the midstream portion showed high positive rates. Based on phylogenetic analysis, SaV strains identified in the river water samples were classified into nine genotypes, namely, GI/1, GI/2, GI/3, GI/5, GI/untyped, GII/1, GII/2, GII/3, and GV/1. To our knowledge, this is the first study describing seasonal and spatial distributions and genetic diversity of SaVs in river water. A combination of real-time RT-PCR assay and newly developed nested RT-PCR assay is useful for identifying and characterizing SaV strains in a water environment.

scholarly journals Comparative Survival of Free Shiga Toxin 2-Encoding Phages and Escherichia coli Strains outside the Gut

1999 ◽  
Vol 65 (12) ◽  
pp. 5615-5618 ◽  
Author(s):  
Maite Muniesa ◽  
Francisco Lucena ◽  
Juan Jofre
Keyword(s):  
Escherichia Coli ◽  
Heat Treatment ◽  
River Water ◽  
Shiga Toxin ◽  
Water Environment ◽  
Somatic Coliphages ◽  
E Coli ◽  
Naturally Occurring ◽  
Shiga Toxin 2

ABSTRACT The behavior outside the gut of seeded Escherichia coliO157:H7, naturally occurring E. coli, somatic coliphages, bacteriophages infecting O157:H7, and Shiga toxin 2 (Stx2)-encoding bacteriophages was studied to determine whether the last persist in the environment more successfully than their host bacteria. The ratios between the numbers of E. coli and those of the different bacteriophages were clearly lower in river water than in sewage of the area, whereas the ratios between the numbers of the different phages were similar. In addition, the numbers of bacteria decreased between 2 and 3 log units in in situ survival experiments performed in river water, whereas the numbers of phages decreased between 1 and 2 log units. Chlorination and pasteurization treatments that reduced by approximately 4 log units the numbers of bacteria reduced by less than 1 log unit the numbers of bacteriophages. Thus, it can be concluded that Stx2-encoding phages persist longer than their host bacteria in the water environment and are more resistant than their host bacteria to chlorination and heat treatment.

Evaluating bioaccumulation of suspected endocrine disruptors into periphytons and benthos in the Tama River

2003 ◽  
Vol 47 (9) ◽  
pp. 71-76 ◽  
Author(s):  
A. Takahashi ◽  
T. Higashitani ◽  
Y. Yakou ◽  
M. Saitou ◽  
H. Tamamoto ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
River Water ◽  
Endocrine Disruptors ◽  
Wastewater Treatment Plants ◽  
Water Environment ◽  
The Other ◽  
Recombinant Yeast ◽  
Bioaccumulation Factors ◽  
17Β Estradiol ◽  
Aquatic Food

There are two major routes through which fish are exposed to endocrine disruptors (EDs); one route is through water that is a habitat; the other is through aquatic food such as algae and benthos. Few studies on the bioaccumulation of EDs in food have been conducted. Therefore, we evaluated the concentration in food of nonylphenol (NP), bisphenol A (BPA) and 17β-estradiol (E2), which were frequently detected in river water and in final discharge of Wastewater Treatment Plants (WWTPs) in Japan. We also evaluated the estrogenicity of samples using recombinant yeast. NP concentrations ranged 0.1-0.4 mg/L in the river water, while they ranged 8-130 mg/kg-wet in the periphytons and 8-140 μg/kg-wet in the benthos. BPA concentrations ranged 0.02-0.15 μg/L in the river water, while they ranged 2-8.8 μg/kg-wet in the periphytons and 0.3-12 μg/kg-wet in the benthos. E2 concentrations ranged 0.0001-0.0076 μg/L in the water, while they ranged 0.09-2.26 μg/kg-wet in the periphytons and <0.01-0.22 μg/kg-wet in the benthos. The estrogenicity ranged 0.0001-0.0464 μg-E2equivalent/L in the water, while it ranged 3.4-66.8 μg-E2equivalent/kg-wet in the periphytons and 7.4-5458 μg-E2equivalent/kg-wet in the benthos. Bioaccumulation factors of NP are estimated as 160-650 for the periphytons, and 63-990 for the benthos, respectively. Bioaccumulation factors of BPA are estimated as 18-650 for the periphytons, and 8-170 for the benthos, respectively. Bioaccumulation factors of E2 are estimated as 64-1,200 for the periphytons, and 100-160 for the benthos, respectively. The ratios of the periphytons and the benthos to the water in terms of the estrogenicity were larger than those in terms of the chemicals. In particularly, the ratio of the benthos to the water is about 106 in the maximum. The results suggest that food may be a more important route for fish exposed to EDs in water environment.

Sign in / Sign up

Export Citation Format

Share Document