Application to Estuarine and Coastal Waters

1982 ◽  
Vol 14 (9-11) ◽  
pp. 1055-1072
Author(s):  
A L H Gameson

The principles underlying the mathematical modelling of parameters of pollution in estuarine and coastal waters are outlined in non-mathematical terms. Attention is drawn to some of the difficulties encountered – such as in assessing the inputs of relevant substances, evaluating coefficients of transformation processes, and ensuring that models can reasonably be used for predictive purposes. Two examples are given, one relating to dissolved oxygen in an estuary, the other to enteric bacteria in the sea. The application of models to the formulation of pollution control policies is reviewed.

1995 ◽  
Vol 31 (1) ◽  
pp. 143-152 ◽  
Author(s):  
Paul L. Bishop ◽  
Tian C. Zhang ◽  
Yun-Chang Fu

The influence of biofilm structure on transport and transformation processes in biofilms has been investigated microscopically using microelectrodes, a micro-slicing procedure and various chemical and microbiological tests. The study demonstrates that the biofilm structure is highly stratified, characterized by an increase of biofilm density, a decrease of metabolically active biomass, and a decrease of porosity with biofilm depth. Both the effective diffusivity for dissolved oxygen and the effectiveness factor decrease with biofilm depth. Competition for substrate and space in biofilms results in this stratified structure, which is also affected by biofilm thickness. The study reveals that there are different trends for the density increase and the decreases of porosity, microbial activity and DO effective diffusivity with biofilm depth for different biofilm thicknesses. The results of this study are helpful in obtaining a clearer physical description of biofilms, and help to bridge the gap between the mathematical modelling and external-phenomenon observation of biofilm systems.


1993 ◽  
Vol 27 (12) ◽  
pp. 223-226
Author(s):  
J.-F. Guillaud ◽  
M. Pommepuy ◽  
E. Dupray ◽  
J.-C. Salomon ◽  
B. Thouvenin

The aim of this paper is to present some results of bacterial studies which were developed by IFREMER in coastal discharge areas of urban wastewaters; they are focused on the determination of bacterial inputs by wastewater treatment plants, the role of environmental factors on the enteric bacteria survival in the coastal zone, and the modelling of bacteria transport and disappearance in order to provide useful management information for minimizing faecal pollution in the coastal zone.


1995 ◽  
Vol 32 (2) ◽  
pp. 95-103
Author(s):  
José A. Revilla ◽  
Kalin N. Koev ◽  
Rafael Díaz ◽  
César Álvarez ◽  
Antonio Roldán

One factor in determining the transport capacity of coastal interceptors in Combined Sewer Systems (CSS) is the reduction of Dissolved Oxygen (DO) in coastal waters originating from the overflows. The study of the evolution of DO in coastal zones is complex. The high computational cost of using mathematical models discriminates against the required probabilistic analysis being undertaken. Alternative methods, based on such mathematical modelling, employed in a limited number of cases, are therefore needed. In this paper two alternative methods are presented for the study of oxygen deficit resulting from overflows of CSS. In the first, statistical analyses focus on the causes of the deficit (the volume discharged). The second concentrates on the effects (the concentrations of oxygen in the sea). Both methods have been applied in a study of the coastal interceptor at Pasajes Estuary (Guipúzcoa, Spain) with similar results.


2015 ◽  
Vol 41 (1) ◽  
pp. 13-19
Author(s):  
Kaniz Fatema ◽  
Wan Maznah Wan Omar ◽  
Mansor Mat Isa

Water quality in three different stations of Merbok estuary was investigated limnologically from October, 2010 to September, 2011. Water temperature, transparency and total suspended solids (TSS) varied from 27.45 - 30.450C, 7.5 - 120 cm and 10 -140 mg/l, respectively. Dissolved Oxygen (DO) concentration ranged from 1.22-10.8 mg/l, while salinity ranged from 3.5-35.00 ppt. pH and conductivity ranged from 6.35 - 8.25 and 40 - 380 ?S/cm, respectively. Kruskal Wallis H test shows that water quality parameters were significantly different among the sampling months and stations (p<0.05). This study revealed that DO, salinity, conductivity and transparency were higher in wet season and TSS was higher in dry season. On the other hand, temperature and pH did not follow any seasonal trends.Bangladesh J. Zool. 41(1): 13-19, 2013


2019 ◽  
Vol 126 ◽  
pp. 627-634 ◽  
Author(s):  
Joseph Y. Abrams ◽  
Mitchel Klein ◽  
Lucas R.F. Henneman ◽  
Stefanie E. Sarnat ◽  
Howard H. Chang ◽  
...  

1991 ◽  
Vol 69 (7) ◽  
pp. 433-441 ◽  
Author(s):  
Jack Ferrier ◽  
Angela Kesthely ◽  
Eva Lagan ◽  
Conrad Richter

A model for cytosolic Ca2+ spikes is presented that incorporates continual influx of Ca2+, uptake into an intracellular compartment, and Ca2+-induced Ca2+ release from the compartment. Two versions are used. In one, release is controlled by explicit thresholds, while in the other, release is a continuous function of cytosolic and compartmental [Ca2+]. Some model predictions are as follows. Starting with low Ca2+ influx and no spikes: (1) induction of spiking when Ca2+ influx is increased. Starting with spikes: (2) increase in magnitude and decrease in frequency when influx is reduced; (3) inhibition of spiking if influx is greatly reduced; (4) decrease in the root-mean-square value when influx is increased; and (5) elimination of spiking if influx is greatly increased. Since there is good evidence that hyperpolarizing spikes reflect cytosolic Ca2+ spikes, we used electrophysiological measurements to test the model. Each model prediction was confirmed by experiments in which Ca2+ influx was manipulated. However, the original spike activity tended to return within 5–30 min, indicating a cellular resetting process.Key words: calcium, electrophysiology, mathematical modelling.


Author(s):  
Ian W.H. Parry ◽  
Hilary Sigman ◽  
Margaret Walls ◽  
Robertson C Williams

2014 ◽  
Vol 1010-1012 ◽  
pp. 635-638
Author(s):  
Yan Juan Xi ◽  
Zhen Liang Zhao ◽  
Chun Long Zhao ◽  
Yan Qin Xi ◽  
Li Yan ◽  
...  

Based on the environmental survey data in off-shore of Qin Huangdao from May to June 2011,correlation analysis was made between population density of Noctiluca scintillans and environmental factors. The results indicates that population density of Noctiluca scintillans does not exist linear correlation with nitrite, nitrate, ammonia, nitrogen, phosphate,dissolved oxygen and PH ,it is positive correlation with temperature and silicate noctiluca and negatively correlation with transparency and salinity.


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