Effects of Global Warming on Critical Dissolved Oxygen Concentrations and on DO Sag Curve in the Nile River

2014 ◽  
Keyword(s):  
Global Warming ◽  
Dissolved Oxygen ◽  
Nile River ◽  
Oxygen Concentrations

A New Life for the St. Croix River

1988 ◽  
Vol 23 (4) ◽  
pp. 568-577
Author(s):  
Harold S. Bailey
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Discharge Rate ◽  
Paper Mill ◽  
Regulated River ◽  
Secondary Treatment ◽  
Pulp And Paper Mill ◽  
Oxygen Regime ◽  
Oxygen Concentrations

Abstract The water quality of the upper 110 kilometres of the St. Croix River is considered to be pristine. A major industrial discharge renders the lower 14 kilometres of the river a water quality limited segment. Prior to 1970 the Georgia-Pacific Pulp and Paper Mill at Woodland, Maine, discharged untreated effluent directly into the river causing dissolved oxygen concentrations to drop well below 5 mg/L, the objective chosen in the interest of restoring endemic fish populations. Since 1972, the Mill has installed primary and secondary treatment, regulated river discharge rate and effluent composition which has greatly improved the summer dissolved oxygen regime. By 1980, dissolved oxygen concentrations were generally above 5.0 mg/L and restocking the river with Atlantic Salmon (Salmo salar) was initiated.

Enhanced human lysozyme production by Pichia pastoris via periodic glycerol and dissolved oxygen concentrations control

2021 ◽  
Vol 105 (3) ◽  
pp. 1041-1050
Author(s):  
Luqiang Jia ◽  
Teng Li ◽  
Yixuan Wu ◽  
Chunsen Wu ◽  
Huaxiang Li ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Dissolved Oxygen ◽  
Human Lysozyme ◽  
Oxygen Concentrations

Hypoxic tolerance of Chinese black sleeper Bostrichthys sinensis embryos at heartbeat stage

2006 ◽  
Vol 86 (6) ◽  
pp. 1473-1476 ◽  
Author(s):  
Shixi Chen ◽  
Wanshu Hong ◽  
Wei Zhou ◽  
Qiyong Zhang
Keyword(s):  
Dissolved Oxygen ◽  
Exposure Time ◽  
Hypoxic Conditions ◽  
Hypoxic Tolerance ◽  
Heartbeat Rate ◽  
Bostrichthys Sinensis ◽  
Oxygen Concentrations

Tolerance of hypoxia in Chinese black sleeper (Bostrichthys sinensis) embryos at heartbeat stage was examined at different oxygen concentrations. Embryonic response to hypoxic conditions was expressed in terms of the intensity of variation in heartbeat rate (V). Exposure of the embryos at 25°C to 0.5, 1.0 and 1.5 mg/l dissolved oxygen (DO), caused bradycardia, which was developed within the first 10 min of hypoxia, followed by a plateau, and lasted until termination of the hypoxia. The V values were significantly affected by DO concentrations (P<0.01). Exposure of the embryos to 0.2 mg/l DO at 25°C caused a periodic heartbeat (including a period of heartbeat and a period of silence). This phenomenon was first recorded in the present study. During the period of heartbeat, the heartbeat rates were faster at first (147±5 beats per min), and then decreased gradually until the period of silence. As the exposure time increased, the duration of heartbeat was prolonged significantly from 43.4±2.4 second to 126.2±8.2 second (P<0.01), and the duration of silence was also prolonged significantly from 68.0±5.5 second to 247.9±11.5 second (P<0.01). At the beginning of exposure, the primary heartbeat rates displayed tachycardia, and their V values were significantly lower than the V values of average heartbeat rates (P<0.05). However, the V values were not significantly different between primary heartbeat rate and average heartbeat rate after 90 min exposure (P>0.05).

Quantifying the areal extent and dissolved oxygen concentrations of Archean oxygen oases

2013 ◽  
Vol 362 ◽  
pp. 35-43 ◽  
Author(s):  
Stephanie L. Olson ◽  
Lee R. Kump ◽  
James F. Kasting
Keyword(s):  
Dissolved Oxygen ◽  
Areal Extent ◽  
Oxygen Concentrations

scholarly journals Change in dissolved oxygen concentrations during aeration and mixing using a combined system

2021 ◽  
Vol 900 (1) ◽  
pp. 012039
Author(s):  
V Singrova ◽  
P Hlustik
Keyword(s):  
Drinking Water ◽  
Czech Republic ◽  
Dissolved Oxygen ◽  
Not Given ◽  
Combined System ◽  
The Czech Republic ◽  
Oxygen Concentrations

Abstract Combined mixing and aeration systems are not given priority in the Czech Republic. Still, they are installed at several WWTPs. Their advantage is mixing and aerating at the same time. This article provides data from actual measurements where a combined system was used for drinking water including necessary chemicals. The text below evaluates the course of changes in the concentration of dissolved oxygen in different points in the reactor depending on time.

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