scholarly journals Thermal and Oxygen Conditions of Lake Charzykowskie in the Years 2014-2016

2018 ◽  
Vol 62 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Jerzy K. Garbacz ◽  
Jacek Cieściński ◽  
Jerzy Ciechalski ◽  
Ryszard Dąbkowski ◽  
Jolanta Cichowska
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Lake Basin ◽  
Oxygen Conditions ◽  
Anaerobic Zone ◽  
Representative Points ◽  
Stagnation Period

Abstract This paper presents an analysis of thermal and oxygen conditions of the Charzykowskie Lake in the years 2014-2016 in the period from May to August. The measurements were carried out once a month, at points representing three different basins in the lake, and the temperatures and oxygen content dissolved in the water were recorded every 1m from the surface to the bottom at the deepest point of each basin. The changes in temperatures and content of dissolved oxygen were analysed in each of the representative measurement points for particular parts of the lake. It has been shown that the deficit of oxygen dissolved in the bottom layers of the water starts occurring by the beginning of the summer stagnation period, whereas at its peak (August) the anaerobic zone includes hypolimnion and part of the metalimnion. The hypothesis that the thickness of the thermal layers varies within the lake basin was confirmed. It was also shown that the oxygen content curve at representative points, in all years of research, evolves to the form of a clinograde at the peak of summer stagnation, where the concentration of dissolved oxygen decreases with the depth.

scholarly journals Dissolved Oxygen in a Shallow Ice-Covered Lake in Winter: Effect of Changes in Light, Thermal and Ice Regimes

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2435
Author(s):  
Galina Zdorovennova ◽  
Nikolay Palshin ◽  
Sergey Golosov ◽  
Tatiana Efremova ◽  
Boris Belashev ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Ice Cover ◽  
Time Intervals ◽  
Model Calculations ◽  
Study Region ◽  
Temperature And Precipitation ◽  
Oxygen Conditions ◽  
Cover Thickness

Oxygen conditions in ice-covered lakes depend on many factors, which, in turn, are influenced by a changing climate, so detection of the oxygen trend becomes difficult. Our research was based on data of long-term measurements of dissolved oxygen (2007–2020), water temperature, under-ice solar radiation, and snow-ice thickness (1995–2020) in Lake Vendyurskoe (Northwestern Russia). Changes of air temperature and precipitation in the study region during 1994–2020 and ice phenology of Lake Vendyurskoe for the same period based on field data and FLake model calculations were analyzed. The interannual variability of ice-on and ice-off dates covered wide time intervals (5 and 3 weeks, respectively), but no significant trends were revealed. In years with early ice-on, oxygen content decreased by more than 50% by the end of winter. In years with late ice-on and intermediate ice-off, the oxygen decrease was less than 40%. A significant negative trend was revealed for snow-ice cover thickness in spring. A climatic decrease of snow-ice cover thickness contributes to the rise of under-ice irradiance and earlier onset of under-ice convection. In years with early and long convection, an increase in oxygen content by 10–15% was observed at the end of the ice-covered period, presumably due to photosynthesis of phytoplankton.

A hybrid model for short-term dissolved oxygen content prediction

2021 ◽  
Vol 186 ◽  
pp. 106216
Author(s):  
Jiande Huang ◽  
Shuangyin Liu ◽  
Shahbaz Gul Hassan ◽  
Longqin Xu ◽  
Cifeng Huang
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Hybrid Model ◽  
Short Term

Effect of Dissolved Oxygen Content on Gelling Strength of Chromium Gel in Block Hai 1

2014 ◽  
Vol 1008-1009 ◽  
pp. 243-246
Author(s):  
Peng Fei Yuan ◽  
Guang Sheng Cao ◽  
Xiao Ma ◽  
Xiao Ping Wang ◽  
Xin Tian
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Good Effect ◽  
Factors Affecting ◽  
Profile Control ◽  
Liaohe Oilfield ◽  
Weak Gel ◽  
Main Factors ◽  
Implementation Effect ◽  
Gelling Time

Jinma company of Liaohe oilfield has carried out weak gel flooding in-depth in block Hai1 and achieved good effect. But in the process of profile and flooding, problems of gelation fluctuating and gelling rate declining seriously affected the implementation effect of the profile control and flooding project. It is researched that one of main factors affecting gelling effect of profile and flooding system is the dissolved oxygen. Aiming at this problem, this paper studies critical value affecting gelling in combination with the actual situation of polymer displacement in block Hai 1. The experimental results show that, content of dissolved oxygen affects both gelling strength and gelling time of weak gel in the way that when dissolved oxygen content is between 0mg/L and 3mg/L, low gelling strength and long gelling time are obtained, while in the range of 4mg/L-10mg/L, gelling effect is good. Two critical values are respective 1.5mg/L and 7mg/L.

Corrosion Risk and Repassivation of Duplex Stainless Steel UNS S82551 in Treated Seawater Injection Service

CORROSION ◽  
10.5006/3697 ◽  
2021 ◽  
Author(s):  
Nicolas Larche ◽  
Perry Nice ◽  
Hisashi Amaya ◽  
Lucrezia Scoppio ◽  
Charles Leballeur ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Dissolved Oxygen ◽  
Duplex Stainless Steel ◽  
Oxygen Content ◽  
Alloy Steel ◽  
Stainless Steels ◽  
Crevice Corrosion ◽  
Low Alloy Steel ◽  
Corrosion Risk ◽  
Service Conditions

In seawater injection wells, the available well tubing materials are generally Low alloy steel, Glass Reinforced Epoxy lined low alloy steel or Corrosion Resistant Alloy’s (CRA) such as super duplex stainless steel. However, in treated seawater the corrosion risk can be controlled and lower grade alloys (low alloy steel) can be considered. But for long well lifetime designs (20 years plus), then low alloy steel tubing can be challenged. In this respect recent efforts have focused attention on better dissolved oxygen control which permits the investigation and on the possible use of more cost-effective materials such as the duplex stainless steels UNS S82551, and UNS S82541 (the latter is a higher strength version, but same PRENw). Full scale testing of tubes joined together with a proprietary premium threaded connection (PCPC couplings) was performed in controlled seawater loops simulating service conditions at 30°C. The flow rate and dissolved oxygen were controlled at 5 m/s and <20ppb, respectively. Weekly dissolved oxygen excursions corresponding to 24h at 100ppb followed by 1 hour at 300ppb were performed during the 5 months exposure. Corrosion results of UNS S82551/S82541 tubing were compared to UNS S31803 and UNS S39274. In parallel, laboratory exposures of creviced coupons for parametric study were performed in dissolved oxygen-controlled cells, allowing the measurement of electrochemical potentials as function of dissolved oxygen content and the related corrosion resistance. The results showed that dissolved oxygen content should be properly controlled below critical values to avoid crevice corrosion of the lesser alloyed duplex stainless steels. The ability of UNS S82541 to recover or re-passivate after prolonged exposures to high dissolved oxygen concentrations (DOC) was also determined with both the use of full sized pipe-coupling premium connection (PCPC) test cells, and electrochemical testing involving a Remote Crevice Assembly (RCA). The re-passivation potential was investigated after different active crevice corrosion durations. The results of the study allowed to precisely define the limits of use of UNS S82541 in treated seawater, i. e. the critical DOC conditions for corrosion initiation and for re-passivation of UNS S82541. For all tested conditions, the UNS S82551/S82541 showed a rather good ability to re-passivation when normal service conditions (i. e. low dissolved oxygen) are recovered.

scholarly journals Morphofunctional changes of phytoplankton community during pluvial anomaly in a tropical reservoir

2015 ◽  
Vol 75 (3) ◽  
pp. 628-637 ◽  
Author(s):  
FRA Câmara ◽  
O Rocha ◽  
EKR Pessoa ◽  
S Chellappa ◽  
NT Chellappa
Keyword(s):  
Species Diversity ◽  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Hydrodynamic Instability ◽  
Electrical Conductance ◽  
Northeastern Brazil ◽  
Tropical Reservoir ◽  
Cyanobacterial Species

AbstractThe present study focuses on the structure and function of phytoplankton community during periods of marked changes in hydrological traits, influenced by an atypical climatic event (La Niña) and its impact on Armando Ribeiro Gonçalves Reservoir of Rio Grande do Norte, situated in the Caatinga biome of northeastern Brazil. The main questions addressed were: What are the effects of environmental factors on the temporal variation of Morphologically Based Functional Group (MBFG) of phytoplankton community? How does the composition of cyanobacterial species shift in relation to high and low trends of phytoplankton diversity? The samples were collected monthly during 2008-2009 and analyzed for pH, temperature, electrical conductivity, dissolved oxygen content and the nutrients, such as, nitrate-nitrogen, ammoniacal nitrogen, total nitrogen and orthophosphate. Phytoplankton samples were collected for both qualitative and quantitative analyses to evaluate species richness index and species diversity index. The data was divided into two distinct hydrodynamic periods of instability and stability. The results demonstrate considerable changes in dissolved oxygen content, water transparency and nitrogen nutrients, which directly influenced the MBFG of phytoplankton community in space and time. The instability of reservoir water was caused by heavy rainfall, which exerts atypical external disturbances. The seasonal variation of MBFG demonstrates a change in cyanobacterial composition and their diversity during instability and stability periods. MBFG VII, composed by colonial cyanobacteria with mucilage, was associated with reduced values of electrical conductance and alterations in pH. The predominance of filamentous species with heterocyst (MBFG III) occurs only during the hydrodynamic stability period and did not show significant association with analyzed parameters. The co-dominance of MBGFs III, V and VII along with high species diversity of phytoplankton community occurred during the second hydrodynamic instability period which was associated with the reduction in water temperature. It is concluded that the decrease in cyanobacterial species dominance and the general increase in the diversity of phytoplankton community are influenced by pluvial anomaly. The higher water level during the period of pluvial anomaly resulted in nutrient pulse and the mixing of water column in the reservoir, which determined the MBPG phytoplankton community distribution.

scholarly journals The spatial variation of oxygen condition in carp pond located in nature reserve „Stawy Milickie” / Przestrzenne zróżnicowanie warunków tlenowych w stawie karpiowym położonym w rezerwacie przyrody „Stawy Milickie”

2013 ◽  
Vol 19 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Bartosz Jawecki ◽  
Tomasz Jaroszewicz-Smyk ◽  
Andrzej Drabiński
Keyword(s):  
Dissolved Oxygen ◽  
Spatial Variation ◽  
Oxygen Concentration ◽  
Water Concentration ◽  
Open Water ◽  
Average Concentration ◽  
Optimum Level ◽  
Emergent Plants ◽  
Oxygen Conditions ◽  
Oxygen Condition

Abstract The paper presents the results of research on the spatial variation of oxygen condition in a carp pond. The analysis of dissolved oxygen was carried out in the summer in 29 measuring points. In the analysed months the differences were determined between dissolved oxygen concentration in the strip of rushes and the part of the pond free from macrophytes. In the strip of rushes, the average concentration of dissolved oxygen was between 4.69-6.49 mg O2·dm-3. In the part of pond located near the strip of rushes the oxygen concentration was between 6.23-7.91 mg O2·dm-3 and in open water concentration of dissolved oxygen was in range 7.60-9.09 mg O2·dm-3. It was found that the biggest differences in oxygen concentration occur between the strip of rushes and the open water column: 40% in June, 26% in July, 28% in August, 38% in September, respectively. In the south-western part of the pond, covered with macrophytes and shaded by trees, the worst oxygen conditions were observed - below the optimum level for carps, sometimes reaching lethal values. The best oxygen conditions, noted in July and August, were in the central and northern part of the pond including the fishery and feeding point. In order to improve the oxygen conditions in macrophytes zone it is recommended to remove the rushes periodically and to remember to leave the part of emergent plants that are necessary for breeding and living avifauna. The scope and timing of the removal of plants has to be consulted and co-ordinated with the Regional Conservator of Nature.

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