Deoxygenation Of Water Research Articles

Water Quality Assessment of Lake Maninjau After the Mass Fish Kill Event

A mass fish kill is often occurring in Lake Maninjau. A lack of oxygen has reportedly resulted in numerous fish kills, including the recent lake Maninjau condition. Deoxygenation of lake water is a natural phenomenon that often occurs after heavy rain events and low sunlight intensity. Additionally, during the strong wind for a long period, the decrease in oxygen could be chemically triggered by the diffusion of sulfide from the bottom layer of the water column. Furthermore, this study examines water quality parameters after the mass fish mortality occurred across locations in Lake Maninjau. Field surveys were conducted by measuring physiochemical parameters and total sulfide at the Fifteen sampling points (five points in the middle and ten points around the lake) from November 26 to December 2, 2022. They were measured directly using the Horriba©U 52 water quality checker (WQC), DO meter YSI ProDO© International and the HACH spectrophotometer DR3900 method. The results show that the average DO levels at each observation point were close to 0 mg/L while the average sulfide level on the surface was 9.5 micro g/L. The average Oxidation Reduction Potential (ORP) of -79.26 mV indicates that the lake is in a reduced state and signifies that much of the dead and decaying material in the water would be slowly broken down and decomposed. Low ORP values indicate that the compound in the water is available in reduced form, which is more toxic. Our diel DO measurement show that sunlight intensity was effective in increasing oxygen concentration in the lake.

On the Electrochemical Deoxygenation of Water with a Nanocomposite Containing Copper Metal Nanoparticles and an Ion-Exchange Polymer Matrix

On the Electrochemical Deoxygenation of Water with a Nanocomposite Containing Copper Metal Nanoparticles and an Ion-Exchange Polymer Matrix

Fast deoxygenation in a miniaturized annular centrifugal device

Corrosion of steel devices and pipelines by dissolved oxygen (DO) is of major concern in many industries. Miniaturization of devices is becoming increasingly important significant for process intensification and distributed production. In this context, we attempted to realize efficient deoxygenation of water using a miniaturized annular centrifugal device (MACD) based on the centrifugal force and microscale effect. The influence of different operational variables on the deoxygenation performance was studied. It was found that the optimal volume mass transfer coefficient and deoxygenation efficiency are 1.01 s−1 and 97.8 %, respectively. The gas-liquid flow patterns in the mixing cavity, liquid film thickness distribution and residence time of water in the separation cavity of the MACD were investigated. The mechanism of fast deoxygenation and phase separation in MACD is explained. Additionally, a dimensionless correlation was obtained to calculate the volume mass transfer coefficient, and the predicted values were in good agreement with the experimental data. The deoxygenation performance of the MACD was also compared to those of other similar rotating deoxygenation devices, proving that MACD has the advantages of efficient deoxygenation performance, fast phase separation, and low energy consumption.

Removal of dissolved oxygen from industrial raw water in a microchannel

The aim of this study is to reach the maximum percentage of dissolved oxygen removal from industrial raw water using microchannel. In this study, two continuous and batch systems were used for the deoxygenation of water. Nitrogen and natural gas were studied as deoxygenation agents for the evaluation of microchannel efficiency. For an accurate investigation of the issue, the Box–Behnken response surface method was utilized for experiment design and analysis of results. The parameters of temperature (T), gas/liquid flow ratio (G/l), and residence time (t) were the effective factors on the efficiency of the system. The temperature was set in the range of 80−120 °C, G/L in the range of 2–8 for both systems, and the residence time was 1–5 s for the continuous system and 120-480 s for the batch system. The maximum elimination percentage for nitrogen and natural gas were obtained to be 97.105 and 98.530 when experiments were carried out at the optimum conditions predicted by Design Expert software (T = 80 °C, G/L = 7.8952, and t = 1.1414 s). • Nitrogen and natural gas were used for dissolved oxygen removal from water. • The effect of temperature, gas/liquid flow ratio, and residence time were studied. • The highest removal were obtained by nitrogen and natural gas to be 97.1 and 98.5%.

Химический и электрохимический вклады в редокс-сорбцию кислорода из водына зернистых слоях медьсодержащих нанокомпозитов

Наночастицы металлов в пористых полимерных матрицах проявляют выраженные сорбцион-ные и окислительно-восстановительные свойства. На этих свойствах металл-полимерных нанокомпо-зитов (НК) основан процесс глубокой деоксигенации воды. Ранее обнаружен существенный вклад электрохимической составляющей процесса восстановления кислорода на тонком катодно поляризу-емом зернистом слое медьсодержащего НК. В начальный период процесс лимитируется стадией внешней диффузии кислорода к поверхности гранул НК. В последующем отмечен все возрастающий со временем вклад химической составляющей, характерной особенностью которой является лимити-рование процесса внутридиффузионной стадией переноса кислорода к наночастицам меди и затрата электричества на электровосстановление оксидов металла. Однако при переходе от тонких пленок и слоев к зернистым слоям НК колоночного типа с распределенными по высоте кинетическими пара-метрами вопрос о соотношении вкладов электрохимического и химического маршрутов требует спе-циального рассмотрения.В настоящей работе исследован процесс редокс-сорбции кислорода из воды на динамических зернистых слоях нанокомпозитов медь-сульфокатионообменник (КУ-23, Lewatit K2620) при различ-ных силах поляризующего тока, оценены вклады химической и электрохимической составляющих общего процесса в стационарный период.Найдено, что количество поглощенного кислорода находится в экстремальной зависимости от силы поляризующего тока в допредельном режиме поляризации. Отмечено образование продуктов окисления металлических наночастиц в виде островковых кластеров, часть зерен окисляется с воз-никновением границ оксидных слоев, одинаковых по высоте зернистого слоя. С увеличением высоты зернистого слоя и силы поляризующего тока в допредельном режиме процесс поглощения кислорода становится все более квазистационарным. Показано, что вклады химического и электрохимического маршрутов восстановления кислорода соизмеримы при длительном процессе (100 ч). Часть кислорода поглощается за счет реакции электровосстановления на частицах меди в основном на поверхности зерен нанокомпозита, а часть – за счет автокаталитической химической реакции кислорода с электро-регенерируемыми наночастицами металла в объеме зерен нанокомпозита. Тот или иной механизм более вероятен в зависимости от состояния системы и силы воздействия на нее электрического тока. За счет постоянной электрогенерации ионов водорода и электрорегенерации наночастиц меди, необ-ходимых для восстановления кислорода, устанавливается стационарный режим редокс-сорбции кис-лорода их воды

Water deoxygenation using a hollow fiber membrane contactor to prevent pipe corrosion for sustainable management of district heating systems: A pilot-scale study

Dissolved oxygen (DO) is a key factor affecting pipe corrosion in district heating systems (DHS). This study demonstrated effective deoxygenation of water in a DHS using a hollow fiber membrane contactor (HFMC) via systematic investigation from lab-to pilot-scale. First, deoxygenation efficiency was evaluated in a lab-scale HFMC with varying operating parameters including an effective membrane area, flow rate and feedwater temperature. Based on the results from the lab-scale investigation, a pilot HFMC system was designed with capacity of 1 m3 per day. To achieve a permeate DO concentration below 10 μg L−1 at feedwater temperatures of 20–60 °C, the vacuum degree needed to be lower than the saturated water vapor pressure of 10–120 Torr. In addition, the primary foulant for membrane fouling was organic matter in the make-up and district heating (DH) return water. A significant change in corrosion response was observed for pipe steel in the DHS after deoxygenation. Immersion tests for 14 days indicated that weight loss values had greatly reduced by the deoxygenation process from 39.3 to 1.3 mg cm−2 and from 21.9 to 2.1 mg cm−2 for steel pipe samples immersed in the make-up water and the DH return water of the DHS, respectively. This improved corrosion resistance from deoxygenation was interpreted by electrochemical analysis. As such, this study offers a pilot-scale demonstration of the feasibility of a hollow fiber membrane-based deoxygenation process as an effective tool to prevent the corrosion of steel pipes.

A note on a design protocol for deoxygenation of water

Abstract Selection of a water deoxygenation method presents some challenges due to the broad range of options including physical, chemical, electrochemical and biological techniques. This communication presents the design of an apparatus developed for efficient and simple deoxygenation of water for the purpose of electrochemical corrosion studies in a lab environment. The design is modular and can be scaled to meet processing needs. The operation of the apparatus is based on the combination of nitrogen bubbling and surface absorption to achieve complete and uncontaminated deoxygenation of water. Tests conducted on this apparatus revealed that pressurisation of the apparatus enhances economy and performance while increasing nitrogen injection rate accelerates deoxygenation. However, a point was identified, at which a balance between economy and performance is achieved and further injection rate increase suffers from diminishing returns.

Thallium isotopes reveal protracted anoxia during the Toarcian (Early Jurassic) associated with volcanism, carbon burial, and mass extinction

For this study, we generated thallium (Tl) isotope records from two anoxic basins to track the earliest changes in global bottom water oxygen contents over the Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma) of the Early Jurassic. The T-OAE, like other Mesozoic OAEs, has been interpreted as an expansion of marine oxygen depletion based on indirect methods such as organic-rich facies, carbon isotope excursions, and biological turnover. Our Tl isotope data, however, reveal explicit evidence for earlier global marine deoxygenation of ocean water, some 600 ka before the classically defined T-OAE. This antecedent deoxygenation occurs at the Pliensbachian/Toarcian boundary and is coeval with the onset of initial large igneous province (LIP) volcanism and the initiation of a marine mass extinction. Thallium isotopes are also perturbed during the T-OAE interval, as defined by carbon isotopes, reflecting a second deoxygenation event that coincides with the acme of elevated marine mass extinctions and the main phase of LIP volcanism. This suggests that the duration of widespread anoxic bottom waters was at least 1 million years in duration and spanned early to middle Toarcian time. Thus, the Tl data reveal a more nuanced record of marine oxygen depletion and its links to biological change during a period of climatic warming in Earth's past and highlight the role of oxygen depletion on past biological evolution.

Catalytic activity of iron hydroxides and manganese hydroxides in the deoxygenation of water

Catalysts prepared by the modification of FIBAN K-4 and FIBAN X-1 fibrous ion exchangers with the hydroxides of iron and manganese were developed and tested in a water deoxygenation process. It was established that the samples obtained by the supporting of Fe(III) hydroxide onto the FIBAN X-1 ampholyte were most effective. The conclusion that the high activity of the catalytic system is caused by the formation of a mixed phase of Fe(II) and Fe(III) hydroxides of the spinel type containing mobile (weakly bound) lattice oxygen was made. A reaction scheme was proposed to explain the reaction mechanism.

Continuously deoxygenation of water in a reactor packed with glucose oxidase immobilized in MnO2/calcium alginate composite

Abstract In this research, removing dissolved oxygen (DO) from water by means of granular biocatalyst (GB) was investigated. GB was prepared by granulation of glucose oxidase (GOx) adsorbed on MnO 2 micro-sized particles by calcium alginate. Prepared biocatalyst was able to remove DO and decompose produced hydrogen peroxide simultaneously. Factors affecting DO removal including temperature, pH and glucose concentration were studied; at the optimum condition which was achieved to be 30 ° C, 6.85 and 80 mM respectively, DO was removed completely. Stability of enzymatic activity of GB was investigated. Besides, Water deoxygenation was studied in a packed bed reactor by GB utilization at optimum operating condition. The highest deoxygenation rate was observed at feed flow rate of 375 mL/min. Residence time distribution of packed bed reactor was calculated at two flow rates with pulse injection of tracer into reactor inlet.

Catalytic deoxygenation of high-purity water using membrane electrode units

A new method for water deoxygenation using membrane technologies was suggested. The method is based on electrochemical reduction of dissolved oxygen on the surface of membrane electrode units in combination with its chemical reduction with hydrogen on a catalytically active sorbent. A pilot setup for deoxygenation of high-purity water with the output of up to 200 L h–1 was developed on the basis of the results obtained.

Sorption-membrane system for deep deoxygenation of water

We have studied the redox sorption of oxygen from flowing distilled water in a multistage sorptionmembrane cell with a metal (Cu)–sulfo cation exchanger (KU-23 in the H+ form) granular nanocomposite in the cathode compartment and a sulfo cation exchanger (KU-23 in the H+ form) in the anode compartments separated by a cation-exchange membrane (MC-40 in the H+ form). It is shown that the redox sorption of oxygen on the granular nanocomposite bed polarized with a current which is less than the limiting external diffusion one is complicated by internal steps (oxygen diffusion in the polymer matrix pores and the chemical oxidation of metal nanoparticles) and proceeds with a mixed diffusion-kinetic control. In the mode of limiting diffusion current polarization, the contribution of internal stages decreases and the process becomes steady due to the transition into the external diffusion region. A theoretical calculation shows that the process performed in series-connected multistage cells with polarization of each stage in the mode of limiting external diffusion current allows obtaining water with a dissolved oxygen content of <10 ppb.

Deep deoxygenation of water with a metal-ion exchanger nanocomposite in closed system

Kinetics and dynamics of the reduction of oxygen dissolved in water by metal-ion exchanger nanocomposites differing in the nature (Ag, Cu, Bi, Ni), quantitative content of the introduced metal, and ionic form of the matrix were studied. It is shown that the process of oxygen absorption occurs to the fullest extent with the copper-containing nanocomposite. As the content of the metal increases, the amount of oxygen reduced by a single grain and granular bed grows and reaches the limiting values. It was found on this basis that the material with a copper capacity of 5.0 ± 0.5 mequiv cm−3 in the H+ form is the most efficient for deep removal of molecular oxygen from water. The advisability of using the nanocomposite with the suggested parameters for deep deoxygenation of water in a closed system was confirmed by experiments and calculations.

Effect of gamma-ray irradiation on the deoxygenation of salt-containing water using hydrazine

In spent fuel pools at the Fukushima Daiichi nuclear power plant, hydrazine was added to salt-containing water in order to reduce dissolved oxygen. Hydrazine is known to reduce dissolved oxygen in high-temperature pure water, but its deoxygenation behavior in salt-containing water at ambient temperature in the presence of radiation is unknown. Deoxygenation using hydrazine in salt-containing water was thus investigated using a 60Co gamma-ray source and artificial seawater at room temperature. Water samples containing a small amount of hydrazine were irradiated at dose rates of 100–10,000 Gy/h. The concentration of dissolved oxygen in the water samples was measured before and after irradiation. Notably, a decrease in the dissolved oxygen was only observed after irradiation, and the dissolved oxygen concentration decreased with increasing dose rate and irradiation time. The rate of decrease in the amount of dissolved oxygen using hydrazine was slow in the presence of salts. Kinetic considerations suggested that the deoxygenation of the salt-containing water exposed to gamma-ray irradiation using hydrazine was suppressed by chloride ions.

Water treatment for steam generators with the aid of ion exchangers

A method for simultaneous desalting and deoxygenation of feed and extra water was developed for through steam generators using ion-exchange mixed bed filters and the filter with ferrous hydroxide electron ion exchanger which eliminates the stage of thermal deaeration.

A study of the electret state of polyethylene formulations with a ferroelectric

A method for simultaneous desalting and deoxygenation of feed and extra water was developed for through steam generators using ion-exchange mixed bed filters and the fi lter with ferrous hydroxide electron ion exchanger which eliminates the stage of thermal deaeration.

Catalytic Deoxygenation of Water: Preparation, Deactivation, and Regeneration of Palladium on a Resin Catalyst

Oxygen dissolved in water is a cause of corrosion in heating installations. On the other hand, in the production of beverages such as beer, it leads to the oxidation of organic matter, decreasing the quality of the product. Therefore, its content must be substantially reduced. In this work, the catalytic deoxygenation of water using a palladium catalyst is studied. The catalyst consists of palladium ion-exchanged on a weak-basic macroporous resin. This work addresses the catalytic deactivation and regeneration of this type of catalyst, comparing results obtained in the laboratory with those obtained from an industrial reactor used to deoxygenate water for beer production. Two deactivation mechanisms are observed: (i) In the short term, the deposition of organic material (humic acids) coming with the water is responsible for activity lost; (ii) in the long term, the cause of the irreversible deactivation is the palladium leaching that occurs during the cleaning-in-place procedure, which is carried out with sodium hydroxide solution at 60 °C. This deactivation occurs in the presence of dissolved oxygen and is strongly favored by the presence of chlorine in the water. This study indicates the conditions necessary to regenerate the catalyst and to largely improve the stability during operation−regeneration cycles.

Effect of drifting macroalgae Cladophora glomerata on benthic community dynamics in the easternmost Baltic Sea

The present study focuses on dynamics of macroinvertebrate communities in shallow waters of northern coast of the Neva Estuary, Russia under eutrophication consequences such as proliferation of fast-growing filamentous algae Cladophora glomerata and oxygen depletion during the algae decomposition. Habitat characteristics (temperature, salinity, total phosphorus, and oxygen in water), taxonomical composition and abundance of zoobenthos were studied from May to October of 2003–2005. Temporary deoxygenation (0.6–2.8 mg cm− 3) of water near bottom caused by the decomposition of detached C. glomerata was recorded annually from July to August. At the same periods, abundance of macroinvertebrates decreased significantly, from 23.6 to 3.6 (2003), 51.9 to 0.4 (2004) and 34.9 to 1.4 thousand ind.m− 2 (2005). The coastal eutrophication in the Neva Estuary causes the destabilizing fluctuations in benthic abundance that can facilitate the shifts in littoral community structure.

NUMERICAL ANALYSIS OF EUTROPHICATION AND THERMOSOLUTAL STRATIFICATION IN RESERVOIRS

Reservoir eutrophication brings deoxygenation of hypolimnetic water and high concentration of metal, nutrients and dissolved materials are released from the bed sediments. Production of dissolved materials then increases fluid density along the reservoir bed. On a sloping boundary, the heavy water mass generates an inclined thermosolutal plume that transports the polluted water and heat energy from the shallow layer to the deep layer. The authors found the plume is responsible for generation of stable salty water with inverse thermal stratification in the bottom layer.The present study is to develop a model that can reproduce eutrophication as well as seasonal variation of the thermal and salinity structure produced by this mechanism. The model is Lagrange-type based on a one-dimensional DY namic Reservoir Simulation Model, DYRESM. The original model was modified so that the thermosolutal convection and chemical and biological processes can be taken into consideration. The present model was verified through comparison between the simulation results and the field data.

BARSA RIVER MONITORING

Barsa River is one of the tributary streams of Olt River in Brasov region, which course is close to industrial areas with significant impact on environmental quality, Zarnesti, Rasnov and Brasov. Oxygen is a vitally important component in water for all the aquatic species. The oxidation of organic matter ({CH2O}), biooxidation of nitrogenous material (NH4+) and chemical or biochemical oxidation of reducing agents (Fe2+, SO32-) can deplete oxygen level. All these processes contribute to the deoxygenation of water; therefore pollution parameters of major importance in aquatic systems is the amount of dissolved oxygen (DO), biological oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD), in different natural waters. This study presents Barsa River water quality focused on the DO, BOD5 and COD values as pollution parameters. Three sampling sites were monitored, up-stream Zarnesti, downriver Zarnesti and up-stream Olt River confluence. The results are presented as annual means, covering 1996-2000 period. The monitoring up-stream Zarnesti site showed that the parameters values corresponds to the natural value, as no pollution sources are noticed in this area. Between up-stream Zarnesti and down-river Zarnesti sites there are two important industrial pollution sources: S.C. Celohart S.A. Zarnesti and S.C. Tohan S.A. Zarnesti. DO, BOD5 and COD parameters show variable values, sometimes even worst than the accepted values for the III water category. More important industrial plants are in the up-stream Olt River confluence area, S.C. Romacril S.A. Rasnov and Brasov Water Treatment Plant, that can be pollution sources. However, the monitored parameters show better water quality compared with down-river Zarnesti, due to the natural oxygenation process, along the river stream.