Influence of Potable Water Origin on the Physicochemical and Antimicrobial Properties of Plasma Activated Water

The interaction between a cold gas plasma and water creates a plasma activated liquid, a solution rich in highly reactive chemical species. Such liquids have garnered considerable attention due to their powerful antimicrobial properties and ease of production. In this contribution, air plasma was used to activate potable water samples from five different countries, including the UK, France, Norway, Slovenia and Palestine. All water samples had an initial pH in the range of 7.9 to 8.2, following plasma activation samples from the UK and Norway reached a pH below 3, whereas water from France and Palestine remained stable at 8. The concentration of NO3− increased in all samples, reaching a maximum concentration of 3 mM after 25 min plasma exposure; whereas the concentration of NO2− showed a non-linear dependence with exposure time, reaching between 10 and 25 µM after 25 min of exposure. To demonstrate the impact of water origin on the antimicrobial potential of each solution, the inactivation of Staphylococcus aureus and Escherichia coli was considered. It was found that activated water from the UK was capable of achieving > 6 log reduction, whereas water from Palestine was only able to achieve a 0.4 log reduction, despite both liquids receiving an identical plasma exposure. The study demonstrates the importance of initial water composition on the level of plasma activation, indicating that additional purification steps prior to activation may be necessary to ensure efficacy and repeatability.

Indirect estimation of turbulent mixing in western route of Indonesian throughflow

The Indonesian Throughflow (ITF) via its western path conveys mainly North Pacific water origin with Smax thermocline water and Smin intermediate water from its entry portal in Sangihe-Talaud arcs to the main outflow straits in Lombok, Ombai and Timor passage. Along its route, the throughflow water characteristics transforms significantly due to strong diapycnal mixing forced by internal tidal waves interaction along complex topography such as passages, sill, straits, and shallow islands chains. This paper reports a brief estimate of turbulent mixing profiles in Sangihe chains, and Makassar Strait. The CTD dataset are obtained from the year of maritime continent (YMC) Cruise in August 2019 on board the R.V. Baruna Jaya I. The Thorpe method is used to analysis dissipation energy ( ε ) and vertical diffusivity (Kz ) from CTD dataset. It is shown that the highest ε epsilon 5.87 × 10−7 Wkg −1 and Kz 4.42 × 10−3 m2s 1 are found in the Sangihe area. In Labani Channel and Dewakang Sill the averaged vertical diffusivity is much weaker at the order of 10−4 m 2s1. Thus, Sangihe Chains station have the highest values compared to other stations at depth 950-1000 meters.

EXPERIENCE IN COMPREHENSIVE ANALYSIS OF THE RADIOCARBON DATING RESULTS AND THE PHYSICAL-CHEMICAL STUDIES OF TWO VESSELS OF THE NETWORK POTTERY CULTURE FROM PESOCHNOYE

При радиоуглеродном датировании по формовочной массе и нагару с поверхности двух сосудов культуры сетчатой керамики с поселения Песочное 1 на озере Неро полученные даты оказались в среднем на ~ 500-700 лет старше радиоуглеродных дат образцов культурного слоя, в котором они были найдены. Причиной мог быть пресноводный резервуарный эффект, обусловленный присутствием сформировавшейся в воде органики. Его проявление можно расценивать как индикатор присутствия происходящего из водной среды органического материала в составе компонентов формовочной массы исследуемых сосудов. В окрестностях поселения Песочное 1 единственным природным материалом, содержащим органику водного происхождения, соотносимого с формовочной массой, является сапропель из озера Неро. Для определения сходств и различий в элементном и минеральном составе методами SEM-/EDS- и XRD-анализов были изучены образцы керамики каждого сосуда и образец сапропеля из озера. Установлено, что компонентами формовочной массы являются иллитовая глина с полевыми шпатами и кварцем в виде частиц песка, сапропель и костная мука. Возможность получения радиоуглеродных дат по формовочной массе, отсутствие в ней химических элементов, свидетельствующих о наличии нередуцированных органических веществ, присутствие иллита показывают, что обжиг сосудов был произведен в интервале примерно от 400 до 800 °С. The article is devoted to the analysis of clay paste and burnt crust adhering to the surface of two vessels attributed to the «network» pottery culture (pottery with textile imprints) from the Pesochnoye 1 settlement on Lake Nero. The radiocarbon dating of these samples shows that on average the dates obtained are older than the radiocarbon dates of the samples from the occupation layer where the vessels were found by ~ 500700 years. The age difference is probably caused by the fresh water reservoir effect related to presence of organic matter in the water and presence of organic matter from water in the composition of clay paste used to make the studied vessels. Sapropel from Lake Nero is the only natural material in the Pesochnoye 1 vicinities which contains organic matter of water origin comparable with the clay used for the vessels making. To determine similarities and differences in the elemental and mineral compositions by the SEM/EDS and the XRD analyses, ceramic samples from each vessel and a gyttja clay sample from the lake were examined. It was found that sapropel tempered with feld spar and quartz sand, sapropel and bone flour were mixed in the clay body. Radiocarbon dates that can be obtained for clay, absence of chemical elements that would demonstrate presence of unreduced organic matter, presence of illite clay imply that the firing temperature fell within ~ 400-800 °С.

Microbial and Geochemical Evidence of Permafrost Formation at Mamontova Gora and Syrdakh, Central Yakutia

Biotracers marking the geologic history and permafrost evolution in Central Yakutia, including Yedoma Ice Complex (IC) deposits, were identified in a multiproxy analysis of water chemistry, isotopic signatures, and microbial datasets. The key study sections were the Mamontova Gora and Syrdakh exposures, well covered in the literature. In the Mamontova Gora section, two distinct IC strata with massive ice wedges were described and sampled, the upper and lower IC strata, while previously published studies focused only on the lower IC horizon. Our results suggest that these two IC horizons differ in water origin of wedge ice and in their cryogenic evolution, evidenced by the differences in their chemistry, water isotopic signatures and the microbial community compositions. Microbial community similarity between ground ice and host deposits is shown to be a proxy for syngenetic deposition and freezing. High community similarity indicates syngenetic formation of ice wedges and host deposits of the lower IC horizon at the Mamontova Gora exposure. The upper IC horizon in this exposure has much lower similarity metrics between ice wedge and host sediments, and we suggest epigenetic ice wedge development in this stratum. We found a certain correspondence between the water origin and the degree of evaporative transformation in ice wedges and the microbial community composition, notably, the presence of Chloroflexia bacteria, represented by Gitt-GS-136 and KD4-96 classes. These bacteria are absent at the ice wedges of lower IC stratum at Mamontova Gora originating from snowmelt, but are abundant in the Syrdakh ice wedges, where the meltwater underwent evaporative isotopical fractionation. Minor evaporative transformation of water in the upper IC horizon of Mamontova Gora, whose ice wedges formed by meltwater that was additionally fractionated corresponds with moderate abundance of these classes in its bacterial community.

A Brief Overview of the Integrated Fish Farming of Three Commercially Popular Fish Species (Snakehead, Tilapia and Catfish) in Malaysia

Aquaculture industry in Malaysia involves culture of many fish species of either fresh or brackish water origin and among the important fish species are Snakehead, Tilapia and Catfish. There is a substantial culture of these fish in Malaysia nowadays, though there are not one hundred percent native fish species but their presence in Malaysia is getting closer to over several decades and for almost a decade now, these species had been among the highest finfish produced in either fresh or brackish waters. As the global aquaculture production continue growing in order to meet up with ever increasing fish demand, especially as fish from capture has levelled off and makes an increase in aquaculture production as the only hope to meet the demand for fish, one of suggested ways in culturing them is by venturing into integrated fish farming. Integrated fish farming of different species is a practice which links together two or more normally separate farming systems, whereby the fish from different species become subsystems of a whole farming system. Although integrated fish farming may not be huge globally based on the available official statistical data but it is becoming important industry in Malaysia and neighboring countries. This review discussed briefly about the integrated fish farming of three commercially popular species (Snakehead, Tilapia and Catfish) in Malaysia and neighboring countries.

A Comparison of Different Natural Groundwaters from Repository Sites—Corrosivity, Chemistry and Microbial Community

In Finland, the repositories for low and intermediate-level radioactive waste (LLW and ILW) will be situated at three different geographical locations in about 60 to 100 m deep granite bedrock where the waste and waste containers can be subjected to anoxic groundwater containing microbes. The composition of groundwater varies in terms of chemistry and microbial activity in different locations. In this study, groundwater from the three repository areas was analyzed in respect to chemistry and microbial community. Corrosion tendency of three steel grades, carbon steel AISI/SAE 1005 and stainless steels AISI 304 and 316L, was studied in these groundwater environments using electrochemical methods. As a reference, measurements were also performed in simulated groundwater without microbes. The measurements show that corrosivity of the water and thus the steels’ performance differs depending on water origin. In addition, the groundwater differed remarkably in their chemical composition as well as abundance and diversity of microbial community between the sites. Consequently, the local environment has to be considered when evaluating the long-term evolution of disposal concepts.

Combining concentration-discharge hysteresis and reach-scale lateral flow modelling to characterize flood water origin and processes: application to karst catchments

<p>We propose a data-driven approach of concentration-discharge (C-Q) relationship analysis, including a new classification of C-Q hysteresis loop at the catchment scale, combined to a simulation of lateral Q and C at the reach scale. We analyse high-frequency, multiple-site records of Q and electrical conductivity (EC) in karst catchment outlets, in which EC informs on water residence time. At the catchment scale, contributions of pre-event water (PEW) and event water (EW) during storm events are investigated through hysteresis loops analysis, which allows inferring hydrological processes. Our new classification of hysteresis loops is based on loop mean slope and hysteresis index. At the reach scale, lateral Q and EC are simulated using a diffusive wave equation model, providing a more spatialized picture of PEW and EW contributions to streamflow during storm events. The methodology is applied to two catchments (Loue river and Cèze river) in France, including 8 gauging stations with hourly Q and EC time series covering 66 storm events.</p><p>For both catchments, a conceptual model of water origin and hydrological-processes seasonal and spatial variability is drawn. Regarding Loue catchment, summer and fall storm-events are characterized by contribution of PEW through piston-type flows, whereas decreasing EC values in winter and spring storm-events indicate the major contribution of EW through surface runoff and following fast infiltration in karst. EW contribution is increasing towards downstream. Regarding Cèze catchment, higher contributions of EW are observed, indicating that fast infiltration and surface runoff are the dominant processes, associated to a PEW signature in summer and fall. PEW contribution also increases in karstified areas. Intra-site water origin seasonality is mostly related to karst aquifer saturation state, whereas inter-site variability is linked to karst areas extension. These results are encouraging to extend this approach to a variety of sites, notably influenced by important surface water/groundwater interactions, and groundwater flooding.</p>

Prevalence of Betanodavirus in Sea Bass (Dicentrarchus Labrax) for All Production Stages in Turkey

Viral Nervous Necrosis (VNN) is one of the most important problems in sea bass aquaculture. Although there are many studies in the world on detection and molecular characterization of betanodaviruses causative agent of VNN, there are not enough studies related to prevalance to provide epidemiological maps. The purpose of this study was to investigate the betanodavirus prevalence in all bass hatcheries actively operating and in some farms in Turkey by RT-qPCR. A total of 2460 samples including fertilized egg, prelarva, postlarva, and fingerling were collected from 16 hatcheries as covering all production stages. A total of 600 sea bass were also collected from 20 farms. Betanodavirus was detected in a hatchery and a farm in fingerling sized sea bass and prevalances were found to be 6.25% and 5%, respectively. Virus isolation initially could not be achieved in E-11 but later SSN-1. Partial genome analysis of both RNA1 and RNA2 segments of the viruses, revealed that they were Redspotted grouper nervous necrosis virus genotype endemic in the Mediterranean basin. The absence of mortality related to VNN in the hatchery and farm, the healthy appearance of the sea bass, the low viral load detected and also output of retrospective epidemiological studies indicate that the infection is subclinical. Not detecting betanodavirus in other age groups where biosafety is implemented indicates that there is no active infection. In the light of these findings, it can be concluded that there are no circulating betanodavirus in hatcheries and the detected virus could be of sea-water origin.

An Integrated Experimental Workflow for Formation Water Characterization in Shale Reservoirs: A Case Study of the Bazhenov Formation

Summary In this study, we aim to develop a new integrated solution for determining the formation water content and salinity for petrophysical characterization. The workflow includes three core components: the evaporation method (EM) with isotopic analysis, analysis of aqueous extracts, and cation exchange capacity (CEC) study. The EM serves to quickly and accurately measure the contents of both free and loosely clay-bound water. The isotopic composition confirms the origin and genesis of the formation water. Chemical analysis of aqueous extracts gives the lower limit of sodium chloride (NaCl) salinity. The CEC describes rock-fluid interactions. The workflow is applicable for tight reservoir rock samples, including shales and source rocks. A representative collection of rock samples is formed based on the petrophysical interpretation of well logs from a complex source rock of the Bazhenov Formation (BF; Western Siberia, Russia). The EM employs the retort principle but delivers much more accurate and reliable results. The suite of auxiliary laboratory methods includes derivatography, Rock-Eval pyrolysis, and X-ray diffraction (XRD) analysis. Water extracts from the rock samples at natural humidity deliver a lower bound for mineralization (salinity) of formation water. Isotopic analysis of the evaporated water samples covered δ18O and δ2H. A modified alcoholic ammonium chloride [(NH4Cl)Alc] method provides the CEC and exchangeable cation concentration of the rock samples with low carbonate content. The studied rock samples had residual formation water up to 4.3 wt%, including free up to 3.9 wt% and loosely clay-bound water up to 0.96 wt%. The latter correlates well to the clay content. The estimated formation water salinity reached tens of grams per liter. At the same time, the isotopic composition confirmed the formation genesis at high depth and generally matched with that of the region's deep stratal waters. The content of chemically bound water reached 6.40 wt% and exceeded both free and loosely bound water contents. The analysis of isotopic composition proved the formation water origin. The CEC fell in the range of 1.5 to 4.73 cmol/kg and depended on the clay content. In this study, we take a qualitative step toward quantifying formation water in shale reservoirs. The research effort delivered an integrated workflow for reliable determination of formation water content, salinity lower bound, and water origin. The results fill the knowledge gaps in the petrophysical interpretation of well logs and general reservoir characterization and reserve estimation. The research novelty uses a unique suite of laboratory methods adapted for tight shale rocks holding less than 1 wt% of water.