Changes In Turbidity Research Articles

DIFFERENCES VALUE OF PT AND APTT IN EXAMINATION OF ELECTROMECHANICAL AND PHOTO-OPTICAL METHOD

Background: Examination of PT and APTT in hospitals and clinical laboratories by utilizing the use of different instruments and methods. Examination of PT and APTT can be implemented through electromechanical or photo-optical techniques to detect changes in plasma turbidity. This method principle isprincipled that addition can affect the increase in plasma viscosity. Purpose: To analyze the differences in the values of PT and APTT between the electromechanical method and the photo-optical method. Method: Analytical observation, 32 plasma citrate without interference and hemolysis were examined at the Clinical Pathology Laboratory of RSU Haji Surabaya and the Ultra Medica Main Clinics Laboratory in Surabaya. The study used SPSS 24.0 program to determine whether there were PT and APTT values with an electromechanical and photo-optical method. Result: The result of PT and APTT with the electromechanical method was significantly higher than PT and APTT with the photo-optical method on samples without interference. In hemolytic samples, the result of PT with the electromechanical method was significantly higher than the PT result with the photo-optical method. Meanwhile, the result of APTT with the electromechanical method was significantly lower than the APTT result with the photo-optical method in hemolytic samples. Conclusion: There were significant differences in PT and APTT results between electromechanical and photo-optical in samples without interference and hemolytic. It is due to the difference in the detection principle between the two methods.

Turbidity Changes during Carbamazepine Oxidation by Photo-Fenton

The objective of this study is to evaluate the turbidity generated during the Fenton photo-reaction applied to the oxidation of waters containing carbamazepine as a function of factors such as pH, H2O2 concentration and catalyst dosage. The results let establish the degradation pathways and the main decomposition byproducts. It is found that the pH affects the turbidity of the water. Working between pH = 2.0 and 2.5, the turbidity is under 1 NTU due to the fact that iron, added as a catalyst, is in the form of a ferrous ion. Operating at pH values above 3.0, the iron species in their oxidized state (mainly ferric hydroxide in suspension) would cause turbidity. The contribution of these ferric species is a function of the concentration of iron added to the process, verifying that the turbidity increases linearly according to a ratio of 0.616 NTU L/mg Fe. Performing with oxidant concentrations at (H2O2) = 2.0 mM, the turbidity undergoes a strong increase until reaching values around 98 NTU in the steady state. High turbidity levels can be originated by the formation of coordination complexes, consisting of the union of three molecules containing substituted carboxylic groups (BaQD), which act as ligands towards an iron atom with Fe3+ oxidation state.

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Highly polluted lake water turbidity was analyzed to detect the changes during COVID-19 lockdown. Total eight Sentinel-2 Multispectral Instrument (MSI) and Landsat-8 Operational Land Imager (OLI) satellite imageries are used to observe the qualitative change of lake water turbidity for pre, during and post lockdown period. The imageries from January to June, and September and October were analyzed for change detections. Cloud free imageries have been chosen for analysis. The water pixels and turbidity are assessed by the Normalized Difference Water Index (NDWI) and Normalized Difference Turbidity Index (NDTI), respectively. The blue, red and NIR band reflectance indicates that most of the lake water becomes clearer than before the lockdown period except May. The turbidity index shows low pollution after the lockdown period. High turbidity was observed evenly distributed from January to June. In September and October, high turbidity only found the upper part of the lake. This probably indicates the floating pollutants in the lake. The qualitative study of lake water turbidity using a remote sensing approach indicates that the COVID-19 lockdown improves the water quality in city lake water.

Assessing the ecological vulnerability of the shallow steppe Lake Neusiedl (Austria-Hungary) to climate-driven hydrological changes using a palaeolimnological approach

Lake Neusiedl, the largest steppe lake in Europe, is particularly sensitive to climate variations due to its extreme shallowness (zmax = 1.8 m) and low ratio of catchment to lake area (3.5 : 1). Changes in water budget, salinity and turbidity have key implications for the lake’s ecology and management. Here, we present a multi-proxy palaeolimnological reconstruction of the evolution of Lake Neusiedl since the end of its last complete desiccation (1865–1868), based on an undisturbed radiometrically dated core taken from the open water portion of the lake. Geochemical and biological (algal) proxies outline the succession of three major ecological stages since 1873 ± 16 yrs, with the first major changes appearing already in the 1930s as driven by climate related hydrological variability. Subfossil diatoms proved to be reliable for tracking long-term changes in the trophic conditions of Lake Neusiedl while diatom-inferred lake conductivity revealed to be unreliable due to a combination of lake environmental settings and the absence of a site-specific training set. Nonetheless, multivariate statistical analyses and comparisons with limnological data confirm a great potential of subfossil diatoms for revealing past ecological changes and tipping points of shallow lakes, as long as studies rely on a multi-proxy approach. In agreement with limnological surveys, the sediment record corroborates the high vulnerability of Lake Neusiedl, both in present and past times, towards climate-driven changes in water level and salinity, and allows the prediction, by analogy with the past, of future ecological changes in a context of global warming and increasing nutrient inputs from non-point sources.

Modified sugar beet pulp and cellulose-based adsorbents as molasses quality enhancers: Assessing the treatment conditions

To tackle the issue of non-sugar compounds reduction in sugar beet molasses towards improved sugar recovery and complete molasses valorisation, various treatments were developed. As a step forward to sustainability, this study explores the applicability of alkaline hydrogen peroxide treated sugar beet pulp (AHPSBP) and commercial cellulose-based adsorbents for molasses purification by monitoring the changes in molasses colour, turbidity and sucrose content. Treatment conditions defined by Box-Behnken design were pH (3–7), molasses dry substance (30–50° Brix), and adsorbent concentration (9–21 g/L) with constant treatment temperature. Favourable conditions for molasses colour reduction were acidic and neutral environment for commercial adsorbents (4.9–27.1%) and AHPSBP (20.3–32.7%), respectively. Turbidity reduction was higher than 90% in neutral environment regardless of applied adsorbent with minimal detected sucrose content reduction. AHPSBP exhibited greater potential regarding molasses colour and turbidity reduction compared to commercial adsorbents obtained at favourable pH with lower applied concentrations.Accordingly, AHPSBP was introduced as a novel, abundant, and low-cost adsorbent for molasses quality enhancement, contributing to the existing results concerning molasses purification obtained by bentonite and activated carbon application.

Assessing Fish Habitat and the Effects of an Emergency Drought Barrier on Estuarine Turbidity Using Satellite Remote Sensing

AbstractEstuaries worldwide are experiencing stress due to increased droughts, which often prompt intervention by environmental managers and government agencies. Effective management of water resources in estuarine systems can be enhanced by new technologies and methodologies to support decision‐making processes. Here, we evaluate the use of high‐frequency, high‐resolution satellite remote sensing within two management‐relevant case studies in the San Francisco Estuary and the Sacramento–San Joaquin River Delta. We used a remote sensing‐derived time series of turbidity maps to (1) identify favorable turbidity conditions for the endangered fish species, delta smelt (Hypomesus transpacificus), during the height of the great California drought in the dry season of 2015, and (2) evaluate changes in turbidity following the installation of an emergency saltwater intrusion barrier. The mapping results indicate several persistent areas of turbidity refugia throughout the summer in the north and west Delta; however, there was infrequent connectivity. A comparison of images captured during ebb tides before and after barrier installation showed a mean increase of 6.6 Nephelometric Turbidity Units (NTU) in the San Joaquin River and 4 NTU in Fisherman’s Cut. Our assessment of the barrier supports previous findings, which used field samples to conclude barrier installation may have resulted in increased turbidity near the barrier and enhances these findings by providing spatial context.

OPTIMIZING PRE LIMING PH FOR EFFICIENT JUICE CLARIFICATION PROCESS IN SRI LANKAN SUGAR FACTORIES

- This study was conducted treating with Milk of Lime to reach different pH levels (T1- with Initial pH, T2, T3 and T4 with 6.5, 7.5 and 8.5 of pH respectively) to determine the optimum pre-liming pH which could result in best cane juice clarification in Sri Lankan sugar industries. The experiment design used was RCBD with five replicates. ANOVA followed by Duncan’s Multiple Range Test (DNMRT) were used to identify significant mean differences. Regression analyses were carried out to model the variation of turbidity, mud volume and CaO with change of juice pH. Quadratic model (R2 = 99.2 %, p <0.001) best fitted to explain the effect of pH on turbidity of juice. Effect of pH on deposited mud volume and CaO were explained by cubic models with R2 = 99.4 % (p <0.001) and R2 = 93.9 %, (p <0.001) respectively. Among tested treatments, pH 7.5 is selected as the best for turbidity improvement of the clarified juice while pH 8.5 is the second best. However pH 8.5 (370 ml) was able to deposited significantly high mud volume than pH 7.5 (270 ml). Further, the amount of residual Ca2+ ions in the clarified juice at pH 7.5 (2715 ppm) is clearly lower than the amount of Ca2+ ions remaining in the clarified juice at pH 8.5 (2945 ppm). It is expected to obtain high turbidity and higher mud volume with low sugar inversion at optimum pH. Therefore the results suggest optimum pH range lie around pH 7.5 to 8.5. Conducting similar experiment by using mixed juice extracted from sugar factory mills with pH range around 7.0 to 8.4 at 0.2 increments is suggested to validate the optimum pH.

Propagation of Guiana dolphin sounds in their habitat: measured transmission loss and influence of environmental factors

ABSTRACT This study aims to determine the influence of distance and environmental parameters of water on Sotalia guianensis sounds. We used recordings of three distinct vocalisations for testing their propagation in places with different environmental characteristics in the Northeast and Southeast of Brazil. We observed that the propagation of all the sounds tested depended on the distance, turbidity, and concentration of oxygen dissolved in the water. Relative amplitude data for each sampled distance were smaller than the values predicted by the cylindrical spreading law. This result indicates that there are probably other factors that can influence sound propagation besides the distance in the sampled areas. The relative amplitude was also proportionally higher when there were lower levels of turbidity and higher concentration of dissolved oxygen in the water. From the data presented here, a model was generated that can be used as a tool to predict acoustic alterations of the environment against natural or anthropic changes in salinity, dissolved oxygen, and water turbidity. In addition, the methodology of this study is an important tool for conservation studies, for it can be replicated in other areas and with other species.

Stability of 5% vancomycin ophthalmic solution prepared using balanced salt solution after freezing for 90 days.

To evaluate the stability of 5% vancomycin ophthalmic solution prepared using balanced salt solution (BSS) and stored at -20°C in polypropylene containers. Six batches of vancomycin 50 mg/mL eyedrops were aseptically prepared. One bottle of each batch was analyzed immediately after preparation, and the rest were stored at -20°C and analyzed using high-performance liquid chromatography (HPLC) at 30, 60, and 90 days to test their physicochemical stability and sterility. Thereafter, bottles were removed from the freezer and stored at 5°C for 30 days, with HPLC and other analyses repeated 105 and 120 days after preparation. All samples were analyzed in triplicate. Stability was defined as the absence of particles, color variation, or changes in pH and a remaining vancomycin concentration of 90% to 110% of the initial concentration. The sterility of the ophthalmic solution was evaluated by using soybean-casein digest broth with resins; samples were incubated for 7 days and checked daily for signs of microbial growth. There was no particle formation or sign of precipitation in any of the solutions throughout the duration of the study, regardless of the storage conditions. No change in color or turbidity was observed. The pH and osmolarity remained unchanged during storage at -20°C and after thawing. The vancomycin concentration remained within 10% of the initial concentration during the 90-day period of storage at -20°C and the subsequent 30 days after thawing. Sterility was preserved in all samples. A 5% solution of vancomycin prepared using BSS was physicochemically and microbiologically stable when stored at -20°C for 90 days. After thawing, this extemporaneous formulation remained stable when refrigerated at 5°C for 30 days.

Pressure‐induced modification of sodium caseinate techno‐functional properties

AbstractSodium caseinate (NaCas) is a quite common ingredient for the manufacture of food products because of its multiple techno‐functional properties. These properties might be enhanced or impaired by high‐pressure treatment, which could be employed both, as a preservation treatment or for transformation purposes. To check whether pressure could be able to produce changes in the techno‐functional properties of NaCas, aqueous solutions of NaCas at mass fractions of 0.026, and 0.052 were prepared and treated under pressures of 200 or 600 MPa during 15 min at 15, 30, or 60°C. Changes in turbidity, viscosity, foaming, gel‐forming, and emulsifying properties of the NaCas solutions before and after pressure–temperature treatments were measured. Turbidity analyses showed that casein aggregates were significantly modified after pressure treatments at 30°C and 60°C. Several techno‐functional properties of NaCas dispersions were concomitantly affected. This study suggests that some properties as viscosity, foamability, or water holding capacity are affected by high‐pressure treatments but as these changes are below 20%, NaCas should be considered as a pressure‐proof additive.

Assessment of the physical compatibility of injectable enrofloxacin with commonly used intravenous fluids and drugs during simulated Y-port administration

To evaluate physical compatibility of small animal (SAE) and large animal (LAE) injectable formulations of enrofloxacin with select IV fluids and drugs. 162 admixtures containing SAE or LAE with saline (0.9% NaCl) solution, lactated Ringer solution (LRS), Plasma-Lyte A (PLA), 6% hydroxyethylstarch 130/0.4 (HES), metoclopramide, or ampicillin-sulbactam. In the first of 2 simultaneously conducted experiments, admixtures containing enrofloxacin (10 mg/kg) and a volume of IV fluid that would be administered over a 20-minute period when dosed at the maintenance infusion rate (40 mL/kg/d for saline solution, LRS, and PLA and 20 mL/kg/d for HES) were created. In the second experiment, enrofloxacin (10 mg/kg) was admixed with saline solution (40 mL/kg/d) and metoclopramide (2 mg/kg/d) or ampicillin-sulbactam (30 mg/kg). In both experiments, admixture components were infused into a flask over 20 minutes assuming patient weights of 5, 10, and 20 kg. Admixtures were created by use of undiluted SAE and SAE diluted 1:1 with saline solution and undiluted LAE and LAE diluted 1:1 and 1:10 with saline solution. Admixtures were assessed for physical incompatibility at 0, 15, 30, and 60 minutes after completion of mixing. Physical incompatibility was defined as gross precipitation, cloudiness, Tyndall effect, or change in turbidity. Admixtures containing undiluted SAE or LAE were physically incompatible with saline solution, PLA, LRS, and HES. Because saline solution was used to dilute SAE and LAE, all admixtures containing diluted SAE or LAE were also physically incompatible. Physical compatibility of enrofloxacin with metoclopramide or ampicillin-sulbactam could not be assessed because those admixtures also contained saline solution. Enrofloxacin was physically incompatible with all tested solutions.

Impacts of invasive quagga mussels (Dreissena rostriformis bugensis) on reservoir water quality, as revealed by progressive-change BACIPS analysis

Invasive quagga mussels (Dreissena rostriformis bugensis) are an emerging threat to the functioning and management of freshwater ecosystems. Quagga mussels were first recorded in the UK in 2014 and have subsequently established at high densities in a number of major reservoirs. Through implementing a Progressive-Change BACIPS (Before-After-Control-Impact Paired Series) analysis, we found that the following trends were observed following quagga mussel establishment: reduced diatom and cyanobacteria abundances; increased soluble reactive phosphorus and reactive silica concentrations; and reduced abundances of Aphanizomenon sp., a potentially toxic cyanobacterium. We also found reservoirs with established quagga mussel populations experienced slightly increased overall chlorophyll a concentration but no changes in turbidity or Microcystis sp. abundance, which are often considered common indicators of dreissenid invasion. Our results show that Progressive-Change BACIPS analysis is a powerful tool which can be used to interrogate industry standard long-term datasets of water quality metrics in order to identify and quantify the impacts of invasive species when the approximate timeframe of species arrival is known. We also demonstrate that quagga mussels may have had significant effects on reservoir ecosystems which, primarily through their impacts on phytoplankton communities, may have implications for reservoir management.

Drop-of-blood acoustic tweezing technique for integrative turbidimetric and elastometric measurement of blood coagulation.

Many patients develop coagulation abnormalities due to chronic and hereditary disorders, infectious disease, blood loss, extracorporeal circulation, and oral anticoagulant misuse. These abnormalities lead to bleeding or thrombotic complications, the risk of which is assessed by coagulation analysis. Current coagulation tests pose safety concerns for neonates and small children due to large sample volume requirement and may be unreliable for patients with coagulopathy. This study introduces a containerless drop-of-blood method for coagulation analysis, termed “integrated quasi-static acoustic tweezing thromboelastometry” (i-QATT™), that addresses these needs. In i-QATT™, a single drop of blood is forced to levitate and deform by the acoustic radiation force. Coagulation-induced changes in drop turbidity and firmness are measured simultaneously at different instants. The parameters describing early, intermediate, and late stages of the coagulation process are evaluated from the resulting graphical outputs. i-QATT™ rapidly (<10 min) detected hyper- and hypo-coagulable states and identified single deficiency in coagulation factors VII, VIII, IX, X, and XIII. The linear relationship (r2 > 0.9) was established between fibrinogen concentration and two i-QATT™ parameters: maximum clot firmness and maximum fibrin level. Factor XIII activity was uniquely measured by the fibrin network formation time (r2 = 0.9). Reaction time, fibrin formation rate, and time to firm clot formation were linearly correlated with heparin concentration (r2 > 0.7). tPA-induced hyperfibrinolysis was detected in the clot firmness output at 10 min. i-QATT™ provides comprehensive coagulation analysis in point-of-care or laboratory settings, well suited to the needs of neonatal and pediatric patients and adult patients with anemia or blood collection issues.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s00216-021-03278-8.

Rapid Determination of Emulsion Stability Using Turbidity Measurement Incorporating Artificial Neural Network (ANN): Experimental Validation Using Video/Optical Microscopy and Kinetic Modeling.

Determination of emulsion stability has important applications in crude oil production, separation, and transportation. The turbidimetry method offers advantage of rapid determination of stability at a relatively low cost with good accuracy. In this study, the stability of an oil-in-water (O/W) emulsion prepared by dispersing heavy oil particles in the aqueous solution containing poly(vinyl alcohol) (PVA) has been determined using turbidity measurements. The turbidimetry theory of emulsion stability has been validated using experimental data of turbidity at different wavelengths (350–800 nm) and storage times (0–300 min). The artificial neural network (ANN) has been found to give good predictive performance of the turbidity data. The characteristic change in turbidity has been supported using particle size and distribution analyses performed using optical/video microscopy. The results obtained from the turbidimetry correlation show that the emulsion destabilization rate constant (κ′, min–1) is in the range of 0.01–0.04 min–1 (at wavelengths between 350 and 800 nm, respectively). The rate constant remains unchanged (κ′ = 0.02 min–1) between the wavelength of 375 and 650 nm. In addition, the demulsification rate constant (κ′ = 0.015 min–1) obtained from kinetic modeling using the bottle test is in close agreement with this value. The overall findings ultimately revealed that the turbidimetry method could be used to determine stability of typical O/W emulsions with an acceptable level of accuracy.

Designing a Mobile Application for Pool Water Quality Monitoring Based on the Internet of Things

Changes in temperature, pH, and turbidity in concrete fish ponds greatly impact to the fish survival. Initial observations showed that among 3.067 fish seeds, 1.633 fish (53%) died and only 1.434 fish (47%) was successfully harvested. The application of water quality monitoring devices from concrete pools designed based on the Internet of Things technology has been tested. The monitoring equipment will not function optimally without an application that functions to receive monitoring data and then take action. Pool water quality monitoring equipment connected to the cloud using a GSM network connection. The recorded data is then displayed on the water quality monitoring application that designed using the Android operating system. Application design is developed using a User-Centered Design approach, where the design process was carried out by considering several variables: ease for use, clarity of information delivery, the fulfillment of needs, and appearance. Based on the results of the design evaluation, weaknesses can be determined, namely, difficulty to find the search menu for click history data, find the refresh button, read the results of searching for historical data, and read data in tables and graphs. Based on this, further improvements can be made to improve the application being made. The monitoring equipment is expected to provide information to pond managers to immediately take action if changing in pH and temperature beyond the limit so that the fish mortality rate can be minimized.

Early Exposure to Water Turbidity Affects Visual Capacities in Cuttlefish (Sepia officinalis).

In La Manche (English Channel) the level of turbidity changes, not only seasonally and daily in seawater but also along the coast. As a consequence, vision in marine species is limited when based only on contrast-intensity. It is hypothesized that polarization sensitivity (PS) may help individuals detect preys and predators in turbid environments. In the cuttlefish, Sepia officinalis, to date, all behavioral studies have been conducted on animals reared in clear water. But the cuttlefish sensory system is adapted to a range of turbid environments. Our hypothesis was that rearing cuttlefish in clear water may affect the development of their visual system, and potentially affect their visually guided behaviors. To test this, newly-hatched cuttlefish, from eggs laid by females brought in from the wild, were reared for 1 month under three different conditions: clear water (C group), low turbidity (0.1 g / l of clay, 50–80 NTU, LT group) and high turbidity (0.5 g / l of clay, 300–400 NTU, HT group). The visual capacities of cuttlefish were tested with an optomotor apparatus at 7 days and at 1 month post-hatching. Optomotor responses of juveniles were measured by using three screen patterns (black and white stripes, linearly polarized stripes set at different orientations, and a uniform gray screen). Optomotor responses of juveniles suggest that exposure to turbid water improves the development of their PS when tested in clear water (especially in LT group) but not when tested in turbid water. We suggest that the use of slightly turbid water in rearing systems may improve the development of vision in young cuttlefish with no detrimental effect to their survival rate. Future research will consider water turbidity as a possible factor for the improvement of cuttlefish well-being in artificial rearing systems.

Effect of sodium bicarbonate and sodium chloride on aggregation and conformation of pork myofibrillar protein

To investigate the effect of sodium bicarbonate instead of sodium chloride, the changes in pH, turbidity, aggregation, and conformation of myofibrillar protein solution with various amounts of sodium chloride and sodium bicarbonate were studied. When the sodium bicarbonate was increased from 0% to 0.4%, accompanied by the sodium chloride being decreased from 2.0% to 0.8%, the pH increased about 1.20 unites; the absolute values of the Zeta potential, active sulfhydryl, and surface hydrophobicity increased significantly (p < 0.05); and the turbidity, particle size, and Ca2+-ATPase activity decreased significantly (p < 0.05). In addition, the Mg2+-ATPase activity was not significantly different (p > 0.05) when increasing sodium bicarbonate, implying that sodium bicarbonate did not affect the actin. Overall, the results indicated that an increase in sodium bicarbonate could improve solubility, expose more hydrophobic residues and sulfhydryl groups, and induce Ca2+-ATPase inactivation and protein unfolding, leading the myofibrillar protein to denaturation easily.

Seasonal shifts in fatty acids and sterols in sponges, corals, and bivalves, in a southern Gulf of Mexico coral reef under river influence

Tropical coral reefs influenced by rivers are exposed to changes in turbidity, sedimentation, and wastewater discharges that might affect the growth and survival of the corals and their associated community. However, riverine nutrients and fine particulate organic matter can constitute food resources for suspension-feeding animals within reef ecosystems. Organic biomarkers from sessile suspension feeders represent their surrounding environment more reliably and can assist in monitoring the health of ecosystems. Here we evaluated the seasonal (dry and rainy) effect of natural and anthropogenic sources of organic matter on fatty acid and sterol biomarkers of sessile suspension and filter-feeding animals such as the sponge Aplysina sp., the great star coral Montastraea cavernosa, and the amber pen shell Pinna carnea in a coral reef under river influence. Sponges did not show significant differences in their fatty acid profiles between dry and rainy seasons, except for increases in fatty acids associated with the consumption of bacteria in the rainy season. However, they shifted from higher proportions of episterol, brassicasterol, and poriferasterol, which are abundant in phytoplankton, red, and brown algae, respectively, in the dry season, to higher proportions of β-sitosterol abundant in higher plants such as seagrass and mangrove, in the rainy season. In contrast, the fatty acid profile of the whole coral M. cavernosa had an 80% multivariate similarity with that of its symbiont Symbiodiniaceae, a fraction which was separated only in the rainy season. The whole coral M. cavernosa also had a higher proportion of gorgosterol, in the dry season. However, during the rainy season, the whole coral shifted from higher proportions of gorgosterol and campesterol to higher proportions of cholesterol, brassicasterol from red algae and episterol, a distinctive sterol of phytoplankton. Bivalves reflected a significant shift in their fatty acids following seasonal phytoplankton changes, but did not show seasonal changes in their sterols. Sterol profiles in sponges, corals, and bivalves were significantly different from the sterol profile in sewage. However, in the rainy season, their similarity increased compared to the dry season. Still, coprostanol, a human feces biomarker indicative of sewage input, was detected in the suspended particulate matter at the surface, but not in any of the suspension-feeding animals studied. This suggests that marine currents dispersed urban sewage before reaching benthic organisms. Alternatively, coprostanol could have been metabolized before reaching the filter feeders or by the filter feeders themselves.

Experimental Studies on Physicochemical Parameters of Water Samples before and after Treatment with a Cold Atmospheric Plasma Jet and its Optical Characterization

Cold plasma-liquid interaction becomes a growing interdisciplinary area of research involving plasma physics, fluid science, and chemistry. Plasma-liquid interaction has gained more interest over the last many years due to its potential applications in different fields. Cold atmospheric plasma jet is an emerging technology for surface drinking water treatment to improve quality and surface modification that is chemical-free and eco-friendly. Cold plasma treatment of water samples results in changes in turbidity, pH, and conductivity and in the formation of reactive oxygen and nitrogen species (RONS). As a result, plasma-activated water has a different chemical composition than water and can serve as an alternative technique for microbial disinfection. CAPJ has been generated by a high voltage 5 kV and a high frequency 19.56 kHz power supply. The discharge has been characterized by an optical method. To characterize the cold atmospheric pressure argon plasma jet, discharge plume temperature, and electron rotational and vibrational temperature have been determined. Cold atmospheric argon plasma jet produced at atmospheric condition contains high energetic electrons, ions, UV radiation, reactive oxygen, and nitrogen species named as cold plasma which has a wide range of applications in the biomedical industry, as well as in water treatment. Nowadays, researches have been carried out on ozonation through plasma jet interaction with surface drinking water. In this paper, we compare the change in physical and chemical parameters of surface water used for drinking purposes. The significant change in the physical parameters such as pH, turbidity, and electrical conductivity was studied. In addition, the significant changes in the concentration and absorbance of nitrate, ferrous, and chromium ions with respect to treatment time were studied. Our results showed that plasma jet interaction with surface drinking water samples can be useful for the improvement of water quality and an indicator for which reactive species play an important role in plasma sterilization.

Pattern of Turbidity Change in the Middle Reaches of the Yarlung Zangbo River, Southern Tibetan Plateau, from 2007 to 2017

Turbidity is an important indicator of riverine conditions, especially in a fragile environment such as the Tibetan Plateau. Remote sensing, with the advantages of large-scale observations, has been widely applied to monitor turbidity change in lakes and rivers; however, few studies have focused on turbidity change of rivers on the Tibetan Plateau. We investigated the pattern of turbidity change in the middle reaches of the Yarlung Zangbo River, southern Tibetan Plateau, based on multispectral satellite imagery and in situ measurements. We developed empirical models from in situ measured water leaving reflectance and turbidity, and applied the best performed s-curve models on satellite imagery from Sentinel-2, Landsat 8, and Landsat 5 to derive turbidity change in 2007–2017. Our results revealed an overall decreasing spatial trend from the upper to lower streams. Seasonal variations were observed with high turbidity from July to September and low turbidity from October to May. Annual turbidity showed a temporally slightly declining trend from 2007 to 2017. The pattern of turbidity change is affected by the confluence of tributaries and the changes in precipitation and vegetation along the river. These findings provide important insights into the responses of riverine turbidity to climate and environmental changes on the Tibetan Plateau.