Unfiltered Samples Research Articles

Diarrhea prevalence in a randomized, controlled prospective trial of point-of-use water filters in homes and schools in the Dominican Republic

BackgroundLack of sustainable access to clean drinking water continues to be an issue of paramount global importance, leading to millions of preventable deaths annually. Best practices for providing sustainable access to clean drinking water, however, remain unclear. Widespread installation of low-cost, in-home, point of use water filtration systems is a promising strategy.MethodsWe conducted a prospective, randomized, controlled trial whereby 16 villages were selected and randomly assigned to one of four treatment arms based on the installation location of Sawyer® PointONE™ filters (filter in both home and school; filter in home only; filter in school only; control group). Water samples and self-reported information on diarrhea were collected at multiple times throughout the study.ResultsSelf-reported household prevalence of diarrhea decreased from 25.6 to 9.76% from installation to follow-up (at least 7 days, and up to 200 days post-filter installation). These declines were also observed in diarrhea with economic or educational consequences (diarrhea which led to medical treatment and/or missing school or work) with baseline prevalence of 9.64% declining to 1.57%. Decreases in diarrhea prevalence were observed across age groups. There was no evidence of a loss of efficacy of filters up to 200 days post-filter installation. Installation of filters in schools was not associated with decreases in diarrhea prevalence in school-aged children or family members. Unfiltered water samples both at schools and homes contained potential waterborne bacterial pathogens, dissolved heavy metals and metals associated with particulates. All dissolved metals were detected at levels below World Health Organization action guidelines.ConclusionsThis controlled trial provides strong evidence of the effectiveness of point-of-use, hollow fiber membrane filters at reducing diarrhea from bacterial sources up to 200 days post-installation when installed in homes. No statistically significant reduction in diarrhea was found when filters were installed in schools. Further research is needed in order to explore filter efficacy and utilization after 200 days post-installation.Trial registrationClinicalTrials.gov, NCT03972618. Registered 3 June 2019—retrospectively registered.

Hydro-Geochemical Mechanisms of Brackish Shallow Groundwater Development- Coastal Greater Accra Region, Ghana

This study investigated the processes influencing the chemistry of surface and shallow groundwater in tropical coastal environments - south east of greater Accra region of Ghana using GIS models and combination of geological and hydro geochemical techniques for sustainable management of freshwater resources and abundantly available brackish water resources. A total of 37 shallow groundwater and 11 surface water samples were collected and analysed for their physico-chemical constituents.
 The samples were adjusted to room temperature after which the hydrogen ion concentration (pH), Total Dissolve Solids (TDS) and Electrical Conductivity were measured with a precision of 0.01 for both parameters using a La Motte, USA in unfiltered samples. The analysis of major and minor ions were performed using ion chromatography (DIONEX-ICS-1000 Series). The geographical locations of the samples were recorded with the aid of a handheld Global Position System (GPS).
 The analysed shallow groundwater indicates minimum salinity values of 70.2 psu/ppm, maximum salinity of 4398.3 psu/ppm with an average of 1571.4 psu/ppm whilst surface water has minimum salinity of 33.8 psu/ppm, maximum of 43574 psu/ppm with an average of 4972.6 psu/ppm therefore highly saline. The total minimum dissolved solid (TDS) concentrations is 87.5 ppm, maximum of 5160 ppm with an average of 1911.96 ppm for shallow groundwater and for surface water minimum of 38.4 ppm, maximum of 27100 ppm and average 3938.12 ppm.

Utilization of low-molecular-weight organic compounds by the filterable fraction of a lotic microbiome.

ABSTRACTFilterable microorganisms participate in dissolved organic carbon (DOC) cycling in freshwater systems, however their exact functional role remains unknown. We determined the taxonomic identity and community dynamics of prokaryotic microbiomes in the 0.22 µm-filtered fraction and unfiltered freshwater from the Conwy River (North Wales, UK) in microcosms and, using targeted metabolomics and 14C-labelling, examined their role in the utilization of amino acids, organic acids and sugars spiked at environmentally-relevant (nanomolar) concentrations. To identify changes in community structure, we used 16S rRNA amplicon and shotgun sequencing. Unlike the unfiltered water samples where the consumption of DOC was rapid, the filtered fraction showed a 3-day lag phase before the consumption started. Analysis of functional categories of clusters of orthologous groups of proteins (COGs) showed that COGs associated with energy production increased in number in both fractions with substrate addition. The filtered fraction utilized low-molecular-weight (LMW) DOC at much slower rates than the whole community. Addition of nanomolar concentrations of LMW DOC did not measurably influence the composition of the microbial community nor the rate of consumption across all substrate types in either fraction. We conclude that due to their low activity, filterable microorganisms play a minor role in LMW DOC processing within a short residence time of lotic freshwater systems.

Analysis of physicochemical water quality parameters for streams under agricultural, urban and forest land-use types: in the case of gilgel Gibe catchment, Southwest Ethiopia

Streams draining to Gilgel Gibe catchment cross agricultural and urban land uses receiving a different pollutant that challenges water quality. A total of 21 sampling sites were selected from seven streams of agricultural (n = 3), urban (n = 3) and forest (n = 1) land-use types. Composite samples were collected from upstream, middle and downstream of all land-use types. Twenty-three physicochemical parameters were measured from each sampling site. Temperature, DO, pH, EC, turbidity, width, depth, current velocity and discharge were measured onsite. Two milliliters of unfiltered water samples was collected from every site for laboratory analysis. Mean of NO3-N was highest in agricultural streams than forested and urban streams. In contrast, mean of SRP, NH4-N and COD and BOD5 concentration was greater in urban streams followed by agricultural streams, whereas forest streams are lowest. Concentrations of nutrients, EC and turbidity were recorded in increasing manner across land-use gradient from forested to agricultural and urban streams. The analysis of one-way ANOVA showed that all physicochemical parameters were significantly different among all sites with different land-use types (P < 0.05), except for water temperature (one-way ANOVA: F = 0.987, P = 0.494). NMDS and cluster analyses have discriminated the sites into three groups of land-use types. Then, we conclude that water quality of urban stream is highly impaired than agricultural streams, whereas forested streams have better water quality. Therefore, stream restoration projects, reforestation, conservation of riparian vegetation appropriate waste disposal need to be encouraged in the study area for sustainable management of freshwater resources.

Monte Carlo simulation in the evaluation of failure probability in waste stabilization ponds

This study used Monte Carlo simulation as a methodology to analyze the percentage of failure in Waste Stabilization Pond (WSP) systems in meeting the discharge standards in water bodies. We used monitoring data from 10 full-scale WSP in operation in Rio Grande do Norte, northeast Brazil. The Kolmogorov - Smirnov (KS) adherence test followed by the Akaike Information Criterion (AIC) allowed the selection of the most representative Probability Distribution Function (PDF) of each sample set. Simulations with 3000 iterations allowed us to construct synthetically the selected distributions and, thus, to calculate the percentages of non-compliance with the standard of interest. Among the simulated parameters, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of unfiltered samples showed the highest percentage of failure over the pond series. The failure percentages of thermotolerant coliforms and pH parameters were correlated with physical and operational variables such as hydraulic retention time, depth and organic loading. The information presented provides an overview of the occurrence of failure and the inherent risks of stabilization pond treatment technology.

Evaluation of Toxicity and Bioremediation of Contaminated Drinking Water Sources in Delta State, Nigeria

Drinking water samples were collected from boreholes in six locations in Ughelli and environs in Delta State of Nigeria and were treated by filtration through a substrate colonized with mycelium of Pleurotus tuber-regium. Water samples were analysed for pH, heavy metal concentration and microbiological content before and after filtration. Results obtained showed that the pH of unfiltered water samples were acidic (5.0 – 5.8) and below the WHO and SON permissible limits for drinking water. The same trend was followed by the concentrations of heavy metals such as lead, iron, zinc and chromium. Water samples from all six locations also had high total bacterial and coliform counts. Filtration through the mycelium colonized substrate showed adjustment of pH to a range within the WHO permissible limits. Reduction in heavy metal concentration ranged from 45.0 – 100%. Total bacterial count of mycofiltered water samples was impressively reduced by 77.3 – 100% and coliform count was not detected. The results obtained in this study makes mycofiltration a potential cost-effective and efficient technique for the treatment of potable water for domestic use.

Assessment of dead-end ultrafiltration for the detection and quantification of microbial indicators and pathogens in the drinking water treatment processes.

A safe water supply requires distinct treatments and monitoring to guarantee the absence of pathogens and substances potentially hazardous for human health. In this study we assessed the efficiency of the dead-end ultrafiltration (DEUF) method to concentrate faecal indicator organisms (FIO) and pathogens in water samples with different physicochemical characteristics. Water samples were collected at the treatment stages of two drinking water treatment plants to analyse the concentration of a variety of 7 FIO and 4 reference microbes which have some species that are pathogenic to humans: Campylobacter spp., enteroviruses, Cryptosporidium spp. and Giardia spp. The samples were analysed before and after concentration by DEUF, detecting FIO concentrations about 1 log10 higher in non-concentrated samples from both catchments. Percent recoveries were highly variable with a mean of 43.8±17.5%, depending on the FIO and inherent sample characteristics. However, DEUF enabled FIO concentration in high volumes of water (100-500l), allowing a reduction in the detection limit compared to the non-concentrated samples due to the high volume processing capabilities of the method. As a consequence, the detection of FIO removal from water in the drinking water treatment process was 1.0-1.5 logarithms greater in DEUF-treated water compared to unfiltered samples. The DEUF method improved the detection of target indicators and allowed for the detection of pathogens in low concentrations in water after the treatment stages, confirming the suitability of DEUF to concentrate high volumes of different types of water. This method could be useful for microbial analysis in water treatment monitoring and risk assessment, allowing the identification of critical points during the water treatment process and potential hazards in water destined for several uses.

The Nutrient App: Developing a smartphone application for on-site instantaneous community-based [formula omitted] and [formula omitted] monitoring

Freshwater ecosystems, particularly those in agricultural areas, remain at risk of eutrophication due to anthropogenic inputs of nutrients. While community-based monitoring has helped improve awareness and spur action to mitigate nutrient loads, monitoring is challenging due to the reliance on expensive laboratory technology, poor data management, time lags between measurement and availability of results, and risk of sample degradation during transport or storage. In this study, an easy-to-use smartphone-based application (The Nutrient App) was developed to estimate NO3 and PO4 concentrations through the image-processing of on-site qualitative colorimetric-based results obtained via cheap commercially-available instantaneous test kits. The app was tested in rivers, wetlands, and lakes across Canada and relative errors between 30% (filtered samples) and 70% (unfiltered samples) were obtained for both NO3 and PO4. The app can be used to identify sources and hotspots of contamination, which can empower communities to take immediate remedial action to reduce nutrient pollution.

Quantitative determination of aloin, antioxidant activity, and toxicity of Aloe vera leaf gel products from Greece.

Aloe vera is a popular medicinal plant used widely by the cosmetic, pharmaceutical, and food industries. The A. vera leaf gel, which is used mostly for its positive effects on human health, contains over 75 different bioactive compounds, including aloin. Aloin is a toxic compound, and its content in A. vera leaf gel products depends on the different cultivation conditions and especially on leaf processing. In this study, A. vera leaf gel products, varied in terms of leaf processing, were analyzed using liquid chromatography for their aloin content, their antioxidant activity by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS·+ ) and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH· ) antioxidant activity assays and their toxicity against Aliivibrio fisheri and SH-SY5Y cells. In the samples processed with industrial methods and in those filtered in the lab, the content of aloin was found below the limit (0.1 mg L-1 ) of the EU legislation however, the unprocessed and unfiltered samples were found to contain more than 10 mg L-1 . Antioxidant activity was estimated to vary from 1.64 to 9.21 μmol Trolox mL-1 for DPPH· and from 0.73 to 5.14 μmol Trolox mL-1 for ABTS·+ . Toxicity values on A. fisheri, expressed as the concentration at 50% loss of initial luminescence, ranged from 0.03 to 0.09 mg mL-1 . The cytotoxic study indicated that aloin A at low concentrations (1 and 10 μg mL-1 ) protects SH-SY5Y cells from toxicity induced by hydrogen peroxide. Consequently, the filtration process of A. vera leaf gels, either laboratory or industrial, resulted in aloin A content below the EU legislation detection limits. © 2020 Society of Chemical Industry.

Filtration Scheduling: Quality Changes in Freshly Produced Virgin Olive Oil.

Filtration is the most widespread stabilisation operation for extra virgin olive oil, preventing microbial and enzymatic changes. However, during the harvest, the workload of olive mills is at its peak. This results in two approaches to filtration: (i) delays it until after harvesting, increasing the risk of degraded oil quality, and (ii) filters it immediately, increasing the workload. The aim of our experiment is to assess the risk of delaying filtration and establish a safe delay time. Changes in the sensory profile and volatile compound contents were evaluated during 30 days in filtered and unfiltered samples. Significant differences were related to filtration: both turbidity grade and microbial contamination; no differences for the legal parameters were found. Two, contrasting, results were obtained with respect to oil quality: (i) the fusty defect, appearing in less than five days in unfiltered oils, leading to the downgrade of the oil’s commercial category, and (ii) filtration removing some lipoxygenase volatile compounds. Consequently, a fruity attribute was more pronounced in unfiltered samples until day five of storage; it seems that, from this point, the fusty defect masked a fruity attribute. Hence, filtering within a few days strongly reduced the risk of degraded oil quality compared to a delayed filtration.

Temporal correspondence of selenium and mercury, among brine shrimp and water in Great Salt Lake, Utah, USA

The specific source of high burdens of selenium (Se) and mercury (Hg) in several bird species at Great Salt Lake (GSL) remain unknown. Frequent co-located water and brine shrimp samples were collected during 2016 through 2017 to identify potential correlations of element concentrations among brines and brine shrimp, a keystone species in the GSL. Like many aquatic systems, GSL is characterized by elevated methylmercury (MeHg) in deep waters. However, in contrast to thermally-stratified aquatic systems, biota in the salinity-stratified GSL do not reside in its deep waters, obscuring the presumed relationship between elevated MeHg in biota and in the deep brine. Brine shrimp and water column (shallow and deep, filtered and unfiltered) samples were collected from six sites spanning the South Arm of GSL approximately every other month. Mercury concentrations in brine shrimp (on average 89% of which is MeHg) were correlated only with total mercury in surface filtered water, and displayed little spatial variability, but consistent seasonal trends across the two sampled years. In contrast to Hg, temporal correspondence was observed between Se concentrations in brine shrimp and those in all water samples regardless of filtering and depth, with maxima and minima at higher-than-seasonal frequency.The data suggest a spatially diffuse source of bioavailable mercury to the shallow brine that responds to seasonal influences, for which the underlying deep brine, surficial sediments, and overlying atmosphere were evaluated in terms of potential temporal correspondence to shallow brine and brine shrimp Hg concentrations, as well as potential to mix across the extent of the shallow brine. Bioaccumulation factors were at the low end of those reported for marine systems, and decreased at higher trace element concentrations in water.

Temperature, turbidity, and the inner filter effect correction methodology for analyzing fluorescent dissolved organic matter in urban sewage.

Dissolved organic matter (DOM) will be increasingly monitored by means of in situ fluorescence spectroscopy devices in order to supervise wastewater treatment plant efficiency, due to their ease of implementation and high-frequency measurement capacity. However, fluorescence spectroscopy measurements are reported to be sensitive to the sample matrix effects of temperature, the inner filter effect (IFE), and turbidity. Matrix effect estimation tests and signal correction have been developed for DOM (tyrosine-like, tryptophan-like, and humic substances-like fluorescent compounds) fluorescence measurements in unfiltered urban sewage samples. All such tests are conducted in temperature, absorbance, and turbidity ranges representative of urban sewage. For all fluorophores studied, an average of 1% fluorescence intensity decrease per degree (°C) of temperature increase could be observed. Protein-like fluorescent compound signals were found to be significantly affected by turbidity (0 to 210 NTU) and IFE (absorbance 254nm > 0.200). Only temperature needs to be corrected for humic substances-like fluorescent compounds since other effects were not observed over the studied ranges of absorbance and turbidity. The fluorescence intensity correction method was applied first to each matrix effect separately and then combined by using a sequential mathematical correction methodology. An efficient methodology for determining the matrix effect correction equations for DOM fluorescence analysis into unfiltered urban sewage samples has been highlighted and could be used for in situ fluorescence measurement devices.

Characterization of Iron and Organic Carbon Colloids in Boreal Rivers and Their Fate at High Salinity.

Riverine colloids are important carriers of macronutrients, trace metals, and pollutants into marine waters. The aim of the current study was to extend the understanding of iron (Fe) and organic carbon (OC) colloids in boreal rivers and their fate at higher salinities. X‐ray absorbance spectroscopy (XAS) and dynamic light scattering (DLS) were combined to explore Fe speciation and colloidal characteristics such as size and surface charge and how these are affected at increasing salinity. XAS confirmed the presence of two Fe phases in the river waters—Fe‐organic matter (OM) complexes and Fe(oxy)hydroxides. From DLS measurements on filtered and unfiltered samples, three particle size distributions were identified. The smallest particles (10–40 nm) were positively charged and suggested to consist of essentially bare Fe(oxy)hydroxide nanoparticles. The largest particles (300–900 nm) were dominated by Fe(oxy)hydroxides associated with chromophoric molecular matter. An intermediate size distribution (100–200 nm) with a negative surface charge was presumably dominated by OM and containing Fe‐OM complexes. Increasing the salinity resulted in a removal of the smallest distribution. Unexpectedly, both the intermediate and largest size distributions were still detected at high salinity. The collective results suggest that Fe(oxy)hydroxides and Fe‐OM complexes are both found across the wide size range studied and that colloidal size does not necessarily reflect either Fe speciation or stability toward salinity‐induced aggregation. The findings further demonstrate that also particles beyond the typically studied <0.45‐μm size range should be considered to fully understand the riverine transport and fate of macronutrients, trace metals, and pollutants.

Microrobots in Brewery: Dual Magnetic/Light-Powered Hybrid Microrobots for Preventing Microbial Contamination in Beer.

Yeasts play a key role in the production of alcoholic beverages by fermentation processes. However, because of their continuous growth, they commonly cause spoilage of the final product. Herein, we introduce dual magnetic/light-responsive self-propelled microrobots that can actively move in a beer sample and capture yeast cells. The presence of magnetic nanoparticles on the surface of the microrobots enables their magnetic actuation under fuel-free conditions. In addition, their photoactivity under visible-light irradiation leads to an overall enhancement of their swimming and yeast removal capabilities. It was found that after the application of the microrobots into a real unfiltered beer sample, these micromachines were able to remove almost 100 % of residual yeasts. In addition, these microrobots could also be added at the initial step of the fermentation process without altering the final beer properties, such as alcohol level, color, and pH. This work demonstrates the potential of using externally actuated microrobots as an innovative and low-cost solution for avoiding yeast spoilage in complex liquid environments, such as alcoholic beverages. Therefore, these autonomous self-propelled microrobots open new avenues for future applications in the food industry.

Factors controlling the degradation of hydrogen peroxide in river water, and the role of riverbed sand.

Diurnal changes of H2O2 in river water during mid-summer were investigated. H2O2 in river water increased with the increase in intensity of solar radiation in the morning, and reached a maximum at 14:00, although solar radiation reached a maximum around 12:00. In the afternoon, a gradual decrease in H2O2 was observed, and H2O2 reached a minimum just before sunrise. Degradation rate constants determined using unfiltered river water samples were 0.081-0.161h-1, corresponding to a half-life of 4.3-8.5h. We simulated diurnal changes in H2O2 using a simple formation, accumulation, and degradation model for static water using formation and degradation rate constants. The results of the modeling suggested that in situ degradation rate constants in rivers could be faster than those determined for unfiltered river water samples. Experiments using river sand indicated that riverbed sand could play an important role in H2O2 decay in rivers. We discussed the decomposition process of H2O2 in rivers.

Rare Earth Elements in Andaman Island Surface Seawater: Geochemical Tracers for the Monsoon?

The Asian summer monsoon affects the lives of billions of people. With the aim of identifying geochemical tracers for the monsoon related freshwater input from the major rivers draining into the Bay of Bengal and Andaman Sea we have taken surface seawater samples from various locations up and down the Andaman Islands during 2011. Importantly, in some locations samples have been taken in March, July and November, covering most of a seasonal cycle and different monsoon phases. Samples were collected from the side of small wooden boats or while swimming and were filtered within a few hours at 0.45 or 0.22 microns using the vacuum produced by a water jet or a hand operated peristaltic pump. Filtered and unfiltered samples were acidified to < pH 2 and analysed for Y and the REEs with an automated online preconcentration ICP-MS technique [1]. The local input of REEs from streams and sediment rich areas such as mangrove environments is clearly identified by middle REE enrichments in the shale normalised patterns of some samples. These middle REE bulges accompany large increases in dissolved REE concentrations at some locations, especially for the July samples obtained during the peak monsoon season with frequent storms. Y/Ho fractionation aslo occurs during the local input of dissolved REEs with affected samples having lower Y/Ho ratios. Conversly, some samples, in particular those taken after heavy rainfall in March, show strong REE scavenging accompanied by the prefferential removal of dissolved light REEs and higher Y/Ho ratios. The time series at a location away from local input sources shows remarkably similar REE patterns and concentraions in March and July. Then in October-November, following the peak in monsoon river discharge, the dissolved REE concentration increases by almost a factor of 2. The notable exception to this seasonal pattern is the Ce anomally which is around 0.3 in March and November but 0.6 in July, implying less oxidative removal of Ce(IV) during the peak summer monsoon rains. With the exception of elevated dissolved Ce concentrations, the North Pacific Deep Water normalised REE patterns are similar to those reported for offshore samples from the Bay of Bengal and Andaman Sea [2]. These seawater normalised patterns are distinctive having a middle REE enriched arc with similar light and heavy REE values suggesting the input from large rivers in the region is traceable using seawater REE chemistry. [1] Hathorne et al. (2012), Online preconcentration ICP-MS analysis of rare earth elements in seawater, Geochem. Geophys. Geosyst., 13, Q01020, doi:10.1029/2011GC003907. [2] Amakawa et al. (2000), Geochim. Cosmochim. Acta 64, 1715-1727.

Identification of Yeasts with Mass Spectrometry during Wine Production

The aim of the present study was to identify yeasts in grape, new wine “federweisser” and unfiltered wine samples. A total amount of 30 grapes, 30 new wine samples and 30 wine samples (15 white and 15 red) were collected from August until September, 2018, from a local Slovak winemaker, including Green Veltliner (3), Mūller Thurgau (3), Palava (3), Rhein Riesling (3), Sauvignon Blanc (3), Alibernet (3), André (3), Blue Frankish (3), Cabernet Sauvignon (3), and Dornfelder (3) grapes; federweisser and unfiltered wine samples were also used in our study. Wort agar (WA), yeast extract peptone dextrose agar (YPDA), malt extract agar (MEA) and Sabouraud dextrose agar (SDA) were used for microbiological testing of yeasts. MALDI-TOF Mass Spectrometry (Microflex LT/SH) (Bruker Daltonics, Germany) was used for the identification of yeasts. A total of 1668 isolates were identified with mass spectrometry. The most isolated species from the grapes was Hanseniaspora uvarum, and from federweisser and the wine—Saccharomyces cerevisiae.

Storage and initial processing of water samples for organic carbon analysis in runoff

Runoff monitoring experiments are often conducted in remote sites. Sample collection and dispatch for analysis are often delayed due to sites’ remoteness and limited local laboratory facilities. The standard method of dissolved organic carbon (DOC) and total organic carbon (TOC) analysis in water samples requires storage of the samples at 4 °C after collection and analysis with a minimum of delay. However, there is no freezing storage time limit specified to avoid degradation. To overcome the limitations of this approach, we investigated the method of storage, that is refrigeration (4 °C) versus freezing (-18 °C), and the effect of storage time on DOC and TOC fractions in runoff water. Storage of samples at 4 °C for more than a week resulted in a decline of TOC and DOC concentrations in runoff water.•Freezing unfiltered water samples immediately after collection minimized TOC losses during storage, however, it may lead to variable DOC results.•Filtering a subsample of runoff or irrigation water immediately after collection using a 0.45 µm filter and freezing both the filtered and unfiltered samples until analysis of DOC and TOC, respectively, can minimize losses during storage.

Effects of filtration process on the minor constituents and oxidative stability of virgin olive oil during 24 months storage time

In this study, effects of filtration and storage time on the chemical composition and sensory profile of the virgin olive oil extracted from a local olive cultivar known as Saurani grown in Hatay province of Turkey were determined. Before storing both filtered (F) and unfiltered (UF) samples were categorized as virgin olive oil (VOO) according to the International Olive Council (IOC) standards. The main characteristics of Saurani olive oils were: a mid-oleic acid (69.3%), low linoleic acid (7.7%) and high linolenic (0.85%) acid contents with high total phenolic content (522.34 ppm as gallic acid). Monitoring of stored samples for 24 months revealed significant differences between F and UF olive oils in terms of free acidity and peroxide values, and filtered oils appeared to be better protected against hydrolysis and oxidative deterioration. Free fatty acidity of F and UF olive oil samples which were initially 0.4% and reached to 0.9% after 23 and 11 months’ storage respectively. Peroxide values of the F and UF olive oil samples were exceeded the limit of IOC standard (20 mEq oxygen/kg oil) after ten and three months, respectively. Total phenol contents were higher in UF samples and their contents decreased with storing. Luteolin was the most abundant phenolic compound and tyrosol contents of both F and UF samples reached maximum values in the ninth month of storage. It seemed filtration had no detectable effect on tocopherols contents and about 50% of α-tocopherol destroyed after 24 months’ storage.

Environmental monitoring of the marine part o f the Caspian Sea within the territory of Aktau

The article presents the results of the stages of research of the marine part of the Caspian sea withinthe territory of the city of Aktau. Currently, despite numerous studies of the Caspian sea, there are stillareas of the sea, the degree of study and coverage of direct observations, which is extremely small. In thisregard, studies of the Caspian sea are relevant and timely. These studies can contribute to environmentalquality management activities. The Caspian ecosystem is assessed as pre-crisis and may deteriorate as aresult of large-scale intrusion into the natural environment due to the planned development of shallowwaters in the North-Eastern part for oil production. Hydrophysical measurements were carried out fromthe side of the catamaran, which was in the drift, only the station on section 3 “Aktau” was anchored. 4sections were made, each section consisted of four hydrological stations (HS), sampling was carried outon the water surface from four points-stations. A portable weather station was installed at an altitude of 5m above sea level at the Marina of the yacht club North of the port of Aktau. At each HS, hydrophysicaland hydrochemical measurements were performed, as well as water sampling with subsequent labo ratory analyses. Determination of hydrochemical parameters was determined using standard methodsadopted in expedition practice. Definitions were made in unfiltered samples. The pH value was determined by the potentiometric method. The total alkalinity was determined by direct titration with a colorending. The content of dissolved inorganic phosphorus (phosphates) was determined colorimetrically.These studies can contribute to environmental quality management activities.Key words: Caspian Sea, water area, salinity, phenols, hydrocarbons, monitoring.