Suchergebnisse

The worldwide population rise corroborated with the raise of the health-care standards have generated an escalation of the antibiotic production and uncontrolled usage. The subsequent effects of this escalation have led to an increase of the antibiotic resistance rates, Romania is in the top of the EU countries regarding the antibiotic resistance rates, and to a continuous presence in the environment, including the aquatic environment. Unfortunately, the present design of the classical WWTPs is not optimized for the efficient removal of antibiotics since these compounds may have highly soluble and polar molecular structures. Instead, antibiotics removal using microorganisms could be an ecofriendly solution to this environmental issue, as long as their antibiotic degradation structures are not more toxic than the antibiotic itself. In the present review, we focus on the environmental presence and biodegradation of the most commonly used antibiotics as well as on their biodegradation, based on bacterial model, monitored by mass-spectrometric methods.

A direct ion chromatographic method for the determination of chlorite, chlorate, and bromate in the presence of fluoride, chloride, nitrate, nitrite, and bromide in treated drinking waters was described. Separation of target analytes was achieved using an AS19-HC analytical column (250 mm x 4 mm), AG 19- HC guard column (50 mm x 4 mm), and KOH 25 mmol/L as mobile phase. Inorganic analytes were eluted using a flow rate of 1 mL/min. The column temperature was set up and maintained at 300C. The analyte ions
were quantified using a suppressed conductivity detector.

This study investigated the spatial and temporal distribution of nitrate and nitrite concentration in groundwater from different geographical regions, in Romania. A special emphasis was put on a descriptive statistical analysis of data, namely on the determination of seasonal indices during dry and wet seasons. Nitrate and nitrite concentrations were monitored in 24 groundwater sources situated in different areas,
between January 2016 and February 2020. The obtained data showed that the values of nitrate concentrations were situated between 8.03 mg/L in the North-Eastern part of Romania, 6.37 mg/L in the South-Eastern part of the country, and 3.55 mg/L in the
Western part towards the center of the country. Nitrite concentration values were situated under the national maximum admitted limit, 0.5 mg/L, in all the investigated areas. The obtained data shows small changes in water quality during the monitoring period, which leads to the conclusion that, in this long interval of time, there were no significant groundwater contaminations with nitrate and nitrite. For adequate control of water pollution and rigorous management of groundwater sources, seasonal indices were calculated.

Chlorine is widely used in Romania and all over the world as a disinfectant of drinking water. During the chlorination process, the natural organic matter and inorganic ions react with chlorine forming disinfection by-products (DBPs). The predominant organic disinfection by-products are trihalomethanes (THMs) while the main inorganic disinfection by-products are chlorate and chlorite ions. THMs were detected in all investigated drinking water samples from Bucharest distribution system with values from 27.8 µg/L up to 75.1 µg/L, which are below the maximum concentration value admitted by Romanian drinking water legislation of 100 µg/L. Chloroform constitutes the major component in total THMs concentration found in all tested drinking water. Chlorate and chlorite anions were not detected in any of the investigated drinking water samples. THMs concentration was correlated with total organic carbon (TOC), residual chlorine and chloride.

Water resources crisis can lead to a new concept of wastewater treatment. Wastewater cannot be considered waste but can be a renewable or non-renewable energy source. Nutrients from wastewater could be recycled and not disposed of. A circular economy can be created that can be based on the ability of algae to absorb and store nutrients: carbon (C), nitrogen (N) and phosphorus (P). This study investigates the stoichiometry between carbon, nitrogen and phosphorus in wastewater from three geographical regions of Romania. The concentrations of inorganic nitrogen, total nitrogen, total phosphorus, and total organic carbon were compared and evaluated. Three wastewater sampling points located in different areas were monitored, in the period 2013-2017 for the sampling point located in the central-northern part of the Romanian Plain and in the period 2015-2017 for the other two studied areas. The obtained results showed very high values of total nitrogen concentrations with values between 28.2 mg/L and 107.2 mg/L for the southeastern part of Romania. The values of the stoichiometric ratio's C/N, C/P, N/P have varied over time with maximums in the autumn and winter seasons which indicates the existence of significant contamination of wastewater. It may be possible in the future to improve the performance of wastewater treatment by adjusting C, N, and P parameters.

Emerging contaminants are a heterogeneous group of chemicals that include daily personal care products and pharmaceuticals (PPCPs), flame retardants, endocrine-disrupting chemicals (EDCs) and nanoparticles (NPs) present in environment which are unregulated. In this review, we present the methods of analysis conducted by INCD-ECOIND regarding some classes of emerging contaminants (neonicotinoid pesticides, beta-blocker drugs) that are not regulated by the legislation, in different types of environmental samples (wastewater, surface water). The present review presents the selective solid-phase extraction (SPE) methods used for isolation of the targeted
compounds from aqueous matrices and also the main instrumental parameters of the separation and detection process. After extraction, the compounds were subjected to liquid phase chromatographic separation with mass spectrometric detection (UHPLC-MS/MS). Finally, the methods were applied in the determination of compounds from different categories of water, carrying out studies on the efficiency of elimination of compounds in several municipal wastewater treatment plants (WWTPs). In addition, the impact of the treatment plants on some receiving surface water used to obtain drinking water was studied.

The purpose of the paper was to create databases that would allow a proper assessment of the degree of marine pollution generated by the shipyard industrial sector. The study was conducted over a period of three years, between 2015 and 2017. The parameters determined for the waters collected from the shipyard were within the maximum allowed limits according to the norms in force. However, values very close to the maximum allowable limit were observed in the case of groundwater for nickel, determined from the drilling located near the fuel depot in 2015 and chlorides determined from the drilling located near the galvanizing workshop, both in 2016 and in 2017. The analyzed parameters for the soil samples, collected from various sampling points and different depths, were below the value of the alert thresholds for less sensitive soils, according to Order 756/97. The databases created for this study can contribute as an incipient basis for the development of larger studies that include other industrial sectors as well as a longer evaluation period.

Using an LC-MS-MS method for detection of 6 neonicotinoid insecticides (imidacloprid, dinotefuran, acetamiprid, clothianidin, thiamethoxam, nitenpyram) was developed a new performant extraction method based on sonication treatment of soil samples, which were previously dried, grounded, homogenized, sieved (2 mm) and subjected to the selective extraction process with acetonitrile. Then the obtained extracts were diluted with ultrapure water (ratio 1: 100) and subjected to purification by Strata C18 SPE extraction using cartridges loaded with 200 mg/6 mL of octa-dodecyl-silica adsorbent phase. The entire methodology allowed obtaining quantification limits at trace level that varied in the range 0.3-0.9 ng/g and recoveries between 71.4% and 109.6%. In the agricultural soil samples, taken from the lands cultivated with wheat, corn, sunflower, beans, located in Prahova and Giurgiu counties (Romania), only four neonicotinoids out of the total of six were quantified imidacloprid (0.38 ng/g-56.9 ng/g), acetamiprid (1.7-7.2 ng/g), thiamethoxam (1.05-6.7 ng/g), clothianidin (1.1-1.5 ng/g).

Trials on ciprofloxacin removal from real aqueous systems were performed using a photocatalytic membrane reactor with catalyst in suspension. Four sets of four treatment cycles were carried out and experimental results were processed from the statistical point of view in order to assess results reproducibility. Global ciprofloxacin removal efficiencies of more than 99.85% were obtained for all treatment cycles. Coupling of photocatalytic degradation with membrane process allowed catalyst separation and reuse within further treatment cycles. Statistical analyse of experimental data recommends the use of photocatalytic membrane reactors as a feasible option for the advanced removal of pharmaceutical products like ciprofloxacin from real wastewater systems.

The aim of the study was to develop a new method for mercury determination from plants grown on mercury-polluted soils as well as to evaluate the mobility and bioavailability of mercury in the soil and its transfer to different plant organs (root, stem, leaves) from three different plants, such as mustard (Sinapis alba), thyme (Thymus serpyllum) and wild thyme. A cold vapor atomic absorption spectrometry (CV-AAS) method for the detection of mercury in plants was developed. The developed method was validated in the laboratory and was verified using two different certified reference materials (CRMs) type matrices, namely: NIST 1515 Apple Leaves and BCR-482 Lichen.

The food and beverage industries are considered essential sources of wastewater contaminated with pollutants discharged into the sewerage networks of cities. This study focused on monitoring the analytical parameters regulated in the environmental legislation in force in Romania for factories with various sectors of activity in the processing industry. The main objective is to understand the presence of conventional contaminants in the effluents from the food and alcoholic beverages industry and raise awareness of the effects of spillage in local networks. The study occurred over three years, between 2020 and 2022 when monthly wastewater samples from factories processing chocolate, meat, and alcohol were monitored. Values that exceed the maximum allowed limits were recorded for the meat processing factory due to the processed raw materials. The effluents resulting from the technological processes of meat processing significantly impact the aquatic environment.

In this paper, a chromatographic method for the determination of volatile organic compounds (VOCs) as a tool for Gram-positive and Gram-negative bacterial strains identification was described. Direct Headspace gas chromatography coupled with mass spectrometry (Headspace-GC-MS) has been used for the qualitative determination of VOCs emitted by certain bacterial strains (Salmonella Typhimurium, Escherichia coli, Serratia rubidae, Staphyloccocus aureus, Enterococcus casseliflavus, and Enterococcus faecalis). In the first stage of the study, pathogenic bacteria were cultured in broth-specific liquid culture medium directly (lauryl sulfate broth) into headspace vials. Subsequently, the VOC emissions were analyzed by airborne screening in the headspace vials. Thus, the objective was to analyze all the resulting volatile organic compounds in order to select only those compounds, which can be exclusively associated with specific pathogenic bacteria. Qualitative analysis by Headspace-GC-MS has proven to be a non-invasive, accurate, and fast method for identifying certain bacterial strains, based on VOCs emission. A considerable number of volatile organic compounds have been determined in the headspace air, a significant difference being observed between the VOCs emitted by bacterial cultures compared to the culture medium but also between the types of bacterial cultures themselves. The study presents preliminary results, which prove that the identification of the studied pathogenic bacteria is possible, based on the determination of certain types of VOCs in the headspace air of these cultures. This method can be used successfully for the rapid identification of bacterial culture types compared to classical methods.