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The present study was carried out to evaluate the efficiency of a municipal wastewater treatment plant (WWTP) that uses biological treatment processes with activated sludge. The WWTP monitoring was carried out at the end of 2023, after the expansion and modernization stage, achieved during the period 2018-2023. The wastewater samples were collected from three important points of the wastewater treatment plant for four weeks, between October and November 2023. The physical-chemical parameters analyzed were: pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), volatile suspended solids (VSS), total nitrogen (TN), ammonia nitrogen (N-NH4+), nitrates (N-NO3-), total phosphorus (TP). The obtained results were beneficial for checking the performance parameters of the sewage treatment plant.

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.

As groundwater is used as a source of drinking water, monitoring its quality is essential due to possible adverse effects on human health. Nitrogen compounds (nitrates, nitrites, ammonia) within certain concentration limits are natural components of the nitrogen cycle. Due to anthropogenic activities, high concentrations of nitrogen compounds are released into groundwater. The aim of this study was to evaluate the chemistry of groundwater in a suburban area in northeastern Romania, the sources of pollution with nitrogen compounds (nitrates, nitrites, ammonium), and the non-carcinogenic risk to human health associated with consumption in different groups age (women, men, and children) in the investigated region. The results showed that the concentration of nitrogen compounds varies from 5.12 to 98.3 mg/L for nitrates, from 0.008 to 85.2 mg/L for ammonium, and from 0.001 to 1.12 mg/L for nitrites. The maximum admissible concentrations have been exceeding 25%, 40% and respectively 10% of the total analyzed samples Bivariate graphs and Principal Component Analysis (PCA) were used to identify potential sources of nitrate, nitrites, and ammonium pollution of groundwater in the study area. The non-carcinogenic risk assessment for water consumption showed a hazard index (HItotal) for nitrogen compounds in groundwater in the investigated region, which ranged from 0.037 to 2.856 for men, between 0.054 and 3.427 for women, respectively between 0.080 and 6.145, for children. Spatial distribution maps using the Inverse Distance Weighting technique presented the geographical areas with the probability of groundwater contamination with nitrate, nitrite, and ammonium and the areas that pose a risk to human health by consuming groundwater in the study area for the three groups: men, women and children.

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.

The purpose of the paper was to create databases that would allow a proper assessment of the degree of marine pollution generated by 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.

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.

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.

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).

A direct ion chromatographic method for 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. Column temperature was set up and maintained at 300C. The analyte ions were quantified using a suppressed conductivity detector.

This study investigated spatial and temporal distribution of nitrate and nitrite contaminants in groundwater from different geographical regions in Romania, with a special emphasis on a descriptive statistical analysis of data, namely determination of seasonal indices (dry season and wet season) and with establishing the standard units for the 24 of groundwater sources. Nitrate and nitrite concentration were monitored in 24 groundwater sources during the period January 2016 - February 2020 for several areas in Romania. The obtained data matrix showed that the maximum values of nitrate concentrations in different areas of Romania were the following: in the northeastern part of Romania the maximum nitrate concentration was 8.03 mg/L, in the south-eastern part of Romania, the maximum nitrate concentration was 6.37 mg/L, and in the western part towards the center of the country, following the evaluation, a maximum of nitrate concentrations of 3.55 mg/L was determined. Nitrite concentration values were

The environment pollution is an important issue influencing on human health and environmental equilibrium. The range of pollutants is very wide due to the industrialization and population growth and the surfactants are one of the most common organic pollutants due to their extensive use and ubiquitous presence from industry to households. Their massive presence in the domestic and industrial wastewater could affect the Wastewater treatment plants by inhibit the activated sludge used in pollutants biodegradation treatment step. This paper aimed to study the inhibition effect of three classes of surfactants (nonionic, anionic and cationic) by measuring of the respiratory activity of microorganisms with the application of the Oxygen Uptake Rate (OUR) test. This study established that the surfactants can activate or inhibit microorganisms activity, depending on surfactant concentration.

The paper aims a review of the water quality monitoring and evaluation studies conducted at National R&D Institute for Industrial Ecology over the last ten years, at the level of aquatic ecosystem complexes in the Danube Delta. The paper will include a broad compendium of data including: a data bank of abiotic variables which control the structure and composition of biotic communities; studies of ecological status assessment; methodology development for assessing the bioaccumulation of chemical pollutants (metals) in the biota; ecotoxicological study of surface water and sediment on aquatic organisms (algae, crustaceans, rotifers); studies on the benthic invertebrate species as biological vectors for pathogens; technical / scientific support for 5 national / international project proposals; 19 papers published in international / national journals; 22 papers presented at international / national scientific conferences.

The market expansion due to globalization generated more anthropogenic contaminants, enhancing their negative impact on the environment. In order to prevent and balanced their negative effect, more rapid, sensitive and eco-friendly ecotoxicological studies as risk assessments were developed. Each country developed national programs to ensure the research infrastructure for implementation and development of new testing methodologies, generating new experimental data transferable to governmental authorities, economic agents and academia. In this review, we intend to highlighted the progress of Romanian researchers in the last 10 years in the field of ecotoxicology and aquatic risk assessment. The studies focused on aquatic systems as a non-targeted system to the anthropogenic pollutants impact. The implemented methodologies according with international requirements for chemical control like REACH Regulation, Detergents Regulation, Biocide Products Regulation or the Aquatic Risk Assessment Guidelines were presented. The ecotoxicological effects of various contaminants such as detergents, pharmaceuticals, pesticides, biocides or heavy metals and environmental polluted samples (surface water, sediment or sludge) were provided. Overall, the studies presented in our studies have a nationally novelty through the variety of test substances, the complexity of laboratory experiments and data processing. The research work has a continue applicability in industry and for control authorities. New accredited testing services that providing useful information about the chemicals and their impact on the environmental were introduced. In addition, the ecotoxicology studies and their challenges were a great source for professional training like PhD and master studies and for impact published papers.