Stoichiometry of carbon, nitrogen, and phosphorus in wastewater from Romania

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

Neonicotinoid insecticides as emerging contaminants in agricultural soil

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)

Assessment of environmental pollution level caused by shipbuilding industry

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

In Vivo Bioconcentration, Distribution and Metabolization of Benzophenone-3 (BP-3) by Cyprinus carpio (European Carp)

Organic UV-filters, such as oxybenzone (BP-3), have attracted researcher attention in recent years due to its capacity to interfere with the proper functioning of the endocrine system and its widespread presence in the aquatic environment. The aim of this study was to investigate the bioconcentration, distribution and metabolization of BP-3 in one of the most common fish species in Romania, namely Cyprinus carp (European carp). Exposure experiments were performed for 11 weeks using a BP-3 nominal concentration level of 100 µg/L. The BP-3 concentration level decreased over time and needed to be re-established daily. Biological samples (fish organs and tissues) from control and test were taken at t0 (before contamination) and at t3, t5, t8 and t11 weeks from the beginning of the experiment. From the third week, BP-3 was identified and quantified, in all organs, in concentration values ranging between 3.2 and 782 ng/g d.w., the highest concentration being detected in the intestinal content, followed by gonads (up to 468 ng/g d.w.) and skin (up to 453 ng/g d.w.). In the case of gill and liver, the BP-3 concentration increased in the first five weeks, and then decreased to 15 and 6 ng/g d.w., respectively, which could be explained by a fast BP-3 metabolization. During the exposure period, six metabolites were identified through LC-MS/MS, all of them known for their endocrine disruptor and toxic properties being higher than those of the parent compound. The study is important from an ecological perspective and also in view of human health concerns involving food quality

Occurrence and Transport of Isothiazolinone-Type Biocides from Commercial Products to Aquatic Environment and Environmental Risk Assessment

This study investigated the occurrence and transport of four isothiazolinone-type biocides from commercial products to wastewater treatment plants (influents, sludges, and effluents) and to natural emissaries (upstream and downstream the wastewater treatment plants) in Romania. All four biocides were determined in personal care and household products, with the highest concentration of 76.4 µg/L OIT (2-octyl-4-isothiazolin-3-one). For environmental samples, three of the four isothiazolinones were determined, CMI (5-chloro-2-methyl-4-isothiazolin-3-one) being the prominent compound for water samples. The maximum concentration of 84.0 µg/L in influent, 122 µg/L upstream, and 144 µg/L downstream the wastewater treatment plants were obtained for CMI. Unlike water samples, in the sewage sludge samples, OIT proved to be the dominant compound, with concentration up to 5.80 µg/g d.w. The extremely high levels of isothiazolinone determined in different WWTPs from Romania may be due to the COVID-19 pandemic situation, during which a much larger amount of cleaning, hygiene, and personal care products was used. The isothiazolinone-type biocides were readily removed from the influents of the five WWTPs, with the mean removal rate up to 67.5%. The mean mass loading value for the targeted biocides based on influent was 20.4 μg/day/1000 people, while the average environmental emissions were 6.93 μg/day/1000 people for effluents. The results obtained for riverine water combine with statistical analysis showed that the anthropogenic activities are the major contamination sources of the surface waters. Preliminary ecological risk evaluation showed that BIT (1,2-benzisothiazol-3(2H)-one), OIT, and CMI could pose a very high risks to different aquatic species living in the receiving aquatic environments

Analysis of Volatile Flavor Compounds in Four Commercial Beverages Using Static Headspace Gas Chromatography/Mass Spectrometry: A Qualitative Approach

Understanding the volatile flavor compounds present in commercial beverages is crucial for the food and beverage industries as these compounds significantly influence product perception and consumer acceptability. This paper aims to comprehensively analyze the composition of volatile organic compounds in various commercial beverages using targeted gas chromatographic–mass spectrometry (GC/MS) approaches. The study employs a screening method based on the Headspace-GC/MS technique to efficiently extract and identify volatile organic compounds found in commercial beverages. This methodology provides a rapid and reliable system for assessing the volatile profile of these beverages. The analysis reveals the presence of a total of 40 volatile organic compounds, including esters, terpenes/terpenoids, alkenes, aldehydes, aromatic hydrocarbons, and alcohols. Medium-chain esters were found to dominate the volatile profile of the beverages, suggesting a significant contribution to their fragrance and taste. This study offers valuable insights into the volatile profile of commercial beverages, creating awareness among consumers about the flavor components present in these products. By understanding the volatile composition, consumers can make informed choices regarding their beverage consumption. The comprehensive analysis provided by this research serves as a foundation for further studies related to flavor characterization and optimization in commercial beverages

Degradation of Carbamazepine from Aqueous Solutions via TiO₂-Assisted Photo Catalyze

Photocatalytic degradation of carbamazepine (CBZ) from spiked aqueous solutions, via a UV/TiO2 system, was investigated, and the optimum photocatalyst type (P25 Degussa) and dose (500 mg/L), as well as irradiation time (45 min), were established. The degradation process kinetics was studied, and a degradation rate constant of 3.14 × 10−5 M min−1 was calculated for CBZ, using the Langmuir–Hinshelwood equation. Experiments performed in the presence of scavengers showed that the main reactive species involved in the degradation process are holes and free hydroxyl radicals; superoxide radicals also play a role in CBZ degradation. Eight transformation products of CBZ were identified, and a possible degradation pathway, consisting of four routes, was proposed. Toxicity and genotoxicity tests were also performed for both untreated and treated CBZ solutions, proving that the use of a UV/TiO2 system represents a suitable treatment approach for aqueous systems with CBZ content

Bacterial Biodegradation of Perfluorooctanoic Acid (PFOA) and Perfluorosulfonic Acid (PFOS) Using Pure <i>Pseudomonas</i> Strains

The principal objective of the present research involved the achievement of high biodegradation degrees of perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) using pure individual bacterial strains. The use of such microorganisms can contribute to the improvement of the wastewater treatment process in sewage treatment plants through bioaugmentation or other bioremediation processes. Thus, in this study, we investigated the biodegradation potential of PFOA and PFOS. Bacterial strains tested in this study were from the Pseudomonas genus, namely: Pseudomonas aeruginosa and Pseudomonas putida, due to their known capacity to degrade xenobiotic compounds. The results indicated that Pseudomonas aeruginosa was able to transform 27.9% of PFOA and 47.3% of PFOS in 96 h, while Pseudomonas putida managed to transform 19.0% of PFOA and 46.9% of PFOS in the same time frame. During the biodegradation tests, PFHxA was recognized as the principal biotransformation product of PFOA in the presence of Pseudomonas aeruginosa, and PFPeA, PFPxA and PFHpA were recognized as the biotransformation products in the presence of Pseudomonas putida. For PFOS, only two biotransformation products (PHHxA and PFHpA) were observed as a consequence of biodegradation by both bacterial strains

Groundwater Quality Affected by the Pyrite Ash Waste and Fertilizers in Valea Calugareasca, Romania

The aim of the study was to assess the groundwater quality in a rural area affected by the abandoned pyrite ash waste dumps. The abundance of major ions in groundwater depends largely on the nature of the rocks, climatic conditions, and mobility. To evaluate geochemical processes, 30 groundwater samples collected from Valea Calugareasca, Prahova County, Romania, were analyzed for the major anions (NO3&minus;, SO42&minus;, Cl&minus;, HCO3&minus;, and F&minus;) and cations (Ca2+, Mg2+, Na+, and K+), which are naturally highly variable due to climatic and geographical location conditions. Ca2+, Na+, Mg2+, and K+ varied between 118 and 275 mg/L, 32 and 160 mg/L, 12.2 and 78.4 mg/L, and 0.21 and 4.48 mg/L, respectively. NO3&minus; levels exceeding the World Health Organization (WHO) limit of 50 mg/L were identified in 17% of the groundwater samples, mainly as result of fertilizers applied to agricultural activities. The hydrogeochemical study identified dolomite dissolution and halite precipitation as natural sources of ions as well as the presence of pyrite as a source of SO42&minus; ions in 60% of the samples. The sulfate content varied between 125 and 262 mg/L. Bicarbonate and chloride concentrations varied between 202 and 530 mg/L and 21 and 212 mg/L. The saturation index indicates the contribution of Ca2+ ions in the groundwater samples came from some processes of dissolving rocks such as aragonites (values between 1.27 and 2.69) and calcites (values between 1.43 and 2.82). Negative halite values indicated that salt accumulation results from precipitation processes. Only 10% of the analyzed groundwater samples were suitable for human consumption, the samples being situated on the hill, far away from the pyrite ash waste dumps and agricultural land