Nitrate (NO₃⁻) and cadmium (Cd²⁺) are common water pollutants with distinct chemical behaviors, often requiring different removal strategies. This study presents a low-cost synthesis of carbonated hydroxyapatite nanopowder (cHA), Ca₅(PO₄)_3-y(CO₃)_y(OH) (y = 0.13–0.17), using eggshell waste as a calcium precursor, aimed at removing both NO₃⁻ and Cd²⁺ from wastewater. SEM and TEM analyses revealed a porous nanostructure with an average particle size of 13.53 ± 6.43 nm and a specific surface area of 7.568 m²/g. Adsorption experiments were conducted under varying conditions, including contact time (0.3–3 h), dosage (0.3–2 g/L), initial concentrations (10–100 mg/L for NO₃⁻; 5–15 mg/L for Cd²⁺), and temperature (22 and 50 ± 2 °C). Cd²⁺ removal reached up to 99% at pH 2–4.5, while NO₃⁻ removal peaked at 38% in competitive systems, within 30 min. In single-ion systems, maximum nitrate uptake was 19.14 mg/g at 50 °C. Characterization using FT-IR, EDS, and XRD (with Rietveld refinement) confirmed carbonate B-type substitution and structural changes due to ion exchange and chemisorption. The results demonstrate that cHA derived from food waste is an efficient and sustainable sorbent, particularly for cadmium removal in contaminated water.

The fragmentation of the Agricultural Real Estate in Romania, which is due to the lack of vision regarding the retrocession of the land and to the ineffective measures for reparcelling farmland, manifests by the existence of a record number of about 3422 million farms in Romania, of which about 92% have a utilized agricultural area (UAA) below 5 ha. The Romanian agricultural sector possesses about 30% of the total European farms but contributes only 3% to the total EU agricultural production. The association of local agricultural producers may be an alternative to reparcelling farmland on a short-term basis in order to reduce the fragmentation degree and increase the competitiveness of the national agricultural sector. According to the statistics of the Ministry of Agriculture and Rural Development, 25 active groups of agricultural producers are registered in the South-East Region in 2018, where these associative entities have been recorded to have a low degree of viability. The paper proposes an analysis on the farmers’ motivation regarding the access to/exit from a form of agricultural association and the identification of some alternatives for increasing the viability of the associative forms in the agricultural sector in the South-East of Romania. In this respect, a study was carried out on a sample of 16 entities that gave up their status of producer groups in the analyzed region in 2011–2018. The Fuzzy Set Quantitative Comparative Analysis (fsQCA) Qualitative analysis method was applied, which identified the main influence factors that have led to the disappearance of this associative form. We consider this study relevant for drawing attention to the main obstacles that Romanian farmers face in joining an associative form. The study has shown that mainly the factors directly influenced by government policies have led to the withdrawal of a relatively large number of producers from producer groups in the studied region.

The most recent assessment (2008) of the IUCN Red List of Threatened Species classified Romanichthys valsanicola as critically endangered (CR). In December 2022, an expert team from the National Institute for Research and Development in Environmental Protection Bucharest investigated the presence of the species in historical locations and in other potential sites. The authors correlated public data to the actual habitat area to calculate the potential species density in relation to the specific territorial behavior. The ecological carrying capacity was represented by the consensus between the behavioral density limitations and the trophic limitations of the actual species potential habitat. Both trophic availability and populational density present encouragingly high values for the sculpin perch in the Valsan River, indicating that the natural habitat could host a considerably higher number of individuals.

This study emphasises the complexity of carbon dioxide (CO₂) emission dynamics by conducting a wetland case study along the Dambovita River. Our evaluation highlights the importance of considering spatial variability, meteorological parameters and water quality parameters. The variations in CO₂ emissions have been monitored using two complementary methods: a closed static chamber and a closed dynamic chamber. The closed dynamic chamber method has the highest level of confidence. The statistical results of correlations facilitated the validation of the closed static chamber method and its independent use in wetland ecosystems. Also, our findings revealed distinct patterns in emissions across locations that are influenced by parameters such as pH, redox potential (ORP), chlorophyll, dissolved oxygen concentration (DO), and temperature for the water–atmosphere interface. These results contribute to the understanding of the carbon cycle in wetlands and contribute to the improvement of greenhouse gas (GHG) reporting by obtaining data with a high level of confidence, regarding the role of wetland ecosystems in the carbon cycle.

On the basis of the in situ analysis of the sturgeon condition within the Lower Danube River, the aim was to carry out a research that would complement the results obtained from the monitoring and ultrasonic tagging methods. Thus, DNA samples were taken selectively from each ultrasonically tagged specimen in order to determine whether or not there is a possibility of hybridization between the species Acipenser stellatus and Huso huso. Thus, the microsatellite loci were investigated and certain parameters like diagnostic alleles, repeated sequences and specific molecular markers which were used to determine the degree of hybridism.