Continuous monitoring of heavy metals content in vegetal products is a priority for food control and a risk assessment strategy for human health. Having in view the importance of heavy metals surveillance, the aim of this paper is to identify, on the basis of literature data, the most suitable procedures and techniques used for accurate determination of them in vegetal samples. In most cases, quantification of heavy metals in vegetal matrix is preceded by digestion performed through different protocols chosen carefully because this is a critical step for obtaining accurate results. Among most used techniques for heavy metals’ assessment from vegetal products reported by literature it worth to be mentioned: atomic absorption spectrometry (AAS), inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma - optical emission spectrometry (ICP-OES), X-ray fluorescence (XRF), neutron activation analysis (NAA), anodic stripping voltammetry (ASV).

Birch ssp. in the sub-Carpathians curvature can be found in composition with beech and other resinous species, unevenly distributed from the mountain peaks at around 1200 m down to 500-600, mainly from high hills to depressions at 600m, rarely seen on plain sites, crossing different geo-morphological structures and overall accounting for 3857.1 ha. The main objective of the paper was to analyze the site and stand characteristics of Betula pendula ssp. Roth. in the sub-Carpathians curvature as followed: stand structure, stand types and stand site types, soils, and different metrics, from growth to yields and its connectivity. The ecological adaptability to climate and soil and early fast growth, makes silver birch fulfill the overall requirements as a pioneer species, mostly naturally regenerated. Birch distribution is highly influenced by stand structure having low proportion in compositions, mean height of 15 m at age 50, and a diameter of 20m. Regarding site, characteristics are more commonly found on fertile soils, corrugated or fragmented site type with a slope of 20-50° and it is distributed as secondary species in stands, averaging 750m in attitude, ranging from 500 to 1200m, 90% being in mixtures with other species with a mean annual increment of approximately 7 m³/year/ha regardless of stand site type. As an early successional species, it serves as a first colonizer but secondary species and is often an ecological instrument to improve the soil characteristics and biodiversity and prevent landslides in certain sites, lacking economic value other than fuelwood or other non-wood products.

This study aimed to assess the water quality of certain lakes (Bogdaproste, Trei Ozere and Radacinos) belonging to the Danube Delta, Romania. Deltaic ecosystems are subject to natural and man-made environmental stressors. If in the past these ecosystems were largely threatened by eutrophication and organic/inorganic pollution, nowadays, we must focus on hydro morphological impact. This refers to the physical character and water content of the aquatic environment, impoundment (dams and flood gate), channelization and embankments, as well as clog/siltation of lakes. Environmental parameters are those physical, chemical and biological indicators used to characterize a freshwater body, and, which vary in time and space. In this regard, 44 water samples were collected in the dry season from the three lakes, for analysis of physical-chemical quality indicators. A series of physical (T, EC, TDS, turbidity, TSS, transparency) and chemical parameters (pH, DO, nutrients, SiO2, TOC, SO42-, ORP, technophilic elements) were considered. The results obtained in the physical-chemical analyses revealed that the majority of parameters were found in line with enforcing environmental regulations. Despite that, P-PO43- and Cd concentration results of some samples were found above certain permissible limits set by the normative. Probably, these inadvertences can be associated with local conditions of the transitional deltaic environment. Further analysis is required conducting repeated measurements with the same question, meaning a routine monitoring, especially P-PO43- and Cd. Finally, it was concluded that the results of this study showed a good quality of water in investigated lakes that did not pose potential health and environmental problems related to the biota.

In this paper, original methods for determining such thermodynamic characteristics as solubility product (KS) or the activity product ( )of slightly soluble hydroxides and acids are communicated. Developed methods for determining KS and solubility S are based only on the pH values of the saturated aqueous solution for a known initial composition of the heterogeneous mixture and the equilibrium constants of an arbitrary set of possible side reactions in the aqueous natural systems. The determination of solubility S and solubility product KS is also possible in the presence of other hydroxides or acids of known concentrations. Deduced equations allow the calculation of such characteristics, as the equilibrium concentrations of the components of slightly soluble compounds in aqueous phase and the degree of precipitation γ of the solid phase for different initial concentrations of the components of the heterogeneous mixture which are known in the process of preparing the mixture, requiring only experimental pH values of a saturated solution. From the known experimental pH data, S and KS were calculated for a series of hydroxides and acids of arbitrary composition. The obtained results correlated well with the known tabular values. Analysis of a number of real systems illustrated the deduced expressions, including calculations and theoretical explanations.

Fusarium root rot in a common pathogen of sweet potato, with a wide range of host plants. In the current study six new isolates of Fusarium sp., collected from infected sweet potato plants, along with a reference strain of Fusarium oxysporum, had their growth behavior studied in various pH and saline conditions. In vitro studies showed that salinity higher than 6% NaCl in the PDA substrate significantly reduces the fungal growth. At 12% NaCl, four of seven strains revealed complete mycelia inhibition. However, for the other two isolates, and for the reference strain, 12% salinity only reduced the growth with 77.4%. Regarding the fungal growth at different pH values, it was noticed that tested fusaria were not perturbed at up to 8.5 alkalinity. However, at a pH of 4.5, the growth rate was reduced, although the growth differences were diminished during prolonged incubation time. Considering the in vitro results, saline water should be tested as preventive immersion treatment on the sweet potato sprouts, before their planting, in order to reduce the incidence of Fusarium infection.

The paper’s aim was to select the optimal mineral medium for LDPE biodegradation by the strain Penicillium verrucosum CNM-FP-02. It was selected five mineral salt media (MSM), which differed in salt content and N/P ratio. After 40 days of submerged cultivation, the following parameters were determined: catalase activity and pH of cultural media, biomass accumulation, rate of LDPE degradation, optical microscopy, and the tensile testing of polyethylene. It was observed that catalase activity on all media, except MSM 4, was higher in the presence of LDPE. The addition of polyethylene to the growth media stimulated the fungal biomass accumulation by 19.3-93.1% (4 media out of 5 tested). The percentage of degradation of LDPE films was different, depending on the culture medium, from 0.41% to 0.92%. The most active LDPE films were degraded on medium MSM 2. Visualization of plastic strips under an optical microscope revealed the immobilization of the microorganism and the damage on the polyethylene surface. The tensile test showed increased elasticity of the plastic in the variants treated with fungal strain. In conclusion, in order to stimulate the biodegradation of LDPE by the strain P. verrucosum CNM-FP-02, the medium MSM 2 (N/P ratio 1:1) was selected.

This study is moving forward some available options for upgrading the biotrickling filters (BTFs) treating volatile organic compounds (VOCs) in air, in the light of lowering their greenhouse gas (GHG) emissions. One of such options refers to the addition of the microalgae component to the biological matrix involved in such systems, by (co)immobilization, for the capture of the carbon dioxide issued from the VOCs biodegradation and potentially contributing to the overall VOCs removal performance. Particularly, alginate beads with (co)immobilised microorganisms (microorganisms isolated from commercial compost and microalgae Arthrospira platensis PCC 8005) are for the first time tested for this purpose, as following: beads with encapsulated compost-based microorganisms and attached microalgae (BTF-I); beads with encapsulated mixture of microalgae and compost-based microorganisms (BTF-II). Although the both options provided promising performances in treating air contaminated with ethanol (as a model VOC in this study), the last option exhibited lower CO2 emissions and higher packing bed durability, being more prone to further development and implementation.

The developed method of determining KS from pH metric data has a number of advantages compared to those used traditionally. First, in place of the residual concentrations of the salt components, only the pH value of the saturated solution is used in the derived expressions. Thus, the number of independent variables, which need to be measured experimentally, is reduced. Furthermore, the potentiometric method, used to determine the pH, is sufficiently accurate, simple, and universal and does not necessitate the use of ion-selective electrodes. At the same time, the residual concentrations are usually measured by chemical methods, which are inferior in most cases, for several reasons, compared to the potentiometric method. Second, the KS value calculated by the developed method has a thermodynamic character. The organization of the experiment must be appropriate to the applied equations. Therefore, it is necessary to draw attention to the need for high accuracy in the process of preparing the initial solutions, because the initial concentrations of the precipitate components are included in the calculation formulas. The developed method for determining Ks can be applied for systems of any degree of complexity, which contain additional complexing agents.

The purpose of this article was to present an assessment of the soil and water quality in some protected areas from Romania in order to establish a series of geochemical thresholds on a spatial and temporal scale. The activities and results presented in this article are based on extensive monitoring, being stage results because the monitoring activities will continue, the project is ongoing. Two protected areas, Cheile Nerei -Beusnita National Park and Piatra Craiului National Park were selected. Surface water, groundwater samples, and soil samples were collected in 2019, respectively 2021 from 16 sampling sites situated in both locations. For each sample, twenty quality parameters/indicators were analyzed and the values were compared with in-force legislations. For Arsenic, Copper, and Nitrates parameters were plotted the distribution of the values in each site. In future monitoring activities, the evolution of the parameters will be followed.

The inventory and evaluation of growth rates for afforested surfaces is extremely important in estimating production levels and in determining the wood quantities that can be harvested. The present research was realized in southeast Romania, on a surface that contains 375h of afforested fields. The monitored surfaces are situated in Hanu-Conachi Independenta Forest, at a relatively low altitude. The study took into account only the surfaces afforested with willow (Salix alba) and extended between 2010 and 2015. The afforested surfaces’ consistency and age were evaluated based on direct observations and measurements. The used numerical analysis on different optimization methods was selected from amongst the most used series from the specialty literature. Our results have showed that evaluations of estimated production growth rates can vary significantly when different statistical analysis and numeric methods are use. By using numerical optimising models, computer simulations can offer precise estimations regarding growth rates, and consequently, for the efficiency of a given forest inventory. Common numerical interpolation methods or the usage of neuronal networks do not always lead to consistent results. Specific numeric methods are preferable for a better evaluation of growth rates and current inventory. In addition, investments in computer simulation methods and software should be encouraged in order to reach a permanent inventory, to improve the efficiency of exploitation operations and to sustain environment protection.

Complex studies were performed combining macroscopic and biochemical analyzes of selected biomonitors, exposed in exposure systems outdoor with mixtures of pollutants as well as controlled exposure with certain concentrations of pollutants in fumigation chambers. In this study, the following plant species were used as bioindicators: Nicotiana tabacum, Petunia hybrida, Ricinus comunis, Trifolium pretense. The exposure plant samples were compared with control samples of biomonitors maintained under standardized conditions in the climate chamber. Classical methods of biochemistry combined with those of exposure biomonitoring have led to the completion of knowledge about the ways of action of plants to pollution. The analysis of some of the antioxidant compounds that are representing a structural class of chemicals (enzymes) with a wide range of biological functions, with the role of free radical inhibition, was performed. Many of the constituent compounds in certain cell types, also called active compounds, in this case polyphenols are present in the body of some plant species. Polyphenol's presence in organisms, that are not usually present or are in normal quantities, is caused by stress, (pollution being a stress factor). Large amounts of polyphenols in plants are also given by the presence of pollutants in the environment. Through these extensive combined studies, it has been demonstrated that pollution can be a degenerative factor at the biochemical and physiological level, at the plant tissue level, with irreversible effects.

The Analytical Hierarchy Process (AHP) methodology was used to rank the tested nutritional solutions and to choose the best nutritional solution in order to reduce environmental pollution with nitrogen. The evaluation methodology consisted in comparing by three evaluators the diets based on the zootechnical performances/thigh meat quality / environmental impact. The diets of tested nutritional solutions were contained either medicinal and aromatic plants (basil, thyme, sage) in a proportion of 1% (batch 2), respectively essential oils (0.05%) of the same plants (batch 1). The application of the AHP methodology indicated that the best nutritional alternative was obtained for basil, either in the form of essential oil or vegetal material.

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.

Aluminum salts are widely used across Romania in surface water treatment as coagulants. It is well-known that the efficiency of these coagulants has a complex dependency on the nature of the raw water, being affected by temperature, pH and suspended solids. The objective of this case study was to compare the coagulation - flocculation efficiency process of raw water from the Bega River, at low temperature and turbidity, taking into account the use of alternative coagulating agents such as alum, poly aluminum chloride (PAC) and their mixing in 1:1 ratio. The raw water samples were treated using "Jar test" procedure, comparable with the current plant conditions at Timisoara Waterworks and taking into account possible operational improvements. For the mixture method applied in which was combined alum and PAC in 1:1 mixing ratio were achieved lower concentrations in aluminum residual, TOC, and turbidity.

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.

The food industry wastewater is known to present a high organic matter content, due to specific raw materials and processing activities. Even if these compounds are not directly toxic to the environment, high concentrations in effluents could represent a source of pollution as discharges of high biological oxygen demand may impact receiving river's ecosystems. Identifying the main organic contaminants in wastewater samples represents the first step in establishing the optimum treatment method. The sample analysis for the non-target compounds through the GC-MS technique highlights, along with other analytical parameters, the efficiency of the main physical and biological treatment steps of the middle-size Wastewater Treatment Plant (WWTP). Long chain fatty acids and their esters were the main abundant classes of non-target identified compounds. The highest intensity detection signal was reached by n-hexadecanoic acid or palmitic acid, component of palm oil, after the physical treatment processes with dissolved air flotation, and by 1-octadecanol after biological treatment.

Medicinal plants are, for a considerable part of the population, an important source of treatment for certain diseases. They contain essential nutrients for the human body such as magnesium, iron and zinc. The present study shows the influence of the addition of As, Cd, Ni, Pb on mineral nutrients in different organs of Mentha piperita. The experiments were carried out in the laboratory for a period of three months (May-July). Mentha piperita plants were AsCd and AsCdNiPb exposed up to final concentrations corresponding to the soil intervention threshold according to Romanian Order no.756/1997 (25 mg/kg As, 5 mg/kg Cd, 150 mg/kg Ni and 100 mg/ kg Pb). Simultaneously with these experiments, a control experiment (M) was performed. To evaluate the effect of the addition of AsCd and AsCdNiPb on the accumulation and transfer of Ca, Cr, Cu, Mn, Mo, Fe and Zn, the transfer coefficient (TC), the translocation factor (TF), and the enrichment factor (EF) were calculated. A higher concentration of Ca, Cr, Cu, Fe, Mn, Mo, and Zn was observed especially in the mint root in the experiments in which AsCdNiPb was added compared to those in which only AsCd was added. The AsCdNiPb addition did not influence the translocation of micro and macronutrients from the root to the aerial (edible) parts of the plant. In the case of the AsCd, addition, the translocation of zinc from the root to the aerial parts (leaves and stem) of the plant was increased.

The study aimed to develop some methods for the compositional characterization of biodegradable waste with relevance to the composting process at the laboratory level. For testing, four waste fractions were selected, such as waste based on dehydrated sludge, waste from parks (leaves, branches), market waste (mixture of vegetable and fruit) and cardboard waste. For metals and phosphorus, several microwave digestion methods were applied. The ammonium nitrogen content (NH4-N) was determined using a number of extraction procedures (water, CaCl2, and KCl). Three certified reference materials were used for testing the validity of the results. Recovery percentages higher than 90% were obtained. The developed and validated methods are suitable for biodegradable waste characterization used in composting processes.

The paper presents an experimental laboratory study of the bioaccumulation of the toxic metal arsenic in the medicinal plant chamomile (Matricaria Chamomilla L.). The study makes a comparison regarding the bioaccumulation capacity of the chamomile plant in which arsenic is found as unique contaminant, as well as in mixtures of 2, 3, or 4 toxic metals (Cd, Ni and Pb) on a natural soil enriched with metals, compared to the chamomile plant developed on an unpolluted substrate. The tests followed the effects of soil pollution with metals on the germination and development of chamomile. The experimental results indicated that arsenic does not bioaccumulate in the chamomile plant, remaining in the soil. The experiment that was an exception is the one with arsenic as the only contaminant (E1) in which at 90 days, the arsenic content in the chamomile plant was 3.58 mg/kg arsenic, the value that is within normal limits, below the phytotoxic value of 5 mg/kg, but was higher than that determined in the plant from the control test experiment (<0.75 mg/kg). The bioaccumulation factor (BCF) after 90 days, in all experiments, either by combination of metals or single contaminant had values lower than 1, indicating that the plant does not accumulate arsenic. The total chlorophyll from the results obtained indicates that the toxicity in the E1 experiment is higher than in the metal mixture.