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.

Nowadays, progressive field crop practice requires modern, reliable, and cost-efficient methods to monitor crop development and yield. The most common and used biochemical parameter for plant physiology, namely the dynamic processes of growth, metabolism, reproduction, defense and communication, is chlorophyll's content in plant leaves. Our paper aims to compare optical in-situ method with a classical in vitro spectrometric chlorophyll detection method. A comparison between a quick and cost-effective screening method using portable CCM-200 plus (Opti-Science, Inc) and a biochemical chlorophyll extraction method was applied. Two sets of chlorophyll concentration data from terrestrial plants such as marigold (Calendula officinalis) and wheat (Triticum sp.) were reported. Chlorophyll pigments has a non-uniform distribution on the leaves surface, thus the concentration differs a lot at different times of the day, and this makes the optical measurements vary a lot between the same leaves. In this study, a mathematical correlation of the optical chlorophyll content conversion to absolute chlorophyll was carried out considering previous studies. The relationships between the CCM-200 measurements and the values obtained for the total chlorophyll concentration and the chlorophyll a/b ratio suggested a wide range of relationships between the two species.

This paper collects the most theoretical and experimental data about the fundaments of ultrasonic cavitation and its application in the domain of water and drinking water treatment. It is describing the most important mechanism of acoustic cavitation based on "Hot spot theory" which is based on free radicals, especially hydroxyl radicals. The experimental examples are focused on organic micropollutants removal from wastewater and drinking water. There are many organic pollutants resistant to classical treatment flows in wastewater and drinking water treatment plants which means there must be updated with new technologies like Advanced Oxidation Processes (AOPs). Ultrasonication and advanced ultrasonication is one of these new approaches. Ultrasonication was the base of a new chemistry domain - sonochemistry and its development led to new and modern degradation methods of natural and industrial organic pollutants: natural organic matter, phenols, organochlorinated compounds, surfactants, etc. with high mineralization degree.

The process of the kinetics of caffeine adsorption from aqueous solutions on activated carbon AC-0-9, obtained from apple wood, was studied. The analyses of nitrogen adsorption-desorption isotherms demonstrated that this carbon adsorbent is basically mesoporous. The pseudo-two model describes best the kinetic process, highlighting the role of functional groups on the activated carbon surface. The pseudo-one model only initially describes the kinetic process of caffeine adsorption on this activated carbon. It was found that the kinetics of the adsorption process of caffeine on AC-0-9 activated carbon takes place in two stages. In the first stage, the speed of intraparticle diffusion is high, due to the adsorption of caffeine molecules in macro- and mesopores, and in the second stage, the speed of intraparticle diffusion is low, given the fact that adsorption takes place in micro- and supermicropores.

Sustainable Development became from the start one of the most essential elements of global policy. The interest in the future of our planet modified people's mentality concerning economic development. A number of changes were developed over the years in direct connection with environmental stability. The linear economy turned into a circular one, preservation of carbon resources, “green processes” in industry and agriculture, as well as pollution elimination from air, land, and water represent ways to safer society progress. New tools were created for sustainable development. Among these, the Sustainable Development Goals are of great importance as they clarify of the targets to be fulfilled. These targets are obviously in close relation to the measures for environmental protection. The paper presents the 17 Sustainable Development Goals with their targets as well as the connection of these to the safety of the environment. The role of education and information in the field and the need for global cooperation are underlined.

Bauxite is the primary source for both metallurgical and non-metallurgical grades of alumina. Metallurgical alumina serves for aluminum production and non-metallurgical alumina, is used in a wide range of industrial applications, which makes it the subject of this review. The total world bauxite production is about 300m tpy, but only 10-15m tpy is estimated to be used for non-metallurgical applications. From the mined bauxite around 80-85% is processed via the Bayer alumina process to make alumina trihydrate (ATH) and further by calcination, the smelter grade alumina (SGA) for electrolytic aluminum. The rest of the crude bauxite remained to produce a range of non-metallurgical bauxite grades (refractories, abrasives, high aluminum cement, activated bauxite, alumina-based ceramic proppants, etc.). There are three main grades of non-metallurgical bauxite: Abrasive-grade bauxite used to produce abrasives; Chemical-grade bauxite used to produce aluminum chemicals, and Refractory-grade bauxite used to produce high alumina refractories. Around 1.2 million tpy of calcined bauxite is used in refractories, with a small amount also going into abrasives. Other ranges of non-metallurgical alumina grades like aluminum chemicals, low soda alumina, and activated alumina, including fillers and pigments for plastics and elastomers, special calcined alumina for ceramics, soft- and hard-burned alumina for alumina cement, calcium-aluminate cement, and mineral wool are produced from alumina trihydrate (ATH). Other uses include aluminum fluoride and zeolites.

Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) are the most common parameters for the characterization of the organic matter content of water. Correlation between BOD5 and COD for different types of waters can provide relevant information about the nature of pollution, the content of organic matter, and its level of biodegradability. This correlation could also be used to assess the quality of effluent after the treatment processes, to improve the performance of wastewater treatment plants (WWTPs), and/or to monitor the quality of river water into which wastewater is discharged. The objective of this study was to assess the degree of biodegradability of different types of water (influents and effluents of 3 important municipal WWTPs of Romania, untreated wastewaters discharged by different economic units from Bucharest; effluents of 5 different hospitals and surface waters - natural receptors of the effluents discharged by the municipal treatment plants), based on the ratios of BOD5/COD. BOD5/COD ratio (also called Biodegradability Index) varied depending on the type of water investigated and should be periodically rechecked due to variations in climatic conditions, untreated industrial wastewater discharged into natural receptors, water supply characteristics, and water availability.

It has been observed the spread of a growing number of antibiotic resistant bacteria (ARB) outside the clinical setting into the environment. The surface water seems to play an important role in ARB dissemination by being both habitats and transport systems for microorganisms, respectively. The ecological and touristic importance of the Danube Delta make it an European priority for a close observation and monitoring of its freshwater system. The main goal of this paper was to analyze how the St. Gheorghe branch of the Danube Delta microbiological contamination and their antibiotic resistant profile were influenced by climate change, especially the global warming from 2013 up to 2019. The bacterial population’s analyses revealed an indirect proportionality between coliform bacteria density in water and sediment during the time. Bacterial strains resistant to commonly used antibiotics in clinical settings were more and more identified and the strains exhibited high rates of beta-lactam resistance, especially to ampicillin and amoxicillin enriched with clavulanic acid.

The obtaining process of sulfuric acid, that involves roasted of pyrite ores, leads to accumulation of a significant amount of secondary matter known as pyrite ash. This waste, that is found worldwide in quantities of millions of tons, it is highlighted by his chemical composition, based on the presence of high concentrations of hematite and magnetite. By implementing worldwide of the concept of circular economy, the use of pyritic ash as an alternative source of iron is a topic of current interest. This study is proposing to present the latest trends in the methods of valorization of pyritic ash that are presented in the specialty literature, which can be implemented in various branches of industry.

Dimethyl phthalate is low molecular weight phthalate used on a wide scale within industry for manufacture of plastics, solvents, adhesives, lubricants, coatings and due to its poor biodegradability is not removed by classic wastewater treatment processes. It was proved that it affects the endocrine system, presenting carcinogenic, teratogenic and mutagenic effects on upon living organisms. Therefore, there is a need for more advanced treatment methods such as advanced oxidation processes for dimethyl phthalate removal from aqueous systems. A hybrid process consisting from photo catalysis and membrane based processes was investigated and the optimum parameters for dimethyl phthalate removal were established. In respect to photocatalytic process the influence of photo catalyst dose, pH, irradiation time were studied and process kinetics were set up using a synthetic dimethyl phthalate solution. In order to recover and reuse the photocatalyst a membrane process was used and optimum working pressure was determined. In the case of real wastewater matrix the addition of hydrogen peroxide was needed, in the photocatalytic stage, in order to improve process efficiency. Four treatment cycles, using real wastewater spiked with dimethyl phthalate, were performed with the reuse of photo catalyst proving that the use of photocatalytic membrane reactor with suspended photo catalyst represents a promising method for phthalates removal from aqueous systems.

A serious problem that arose with the evolution of modern industry is electrical and electronic equipment waste. In the last decades, the generation of electronic waste has increased quite a lot. It is estimated that by 2030, almost 74 tons of electronic waste will be produced, which will be a significant threat to the environment. The purpose of this article is to track the potential impacts on the environment and highlight the importance of waste management strategies to provide the latest information. Presentation of the countermeasures that must be taken at the national and international level to address the sensitive problem of waste management.

In this paper, the detection protocols for the selective and simultaneous determination of diclofenac (DCF) and tetracycline (TC) in aqueous solutions were developed using a commercial boron-doped diamond electrode modified with graphene oxide and silver, as the Ag/GG/BDD electrode. This electrode presented the possibility to detect only DCF and TC selectively by applying amperometric techniques. However, the pulsed voltammetric techniques operated in optimized working conditions allowed the selective/simultaneous detection of DCF and TC characterized by the improvement of the performance parameters compared to CV. Following the research study related to the electrochemical detection application of the two emerging target pollutants (DCF and TC), the Ag/GR/BDD electrode presented good stability and reproducibility of the results obtained

In the current context of the transition to a circular economy, efforts are primarily focused on recycling, the reintegration of some wastes into the economy, as a secondary raw material. The recovery of wastes specific to the mining industry and the metallurgical industry, which through the quantities deposited and through the chemical composition put a great pressure on the environment, represents a major concern of the society. Starting from this aspect, the paper presents the results of the research carried out in order to obtain new building materials (mortars) by adding two mineral wastes - red sludge from the manufacture of alumina and mine tailings - in the basic raw material, cement. The performances of the new materials containing the two wastes prove the viability of the technical solutions so that they can be used in the field of construction, both as masonry mortars and as plastering mortars.

The wide distribution of bacteria and their highly dynamic activities have a great impact on the aquatic ecosystem. Surface water bodies constitute an important drinking water source that approximatively cover half of the worldwide need. Considering the main health threats, the microbial profile represents the most important indicator on the biology quality of water environments. One of the most important criterion is fecal indicators and in consequence the aim of this study was to monitor the seasonal fecal pollution variability in the surface water of Arges and Dambovita River during 2021. These rivers are part of the Arges-Vedea basin that cover 9% of Romania’s surface and they are located in the proximity of the Bucharest, the capital city of Romania.

Good knowledge of the concentrations of chemical elements in soil in some geographical regions is fundamental to understanding the pre-existing natural background, on top of which the anthropogenic input is added, especially through pollution. There are many areas left without a geochemical assessment. In these cases knowing the areas where the contribution of the anthropic factor is non-existent or minimal is particularly important from the point of view mentioned previously. This article aims to highlight the spatial and temporal variation of 5 heavy metals identified in soil and water (surface water and underground water) within 5 protected geographical areas in Romania, chosen as case studies. In these areas, the manifestation of natural factors, namely geomorphological, lithological, edaphic, climatic, and, last but not least, the anthropogenic factor that cannot be neglected, gives the possibility of an objective, quantifiable evaluation of the areas under study. The comparisons made highlighted the zonal variability underlying the influencing factors, as well as the way in which the normal values are or are not exceeded.

Chemicals may generate accidents that can affect workers as well the general population and the environment. Decision making in such circumstances might be very difficult, especially for enterprises that do not have their own experts. A decision support system – SSD SmartRisk- was developed to help in such situations. SSD SmartRisk may be used as a roadmap with links to reliable and relevant sources of information and tools or employing commercially available decision support software. The exemplification presented here refers to chemical hazards, but the system may be adapted for other type of risks.

The aim of this study was to evaluate the quality of environmental factors of soil and water in a protected area in Romania, namely the Preajba-Facai lake system in Dolj county. Highlighting the evolutionary aspects of the analyzed quality parameters (20 physico-chemical indicators) on a spatio-temporal scale in order to establish geochemical thresholds is the final result of a larger project. The presented results were obtained through seasonal monitoring over a period of 3 years, which involves water and soil sampling and subsequent laboratory analysis. The results obtained were interpreted in relation to the legislation in force and through a more suggestive evaluation by calculating the pollution indices: the global pollution index (IPC) for water and the Nemerov synthetic soil contamination index. Following the field visits, additional information was brought, which contributed to a good knowledge of this region. The area, although protected, is influenced by the anthropogenic factors, which have a negative impact on the environment. In some cases, non-conformities were identified and validated through the analysis performed.