Mapping nitrogen transformation potential in anoxic alluvial aquifer using PCA and CA analysis

Increase in worldwide population has led to increase in food production. Increased food production consequently increased pesticide and fertilizers use. In fertilizers, nitrogen is in form of nitrate, ammonia or amide. Nitrates expressed solubility as well as inability of negatively charged ions to sorb on sediment particles, are usually the reasons why nitrates are considered as the final mobile compound of nitrogen transformation in soil. Information about the final compound of nitrogen resulting from transformation in water is important as an indication of aquifer potential for nitrogen conservation (NH4 ) or loss (N2O, N2). To evaluate the results of groundwater quality monitoring, during four years period, Principal Component Analysis (PCA) and Cluster Analysis (CA) were performed. Displayed map, developed as part of this study, presents an intersection of the conclusions based on two main factors, revealed by PCA analysi. Mapped local potential for nitrogen conservation or loss in the first drainage line of Kovin-Dubovac aquifer could be useful for managing the fate of nitrate entering the anoxic groundwater systems

Determining seasonal correlation among anoxic nitrogen transformation conditions

We examined seasonal change in physicochemical parameters NH4, NO3, Cl, SO4 2- , Fe2+, Mn and TOC for anoxic alluvial groundwater from the first drainage line at Kovin-Dubovac and Danube water level. To evaluate the results of four year monitoring programme Principal Component Analysis (PCA) and Cluster Analysis (CA) were performed. Principal component analysis (PCA) as a multivariate statistical method was used for data filtering in order to indicate if there is a connection between groundwater chemistry, surface water levels and sampling season. NH4, NO3, Fe2+, Mn, SO4 2- and TOC were chosen as important indicators of nitrogen transformation potential. Cl and Danube levels were included in analysis as indicators of groundwater recharge. Cluster analysis (CA) was applied for grouping the months of groundwater sampling with similar pattern

Attenuation of selected pharmaceuticals during riverbank filtration in Danube river alluvion

The paper presents the results of the transport analysis for selected pharmaceuticals during riverbank filtration from the river Danube to the drainage wells at the specific site KovinDubovac. In the Republic of Serbia the occurrence of pharmaceuticals in surface and groundwater was not sufficiently analyzed, so there is a need for research and testing of the occurrence and behavior of pharmaceuticals in order to better understand the flow of pharmaceuticals in the environment and transport of pharmaceuticals in groundwater during riverbank filtration. During the investigation period between 2009-2015, a total of 25 pharmaceuticals were analyzed in 52 samples, of which 13 samples of surface water and 39 samples of alluvial groundwater. A total of 7 pharmaceuticals in Danube River and 6 pharmaceuticals in alluvial groundwater were detected. Carbamazepine and metamizole metabolites N-acetyl-4-amino-antipyrine (4-AAA) and N-formyl-4-amino-antipyrine (4-FAA) have the highest frequency of occurrence in surface water and in groundwater samples, respectively. Results showed that riverbank filtration could significantly remove investigated pharmaceuticals. Percentage of removal during riverbank filtration was determined for carbamazepine (35%), trimethoprim (100%), 4-AAA (82%) and 4-FAA (43%). These results are extremely important for better understanding of self-purification potential of alluvial aquifers and protection from potential impacts of anthropogenic pollution to the groundwater sources in the Republic of Serbia

Supplementary data for the article: Pavlović, T.; Dimkić, I.; Andrić, S.; Milojković-Opsenica, D.; Stanković, S.; Janaćković, P.; Gavrilović, M.; Ristivojević, P. Linden Tea from Serbia – an Insight into the Phenolic Profile, Radical Scavenging and Antimicrobial Activities. Industrial Crops and Products 2020, 154, 112639. https://doi.org/10.1016/j.indcrop.2020.112639

Supplementary material for: [https://doi.org/10.1016/j.indcrop.2020.112639]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/4040

Content and distribution of iron in river sediments at borehole site Rb-6/P-5d in area of Belgrade water supply

The current problem of water supplying systems for large cities with quality drinking water be‐ comes more and more complex every day. Consumption is growing rapidly due to an increase in the number of inhabitants, an increase in per capita consumption, and a number of large water consumers, such as industry and agriculture. For many cities, including Belgrade, the main source of drinking water is groundwater. The captured groundwater of Belgrade water source is formed in alluvial deposits of the Sava River and layers of Pleistocene age, previously formed from torrential flows of melted glaciers. Beside the limiting factor of the "capacity of the site", during the exploitation of the wells, due to the rapid ageing of wells, reducing of the capacity of the well and screen is observed (Dimkić, 2017). Reducing of the capacity of the well and screen happens due to hydrogeological, hydrological, hydraulic factors, as well as geochemical, mechanical and biological processes that take place in the collector of groundwater. Interaction of these factors leads to the formation of "deposits" (e.g. Majkić‐Dursun et al., 2015), which causes clogging the perforations on well screen structures and thus reduces the capacity of wells. Preliminary studies of water supply wells of the Belgrade groundwater source indicated to the increased content of iron in the deposits which causes clogging the filter perforations. The aim of this research is to determine the content of iron in individual lithological layers, as well as the distribution of iron content along the stratigraphic column, particularly in the aquifer, as a potential source of iron and the causative agent for the formation of the deposits on the well screen. These studies are part of the activities on the definition of the mechanism of transport of iron from the primary lithological setting, as well as on elucidation of the mechanism responsible for the precipitation of iron‐bearing deposits (i.e. iron minerals) on the well screen

Mobility of selected pesticides in groundwater

The use of pesticides in plant protection products could result in their occurrence in all environmental mediums. Due to the concern about their environmental impact, the presence of pesticides is monitored in air, soil, water, and also in food and tissues. Jaroslav Černi Institute for the Development of Water Resources has conducted surface and groundwater sampling campaigns, in order to monitor fifteen different pesticides from priority and emerging substances lists. This paper is focused on the results of the groundwater sampling, where the most frequently detected pesticides were herbicide atrazine, fungicide carbendazim and insecticide carbofuran. In this paper, the fact that these pesticides were most frequently detected in groundwater was used for further research of their mobility. The most important process that influences the mobility of pesticides in the environment is the sorption. Therefore, sorption process was observed in the terms of linear sorption coefficient. Multiple linear regressions were used to establish the relationship between the linear sorption coefficient of each pesticide and various soil parameters, that have the highest impact on the sorption process. A thorough understanding of pesticides sorption behavior is crucial for predicting the movement rate of the pesticide in the environment. Information based on these processes will help with predicting the fate of pesticides in the groundwater, but also in the surface waters

The first nationwide multicenter study ofAcinetobacter baumanniirecovered in Serbia: emergence of OXA-72, OXA-23 and NDM-1-producing isolates

Background The worldwide emergence and clonal spread of carbapenem-resistantAcinetobacter baumannii(CRAB) is of great concern. The aim of this nationwide study was to investigate the prevalence of CRAB isolates in Serbia and to characterize underlying resistance mechanisms and their genetic relatedness. Methods Non-redundant clinical samples obtained from hospitalized patients throughout Serbia were included in the prospective, observational, multicenter study conducted from January to June 2018. Samples were initially screened for the presence ofAcinetobacter baumannii-calcoaceticus(Acb) complex using conventional bacteriological techniques. Acb complexes recovered from clinical samples obtained from inpatients with confirmed bacterial infections were further evaluated for the presence ofA. baumannii. Identification to the species level was done by the detection of thebla(OXA-51)gene andrpoBgene sequence analysis. Susceptibility testing was done by disk diffusion and broth microdilution method. CRAB isolates were tested for the presence of acquired carbapenemases(bla(OXA-24-like),bla(OXA-23-like,)bla(OXA-58-like),bla(OXA-143-like),bla(IMP),bla(VIM),bla(GIM),bla(SPM),bla(SIM),bla(NDM)) by PCR. Clonal relatedness was assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Results Acb complex was isolated in 280 out of 2401 clinical samples (11.6%). Overall,A. baumanniiwas identified in 237 out of 280 Acb complex (84.6%). CRAB prevalence was found to be 93.7% (237/222). The MIC50/MIC(90)for imipenem and meropenem were 8/ gt 32 mu g/mL and 16/ gt 32 mu g/mL, respectively. Although susceptibility was high for colistin (95.7%;n = 227) and tigecycline (75.1%;n = 178), ten isolates (4.3%) were classified as pandrug-resistant. The following carbapenemases-encoding genes were found: 98 (44.2%)bla(OXA-24-like), 76 (34.5%)bla(OXA-23-like), and 7 (3.2%)bla(NDM-1). PFGE analysis revealed six different clusters. MLST analysis identified three STs: ST2 (n = 13), ST492 (n = 14), and ST636 (n = 10). Obtained results evaluated that circulating CRAB clones in Serbia were as follows:bla(OXA66)/bla(OXA23)/ST2 (32.4%),bla(OXA66)/bla(OXA23)/bla(OXA72)/ST2 (2.7%),bla(OXA66)/bla(OXA72)/ST492 (37.8%), andbla(OXA66)/bla(OXA72)/ST636 (27.1%). Conclusion This study revealed extremely high proportions of carbapenem resistance amongA. baumanniiclinical isolates due to the emergence ofbla(OXA-72),bla(OXA-23), andbla(NDM-1)genes among CRAB isolates in Serbia and their clonal propagation

Combined effect of cover crops and bio-fertilizer on sustainable popcorn maize production

Cover crops play an important role in low-input cropping systems, increasing the use of agro-ecosystem services. Due to the lack of information about the impact of cover crops and bio-fertilizers on popcorn maize (Zea mays everta Sturt.) growth and yield quality, especially the popping volume and nutritive quality, such as concentrations of protein and mineral elements, this research aimed to provide essential information. The interrelation between popcorn maize productivity and quality with important groups of soil microorganisms presents additional novelty. The results demonstrated that field pea is a beneficial cover crop, especially when combined with a bio-fertilizer, supporting the accumulation of maize biomass, chlorophyll, yield potential, and the concentrations of protein, Ca, Mg, Fe, and Zn. In addition, field pea residues promoted N-fixing bacteria, and the number of total microorganisms, especially actinomycetes and decomposing bacteria, which could promote nutrient uptake and grain quality. Residues of cover crop mixtures, common vetch + winter oats and field pea + winter oats, promoted the total number of microorganisms in the soil, and up to the end of vegetation, a greater number of decomposition and ammonification microorganisms were found, especially when the bio-fertilizer was applied, which consequently could support greater maize biomass. Popping volume, as a main trait of popcorn maize, had the highest value in the common vetch + winter oats variant, supporting again the statement that quality traits could be enhanced in sustainable production. Unlike living cover crops, mulch mainly affected soil microbial communities and promoted the development of actinomycetes and cellulolytic microorganisms during the growing season. The results of this research could contribute to the development of sustainable popcorn maize production for improved grain quality. They could also serve as a basis for isolating beneficial soil microorganisms to develop new bio-fertilizers that could improve maize production in synergy with cover crop

New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts: phytochemical analysis, cytotoxicity and antimicrobial activity

Ethnobotanical and ethnopharmacological studies of many Centaurea species indicated their potential in folk medicine so far. However, investigations of different Centaurea calcitrapa L. extracts in terms of cytotoxicity and antimicrobial activity against phytopathogens are generally scarce. The phenolic profile and broad antimicrobial activity (especially towards bacterial phytopathogens) of methanol (MeOH), 70% ethanol (EtOH), ethyl-acetate (EtOAc), 50% acetone (Me2CO) and dichloromethane: methanol (DCM: MeOH, 1: 1) extracts of C. calcitrapa leaves and their potential toxicity on MRC-5 cell line were investigated for the first time. A total of 55 phenolic compounds were identified: 30 phenolic acids and their derivatives, 25 flavonoid glycosides and aglycones. This is also the first report of the presence of centaureidin, jaceidin, kaempferide, nepetin, flavonoid glycosides, phenolic acids and their esters in C. calcitrapa extracts. The best results were obtained with EtOAc extract with lowest MIC values expressed in µg/mL ranging from 13 to 25, while methicillin resistant Staphylococcus aureus was the most susceptible strain. The most susceptible phytopathogens were Pseudomonas syringae pv. syringae, Xanthomonas campestris pv. campestris and Agrobacterium tumefaciens. The highest cytotoxicity was recorded for EtOAc and Me2CO extracts with the lowest relative and absolute IC50 values between 88 and 102 µg/mL, while EtOH extract was the least toxic with predicted relative IC50 value of 1578 µg/mL. Our results indicate that all tested extracts at concentration considered as non-toxic can be one of great importance in combat towards phytopathogenic and human pathogenic strains, as well as natural sources of antimicrobials