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Application of Molecular Imprinted Polymers for Selective Solid Phase Extraction of Bisphenol A

Abstract

Selective molecularly imprinted polymers (MIPs) with bisphenol A as template were synthesized using the non-covalent imprinting approach. MIPs were prepared using thermally initiated polymerization with 1,1’-azobis(cyclohexanecarbonitryle) (ACHN) as initiator and ethylene glycol dimethacrylate (EDMA) as a cross-linking agent. The tested functional monomers included methacrylic acid, acrylamide, and 4-vinylpyridine. The selectivity of the BPA-MIP for the solid phase extraction of bisphenol A was tested in samples containing other related alkylphenols. The polymers prepared in acetonitrile using methacrylic acid or acrylamide as monomer showed the highest selectivity towards target analyte (the selectivity ratio 8:1, respectively for MIP and NIP). The proposed procedure has been proven to be an effective for selective extraction of bisphenol A in aqueous samples (recoveries over 85%) enabling detection and quantification limits of 25 and 70 μg/dm3, respectively based on 10 cm3 of sample volume, with relative standard deviations (RSD) lower than 6%. The obtained molecularly imprinted material showed interesting properties for selective extraction and preconcentration of studied analyte from large volumes of aqueous samples without any problems of cartridge clogging.

Open access
Biochemical Changes in Nostoc linckia Associated with Selenium Nanoparticles Biosynthesis

Abstract

The cyanobacterium Nostoc linckia was used to study the biotechnology of selenium nanoparticles synthesis for the first time. The experimental conditions of the nanoparticle production by the studied cyanobacteria in aqueous cobalt selenite solutions were examined. Neutron activation analysis allowed characterization of the dynamics of accumulation of the total selenium quantity by Nostoc linckia. Scanning Electron Microscope images demonstrated extracellular formation of amorphous nanoparticles. Released selenium nanoparticles ranged in size from 10 to 80 nm. The changes of essential parameters of biomass (proteins, lipids, carbohydrates, and phycobilin) content during the nanoparticle formation were assessed. During the first 24 h of nanoparticle synthesis, a slight decline of proteins, lipids and carbohydrates content in the biomass was observed. The most extensive was the process of phycobilin degradation. Furthermore, all biochemical component content as well as an antioxidant activity of the biomass extracts significantly decreased. The obtained substance of Nostoc biomass with selenium nanoparticles may be used for medical, pharmaceutical and technological purposes.

Open access
Cheap Sensor Made of Multicrystalline Silicon for Insolation and Temperature Measurements

Abstract

In the paper some results on measurement of insolation and „real” cell’s temperature carried out with use of standard silicon solar cells are presented. Two identical cells are applied in such a sensor. Short circuit current of one cell is a direct indication of insolation value and open circuit voltage of the other cell is indirect indication of actual sensor’s temperature but in this case more complex formula must be used for temperature calculation.

Open access
Evaluation of Environmental Hazard During Shale Gas Exploration Process in Poland in the Years 2012-2014

Abstract

This paper is a summary of results of environmental analysis conducted by PGI-NRI, AGH-UST within the monitoring of natural gas prospecting in unconventional deposits. All elements of natural environment were analyzed and on this basis the qualitative and quantitative impact of drilling and hydraulic fracturing of shales could be assessed. Special attention was drawn to the analysis of the physicochemical condition of post-reaction fluids, soil gas in the well pad area and drilling fluids. The results of analysis reveal that prospecting works do not create a significant environmental hazard. Some indices connected, e.g. with the noise climate lightly exceeded permissible values. Nonetheless, if extensive prospecting and production of shale gas are involved, the environmental studies need to be broadened to supplement this report.

Open access
Green Synthesis: Nanoparticles and Nanofibres Based on Tree Gums for Environmental Applications

Abstract

The recent advances and potential applications of nanoparticles and nanofibres for energy, water, food, biotechnology, the environment, and medicine have immensely conversed. The present review describes a ‘green’ method for the synthesis and stabilization of nanoparticles and ‘green electrospinning’ both using tree gums (arabic, tragacanth, karaya and kondagogu). Furthermore, this review focuses on the impending applications of both gum stabilized nanoparticles and functionalized membranes in remediation of toxic metals, radioactive effluents, and the adsorptive removal of nanoparticulates from aqueous environments as well as from industrial effluents. Besides, the antibacterial properties of gum derivatives, gum stabilized nanoparticles, and functionalized electrospun nanofibrous membranes will also be highlighted. The functionalities of nanofibrous membranes that can be enhanced by various plasma treatments (oxygen and methane, respectively) will also be emphasized.

Open access
Impact of Use of Chemical Transformation Modules in Calpuff on the Results of Air Dispersion Modelling

Abstract

Assessment of the impact on air quality for combustion sources should be carried out using advanced modelling systems with chemical transformation modules taken into account, especially for the facilities characterized by significant emission of gaseous air pollutants (including SO2). This approach increases the reliability of the obtained evaluation results by modelling the formation of secondary inorganic aerosol (SIA) in the air which can substantially contribute to PM10. This paper assesses in this regard selected chemical transformation modules (MESOPUFF, RIVAD/ARM3, ISORROPIA/RIVAD) available in the CALPUFF model (v. 6.42) and its application in the atmospheric dispersion modelling of air emissions from a coal-fired large combustion plant (LCP) not equipped with a flue gas desulphurization (FGD) system. It has been proven that consideration an additional mechanism of secondary sulfate aerosol formation in aqueous phase in the ISORROPIA/RIVAD module (AQUA option) causes a significant increase in the annual average concentration of PM10 in the air compared to the other considered options, along with the calculation variant which excludes chemical transformation mechanisms. Type of the selected chemical transformation module has no significant effect on the results of modelled NO, NO2 and NOx concentrations in the air. However, it can lead to different SO2 results, especially for annual averaged, and in some points, for the hourly averaged concentrations.

Open access
The Influence of Natural and Model Forms of Humic Acids on the Dynamic Parameters of Model Membranes

Abstract

In this paper the influence of humic acid concentrations extracted from Histosols (HA-A) and their model forms (HA-B) separated from humic substances commercially produced by Carl Roth GmbH + Co.KG on the dynamic properties of liposome membranes was determined. Differences in the quality of the humic acids (HA-A and HA-B) were determined by the 1HNMR and FTIR methods. Liposomes from the sonication of egg yolk lecithin (EYL) in an aqueous solution and synthetic Dipalmitoylphosphatidylcholine (DPPC) were used. Fluidity of liposome membranes was determined by the EPR technique with spin probes (TEMPO, 16DOIXYL). The electrical parameters of membranes were found using a Keithley 6517 electrometer. Our study showed significant differences in the influence of HA-A and HA-B on the membranes. In the bilayer membranes of the liposomes of HA-A admixture there was slightly more stiffening of the interior of the membrane in comparison to HA-B. A similar effect was observed in the surface layer of the liposome membranes. This difference is particularly evident for DPPC liposomes, however, the EYL liposomes admixture with HA-B slightly increased the fluidity of the surface layer. Electrical study confirmed this effect. The study shows that natural and model forms of humic acids differ in their effects on the activity of tested membrane models. The strong differences in the interaction of HA-A and HA-B on parameter F in DPPC liposomes can be result from the transport of humic acids connected to the metal ions inside the membranes (xenobiotics present in the environment).

Open access
Modelling of Mercury Emissions from Large Solid Fuel Combustion and Biomonitoring in CZ-PL Border Region

Abstract

Tightening of norms for air protection leads to a development of new and significantly more effective techniques for removing particulate matter, SOx and NOx from flue gas which originates from large solid fuel combustion. Recently, it has been found that combinations of these environmental technologies can also lead to the reduction of mercury emissions from coal power plants. Now the greatest attention is paid especially to the coal power plant in Opatovice nad Labem, close to Hradec Kralove. Its system for flue gas dedusting was replaced by a modern type of cloth fabric filter with the highest particle separation efficiency which belongs to the category of BAT. Using this technology, together with modernization of the desulphurisation device and increasing of nitrogen oxides removal efficiency, leads also to a reduction of mercury emissions from this power plant. The University of Hradec Kralove, the Opole University and EMPLA Hradec Kralove successfully cooperate in the field of toxic metals biomonitoring almost 20 years. In the Czech-Polish border region, comprehensive biomonitoring of mercury in bioindicators Xerocomus badius in 9 long-term monitored reference points is done. The values of mercury concentration measured in 2012 and 2016 were compared with values computed by a dispersion model SYMOS′97 (updated 2014). Thanks to modern methods of dedusting and desulphurisation, emissions of mercury from this large coal power plant are now smaller than before and that the downward trends continues. The results indicate that Xerocomus badius is a suitable bioindicator for a long-term monitoring of changes in mercury imissions in this forested border region. This finding is significant because it shows that this region is suitable for leisure, recreation, and rehabilitation.

Open access
Nitrogen Transportation and Transformation Under Different Soil Water and Salinity Conditions

Abstract

Soil nitrogen transportation and transformation are important processes for crop growth and environmental protection, and they are influenced by various environmental factors and human interventions. This study aims to determine the effects of irrigation and soil salinity levels on nitrogen transportation and transformation using two types of experiments: column and incubation. The HYDRUS-1D model and an empirical model were used to simulate the nitrogen transportation and transformation processes. HYDRUS-1D performed well in the simulation of nitrogen transportation and transformation under irrigated conditions (R 2 as high as 0.944 and 0.763 for ammonium and nitrate-nitrogen simulations, respectively). In addition, the empirical model was able to attain accurate estimations for ammonium (R 2 = 0.512-0.977) and nitrate-nitrogen (R 2 = 0.410-0.679) without irrigation. The modelling results indicated that saline soil reduced the rate of urea hydrolysis to ammonium, promoted the longitudinal dispersity of nitrogen and enhanced the adsorption of ammonium-nitrogen. Furthermore, the effects of soil salinity on the nitrification rate were not obviously comparable to the effects of the amount of irrigation water. Without irrigation, the hydrolysis rate of urea to ammonium decreased exponentially with the soil salinity (R 2 = 0.787), although the nitrification coefficient varied with salinity. However, the denitrification coefficient increased linearly with salinity (R 2 = 0.499).

Open access
Open access