Browse

61 - 70 of 360 items :

  • Sustainable and Green Chemistry x
Clear All
Alleviation Effect of Selenium on Manganese Stress of Plants

Abstract

Mn, as Fe, Zn, Cu and Ni is a heavy metal and also a necessary element all the living organisms. Excessive Mn nutrition causes a strong oxidative stress. The aim of the studies was to determination the effect of Se treatment (as sodium selenite Na2O4Se3) to alleviate the Mn stress of plants. Because of its sensitivity to oxidative stress induced by excessive concentrations of Mn a model plant was lettuce (Lactuca sativa L. ‘Sunny’). The studies were conducted in a controlled environment growth room in stable climate conditions: 16 h photoperiod; temperature light/dark 18.0 ±0.5°C/16.0 ±0.5°C; relative humidity 70-80%; quantum flux density 195-205 μmol m−2 s−1. Plants were grown hydroponically in nutrient solution characterized by excessive Mn content (19.2 mg dm−3) and different contents of Se (control; 0.77, 1.05, 1.33 mg dm−3). In all the combination were also tested different foliar sprays (distilled water and a 0.005% Se solution). Plants grown under conditions described above take up and transported Se from nutrient solutions into their leaves with a significant reduction of Mn concentration and changes in the plant nutrient status. With the increase in the concentrations of Se clearly narrowed quantitative relations in the leaves between this element and micro-metallic. Increasing Se levels in nutrient solution has a positive influence on the growth of plants, but Se foliar treatment generally decreases plant yield. The study shown that Se application may lead to alleviation of Mn stress of plants, with simultaneous reduce in Mn concentration in leaves - which may be of practical importance also in the cultivation of more economically important species.

Open access
Antioxidant Phenolic Compounds in Salvia officinalis L. and Salvia sclarea L.

Abstract

The differences in the chemical composition of the phenolic compounds of Salvia officinalis versus Salvia sclarea growing in different habitats, were studied. First, the optimal solvent - methanol - for ultrasonic extraction of phenolic compounds from these plants was chosen experimentally. Total phenolic content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were determined spectrophotometrically. Total phenolic content was in the range of 63.9 to 134.4 mg GAE/g of plant depending on the studied species. The highest antiradical activity was displayed by the methanol fractions of S. sclarea varieties (83 and 67%). HPLC-DAD analysis of extracts was done in order to identify the presence of individual phenolic compounds. This was done by comparison of their retention times with those observed for 17 commercially available standard compounds. The results showed differences in the phenolics composition, with plants collected on Crimean peninsula accumulating more phenolic acids than Polish varieties. In turn, the Polish varieties of sage contain bigger amount of flavonoids in their tissues.

Open access
Computer Simulation of Chemical Coagulation and Sedimentation of Suspended Solids

Abstract

The computer program ZB2 was used to study simulated coagulation rate for the system containing spherical sol particles and spherical coagulant particles. The system performance was verified to the particle-cluster model of a fast and perikinetic coagulation process that fulfils Smoluchowski and/or Muller equations. The rate of the coagulation process satisfied both the kinetic equation of a first-order reaction and a second-order reaction. However, chosen concepts and models in the theory of bidispersive sol coagulation have been negatively verified. Also, attempts have been made to modify the Muller integral equation for selected boundary conditions.

Open access
Effect of Nanoaquacitrates on Physiological Parameters of Fodder Galega Infected with Phytoplasma

Abstract

The laboratory experiments have been found that soaking seeds Galega orientalis L. (Fodder galega) in nanoaquacitrates solutions of Mn (10 and 20 mg/dm3), Mo (4 mg/dm3) and Mg (2 and 4 mg/dm3), has been lead to germination energy rise, while Mn (10 and 20 mg/dm3) and Mo (4 mg/dm3) concentrations has been influenced germinating ability. At the same time, the soaking seeds in solution of nanoaquacitrates Mn (20 mg/dm3) had the biggest stimulatory effect on the accumulation 7 daily sprouts mass (on 18%). It has been shown that soaking seeds in nanoparticles Mn and Mo solutions leads to the increase of catalase activities (especially under the influence of manganese) and peroxidase activities (under molybdenum influence). Applying the method of chlorophyll a fluorescence in the field and greenhouse experiments with Galega orientalis L. plants, artificial infected with phytoplasma Acholeplasma laidlawii var. granulum st. 118 the following changes in the photosynthetic apparatus has been indicated: reduction in the length of the light-antenna, blocking transport of electrons in plastoquinone pool PSII with reducing the pool of electron acceptors. It has also been indicated that photochemical activity resistance of the photosynthetic apparatus decreases while its stability increases, as result of described above effects the concentration of chlorophyll a and b in plants leaves decreases. The above-mentioned negative effects have been deactivated through foliar treatment of infected Galega orientalis L. plants with nanoaquacitrates solution Mo (4 mg/dm3) that allow increasing of photochemical resistance of photosynthetic apparatus as well as chlorophyll content in leaves. The foliar treatment with Mn (20 mg/dm3) solution of the infected plants, in compared with infected plants without treatment, resulted in more significant increase of Ki value (which correlate to the ribulose-1,5-bisphosphate carboxylase/oxygenase activity), which is explaining anti-mycoplasma effect of this solution.

Open access
Effects of Silicate Fertilizer on Seed Yield in Timothy-Grass (Phleum pratense L.)

Abstract

A field experiment was conducted in the years 2012-2014, at the Plant Breeding Station in Polanowice near Krakow (220 m a.s.l.). The aim of the study was to investigate the effect of silicon (Si) on seed yield and quality of timothy-grass (Phleum pratense L.) of “Egida” cultivar. A univariate field experiment in randomized block design was repeated four times, and the area of the experimental plots was 10 m2. The soil on the experimental plots was a loess derived haplic phaeozem of bonitation class I. The experimental factor was spraying with a silicon formulation in the form of Optysil® fertilizer at three doses: 0.2, 0.5 and 0.8 dm3·ha−1. During the growing season, the plants were evaluated for their height, leaf greenness index (SPAD) and general condition. After harvesting, the seed yield and quality were assessed. The study revealed a significant effect of silicon on plant height, general condition and yield and quality of the seeds. The plants treated with silicon showed lower infestation rate with pathogens and pests than the control ones. Foliar fertilization with the highest dose of the silicon formulation (0.8 dm3·ha−1) caused a significant increase in seed yield as compared with control. The effects were also satisfactory in the plants treated with the formulation at 0.5 dm3·ha−1. The seeds obtained from silicon-treated plants were bigger, as revealed by the weight of 1000 seeds, and exhibited higher germination ability than the control seeds.

Open access
Impact of the Solar Irradiation Angle on the Work of Modules with Spherical Cells - Simulation

Abstract

The main purpose of all PV modules is to convert solar energy into electricity, but in the era of building integrated photovoltaics, there are additional opportunities to use them. The use of them as a composite of architectural structures in the form of facade cladding, roofing, stained glass windows or noise barriers on highways, in addition to generating electricity embellish also the aesthetic value of the facilities. However, these atypical their use, cause that the modules should have quite different properties then in the traditional application, which is related to their unusual way of positioning. Particularly for structures such as the modules made of spherical cells with the two active planes of operation. The article presents a comparison of the results of simulation of module with two active surfaces containing spherical solar cells in an open space in relation to a typical flat photovoltaic module. A comparison of its work with different orientation and inclination. Article shows the basic difference in its properties occurring at some settings in relation to a typical module and makes predictions about its future use.

Open access
Major Advances and Challenges in Heterogeneous Catalysis for Environmental Applications: A Review

Abstract

Heterogeneous catalysis is one of the fastest developing branches of chemistry. Moreover, it is strongly connected to popular environment-related applications. Owing to the very fast changes in this field, for example, numerous discoveries in nanoscience and nanotechnologies, it is believed that an update of the literature on heterogeneous catalysis could be beneficial. This review not only covers the new developments of heterogeneous catalysis in environmental sciences but also touches its historical aspects. A short introduction to the mechanism of heterogeneous catalysis with a small section on advances in this field has also been elaborated. In the first part, recent innovations in the field of catalytic air, water, wastewater and soil treatment are presented, whereas in the second part, innovations in the use of heterogeneous catalysis for obtaining sustainable energy and chemicals are discussed. Catalytic processes are ubiquitous in all branches of chemistry and there are still many unsolved issues concerning them.

Open access
New Methods of Natural Gas Adjusting for Technological Purposes Based on Modern Filtration Materials

Abstract

Reservoir gas treatment technologies currently in use require significant investments in equipment and materials. Considering the foregoing, new technologies are sought for treatment and separation of components of extracted gas. They will guarantee compliance with gas quality requirements arising from applicable standards while at the same time lowering the costs of investment, service and environmental protection. Therefore, the purpose of this work was to develop an efficient mobile technology for natural gas treatment, on the basis of advanced filtering and coalescing materials and membranes, which eliminate the existing, economically non-viable processes and reduce the costs related to development of new reservoirs. The purpose of designed materials was removal of solid particles, water, higher hydrocarbons and nitrogen from natural gas. Presented integrated filtration and membrane system, characterized by a highly compact design enabling installation in container stations and transporting the system between specific points of production.

Open access
Online Measurement Method of Water Quality in the Sulejow Reservoir

Abstract

The paper presents methodology of accurate mobile measurements of water quality parameters such as temperature, dissolved oxygen, chlorophyll “a” concentration, ammonium ion concentration, conductivity, pH and blue-green algae content in water. The measurements (probe EXO 2, YSI, USA) were made on various depths of probe immersion (1.5, 2.5 and 3.5 m) and at different towing speeds of the probe (approx. 5.4 and 9.0 km/h). Static measurements carried out on the same route provided reference values for the measurements in motion to compare the repeatability of static and mobile methods. The tests were also evaluated by observation of probe behavior in motion, e.g. water disturbance intensity, access of light (sun rays) to the sensors. Statistical tests confirmed that the mean values of water quality parameters from mobile measurements with the speed of 5.4 km/h at the depth 1.5 m does not differ from the stationary measurements. Results of statistical analysis prove that water quality parameters can be measured accurately keeping established speed of towing the probe at the fixed depth. Methodology of mobile measurements elaborated in the frame of this work allows to collect vast number of data which can be used to obtain GIS point maps of water quality parameters in large water bodies.

Open access
Quality of Rivers: Comparison of Hydro-Morphological, Physical-Chemical and Biological Methods

Abstract

The study was performed in five fourth-order tributaries of the Bystrzyca Lubelska River (Eastern Poland, Lublin Upland), differing in the degree of river-bed transformation and level of pollution. Hydro-morphological methods (descriptive method by Ilnicki and Lewandowski - IL, and index method by Oglecki and Pawlat - OP) and biological indices based on the composition of zoobenthos (Diversity - D, and index based on proportions between the density of Oligochaeta and Chironomidae - O/Ch) permitted distinguishing of four classes, from II to V. The distinguishing of only two quality classes (III and IV) was possible by means of physical-chemical methods and by benthic index BMWP_PL. Those two methods seem to show the lowest sensitivity to the spatial variability of the environment quality. The BMWP_PL index was the least sensitive to year-to-year environmental changes, and O/Ch was the most sensitive. Relatively high conformity was obtained between hydro-morphological assessments performed by means of the OP and IL methods. Results obtained by means of these tools weakly corresponded with the physical-chemical assessments. The latter assessments were the most similar to those obtained by means of the BMWP_PL (degree of similarity = 57%) and D (47%) indices, and considerably less in the case of O/Ch (36%). The BMWP_PL and D indices better corresponded with the results of the hydro-morphological assessment performed by means of the IL method than with those performed by means of the OP method while D index showed a reverse pattern. The O/CH index proved useful for the assessment of the degree of organic pollution of the river’s water, but not the sediments.

Open access