The Role of Concentration Polarization with Concentration Dependent Diffusion Coefficient in Polymeric Membrane During Pervaporation

The increase of the diffusion coefficient, due to its concentration dependency, can strongly increase the mass transfer rate through the membrane. Accordingly, the negative effect of the mass transfer resistance of the polarization layer can essentially be increased on the separation efficiency, especially in the case of low solute concentration in the feed phase. This effect can also exist at high solute concentration at extremely high pervaporation rate as it is illustrated by the case study. The simultaneous effect of the concentration polarization and membrane layers is discussed in this paper in case of exponentially or linearly concentration dependent diffusion coefficient. Mass transfer rate, enrichment and the polarization modulus are expressed in implicit, closed mathematical equations involving the transport parameters of the two layers, i.e.the kL, Pe, km, H values. How the increasing diffusion coefficient affects the concentration distribution in the polarization and the membrane layers and due to it, the mass transfer rate, enrichment or the polarization modulus, indicating the effect of the polarization layer, is discussed. It is shown how strongly the a~ dimensionless plasticizing coefficient can decrease the polarization modulus and can affect the concentration distribution in the polarization and the membrane layers as well as the ratio of the diffusion dependent mass transfer rate to that without plasticizing effect, namely if a~=0. The case study illustrates the effect of the external mass transfer resistance on the mass transfer rate and on the concentration distribution in the case of high value of a plasticization coefficient

The Effect of Molasses Application on Soil Biological Indicators and Maize Growth of Different Tillage Soil: A Pot Experiment

Soil enzyme activity and labile carbon (LC) have long been used as soil health indicators. Soil health can be improved by molasses addition resulting in better plant growth and productivity. The effect of molasses on soil biological activity and plant growth under different tillage soil has not been discussed in many studies in Hungary. We assessed two soil types under different long-term tillage practices: conservation tillage (CT), which leaves 30% or more residue on the soil surface, and conventional-ploughing tillage (PT). A pot experiment with maize as the crop was carried out using the composite soil (0-20 cm) of CT and PT; a randomized block design with four replications was employed. Three levels of molasses concentration, 0 g L-1, 0.05 g L-1, and 0.2 g L-1 were applied. LC, dehydrogenase (DHA), β-glucosidase activity, plant height, and dry weight biomass were measured at the end of the experiment (after eight weeks). The results indicated that LC in CT increased by 7.61-21.23% over the increase in molasses concentration. LC concentration was significantly higher in the CT than in the PT soil. β-glucosidase activity increased along with the increase of molasses concentration by 11.42-30.43% in CT and 16.03-56.67% in PT; however, the significantly different appeared only in PT soil. The molasses application affected the DHA as well. The activity of dehydrogenase increases by 39.49-80.76% and 30.43-50.59%, respectively, in CT and PT. Nevertheless, no significance occurred in the tillage system or the molasses concentration. Our study also found that the different molasses concentrations did not affect the plant height and dry weight biomass in CT and PT. However, applying each molasses concentration in CT markedly escalated the plant height and dry weight biomass compared to PT. The enhancement of soil biological activity and plant growth by the molasses application allows a promising strategy for maintaining the soil health of agricultural land

Comparison Of Some Soil Enzymatic Activities In Luvisol Of Conservation And Conventional Tillage In A Model Experiment = Enzim aktivitások összehasonlító vizsgálata talajkímélő és hagyományos művelésű modellkísérletben Luvisols talajokon

The effect of soil tillage operation on soil biological properties has not been extensively studied in Hungary. We investigated some soil biological enzymatic activities (dehydrogenase, β-glucosidase, and phosphatase) of a Luvisol, treated by different tillage, management intensities, i.e., conservation tillage (CT), fully conventional tillage with mouldboard ploughing every year (PT), and moderately conventional tillage with shallow and deep ripping intermittently in every two years (BR). A pot experiment was carried out in climate-controlled growth chamber for six weeks as a model experiment, of using the composite soils (0-20 depth) with the three types of tillage intensity. Our finding suggested, that adding of the crop residues might increase the soil organic matter content, that is reflected by the high concentration of labile carbon in the CT soil. The greater intensified soil aeration at the conventional tillage operation, contributed to the much higher dehydrogenase activity in the PT and the BR soil. Otherwise, the higher aeration of soil resulted a decreased β-glucosidase activity in the conventional tillage (BR) soil. The high phosphorus availability of soil correlated by the lowest phosphatase enzymatic activity and the improved available P ratio in CT soil, indicating the inhibition of phosphatase activity. The soil biological enzymatic activities was shown to be affected by the presence of different substrates at the three management practices. = Vizsgáltuk a Luvisol talajbiológiai, enzim-aktivitását különböző talajművelési intenzitások mellett, azaz kímélő (CT), teljesen hagyományos (PT) és mérsékelt-hagyományos talajművelési gyakorlat (BR) mellett modell-kísérleti háttérrel. A klímaszabályozott növényszobában hat héten át tenyészedényes kísérletet végeztünk a háromféle talajművelésből származó talaj felhasználásával. Eredményeink azt mutatták, hogy a növényi maradványok hozzáadása növeli a talaj szervesanyag-tartalmát, amit a CT talajban lévő labilis szén magas koncentrációja is tükrözött. A hagyományos talajművelés mellett az erősebb talajművelés valószínűleg hozzájárult a PT és a BR talajok magasabb dehidrogenáz enzim aktivitásához. A nagyobb-fokú művelés csökkentette a β-glükozidáz enzim aktivitását is a hagyományos művelésű talajban (BR). A magas foszfor hozzáférhetőség a foszfatáz enzim aktivitás csökkenését váltotta ki a rendelkezésre álló foszfor mennyiségével összhangban a CT talajban. Megállapítottuk, hogy a talajok biológiai aktivitását a rendelkezésre álló szubsztrátok jelenléte befolyásolja a különböző művelésű talajokban, szoros összefüggésben a talajok nedvességtartalmával

The Effect of Molasses Application on Soil Biological Indicators and Maize Growth of Different Tillage Soil

Soil enzyme activity and labile carbon (LC) have long been used as soil health indicators. Soil health can be improved by molasses addition resulting in better plant growth and productivity. The effect of molasses on soil biological activity and plant growth under different tillage soil has not been discussed in many studies in Hungary. We assessed two soil types under different long-term tillage practices: conservation tillage (CT), which leaves 30% or more residue on the soil surface, and conventional-ploughing tillage (PT). A pot experiment with maize as the crop was carried out using the composite soil (0-20 cm) of CT and PT; a randomized block design with four replications was employed. Three levels of molasses concentration, 0 g L-1, 0.05 g L-1, and 0.2 g L-1 were applied. LC, dehydrogenase (DHA), β-glucosidase activity, plant height, and dry weight biomass were measured at the end of the experiment (after eight weeks). The results indicated that LC in CT increased by 7.61-21.23% over the increase in molasses concentration. LC concentration was significantly higher in the CT than in the PT soil. β-glucosidase activity increased along with the increase of molasses concentration by 11.42-30.43% in CT and 16.03-56.67% in PT; however, the significantly different appeared only in PT soil. The molasses application affected the DHA as well. The activity of dehydrogenase increases by 39.49-80.76% and 30.43-50.59%, respectively, in CT and PT. Nevertheless, no significance occurred in the tillage system or the molasses concentration. Our study also found that the different molasses concentrations did not affect the plant height and dry weight biomass in CT and PT. However, applying each molasses concentration in CT markedly escalated the plant height and dry weight biomass compared to PT. The enhancement of soil biological activity and plant growth by the molasses application allows a promising strategy for maintaining the soil health of agricultural land

Effects and changes of zearalenone and fumonisin contamination in corn-based bioethanol process

Bioethanol production is a growing industry nowadays. In this work dry-grind ethanol production was carried out from different corn samples (uncontaminated; zearalenone; fumonisin B1+B2 contaminated) and the changes of the ratio of the solid-liquid phase as well as toxin concentrations were examined in laboratory scale. The ethanol yields of mycotoxincontaminated corn-mashes were 27% lower, due to 10% less produced glucose-concentrations from these raw materials, compared to uncontaminated ones. By the end of the whole process, the initial 20% solid content was reduced below 7% both in contaminated and uncontaminated corn-mashes. Differences were observed in the concentration changes of examined toxins. Zearalenone was localized in the solid phase, and its concentrations did not alter during the ethanol production process. Fumonisin concentration increased 3 times at the end of the process, and it dissolved in the liquid phase in significant amount

A comprehensive analysis of soil health indicators in a long-term conservation tillage experiment

Conservation tillage (CT) is a ploughless tillage with a reduced number of operations, and its positive effect on soil functions and health is widely known. Multivariate analyses are required to choose indicators that adequately characterize the changes in soil health. However, there is little research on the comprehensive analysis of the full spectrum of soil physical, chemical and biological properties. Therefore, we examined 21 soil parameters in a long-term CT experiment conducted in Hungary. Four pairs of similarly sized CT and conventional ploughing tillage (PT) plots were set up in 2003 on Luvisols. The soil samples were collected after 17 years. The total organic carbon (TOC) increased significantly in the 0–15 cm layer at CT sites compared to those in PT, indicating a total increase of 5.22 t ha−1 TOC stock. In addition, the increasing biological activity and improved soil structure were the most important processes at the CT sites. Furthermore, more complex humic substances with higher molecular weights are characteristic of water-extractable organic matter (WEOM) as a result of CT. The potentially available nitrogen, phosphorus and potassium were also measured with a relatively high response ratio. Slowly changing parameters, such as cation exchange capacity and base saturation, are important soil physical and chemical parameters, but are not good indicators of the impact of tillage practices. Based on principal component analysis, we suggest the use of water-extractable organic C, amino-nitrogen, water-stable aggregates, available P and K and photometric analysis of WEOM to identify the soil improving processes