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MÚLT-JELEN-JÖVŐ a hazai mezőgazdasági talajvizsgálatokban
PAST-PRESENT-FUTURE in Hungarian soil analyses
The purpose of the present paper is Authors aim was to deliver a compilation of to summarize the Hungarian soil analysies methods and theas well as to present the advisory system for nutrient management advisory system. Both of them are based on several decades of work. We need to should learn from these past experiences of reasonable and good agricultural practices. We can only apply the present and future results of soil science and find out what direction should we develop, if we were aware of the results of the past and we calculate with their governing effects. The majority of our recent methods are based on historical researches and the present current statesituation of our field of scientific fieldce can only be judged and developed further if we knew the former history of the methodological findings. The recent Hungarian soil analysis system provides useful results that can be used very well today, however, the adaptation of the new international methods , learned from the follow-up of the international trends can might provide open new perspectives in for the Hungarian laboratory analyses methodology. TThe subject is extremely timely because there are hea never- met demand for cost and time effective, environmentally friendly soil analysis methods underpin how actual and hot the topic is. nowadays.
A talaj fixált ammónium-ion tartalmának hatása a talajvíz tisztulási folyamataira a szennyezőforrás felszámolását követően települési környezetben
Effects of fixed ammonium ion content of the soil on groundwater purification processes after the elimination of the pollution source in municipal environment
Growing NH4 + content of groundwater results in increasing exchangeable and fixed ammonium ion content of the soil. NH4 + bond in the soil may go again into solution parallel with the dilution of the soil solution but at a slower rate than fixing. This process influences significantly the NH4 + content of the soil. In settlements with no sewerage system the high NH4 + content of sewage flowing out of uninsulated septic tanks may increase the fixed NH4-N content of the soil that could have a significant effect on the quality of groundwater even after the potential disappearance of pollution sources.
In this study the effects of the fixed NH4-N content of the soil around an uninsulated residential septic tank on the purification processes of the groundwater were investigated. The septic tank in the study area was dismantled in 2014 after 27 years of operation as a sewerage system was constructed. When the tank was still in operation in 2012 and 2013, very high, 55–75 mg l-1 NH4 + content was measured in the water of the monitoring well 1 metre from the tank in the course of seasonal sampling. When sewage outflow was terminated in 2014 concentrations decreased right away but even 5 years after pollutant supply was stopped, concentrations (35–57 mg l-1) highly exceeding the pollution limit (0.5 mg l-1) were measured. Considering this very high concentration, it can be assumed that great amount of NH4 + is still released into the groundwater.
In order to prove this, the exchangeable and fixed NH4-N and NO3-N contents of the soil were determined by 20 cm down to a depth of 4 metres (2019). The measurements indicated the significant accumulation of exchangeable and fixed NH4-N in the zone between 220 and 400 cm. Highest fixed NH4-N concentrations of 457 mg l-1 were found between 220 and 240 cm suggesting that sewage outflow was most intense at this depth. Slow decrease in concentrations can be observed in deeper zones but concentrations higher than 350 mg l-1 were measured between 220 and 380 cm. Based on correlation analyses, the quantity of fixed NH4-N shows no correlation with the soil texture thus it can be stated that the vertical pattern of NH4-N content is determined dominantly by sewage outflow and its depth. In the unsaturated zone of the borehole a significant accumulation of NO3-N was also identified. The maximum of NO3-N was found in the zone between 100 and 140 cm. The peak nitrate calculated for NO3 - ion with a value >1300 mg kg-1 is 2.5 times the limit set for the nitrate content of the geological medium.
Based on the results, exchangeable and fixed NH4-N contents in the soil are still very high, 5 years after sewage outflow was stopped. The continuous solution of this component still contributes to the high NH4 + content of the groundwater. As a result, the contaminated soil in the immediate environment of the septic tank is still a pollution source.
Abstract
In the last years, an alternative and convenient way to composting and/or bio-gasifying food waste is represented by the extraction of high value bioactive components from such materials. In particular, essential oils contained in matrices such as orange or lemon peels may represent high value bioactive components for the nutraceutical and pharma industry. In recent years, microwave assisted processes have been considered for use in solvent-free extraction. However, the microwave assisted extraction is often performed in very simple microwave systems, without an accurate control, if any, of the power release.
In this work, the linear tuning of microwave power for the extraction of bioactive components from citrus peels is discussed, with emphasis on the consequent process yield and extract characteristics. Chemical analysis of the extracted mixture showed the presence of quite a number of active molecules of relevant interest for pharmaceutical and nutraceutical industries, such as glycoside flavanone (Hesperidin and Eriocitrin) in lemon peels, and polymethoxylated flavones (Nobiletin and Sinensetin) in orange peels.
Abstract
Bicolor (Rosaline) and black (Regina) sweet cherry cultivars were treated with chitosan-Ca-lactate and chitosan-alginate solutions. The chitosan coating is biocompatible, nontoxic and possesses antimicrobial activity. The sample series (five replicates of thirty pieces from each variety and each treatment, and a control) were refrigerated at 4 °C for 21 and 28 d, to the end of shelf-life. Physical (visual sorting, weight loss and texture of intact fruit), physicochemical (TSS, antioxidant activity, and pH of the pulp), and microbiological properties (total number of microorganisms, Escherichia coli, fungi and yeasts) were investigated weekly. For the last week only the Regina cultivar had acceptable appearance, the other cultivar was discarded after 21 d. The chitosan-alginate treatment preserved the texture, showed smaller weight loss, higher antioxidant preservation and smaller microbial contamination than the samples with chitosan-Ca-lactate on both cultivars. Based on the results, the edible coating can help to preserve the nutritional value of fresh fruit and this technology can be useful in preparing the ready-to-eat fruit salads or in decoration of confectionery products.
