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Changes in toxic elements content of soil after sewage sludge treatment in energy willow plantation
7-10Views:116The primary purpose of our experiment was the solution of municipal excess sludge treatment by a renewable energy resource used willow (Salix viminalis L.) plantation. Tests were carried out to state whether the applied sewage sludge has caused any accumulation of the toxic elements in the studied soil layers, and - based on the results –to see whether the plantation is suitable for the treatment of municipal sewage sludge.
The excess sludge (sludge before dewatering) is beneficial for the willow, because it contains a 3–5% dry matter and therefore, a lot of water, too. This high water content ensures the high water amount needed for the intensive growth of the willow. On the other hand, the wastewater treatment plant can save the dewatering cost which corresponds to about 30% of the water treatment process costs. The amounts of the sprinkled sewage sludge were calculated on the basis of its total nitrogen content. Treatments were the followings: control, 170 N kg ha-1 year-1 and 250 N kg ha-1 year-1. The mean values of the toxic element concentrations in the sewage sludge did not cross the permitted limits of the land accommodating.The measured toxic element values of the soil were compared to the limits of the 50/2001. (IV.3.) Government Regulation.The sprinkled sewage sludge on the bases of the total N content did not cause accumulation of heavy metals in the soil and the treated plants were also healthy without any signs of toxicity.
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Regulation in Hungary of the Use of Waste Water and Sewage Sludge in Agriculture
143-149Views:104Regulating the use of waste water and sewage sludge in agriculture in such a way as to prevent harmful effects on soil, vegetation, animals and man.
In European Union there is a Council Directive (86/278/EEC) on the protection of the environment, and in particular of the soil, when sewage sludge is used in agriculture.
In the enlargement process of the European Union the Hungarian Government created a new rule (50/2001. (IV. 3.) Government regulation) which regulate using of waste water and sewage sludge in agriculture. This Hungarian rule is legal and reconcilable with the Council Directive.
The Regulation lays down limit values for concentrations of heavy metals in the soil, in waste water, in sludge and for the maximum annual quantities of heavy metals which may be introduced into the soil.
Waste water, sludge and soil on which it is used must be sampled and analysed.
Sewage sludge must be treated for six months before being used in agriculture.
The use of waste water and sludge prohibited on grassland, on nature reserved areas, in ecological farming, and soil in witch fruit and vegetable crops are growing, with the exception of fruit trees.
The states soil conservation authority must keep records registering the following:
– the quantities of waste water and sludge produced;
– the composition and properties of sludge;
– the type of treatment carried out;
– the names and addresses of the recipients of the sludge and places where the sludge is to be used.
The Government every four years must prepare a consolidated report on the use of sludge in agriculture, specifying quantities used, criteria followed and any difficulties encountered. This report must be forwarded to the Commission.
Last but not least in the light of Member States reports, the Commission will if necessary submit appropriate proposals for increased protection of the soil and the environment. -
The applied mechanical equipments for wastewater treatment in the észak-Alföld region
171-178Views:148In this study we presented the results of a survey research, which was performed during 2015 at 34 sewage treatment works, operating in Észak-alföld region (Hungary). The survey focused on applied mechanical equipment and works of art of the sewage treatment establishments.
The results of the survey showed that the majority of the examined sites (approx 65%) are working with capacity utilization of 50–100%,merely the 12% of plants was overload. It was found analyzing of specific energy consumption of the sites that the largest value (1.1 kWh per m3) was at the plants with smaller capacity (0–1000 m3 per day). It was clear during the questionnaire processing of the survey that almost all of the works applied activated sludge for sewage treatment The sludge treatment of the sewage plants is conducted by two methods; aerobic- and mixed (anaerobic and aerobic) sludge stabilization. We suggest for the plants with small capacity to use deep aerators, since anachronistic method used the at 3% of the settlements.
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Investigation of the impacts of the by-product of sewage treatment on some characteristics of maize in the early growth stage
77-82Views:38The use of sewage sludge on arable land has been widespread for many years. This by-product, treated as waste, can provide valuable nutrients to the soil, but the applied amount of sewage sludge to arable land is limited. The possibility of application of sewage sludge is essentially determined by the composition of the sludge. The goal of the experiment was to demonstrate that the physiological, morphological, and biochemical parameters of maize (Zea mays L. cv. Armagnac) linearly change with increasing concentrations of sewage sludge (25%, 50%, and 75% as m/m%). The experiment was set up in a glasshouse. The following parameters were investigated: plant height, relative chlorophyll content, photosynthetic pigments (chlorophyll-a, chlorophyll-b, carotenoids), and leaf proline and malondialdehyde (MDA) content, and PS II quantum efficiency in the 3-leaf stages of the plants. Sewage sludge applied in lower doses had a beneficial effect on the initial growth of maize. The relative chlorophyll content was significantly higher in all treatments compared to the control. There was no significant difference in the maximum quantum efficiency of PS II reaction centers among the treatments. In this experiment, different concentrations of sewage sludge treatments had different impacts on the MDA and proline content of maize leaves. The proline content was significantly higher in all treatments, while the MDA content did not change significantly compared to the control.
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Novel Applications of Microwave Techniques in the Food and Environmental Industries
29-34Views:90During the microwave processing, despite the conventional heating, the material heats consistently inside. This property of microwave is utilized by drying and dehydration processes. The thermal sensitivity of raw materials of food industry requires development of gentle, fast and controllable technologies, which is realizable by means of combination of conventional and microwave techniques. The other important application area of the microwave technique is food industrial practice is enhancing the microbial safety of products, mainly by pasteurization processes. In recent time the strict environmental regulation necessitate developing more effective treatment of wastes, waste waters and sewage sludge. Because a part of these techniques are heat and power demanded, the microwave technique may be an alternative process in execution of sludge conditioning, drying or gasification and pyrolysis.
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The effect of compost application on physical properties of sandy soil
67-70Views:150The sewage sludge compost is suitable to improve the colloid-poor sandy soils, which are common characteristics of poor water- and nutrientholding capacity. The general characteristics of sandy soils are the light mechanical composition, the low content of humus and mineral colloids, large pore size and a bad aggregate stability. They have a poor nutrient supply capacity, due to its high porosity the organic matter is degraded very quickly to mineral colloids (Stefanovits et al., 1999).
By the compost application the soil is enriched mineral and organic colloids, thereby improving the soil structure. The effect of addition of compost to soil the water- and nutrient-holding capacity and porosity could be increased and the bulk density could be decreased (Martens and Frankenberger, 1992).
The aim of our experiment is to carry out physical measurements to determine the effects of compost treatment. In this study the results of the first year are presented.
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The effect of various composts on vegetable green mass on two soil types
179-183Views:136Composting of sewage sludges makes easier the utilization of sewage sludge in the agriculture and the composts in good quality could increase the nutrient content of soil. Due to the composting process, the sewage sludge composts with high organic matter content can be utilized in the same way as other composts or farmyard manure.
Composts produced in different ways have different effects on the physical, chemical and biological properties of different soils, although their positive effects have already proved in the literature. In our study the effects of composts from different composting processes were investigated in soil-plant systems. The different physical and chemical properties of the two examined soil types (arenosol and chernozem)strongly influenced the nutrient supply capacity of composts which could be characterized by the growth of ray-grass as a test plant in the pot experiment. In this work we examined the effects of three different composts on the green weight of plants on the fourth and eighth weeks after the treatment and sowing.