Wyniki wyszukiwania - BazTech

1

Critical assessment and recommendations for sewage sludge management in Poland

Wiśniewski Zbigniew, Kuczmaszewski Józef, Halicka Katarzyna, Kuboń Maciej, Kocira Sławomir, Marczuk Andrzej, Oleksiak Beata

Economics and Environment

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2023

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No. 4

1--28

EN

The purpose of the article is to demonstrate practices used to supervise the use of sewage sludge for agricultural purposes. The presented research and conclusions are a trend analysis and are not to be used to penalise entities. Sewage sludge, which comes from the illegal dumping of wastewa-ter into municipal wastewater by industrial plants, contains large amounts of heavy metals. Treatment plants transfer the sludge for agricultural use. Regulations specifically restrict the mode and condi-tions for such use of sludge. Methods: the research was carried out using a proprietary questionnaire, which is a supplement to the reporting questionnaire of the National Urban Wastewater Treatment Program implemented by the State Water Company "Wody Polskie". Results: The survey was con-ducted at 208 wastewater treatment plants in Poland. The results show that the majority of wastewater treatment plants do not properly supervise the process of introducing sewage sludge into the soil. They also lack supervision of how much heavy metals from wastewater are introduced into the soil. This means that there is a very high risk of contamination of agricultural soils. The results obtained could initiate a detailed analysis of this phenomenon in Poland. A comprehensive study of the scale of the practice and its current effects is required to determine the actual condition of soil treated with sewage sludge.

PL

Celem artykułu jest przedstawienie praktyk stosowanych w ramach nadzoru nad rolniczym wykorzystaniem osadów ściekowych. Przedstawione badania i wnioski mają charakter analizy trendów i nie powinny być wykorzystywane do karania podmiotów. Osady ściekowe, pochodzące z nielegalnego zrzutu ścieków komunalnych przez zakłady przemysłowe, zawierają duże ilości metali ciężkich. Oczyszczalnie przekazują osad do wykorzystania w rolnictwie. Przepisy wyraźnie ograniczają tryb i warunki takiego wykorzystania osadów ściekowych. Metody: badania przeprowadzono z wykorzystaniem autorskiej ankiety, będącej uzupełnieniem ankiety sprawozdawczej Krajowego Programu Oczyszczania Ścieków Komunalnych realizowanego przez Państwowe Gospodarstwo Wodne „Wody Polskie”. Wyniki: Badanie przeprowadzono w 208 oczyszczalniach ścieków w Polsce. Wyniki pokazują, że większość oczyszczalni ścieków nie prowadzi właściwego nadzoru nad procesem wprowadzania osadów ściekowych do gleby. Brakuje również nadzoru nad ilością metali ciężkich ze ścieków wprowadzanych do gleby. Oznacza to, że istnieje bardzo duże ryzyko skażenia gleb uprawnych. Uzyskane wyniki mogłyby zapoczątkować szczegółową analizę tego zjawiska w Polsce. Konieczne jest kompleksowe zbadanie skali takich praktyk i ich skutków, aby określić rzeczywisty stan gleby poddanej działaniu osadów ściekowych.

2

Investigations of Adhesive Properties of Polyamide Modified with Friction Reducing Agents

Anasiewicz Kamil, Kuczmaszewski Józef

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 1

113--121

EN

Polyamide is a material used in various industrial sectors. In moving connections, in order to reduce friction between elements made of polyamide, lubrication is used or other substances reducing friction are added, such as molybdenum disulfide. It can be hypothesised that improving the sliding properties of polyamide will adversely affect polyamide’s ability to form effective adhesive bonds. An interesting question is whether a possible unfavourable change in adhesive properties of such modified polyamide will significantly influence the strength of adhesive bonds of this material. This paper analyses the adhesive properties of polyamide with respect to the strength of adhesive bonds. In order to verify the hypothesis, comparative tests of tensile shear strength of bonded doubleoverlap samples were carried out. Tests were conducted in accordance with ASTM D3528. Samples were prepared using Polyamide PA6, PA6 – MoS2, PA6G + oil and EN AW 2024 aluminium alloy. The following technologies were used to prepare the surface prior to bonding: plasma, sol-gel and abrasive jet machining. The summary of the article indicates that adding friction reducing agents to polyamide does not significantly affect the deterioration of its adhesive properties. Samples prepared with sandblasting achieved form 81.8% up to 114% higher shear strength than samples prepared with plasma and sol-gel treatments, disregard of added friction reducing agents to the adhered polyamide material. It is also interesting information of a utility character. A general conclusion can be formulated that the appropriate preparation of the polyamide surface, regardless of its material modification with friction reducing agents, in the technologies analysed, particularly by sandblasting, can ensure satisfactory results of joining the polyamide by adhesive bonding.

3

Chip Temperature Measurement in the Cutting Area During Rough Milling Magnesium Alloys with a Kordell Geometry End Mill

Kuczmaszewski Józef, Zagórski Ireneusz, Zgórniak Piotr

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 2

109--119

EN

The paper presents the results of measurements of chip temperature in the cutting zone during milling. The main aim of the research was to record and compare the maximum chip temperature in consecutive frames of thermal images. An additional goal may be the influence of changes in technological parameters on the temperature of the chips in the cutting zone. Two grades of magnesium alloys were used for the tests: AZ31 and AZ91HP. The research used a carbide milling cutter with an additional chip breaker, dedicated to effective roughing of light alloys. These tool geometries can assist in the high-performance machining of magnesium alloys by efficiently splitting the chip and consequently reducing friction in the machining zone. This can reduce the cutting area temperature. The results of the research work were showed as exemplary "time" charts, box-plot charts and a summary table, which additionally included an error analysis of the measurement method. On the basis of the tests and measurements performed, it can be concluded that despite the observed chip fragmentation, the obtained temperatures can be defined as the so-called safe milling areas. During the machining tests, the risk of chip ignition during machining was not observed, also the characteristic melting points, which clearly indicates the safety of the milling process of these alloys. It has been observed that with the increase of vc and fz, there was no increase in the maximum temperature of the chip in the cutting area. This situation only occurs when increasing ap.

4

Quality of Samples in Adhesive Joint Testing

Kuczmaszewski Józef, Zawada-Michałowska Magdalena

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 3

182--191

EN

The study attempts to assess the quality of various types of samples used in the adhesive joint testing. One great weakness of the scientific research conducted on this type of joints is that the published papers generally do not include an analysis of the samples quality. Although the standards define the tolerances of individual dimensions, detailed reports are in fact rarely presented. Above all, it is very important to control the thickness of the adhesive, which significantly affects the strength of adhesive bonds. It was found that obtaining high quality samples depends mainly on observing the technological discipline and using appropriate instrumentation. The paper presents the standards that should be a reliable model for the scientific research on adhesive joints.

5

State of residual stresses after the process of milling selected aluminium alloys

Kuczmaszewski Józef, Łogin Waldemar, Pieśko Paweł, Zagórski Ireneusz

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 1

63--73

EN

The purpose of this paper was to analyse the structure and the state of residual stresses in the samples made of rolled AW-2024 and AW-7075 aluminium alloy plates, prior to machine cutting and after the process of milling under various machining conditions. The state of stresses was evaluated on the basis of measurements by means of sin2vF X-ray diffractometry and layer removal method. Furthermore, top layer microstructures were compared in half-finished product, machined product, and core material samples.