Purpose: The aim of the study was to present the actual efficiency of a gas-fired instantaneous water heater for the production of domestic hot water. Design/methodology/approach: The object of the study was a gas-fired instantaneous domestic hot water heater located in a flat in Krakow. Measurements with a suitable device were carried out for three basic variants of hot water preparation, defined as showering, washing hands and washing dishes. Findings: The tests and analyses carried out have revealed that the current efficiency (average efficiency based on 3 measurements - 77.61%) differs radically from that indicated on the water heater data sheet. Such a drop in efficiency may be caused e.g. by fouling of the surface of the heat exchanger on the flue gas side and scaling of the exchanger on the heated side. Research limitations/implications: The tests proved that the heater did not reach its nominal efficiency during the tests, but on the other hand, simulations of different intensities and durations of water consumption did not drastically change the efficiency of hot water preparation. Practical implications: Regular cleaning of the exchanger would probably reduce the difference between the efficiency declared by the manufacturer and the one achieved during the tests. A clean heater will also ensure a sufficiently low level of carbon monoxide in the flue gas, which has a real impact on the safety of the appliance. Social implications: The values obtained from the measurements for each operating mode can help occupants understand how to prepare water most efficiently with this particular appliance, which will have a real impact on the bills they pay. The user will be provided with information on what percentage of energy they use from the volume of gas burned. Originality/value: Gas-fired instantaneous water heaters provide an efficient and energysaving solution, especially in situations where the demand for hot water is low, and immediate access to it is crucial.
Purpose: The aim of the study was to investigate the possibility of using engineering waste materials in the form of brick dust and volcanic tuff as corrosion inhibitors. The corrosion tests were carried out on the aluminium alloys against aggressive corrosive environments with acidic pH containing chlorine compounds. Design/methodology/approach: The specimens for corrosion tests were cut from a sheet made of aluminium alloy EN AW-6060. In the first step the aluminium specimens was covered with a coating of clear alkyd varnish without any additives. In the next step used additives in the form of brick dust and vulcanic tuff were used. The tests were carried out using a RADWAG AS 310.R2 laboratory analytical balance to obtain the weight loss results for the specimens tested. Findings: Brick dust used in concentrations of 10% to 40% by weight cannot be considered as a material that allows achieving satisfactory results. This is due to the absorption of the corrosive medium by the brick dust. On the other hand, the volcanic tuff addition of 30% by weight creates conditions that slow down the corrosion process in the long term. Research limitations/implications: Consideration should be given to preparing all types of structural components for corrosion protection by blunting sharp edges for better adhesion of corrosion protection coatings. Therefore, further work should focus on obtaining a coating with an adequate adhesion as well as checking the action of volcanic tuff as an inhibitor in other corrosive media. Practical implications: The introduction of appropriately prepared volcanic tuff additives into protective coatings is expected to increase the effectiveness of the protection of the metal substrate against the corrosion process. It is therefore important to manage and monitor the factors that affect the coating and occur during the painting process. Originality/value: In tests confirmed the good properties of volcanic tuff, which slows down corrosion processes and preserves the uniform corrosion of aluminium. The result obtained has the lowest mass loss values of all the specimens prepared in the experiment, which proves the validity of using the volcanic tuff additive.
W artykule określono wpływ stosowania silnych utleniaczy w technologii uzdatniania wody na powstawanie ubocznych produktów dezynfekcji. Przedmiotem badań były wody pobierane z czterech zakładów uzdatniania wody Miejskiego Przedsiębiorstwa Wodociągów i Kanalizacji w Krakowie oraz z wybranych punktów sieci wodociągowej. Analizie poddano wybrane wskaźniki jakości wody (chlor wolny, sumę chloranów(III) i chloranów(V) oraz sumę trihalometanów) po procesie uzdatniania w latach 2011–2017. Z przeprowadzonych badań wynika, że stężenie chloru wolnego w sieci wodociągowej malało w miarę wzrostu odległości od zakładu uzdatniania. Zależność tę stwierdzono w 19 z 28 punktów poboru wody. Analizując średnioroczne stężenia chloru wolnego w wodzie wodociągowej, zauważono, że najwyższe wartości w badanych punktach występowały w 2011 r. W pozostałych latach obserwowano spadek tego wskaźnika. Z przeprowadzonej analizy wynika, że produkty uboczne dezynfekcji wody nie przekraczały dopuszczalnych norm.
EN
This paper specifies the effect of using strong oxidants in water treatment technologies on the formation of disinfection by-products. The study was developed by collecting water samples from four water treatment plants of the Municipal Water and Sewerage Company (MPWiK) in Krakow and at selected sampling points within the water supply networks. The analysis was comprised of selected indicators of water quality after the treatment process during the years of 2011–2017. From the carried-out investigation, it was concluded that the concentration of free chlorine in the water supply network concurrently decreased with increases in the distance from the treatment plant. This dependence was found in 19 out of 28 water supply points. While analyzing the annual average concentrations of free chlorine in the municipal water, it was noted that the highest values at the study points occurred in 2011. During the other years, decreases in this indicator were observed. This follows from the analysis that the water disinfection by-products did not exceed permissible limits.
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W artykule dokonano oceny korozyjności wody pitnej produkowanej przez Zakłady Uzdatniania Wody Miejskiego Przedsiębiorstwa Wodociągów i Kanalizacji w Krakowie, na podstawie indeksu Larsona. Z zastosowanego wzoru wynika, że własności korozyjne wody rosną wraz ze wzrostem stężenia jonów siarczanowych(VI) i chlorkowych. Natomiast maleją, ze wzrostem wodorowęglanów. W tym celu, analizie poddano powyższe aniony oznaczone w wodach pochodzących z czterech zakładów po procesie uzdatniania. Wnioski i uwagi końcowe.
EN
The article assesses the corrosivity of drinking water produced by water treatment plants Municipal Water and Sewage Company in Krakow, based on the index Larson. In the model used that the corrosive properties of water increase with increasing concentration of sulfate ions (VI) chloride. On the other hand decrease, with an increase in bicarbonate. For this purpose, the analysis indicated above anions in the waters from four plants after the treatment proces.
The objective of the paper is to use life cycle assessment to compare environmental impact of different technologies used in the process of water disinfection. Two scenarios are developed for water disinfection life cycle at ZUW Raba water treatment plant: (1) historical, in which gaseous chlorine is used as a disinfectant and (2) actual, in which UV radiation and electrolytically generated sodium hypochlorite are used for that purpose. Primary data is supplemented with ecoinvent 3 database records. Environmental impact is assessed by IMPACT2002+ method and its midpoint and endpoint indicators that are calculated with the use of SimaPro 8.4 software. The focus of the assessment is on selected life cycle phases: disinfection process itself and the water distribution process that follows. The assessment uses the data on flows and emissions streams as observed in the Raba plant. As the results of primal analysis show, a change of disinfectant results in quantitative changes in THMs and free chlorine in water supplied to the water supply network. The results of analysis confirm the higher potential of THMs formation and higher environmental impact of the combined method of UV/NaClO disinfection in distribution phase and in whole life cycle, mainly due to the increase of human toxicity factors. However, during the disinfection phase, gaseous chlorine use is more harmful for environment. But the final conclusion states that water quality indicators are not significant in the context of LCA, while both disinfection and distribution phases are concerned.
PL
Celem artykułu było pokazanie wykorzystania środowiskowej oceny cyklu życia (LCA) do porównania wpływu na środowisko różnych technologii stosowanych w procesie dezynfekcji wody. Dla cyklu życia procesu dezynfekcji wody w zakładzie uzdatniania wody Raba Miejskiego Przedsiębiorstwa Wodociągów i Kanalizacji (MPWiK) w Krakowie w niniejszej pracy zostały sformułowane dwa scenariusze: (1) historyczny, w którym dezynfektantem jest chlor gazowy oraz (2) bieżący, w którym tę rolę spełnia układ dwustopniowy z promieniowaniem UV i podchlorynem sodu. Podstawowe dane były uzupełniane rekordami bazy danych ecoinvent 3. Oddziaływanie środowiskowe poddano ocenie przy wykorzystaniu metody IMPACT2002+. Pośrednie i końcowe wskaźniki kategorii wpływu wyliczono przy wykorzystaniu oprogramowania SimPro 8. Analiza obejmowała wybrane fazy cyklu życia: sam proces dezynfekcji i następujący po nim proces dystrybucji wody. W ocenie wykorzystano dane ilościowe o przepływach i emisjach w procesie dezynfekcji wody z wybranego zakładu uzdatniania wody. Wyniki wstępnych analiz pokazują, że zmiana dezynfektanta powoduje zmiany ilościowe trihalometanów (THM) i chloru wolnego w wodzie dostarczanej do sieci wodociągowej. Analiza wskazuje, że w fazie dezynfekcji użycie chloru gazowego jest bardziej szkodliwe dla środowiska. Natomiast wyniki analizy potwierdzają wyższy potencjał tworzenia się THM i większy wpływ na środowisko połączonej metody dezynfekcji UV/NaClO w fazie dystrybucji wody.
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