scholarly journals Complex mechanism of sulphane odour production in water heating and suitable remedial measures

Author(s):  
Jaroslav Šašek ◽  
František Kožíšek

Abstract Drinking or heated water can have a wide range of disturbing odours which have many various causes. A well known example is sulphane (hydrogen sulfide) odour, reminiscent of rotten eggs, which naturally occurs in some underground waters. Less known and hitherto unexplained is this odour arising from hot water in water heaters. As a response to complaints by consumers we investigated 14 sites and thanks to experimental work in one of these recognised a complex mechanism at work. For production of sulphane to occur in a water heater the following conditions must be met: presence of sulphate-reducing bacteria, presence of sulphates, reduction properties of water indicated by a very low nitrate content (highest value was 10 mg/L, mostly <2 mg/L), and presence of sacrificial magnesium anode. We identified four possible remedial measures, some of which are less effective or only short-term, or have an undesirable side-effect (corrosion). The most effective measure was replacement of the magnesium anode for an aluminium or zinc anode, which retains the anticorrosion protection of the heater.

1986 ◽  
Vol 21 (1) ◽  
pp. 50-57 ◽  
Author(s):  
D. R. Cullimore ◽  
N. Mansuy

Abstract A small diameter water well drilled in 1977 in the Town of Bulyea, Saskatchewan generated such a rapid plugging (biofouling) that by 1979 the flow rate was reduced by 59%. Heavy growths of non-specific iron bacteria were found in the water and biofouling projected to be the principal cause of the flow loss. Tyndallization (repeated pasteurizations) treatment was applied using a hot water recycling system installed above the well head. Using a displacement passive gravity direct injection of hot water at 82°C from a water heater into the well, a sequential elevation of water column temperatures occurred until bio-film dispersion occurred (pasteurization) at 45°C+. A recovery to original flow specifications was repeatedly obtained at time intervals ranging from 6 to 403 days. Between treatments, a recurrence of biofouling was noted with flow reductions of 0.06 – 0.07 1/min/day frequently being noted. The rate of plugging appeared to be affected by the previous sequence of pasteurization treatments. Tyndallization was found to satisfactorily control iron bacterial biofouling and maintain flow rates.


Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Martin Pullinger ◽  
Jonathan Kilgour ◽  
Nigel Goddard ◽  
Niklas Berliner ◽  
Lynda Webb ◽  
...  

AbstractThe IDEAL household energy dataset described here comprises electricity, gas and contextual data from 255 UK homes over a 23-month period ending in June 2018, with a mean participation duration of 286 days. Sensors gathered 1-second electricity data, pulse-level gas data, 12-second temperature, humidity and light data for each room, and 12-second temperature data from boiler pipes for central heating and hot water. 39 homes also included plug-level monitoring of selected electrical appliances, real-power measurement of mains electricity and key sub-circuits, and more detailed temperature monitoring of gas- and heat-using equipment, including radiators and taps. Survey data included occupant demographics, values, attitudes and self-reported energy awareness, household income, energy tariffs, and building, room and appliance characteristics. Linked secondary data comprises weather and level of urbanisation. The data is provided in comma-separated format with a custom-built API to facilitate usage, and has been cleaned and documented. The data has a wide range of applications, including investigating energy demand patterns and drivers, modelling building performance, and undertaking Non-Intrusive Load Monitoring research.


Author(s):  
Martin Mittermayer ◽  
August Gilg ◽  
Franz-Xaver Maidl ◽  
Ludwig Nätscher ◽  
Kurt-Jürgen Hülsbergen

AbstractIn this study, site-specific N balances were calculated for a 13.1 ha heterogeneous field. Yields and N uptake as input data for N balances were determined with data from a combine harvester, reflectance measurements from satellites and tractor-mounted sensors. The correlations between the measured grain yields and yields determined by digital methods were moderate. The calculated values for the N surpluses had a wide range within the field. Nitrogen surpluses were calculated from − 76.4 to 91.3 kg ha−1, with a mean of 24.0 kg ha−1. The use of different data sources and data collection methods had an impact on the results of N balancing. The results show the need for further optimization and improvement in the accuracy of digital methods. The factors influencing N uptake and N surplus were determined by analysing soil properties of georeferenced soil samples. Soil properties showed considerable spatial variation within the field. Soil organic carbon correlated very strongly with total nitrogen content (r = 0.97), moderately with N uptake (sensor, r = 0.60) and negatively with N surplus (satellite, r = − 0.46; sensor, r = − 0.56; harvester, r = − 0.60). Nitrate content was analysed in soil cores (0 to 9 m) taken in different yield zones, and compared with the calculated N surplus; there was a strong correlation between the measured nitrate content and calculated N surplus (r = 0.82). Site-specific N balancing can contribute to a more precise identification of the risk of nitrate losses and the development of targeted nitrate reduction strategies.


2021 ◽  
Vol 11 (15) ◽  
pp. 7043
Author(s):  
Tun-Ping Teng ◽  
Shang-Pang Yu ◽  
Yeou-Feng Lue ◽  
Qi-Lin Xie ◽  
Hsiang-Kai Hsieh ◽  
...  

This study selects titanium dioxide (TiO2) and multi-walled carbon nanotubes (MWCNTs) as far-infrared materials (FIRMs), and further adds water-based acrylic coatings to prepare far-infrared coatings (FIRCs). FIRCs are uniformly coated on #304 stainless steel sheets to make the test samples, which are then installed between the shell and insulation material of the hot water heater to measure the influences of various FIRCs on the performance of the hot water heater. The research results show no significant difference in the heating rate or heat insulation performance of the hot water heater with or without FIRCs coating. However, the uniformity of the water temperatures of the test samples is significantly improved with FIRCs. Considering that the uniformity of water temperature will inhibit the heating rate and heat insulation performance of the hot water heater, TiO2-FIRC should provide better performance improvement when applied to the hot water heater in this study. The application of TiO2-FIRC to large-scale hot water heaters with a high aspect ratio will effectively improve the quality of hot water supply in the future.


Author(s):  
Ramses Vega ◽  
Hector E. Campbell ◽  
Juan de Dios Ocampo ◽  
Diego R. Bonilla G.

This paper shows the simulation and design of a flat plate solar collector system, used to feed hot water to a typical home located in the city of Mexicali, Baja California, México. The system consists of a solar collector, a storage tank, a water pump and accessories and special tools that allow its proper operation. Analyzing the consumption and end use of water in a typical House, a demand profile is established, which combined with the weather information of the region, constitutes the input parameters required for the simulation of the system, which is performed with the software package TRNSYS. Mexicali, due to its location (latitude 32 °, longitude 114 °) and semi-desert condition presents high temperatures in the summer and low in winter, so the design and operation of such systems require special features, not always considered in the conventional ratings. This paper presents methods for simulation and design oriented to optimize the dimensioning and operation of this type of solar heaters in regions with extreme temperature conditions.


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