Page 49 - חוברת תזות הנדסה ירוקה 2023

Disinfection of water and surfaces using a system that generates monovalent copper ions
Bar Sabag1: barcohen72@gmail.com
Dr. Magal Saphier2, Dr. Oshra Saphier1
1SCE - Shamoon College of Engineering, Be’er-Sheva, 2Negev Nuclear Research Center
Sweet water is vital for humans, animals, plants, and various ecological systems. The prominent factors leading to the reduction of freshwater availability worldwide include population growth, climate change, the spread of diseases like COVID-19, and water source pollution. Water pollution is a complex problem that significantly affects public health systems by facilitating the spread of Escherichia coli bacteria, which serves as an indicator of contamination. Currently, a purification process for wastewater reuseexists that involves multiple stages. The final stage is water disinfection, which is mostly done by chlorination. However, this method is complex and may produce toxic and carcinogenic byproducts. Therefore, there is a demand for green and safe disinfection technologies.
The main objective of this research is the development of antimicrobial systems based on monovalent copper ions )Cu+( at low and non-toxic concentrations, as alternatives to chlorination. This objective may be achieved via three methods. In the first method, a system was constructed with a batch reactor containing water contaminated with E. coli bacteria. The reactor contains a positive copper amino phosphate ion exchanger charged with divalent copper ions )Cu2+( and metallic copper )Cu0( particles with large surfaces. The contained water releases Cu2+ ions that react with copper to produce Cu+ ions. Complete disinfection is achieved after 10 minutes )37°C( in a batch system. In a continuous system using the same method, although the E. coli bacteria have been eradicated, different strains of bacteria were observed. As such, this suggests that these other types of microorganisms have developed a certain resistance to monovalent copper ions.
The second method for disinfection involves the use of an electrochemical potential to convert Cu2+ ions to Cu+ ions, in which the system maintains a constant concentration and amount of copper ions without the addition of additional substances. The initial experiments were conducted on a small-scale batch system with a volume of 100 mL and 1 L to test the feasibility of the electrochemical method for disinfection and find ideal conditions for the system. According to the results, an optimal disinfection voltage of 0.3 V was determined; the electrode material was bronze with 7% tin )Sn( and 93% copper )Cu(, compacted )grains with a diameter of 50 μm( and sintered.
Three spinning systems for water disinfection were constructed to simulate swimming pools: A-50L, B-1000L, and C-2000L. Different parameters were tested: pH, temperature,
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