Achieved test results

EcoSeaSafe addresses one of the major challenges with current state-of-the-art technologies, which is the possible formation of long-lived toxic substances both from UV and electrolytic treatment. So far, the project consortium has been successful in meeting the planned scientific and developmental project objectives.

Inactivating coliform bacteria
Tests have confirmed the principle of inactivating coliform bacteria by reverse pulsed DC. The hypothesis that harmful secondary products are not likely to be formed by reverse pulsed DC was also positively confirmed during tests. The active substances and mechanisms involved in inactivating coliform bacteria have been studied by Teknologisk Institutt (TI), Norway. All the six pure metals tested showed inactivating effect on E.coli at some level under the test conditions used, while only one metal was >99 % effective. Also, it was proved that the most likely oxidation products, i.e., free chlorine, were not produced in noticeable quantities.  Using theory it is deducted that this is due to the very short reaction time available for electrolysis of sea water by the reversing polarity technology.  A prime goal was met; namely to avoid secondary products of chlorine while still inactivating coliform bacteria.

Properties of electrode materials
The over-potential properties of electrode materials were also studied theoretically. It is likely that high over-potentials are related to the reaction mechanisms at the electrode surface, depending on both the metal in question and the actual red ox reaction. Some metals leak quite rapidly into seawater, thus providing a possible independent mechanism of inactivation. From a list of more than 10 candidate metals, the list was narrowed down to 4 selected for further testing as electrodes.

Water quality parameters
Water quality parameters are important for effective inactivation of target organisms and energy consumption. Increased voltage can compensate for high resistance, more organic material or more organisms. Continued work will focus upon electrode cell construction, materials testing, process control, integration and optimization and on documentation of energy efficiency.

Development of pulse generator
A dedicated pulse generator has been developed by the RTD performer Labor, Italy. The architecture of the alpha prototype pulse generator is composed by three main blocks: (1) Power supply section with programmable output voltage, (2) pulse shape section where DC voltage are reversed and turned on/off according to the desired duty-cycle and frequency, and (3) control unit providing interface with the main control system and/or human manual intervention and control signals for the other sections. The pulse generator can be connected to a PC via serial USB interface.

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