Removal Efficiency of Radioactive Cesium and Iodine Ions by a Flow-Type Apparatus Designed for Electrochemically Reduced Water Production

Abstract

The Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011 attracted people’s attention, with anxiety over possible radiation hazards. Immediate and long-term concerns are around protection from external and internal exposure by the liberated radionuclides. In particular, residents living in the affected regions are most concerned about ingesting contaminated foodstuffs, including drinking water. Efficient removal of radionuclides from rainwater and drinking water has been reported using several pot-type filtration devices. A currently used flow-type test apparatus is expected to simultaneously provide radionuclide elimination prior to ingestion and protection from internal exposure by accidental ingestion of radionuclides through the use of a micro-carbon carboxymethyl cartridge unit and an electrochemically reduced water production unit, respectively. However, the removability of radionuclides from contaminated tap water has not been tested to date. Thus, the current research was undertaken to assess the capability of the apparatus to remove radionuclides from artificially contaminated tap water. The results presented here demonstrate that the apparatus can reduce radioactivity levels to below the detection limit in applied tap water containing either 300 Bq/kg of 137Cs or 150 Bq/kg of 125I. The apparatus had a removal efficiency of over 90% for all concentration ranges of radio–cesium and –iodine tested. The results showing efficient radionuclide removability, together with previous studies on molecular hydrogen and platinum nanoparticles as reactive oxygen species scavengers, strongly suggest that the test apparatus has the potential to offer maximum safety against radionuclide-contaminated foodstuffs, including drinking water.

Electrochemically reduced water exerts superior reactive oxygen species scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water

“…As shown in Table 1 , pH, ORP negativities and DH values increased and were dependent on the electrolysis strength, whereas EC and DO remained essentially constant. Such fundamental characteristics of ERWs produced by the test apparatus are in agreement with previously published data, demonstrating the reproducibility of the apparatus [ 3 , 9 ]. Using these waters as starting materials, we examined whether the ERWs have ROS scavenging activity in HT1080 cells after H 2 O 2 stimulation.…”

“…Detailed information is given in ref. [ 3 ] LV1, LV2, LV3 and LV4 represent FW electrolyzed at levels 1, 2, 3 and 4 with a maximum of 50 V using the test apparatus. NAC, 5 mM N-acetyl cysteine.…”

“…Thus, we used a water flow-type apparatus (Trim Ion Hyper, Nihon Trim Co. Ltd., Osaka, Japan) as the test apparatus. The test apparatus has the same structure to the previously reported apparatus [ 3 ]. Briefly, the test apparatus contains two units, a micro-carbon cartridge unit and an electrolysis unit.…”

“…Consequently, 200,000 apparatuses have been sold each year in Japan [ 2 ]. An alkaline ionized water generator produces electrolyzed water on the surface of the cathode during electrolysis where produced water is commonly referred to as electrochemically reduced water (ERW) [ 3 ]. Typically, apparatuses that produce ERW are composed of two units, a micro-carbon cartridge unit for removal of contaminants and an electrolysis unit that acts on the purified water.…”

“…Typically, apparatuses that produce ERW are composed of two units, a micro-carbon cartridge unit for removal of contaminants and an electrolysis unit that acts on the purified water. Purified tap water passed through a micro-carbon cartridge unit flows into the electrolysis unit, which is composed of five platinum (Pt)-coated electrode plates, separated by semi-permeable membranes and the water is electrolyzed while passing through the gaps between the electrodes [ 3 ]. ERW exhibits suppressive effects against oxidative stress, which correlates with DNA protection [ 4 , 5 ], carbon tetrachloride-induced liver damage [ 6 ], lifespan extension of Caenorhabditis elegans [ 7 , 8 ], alloxan-induced type 1 diabetes [ 5 , 9 ], hemodialysis-induced oxidative stress during end-stage renal disease [ 10 , 11 ] and lipopolysaccharide-induced neuroinflammation [ 12 ].…”