Decontamination of low-level contaminated water from radioactive cesium and cobalt using microalgae

This study selects microalgae suitable for the decontamination of radioactive cobalt (Co-60) in radioactive solutions based on the decontamination efficiency of Co-60 and Cs-137 by various microalgae. The biosorption rates of Co-60 in the low-level contaminated water have been measured using three different types of microalgae Haematococcus sp., Vacuoliviride crystalliferum , and Chlorella vulgaris, which are known to uptake Cs-137 and Sr-90 effectively. In the comparative experiments, Haematococcus sp. showed the highest decontamination efficiency within 48 h, and it could be a suitable bio-adsorbent out of three types of microalgae for the removal of Co-60. Haematococcus sp. also removed 88.0% of Cs-137 from contaminated water for 48 h. Our findings indicated that the low-level radioactive solution was decontaminated to a very low-level state through the biosorption process of microalgae.