2009 Volume 20 Issue 2 Pages 111-118
Currently, over 90% of medical waste in Japan is treated at off-site facilities where incomplete treatment and illegal dumping is highly likely. This study proposes a novel detoxification treatment for medical wastes, specifically infected plastic syringes, using supercritical water oxidation (SCWO).
We conducted SCWO of polypropylene (PP) microtubes, disposable plastic syringe and evacuated blood collection tubes selected as model medical disposable wastes. Experiments were conducted in a compact batch reactor at 450°C and 25MPa. Results showed that not only the single component sample (PP) but also multiple component samples (disposable syringes with needles attached and evacuated blood collection tube) were decomposed successfully except for their metal parts. In addition, Escherichia coli (coliform bacillus) were eliminated simultaneously with the PP decomposition. These results confirm the prospect of employing SCWO systems for practical applications in the treatment of infectious medical wastes.
