Oyster shells are to clean up waste water in Oshima, Japan. ‘Oyster shells harbour large numbers of anaerobic and aerobic microbes on their surfaces. Dirty water is food for these microbes,’ explains Toyokuni Asahina, one of the designers of the wastewater plant. Around 250 tonnes of shells will be used annually to form layers in filtration tanks where the oyster-shell microbes can feast on kitchen, bath and laundry water from 265 households.
New Scientist Vol 161 No 2169