Effects of Prototype Hydroxylated Water Treatment on Sanitizing Wastewater Spiked with Bacillus subtilis Spores

A wastewater treatment study evaluated the effects of a prototype hydroxylated water treatment on water spiked with Bacillus subtilis spores. The study objectives were to determine the impact of water exposure time and humic acid water treatments on spore inactivation rates. This factorial study included seven water sample collection times and three humic acid concentrations with 21 water treatments. The prototype hydroxylated water treatment system reduced viable B. subtilis spore by 2.47 log10 after a 12-minute exposure without any quenching agents in the water. The average B. subtilis spore concentration for the control water samples was 4.86 x 105 CFU/ml. Adding humic acid at 0.5% (v/v) as a quenching agent reduced spore inactivation from 3 to 1 log10. Also, adding humic acid as a quenching agent reduced oxidation-reduction potential (ORP) from 600 to about 250 mV. Wastewater treatments based on hydroxylated water technologies can sanitize bio-contaminated water if the water is first filtered to remove most organic contaminants. Alternatively, hydroxylated water treatments should use extended water exposure times, beyond 12 minutes, to minimize the quenching effects of the organic matter in wastewater.