Biodegradation of multiple nitrosamines by the Bacillus species LT1C in drinking water biofilters

To better clarify the biodegradation mechanism of nitrosamines at low concentrations and characterize the nitrosamine-reducing strains isolated from biological activated carbon (BAC) filters in drinking water treatment plants. The nitrosamine-reducing bacterial culture Bacillus species LT1C was cultivated, isolated and purified from a pilot filter system using BAC, and was then applied to evaluate the biodegradable capacity for nitrosamines. Five nitrosamines (N-nitrosomethylethylamine, N-nitrosodi-n-propylamine; N-nitrosopyrrolidine and N-nitrosodi-n-butylamine, N-nitrosopiperidine) were biodegraded in mineral salts medium with removal ratios which ranged from 23.6 to 51.2%. The removal ratios achieved by the isolate were in accordance with the structure, LogK_ow and Henry's constant of the nitrosamines examined. The findings of this study demonstrate increased potential for the establishment of nitrosamine control strategies in the water supply industry.