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

Abstract

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, LogKow 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.