Elimination of β-N-methylamino-l-alanine (BMAA) during UV/chlorine process: Influence factors, transformation pathway and DBP formation.

As a new cyanobacterial neurotoxin generated by cyanobacteria, BMAA was closely related to amyotrophic lateral sclerosis-parkinsonism dementia complex (ALS/PDC). In this study, the degradation of BMAA by UV/chlorine process was investigated under the impacts of chlorine dosage, NOM dosage, pH and alkalinity. Results showed that only 10% of BMAA was removed by UV irradiation and 46.8% by chlorination in 5 min, however, 98.6% of BMAA was removed by UV/chlorine process in 5 min. The reaction rates were increased under alkaline conditions, but all achieved complete degradation in 5 min. Besides, HCO3- had slight inhibition, while NOM had significant inhibition on the degradation of BMAA. Furthermore, based on the detected degradation products of BMAA during UV/chlorine process, the possible degradation pathways were concluded. Overall, outcomes of this study exhibited that the use of the UV/chlorine process for BMAA degradation was appropriate in practical applications.