%0 Journal Article
%T Transfer organic chloramines to monochloramine using two-step chlorination: A method to inhibit N-DBPs formation in algae-containing water treatment.
%A Sheng D
%A Bu L
%A Zhu S
%A Deng L
%A Shi Z
%A Zhou S
%J J Hazard Mater
%V 443
%N 0
%D 02 2023 5
%M 36444058
%F 14.224
%R 10.1016/j.jhazmat.2022.130343
%X Organic chloramines formed in chlorination of algae-containing water are typical precursors of nitrogenous disinfection byproducts (N-DPBs). The objective to simultaneously enhance the removal efficiency of organic chloramines and control DBP formation remains a challenge. In this study, we report a two-step chlorination strategy for transferring organic chloramines to monochloramine based on the decomposition mechanisms of mono- and di-organic chloramines, which could limit organic chloramines formation and inhibit N-DBPs formation. We demonstrated that two-step chlorination could decrease the organic chloramines formation by nearly 50% than conventional one-step chlorination. Furthermore, two-step chlorination not only blocked the pathway that organic chloramines decomposed to nitriles, but also led to the conversion of organic chloramines to monochloramine. During two-step chlorination of algal organic matter, the organic chloramine transfer proportion decreased by 6.5% and the monochloramine transfer proportion increased by 17.0%. The N-DBP formation, especially haloacetonitriles (HANs), decreased significantly as organic nitrogen became inorganic nitrogen (monochloramine) in two-step chlorination. This work further clarified the process from algal organic matter to N-DBPs, which could expand our understanding of algae-derived organic chloramines removal and DBPs control.