Abstract：
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.
摘要：
在含藻类水的氯化中形成的有机氯胺是含氮消毒副产物（N-DPB）的典型前体。同时提高有机氯胺的去除效率和控制DBP形成的目标仍然是一个挑战。在这项研究中,我们报告了一种两步氯化策略，用于将有机氯胺转移到一氯胺，基于单和二有机氯胺的分解机理，这可以限制有机氯胺的形成并抑制N-DBPs的形成。我们证明，两步氯化可以使有机氯胺的形成比常规的一步氯化减少近50％。此外，两步氯化不仅阻断了有机氯胺分解成腈的途径，但也导致有机氯胺转化为一氯胺。在藻类有机物的两步氯化过程中，有机氯胺转移比例下降了6.5%，一氯胺转移比例上升了17.0%。N-DBP地层,尤其是卤代乙腈（HAN），在两步氯化中，随着有机氮变为无机氮（一氯胺），显着降低。这项工作进一步阐明了从藻类有机物到N-DBPs的过程，这可以扩大我们对藻类衍生的有机氯胺去除和DBPs控制的理解。
