Pilot-scale evaluation of oxidant speciation, 1,4-dioxane degradation and disinfection byproduct formation during UV/hydrogen peroxide, UV/free chlorine and UV/chloramines advanced oxidation process treatment for potable reuse

Control of sulfides and coliphage MS2 using hydrogen peroxide and UV disinfection for non-potable reuse of pilot-scale anaerobic membrane bioreactor effluent

“…Although lower H 2 O 2 doses are required at pH < 7.1, filtration would be required to remove the particulate elemental sulfur. Even though sulfide oxidation to sulfate requires the same molar equivalents of H 2 O 2 and chlorine, H 2 O 2 is nearly half the cost of chlorine ( Zhang et al., 2019 ; City of Oxnard, 2012 ). Chlorine addition after sulfide oxidation by H 2 O 2 would form chloramines in situ .…”

Degradation of contaminants of emerging concern by UV/H2O2 for water reuse: Kinetics, mechanisms, and cytotoxicity analysis

“…LW-DOM would react with OH at higher rate (Appiani et al, 2014), which could pass through the MF and RO pretreatment (Chuang et al, 2017;Kwon et al, 2019;Patton et al, 2018). Additionally, due to the reactions of chlorine added before MF with the residual/bio-generated ammonia in the wastewater, UV/H 2 O 2 in the GWRS RO permeate is actually a de facto UV/H 2 O 2 -chloramines AOP, which are less effective in removing organic contaminants and more susceptible to the DOM (Zhang et al, 2019). Therefore, the higher ROS demand of RO I might be due to the varied quality of sewage and wastewater discharges as secondary treatment influent (i.e.…”

Disinfection and antimicrobial processes

“…In another research, Zhang et al (2019) conducted a pilot‐scale study to test the application of different AOPs (mainly: UV/H 2 O 2 , UV/free chlorine, and UV/chloramines) for the removal of 1,4‐dioxane and DBP control. Oxidant speciation was found to change rapidly even at short treatment times.…”

“…However, the study suggested that the kinetic modeling could be improved through quantifying ·Cl reaction rate constants within the dissolved organic carbon in the RO permeate. Also, the study found that minimizing UV fluence during the degradation of 1,4‐dioxane was better achieved using UV/free chlorine (Zhang et al, 2019). Both Chuang, Szczuka, Shabani, et al (2019) and Zhang et al (2019) research articles highlighted the importance of providing a realistic irradiation time when assessing AOPs (<1 min in pilot‐scale systems to achieve the ~700−1,000 mJ/cm 2 fluence).…”

“…Also, the study found that minimizing UV fluence during the degradation of 1,4‐dioxane was better achieved using UV/free chlorine (Zhang et al, 2019). Both Chuang, Szczuka, Shabani, et al (2019) and Zhang et al (2019) research articles highlighted the importance of providing a realistic irradiation time when assessing AOPs (<1 min in pilot‐scale systems to achieve the ~700−1,000 mJ/cm 2 fluence). This was because most of the bench‐scale studies reported prolonged irradiation time (~0.5 hr) to reach the previously mentioned fluence relevant to AOP practice which might promote very high halogenated DBP formation because of the dark reactions formed with free chlorine.…”