• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Bromate formation during oxidation of bromide-containing water by the CuO catalyzed peroxymonosulfate process

    2022-12-07 08:26:34JingxinYngHongruiChunWngHongLiu
    Chinese Chemical Letters 2022年11期

    Jingxin Yng, Hongrui M, Chun Wng,?, Hong Liu

    a Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay,Guangzhou University, Guangzhou 510006, China

    b Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China

    Keywords:Bromate Peroxymonosulfate (PMS)CuO SO4??Bromide Heterogeneous catalyst

    ABSTRACT Bromate formation has been found in the SO4??-based oxidation processes, but previous studies primarily focused on the bromate formation in the homogeneous SO4??-based oxidation processes.The kinetics and mechanisms of bromate formation are poorly understood in the heterogeneous SO4??-based oxidation processes, although which have been widely studied in the eliminations of micropollutants.In this work, we found that the presence of CuO, a common heterogeneous catalyst of peroxymonosulfate (PMS),appreciably enhanced the bromate formation from the oxidation of bromide by PMS.The conversion ratio of bromide to bromate achieved over 85% within 10 min in this process.CuO was demonstrated to play a multiple role in the bromate formation: (1) catalyzed PMS to generate SO4??, which then oxidizes bromide to bromate; (2) catalyzed the formed free bromine to disproportionate to bromate; (3) catalyzed the formed free bromine to decomposed back into bromide.In the CuO-PMS-Br system, bromate formation increases with increasing CuO dosages, initial CuO and bromide concentrations, but decreases with increasing bicarbonate concentrations.The presence of NOM (natural organic matter) resulted in a lower formed bromate accompanied with organic bromine formation.Notably, CuO catalyzes PMS to transform more than 70% of initial bromide to bromate even after recycled used for six times.The formation of bromate in the PMS catalysis by CuO system was also confirmed in real water.

    Bromate is a well-known disinfection byproduct in drinking water treatment [1].As a class 2B carcinogen stipulated by World Health Organization (WHO), bromate is regulated at a maximum contaminant level (MCL) of 10 μg/L in drinking water in many countries [2,3].It is typically detected during the ozonation of bromide-containing water [4,5].The kinetics and mechanisms of bromate formation during ozonation have been well understood previously [1,6,7].

    In recent decades, bromate was also found to form in the bromide-containing water treated by sulfate radical-based advanced oxidation processes (SO4??-based AOPs) [8–10].For example, significant bromate formation was observed in both UV/persulfate and Co(II)/peroxymonosulfate processes, where SO4??is reported to play a critical role in the bromate formation[8,11].However, previous studies involving the bromate formation in the SO4??-based systems almost focused in the homogeneous processes [12].Apart from homogeneous catalysts, heterogeneous catalysts can also activate peroxymonosulfate (PMS) or persulfate(PDS) to produce SO4??[13–16].As compared to the homogeneous processes, the advantages of the heterogeneous process include applicability over a wide pH range, low toxicity, high stability and easy separation [17,18].However, little information is available on the bromate formation in the heterogeneous SO4??-based systems in the bromide-containing water.

    Cupric oxide (CuO) has been reported to be an effective heterogeneous catalyst of PMS for the generation of SO4??to eliminate various emerging micropollutants in aqueous solution [19–20].More importantly, CuO was found to appreciably catalyze and accelerate the slow disproportionation of free bromine to form bromate and bromide during chlorination in a recent decade [21,22].Accordingly, the kinetics and mechanisms of bromate formation in the CuO/PMS process must be different from that in the homogeneous processes reported previously due to the involvement of CuO.Thus, the bromate formation in the CuO/PMS process should be comprehensively evaluated.To the best of our knowledge, however, the bromate formation in the CuO/PMS process still remains unexplored.

    Therefore, the main objectives of this study are (1) to investigate the kinetics of bromate formation in the CuO/PMS process as a function of CuO, PMS, bromide, bicarbonate and humic acid concentrations and pH; (2) to elucidate the mechanisms of the bromate formation in the CuO/PMS process; (3) to evaluate the bromate formation in the real water by CuO/PMS process.

    All chemical solutions in this work were prepared with reagent-grade chemicals and ultrapure water produced from the Millipore system (18.2 MΩcm).Peroxylmonosulfate (Oxone, KHSO5·0.5KHSO4·0.5K2SO4), potassium bromide (KBr), potassium bromte (KBrO3), copper nitrate trihydrate (Cu(NO3)2·2H2O),sodium hypochlorite solution (NaOCl, 6%?14% active chlorine), 2,6-dichlorophenol (99.0%),tert–butyl alcohol (t-BuOH, ≥99.8%) and sodium sulfite (Na2SO3, 98.0%) were obtained from Aladdin Industrial Corporation.Sodium bicarbonate (NaHCO3, ≥99.5%), sodium hydroxide (NaOH, ≥96.0%) and nitric acid (HNO3) were purchased from Sinopharm Chemical Reagent Co., Ltd.5,5-DimethylpyrrolidineN-oxide (DMPO) was purchased from Sigma-Aldrich.CuO particles were prepared by the previously reported method[18].The real water samples used in this work were characterized as follow: pH 8.0, UV254= 0.016, DOC = 3.8 mg/L, Br?was not detected for tap water, and pH 7.8, UV254= 0.057, DOC = 6.6 mg/L,[Br?] = 12.9 μmol/L for surface water.The real water samples were filtered through a 0.45-μm membrane before use.

    All experiments were performed in a 500 mL batch-reactor covered with aluminum foil, which were under continuous agitation using a magnetic stirrer.The pH value of experimental solution was adjusted to the desired value with HNO3(0.1 mol/L) and NaOH(0.1 mol/L).Reactions were initiated by adding desired amounts of PMS and CuO into bromide-containing solutions.Water samples were withdrawn at predetermined reaction times and filtered through a 0.22 μm syringe filter, which were rapidly quenched with 2,6-dichlorophenol initially followed by adding 10 mmol/L sulfite for the analysis of reactive bromine, bromide and bromate.All experiments were conducted in duplicate and the results represent the average values.Standard deviations (± SD) were all within 10%.

    Bromide and bromate were quantified using ion chromatography (IC, Thermo Dionex ICS 3000) with an eluent containing 30 mmol/L KOH.Reactive bromine was determined as 4–bromo-2,6-dichlorophenol, an intermediate product of reactive bromine with 2,6-dichlorophenol.It is measured using high performance liquid chromatography (HPLC) equipped with a C18 column(4.6 mm × 250 mm; 5 μm particle size), with an eluent containing 0.5% acetic acid, and acetonitrile (30:70, v/v) atλ= 252 nm.PMS was determined using spectrophotometric method.Total organic bromine (TOBr) was measured using a Multi 2500 TOX analyzer (Jena).Electron paramagnetic resonance (EPR) experiments were conducted on a Bruker A200 spectrometer.

    Fig.1 shows the time-dependent evolution of bromide, free bromine, bromate and the total bromine from the CuO/PMS process in synthetic water, at initial concentration of bromide, PMS and CuO of 20 μmol/L, 1 mmol/L and 0.2 g/L, respectively.The concentration of bromide declined rapidly within the first 4 min of the reaction and then almost remained unchanged.The evolution of free bromine exhibited a sharp increase followed by a decrease as the reaction proceeded and peaked at 11.0 μmol/L within 2 min.The formed bromate increased rapidly within first 10 min and then reached a plateau, which accounted for 89.4% of the initial bromide.It indicated that PMS transforms bromide into bromate rapidly in the presence of CuO.The total bromine almost kept steady at 20 ± 0.5 μmol/L throughout the 30-min reaction, which implied that free bromine was a requisite intermediate during the bromate formation in the CuO/PMS process.

    Fig.1 .Evolution of bromine species during the oxidation of bromide in the CuO/PMS process.Experimental conditions: [CuO] = 0.20 g/L, [PMS] = 1 mmol/L,[Br?] = 20 μmol/L, at initial pH 7, 20 ± 1 °C.

    The evolution of PMS was measured simultaneously in the CuO/PMS process in this study.As shown in Fig.S1 (Supporting information), the concentration of PMS declined by around 96.9%within the first 10 min during the process.This trend was compatible to the bromate formation during the CuO/PMS process.It implied that bromate formation might be closely relative to the catalysis reaction of PMS by CuO in this process.

    Based on the results mentioned above, free bromine is confirmed to be the main intermediate product for the bromate formation in the CuO/PMS process.Accordingly, the formation of bromate in the CuO/PMS process involved two steps: the oxidation of bromide to free bromine and the further oxidation of free bromine to bromate.The two-step process of bromate formation is commonly observed in other chemical oxidation processes as reported in previous literatures [6,23].

    Fig.2 shows the bromide decay and free bromine formation in the CuO a, PMS alone, CuO/PMS, CuO/PMS/t-BuOH and CuO/PMS/MeOH processes at an initial bromide concentration of 20 μmol/L and pH 7.Bromide showed no obvious concentration change in the CuO alone, where no formed free bromine was detected.It implies that CuO alone has neither absorption nor transformation effect on bromide in aqueous solution.PMS alone transformed 28% of the initial bromide into free bromine within 30 min.The formed free bromine increased and accumulated throughout the reaction time.The loss rate of bromide by PMS alone is compatible to the second-order rate constant of PMS with bromide(k1= 0.16 L mol?1s?1) as Eq.1 [24].It indicates that PMS contributes partially to the free bromine formation in the CuO/PMS process.It should be noted that the concentration of leached Cu(II)from CuO was determined to be 76.3 μg/L.As shown in Fig.S2(Supporting information), Cu(II)/PMS and PMS alone shared a similar bromide transformation at pH 7.This result indicated that the leached Cu(II) played a negligible role in the transformation of bromide in the presence of PMS.Taking into account that over 86% of initial bromide was rapidly transformed within 4 min in the CuO/PMS process, the oxidants produced in the CuO/PMS process were assumed to contribute primarily to the bromide transformation.As has been reported in previous literature, sulfate radical (SO4??) and hydroxyl radical (?OH) are generated from the CuO/PMS process.These two radicals are typically found to play essential roles in bromide transformation in other advanced oxidation processes [10,11].As shown in Fig.S3 (Supporting information), SO4??and?OH were confirmed to generate in the CuO/PMS processviaEPR experiments using DMPO as a spin-trapping agent.Thus, radical scavenging experiments by spiking 2% alcohol(t-BuOH or MeOH) were conducted.Over 35% of the initial bromide was transformed within 4 min in the presence of excessivet-BuOH, while less than 3% of the initial bromide was converted in the presence of excessive methanol.These results fully convinced that SO4??rather than?OH was the main reactive species responsible for the bromide transformation in the CuO/PMS process.

    Fig.2 .(a) Bromide decay and (b) free bromine formation in the CuO, PMS, CuO/PMS, CuO/PMS/t-BuOH and CuO/PMS/MeOH processes.Experimental conditions:[CuO] = 0.20 g/L, [PMS] = 1 mmol/L, [Br?] = 20 μmol/L, 2% t-BuOH or 2% MeOH, at initial pH 7, 20 ± 1 °C.

    Fig.S4a (Supporting information) shows the time-dependent HOBr/?OBr decay in the HOBr/?OBr disproportionation, CuO alone,PMS alone and CuO/PMS processes at pH 7.In the absence of CuO, the loss of HOBr/?OBr was negligible within 30 min.It implied that the disproportionation of HOBr/?OBr without catalysis of CuO was an extremely slow process.In the presence of CuO, the HOBr/?OBr decay was accelerated appreciably.Approximately 69%of initial HOBr/?OBr was depleted within 30 min, suggesting that catalysis of CuO enhanced the decomposition of HOBr/?OBr.The HOBr/?OBr decay in the CuO/PMS process was the fastest among the four processes mentioned above, over 90% of HOBr/?OBr was depleted within 10 min.These results indicated that the SO4??oxidation combined with the CuO catalysis was mainly responsible for further transformation of free bromine.

    Fig.S4b (Supporting information) shows the time-dependent bromate formation from the oxidation of Br?and HOBr/?OBr at an initial Br concentration of 20 μmol/L in the CuO alone, PMS alone and CuO/PMS processes at pH 7.The initial rate of bromate formation during the oxidation of HOBr/?OBr was much higher than that during the oxidation of Br?by CuO/PMS process, although they have the same quantity of formed bromate after 30 min reaction.The CuO catalysis of HOBr/?OBr also formed bromate, revealing that the catalysis of HOBr/?OBr contributed partially to the bromate formation in the CuO/PMS process.In addition, it should be noted that the amount of formed bromate accounted for approximately 15% of the loss of free bromine from the CuO catalysis.It indicated that CuO primarily catalyzed HOBr/?OBr to decompose into bromide as Eqs.2 and 3.No bromate formation was observed in the CuO catalysis of Br?process.The oxidations of Br?and HOBr/?OBr by PMS in the absence of CuO did not form any bromate, suggesting that PMS fails to further oxidation of HOBr/?OBr to bromate although it is capable of converting Br?to free bromine.

    All the above results imply that the bromate formation follows reaction pathways as presented in Fig.3.Bromide is initially oxidized to free bromine by SO4??and PMS.The formed free bromine is further oxidized by SO4??or catalyzed by CuO to form bromate.Some HOBr/?OBr can be converted back to Br?by CuO catalysis,which can then be re-oxidized to HOBr/?OBr by SO4??and PMS until most of Br?is converted to bromate as long as PMS is present in excess.

    Fig.3 .Mechanism of the bromate formation in the CuO/PMS process.

    The effect of CuO on the bromate formation in the CuO/PMS process is manifested in Fig.S5a (Supporting information).Results indicate that the formation of bromate increased as CuO dosage increased in the range of 0.05–0.2 g/L and almost remained steady in the range of 0.2–0.3 g/L in the CuO/PMS process.A lag-phase of bromate formation was observed at the low CuO dosage of 0.05 g/L.The conversion ratios of bromide to bromate by CuO/PMS process in 30-min time frame were 32.1%, 75.6%, 81.2%, 88.6%,88.3% and 88.6% at the CuO dosages of 0.05 g/L, 0.1 g/L, 0.15 g/L,0.2 g/L, 0.25 g/L and 0.3 g/L, respectively.It should be noted that the bromate formation generally followed pseudo-zero-order kinetics within initial reaction time, when both PMS and bromide were sufficient.Fig.S5b (Supporting information) shows the relationship between the initial formed rate of bromate and the CuO dosage of 0.05–0.3 g/L.The rate increased linearly with increasing CuO dosage, but the regression line did not go through the origin.This result confirmed the bromate formation is a two-step process again.Simultaneously, the evolutions of free bromine in the presence of different dosages of CuO were shown in Fig.S5c (Supporting information).The free bromine concentration exhibited a monotonous increase at a CuO dosage of 0.05 g/L, whereas increased sharply followed by declining gradually in the CuO dosage range of 0.1–0.3 g/L.Moreover, the formed free bromine after achieving the maximum depleted more rapidly at a higher CuO dosage.These results confirmed the essential role of CuO in the transformation of free bromine into bromate.

    Fig.S6a (Supporting information) shows the bromate formation in the PMS dosage range of 0.01–1.0 mmol/L in the CuO/PMS process.The formed bromate increased with increasing PMS dosage.No bromate was detected at the PMS dosage of 0.01 mmol/L.The conversion ratio of bromide to bromate by CuO/PMS process in 30-min time frame were 1.5%, 4.7%, 10.5%, 25.8%, 52.1%, 69.5% and 88.6% at the PMS dosage of 0.02 mmol/L, 0.05 mmol/L, 0.1 mmol/L,0.2 mmol/L, 0.5 mmol/L, 0.8 mmol/L and 1 mmol/L, respectively.It should be noted that bromate formation exhibited two stages at different PMS dosages: (1) An initial rapid formation stage, and(2) a slower formation stage.For example, the formed concentration of bromate achieved 9.3 μmol/L within 10 min and further increased to 10.4 μmol/L in the following 20 min in the presence of 1 mmol/L PMS.As mentioned above, over 95% of initial PMS depleted within 10 min.It implies that SO4??generated from the CuO catalysis of PMS is mainly responsible for the bromate formation in the initial phase.The CuO catalysis of HOBr/?OBr plays a critical role in the bromate formation in the following phase.As shown in Fig.S6b (Supporting information), the formed concentrations of free bromine increased to the maximum and then declined gradually for all the selected PMS dosages in CuO/PMS process.Interestingly, the maximum concentration of free bromine increased with the PMS concentration increasing from 0.01 mmol/L to 0.1 mmol/L, but decreased with the PMS concentration increasing from 0.1 mmol/L to 1 mmol/L.In the PMS concentration range of 0.01–0.1 mmol/L, most of SO4??generated from the CuO catalysis of PMS oxidized bromide to free bromine, only few of them further oxidized free bromine to bromate.In the PMS concentration range of 0.1–1 mmol/L, an increasing number of SO4??generated from the CuO catalysis of PMS further oxidized the formed free bromine to bromate.

    The effect of bromide concentrations on bromate formation was also investigated in CuO/PMS process in the initial bromide concentration range of 2.5–80 μmol/L at pH 7.As shown in Fig.4a, the formed bromate was enhanced with the initial bromide concentration increasing from 2.5 μmol/L to 40 μmol/L after 30 min reaction.However, further increasing the initial bromide concentration from 40 μmol/L to 80 μmol/L did not significantly change the bromate formation in CuO/PMS process.It was also found that, in the initial bromide concentration range of 2.5–20 μmol/L, over 80% of the initial bromide has been transformed to bromate.But the conversion ratio of bromide to bromate reduced sharply to approximately 30% as the initial bromide concentration increased to 80 μmol/L in the CuO/PMS process.This observation was attributed to the fact that excessive bromide competes for SO4??with the formed free bromine to inhibit the further oxidation of free bromine to bromate.

    Fig.4 .Effect of bromide concentration (a), pH (b), HCO3? (c) and temperature (d) on the bromate formation in the CuO/PMS process.Experimental conditions:[CuO] = 0.2 g/L, [PMS] = 1 mmol/L; (a): [Br?] = 3–80 μmol/L, at initial pH 7, 20 ± 1 °C; (b): [Br?] = 20 μmol/L, at initial pH 6–10, 20 ± 1 °C; (c): [Br?] = 20 μmol/L,[HCO3?] = 0–4 mmol/L, at initial pH 7, 20 ± 1 °C; (d): [Br?] = 20 μmol/L, at initial pH 7, 20–40 °C.

    The solution pH is a critical factor for the bromate formation in the oxidation of bromide-containing water [25].Fig.4b shows the bromate formation at different initial pH in the CuO/PMS process.The formed bromate increased rapidly and then reached a plateau at each initial pH.The steady concentrations of bromate were quite close to each other for different initial pH after 30 min.This observation can be ascribed to the variations of pH during reactions.As shown in Fig.S7 (Supporting information), the solution pH rapidly changed to be consistent for each initial pH.Moreover, the bromate formation exhibited less pH-dependent in the CuO catalyzed PMS oxidation process than in other homogeneous catalytic PMS oxidation processes.It implied that the bromate formation in the heterogeneous catalytic oxidation process might have a higher potential risk than in the homogeneous catalytic oxidation process.

    The evolutions of bromate formed at bicarbonate concentrations of 0.1, 0.5, 1, 2 and 4 mmol/L were investigated and compared with that in the absence of bicarbonate in the CuO/PMS process.As shown in Fig.4c, the formed concentration of bromate decreased with increasing bicarbonate concentrations.For example, the conversion ratio of bromide to bromate reduced from 79.0% to 60.2% as the bicarbonate concentration increased from 0.1 mmol/L to 4 mmol/L after 30 min reaction.It was also found that the bromate formation in the absence of bicarbonate was higher than that in the presence of bicarbonate.It indicated that bicarbonate inhibited the bromate formation in the CuO/PMS process.The inhibiting effect was ascribed to the scavenge of SO4??generated from the CuO catalysis of PMS by bicarbonate as Eqs.4 and 5.Although carbonate radical (CO3??) formed from the reaction of bicarbonate with SO4??can also oxidize bromide and free bromine [5], its oxidation rate of bromide by CO3??(k(CO3??,Br?) = 1.0 × 105L mol?1s?1) is four orders of magnitude lower than the oxidation rate of bromide by SO4??(k(?OH, Br?) = 1.1 ×109L mol?1s?1) as Eqs.6-8 [26].

    Fig.4 d shows the evolutions of bromate formation in the CuO/PMS process at 10 °C, 20 °C, 30 °C, and 40 °C, respectively.Results showed that the formed concentrations of bromate were stable in the temperature range of 10–40 °C in the CuO/PMS process after 30 min reaction.However, a higher temperature was favored to the initial formation rate of bromate.For example, the initial formation rate of bromate was 2.3 μmol L?1min?1at 10 °C,and 3.9 μmol L?1min?1at 40 °C.The rate at 40 °C is 71.3% higher than that at 10 °C.It indicated that high temperature accelerates the oxidation of bromide to bromate in the CuO/PMS process.

    Humic acid as a significant constituent of NOM (natural organic matter) has been widely used as a surrogate of NOM in a considerable number of previous studies [27–29].In this study, a commercial humic acid purchased from Aladdin Industrial Corporation was chosen to investigate the effect of NOM on the bromate formation in the CuO/PMS process.Fig.S8 (Supporting information)shows the bromate formation in the NOM concentration range of 1–4 mg-C/L in the CuO/PMS process.The formed concentrations of bromate after 30 min reaction were 13.0 μmol/L, 9.2 μmol/L,5.5 μmol/L and 2.3 μmol/L in the presence of NOM concentrations of 1 mg-C/L, 2 mg-C/L, 4 mg-C/L and 8 mg-C/L, respectively.In contrast, the formed bromate reached 17.4 μmol/L in the absence of NOM.It implied that NOM inhibited the bromate formation in the CuO/PMS process, which was also observed in other oxidation processes treating bromide-containing water [6,30].The inhibiting effect of NOM on the bromate formation can be explained by three aspects: (1) NOM may consume the formed free bromine.The peak concentrations of accumulated free bromine decreased from 8.6 μmol/L to 2.0 μmol/L as NOM concentrations increased from 1 mg-C/L to 4 mg-C/L.It should be noted that the reaction of free bromine with NOM resulted in the generation of organic bromine as reported in previous literature.The formed concentrations of total organic bromine were 1.2 μmol/L, 2.7 μmol/L, 5.0 μmol/L and 7.8 μmol/L at the NOM concentrations of 1 mg-C/L, 2 mg-C/L, 4 mg-C/L and 8 mg-C/L after 30 min reactions, respectively.It meant that the conversion ratios of inorganic bromine to organic bromine increased from 5.7% to 38.9% as NOM concentrations increased from 1 mg-C/L to 4 mg-C/L.(2) NOM may compete with bromide for the reactive oxygen species (e.g., SO4??and PMS).The conversion ratios of bromide after 30 min reaction were 77.1%, 66.4%, 53.2% and 46.5% at the NOM concentrations of 1 mg-C/L, 2 mg-C/L, 4 mg-C/L and 8 mg-C/L, respectively.It confirmed that the presence of NOM inhibits the transformation of bromide in the CuO/PMS process.In addition, NOM can also convert free bromine back to bromide, which results in a decrease in the bromide transformation as well.

    The stability and recyclability of CuO were investigated in a series of continuous experiments.The bromate formation in the PMS combined with CuO recycled for 6 times is shown in Fig.S9 (Supporting information).After reusing CuO for twice, the formed concentration of bromate was lower than that using CuO for the first time.The decreased bromate formation could be attributed to the loss of the active site formed in the first run on the CuO surface.When CuO was further reused, the bromate formation fairly remained constant, which accounted for around 70% of the initial bromide.It indicated that the reused CuO can still result in the bromate formation that accounted for up to 70% of the initial bromideviaactivating PMS in the bromide-containing water.

    To investigate the bromate formation in a more realistic water matrix in the CuO/PMS process, experiments were conducted in two real water samples including a tap water and a surface water spiked with certain volumes of bromide solutions to remain 20 μmol/L of the initial bromide.As shown in Fig.S10a (Supporting information), 73.2% of the initial bromide was decomposed in the tap water, while the formed bromate increased with increasing reaction time and reached 6.4 μmol/L after 30 min.The formed free bromine was rapidly accumulated and decomposed gradually after reaching its peak.Total organic bromine that accounted 7.7% of the initial bromide was observed in tap water treated by CuO/PMS process.As shown in Fig.S10b (Supporting information), the formed concentration of bromate was 0.7 μmol/L after 30 min reaction,while the total organic bromine reached 8.3 μmol/L that accounted for 41.3% of the initial bromide in the surface water.It means that the formed bromate in the tap water was higher than that in the surface water, while the total organic bromine in the tap water was much lower than that in the surface water.This phenomenon can be ascribed to a higher concentration of dissolved organic matter in the surface water (DOC = 12.6 mg/L) than in the tap water(DOC = 3.8 mg/L).Interestingly, the bromide concentration decomposed from 20 μmol/L to 4.4 μmol/L within first 6 min and then increased to 7.4 μmol/L in the following 24 min reaction in the surface water, while decomposed rapidly to 5.3 μmol/L and remained steady in the tap water.The difference in bromide conversion can be explained by the different concentration and nature of dissolved organic matter in two real water samples.The reaction mechanism of bromine varies for different organic compounds.One part of NOM and bromine undergo electron transfer reactions, while the other part of NOM and bromine proceed bromine atom transfer[31].Accordingly, the CuO/PMS process could transform bromide into bromate and brominated disinfection byproducts, when treating real water containing bromide.

    In Summary, this study investigated the catalytic enhancement of CuO on the formation of bromate during the treatment of bromide-containing waters using PMS.Results showed that the presence of CuO resulted in appreciable yields of bromate formation from the oxidation of bromide by PMS, although PMS alone cannot transform bromide into bromate.Besides activating PMS to generate SO4??to oxidize bromide to bromate, CuO was also demonstrated to catalyze the disproportionation of the formed bromine to bromate and bromide.The presence of NOM suppressed the bromate formation but increased the organic bromine.It should be noted that CuO still catalyzed PMS to transform bromide into bromate even after recycling several times.Therefore,CuO/PMS process has to be carefully examined before treating bromide-containing water or brominated organic contaminants.

    Declaration of competing interest

    We confirm this manuscript has not been published elsewhere and also not under consideration in any journal.All authors enclosed approve the submission.The authors declare no conflicts of interest.

    Acknowledgment

    This work was financially supported by the National Natural Science Foundation of China (Nos.42077159 and 51978181).

    Supplementary materials

    Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.cclet.2022.01.008.

    色综合亚洲欧美另类图片| 久久久久久久国产电影| 七月丁香在线播放| 成人毛片60女人毛片免费| 人人妻人人看人人澡| 中文字幕制服av| 国模一区二区三区四区视频| 亚洲精品国产成人久久av| 2021天堂中文幕一二区在线观| 人妻制服诱惑在线中文字幕| 精品久久久久久久人妻蜜臀av| 免费黄网站久久成人精品| 国产人妻一区二区三区在| 日韩成人av中文字幕在线观看| 亚洲久久久久久中文字幕| 国产亚洲av嫩草精品影院| 日韩三级伦理在线观看| 久久热精品热| 精品少妇黑人巨大在线播放 | 欧美潮喷喷水| 狂野欧美白嫩少妇大欣赏| 听说在线观看完整版免费高清| av国产免费在线观看| 边亲边吃奶的免费视频| 岛国毛片在线播放| 免费人成在线观看视频色| 99热这里只有精品一区| 99在线视频只有这里精品首页| av线在线观看网站| 男人的好看免费观看在线视频| 青春草亚洲视频在线观看| 亚洲欧洲国产日韩| 国产乱人视频| 一个人看视频在线观看www免费| 天堂影院成人在线观看| 麻豆成人午夜福利视频| 乱人视频在线观看| 菩萨蛮人人尽说江南好唐韦庄 | 国产三级中文精品| 亚洲成人av在线免费| 小蜜桃在线观看免费完整版高清| 国产乱人偷精品视频| 超碰97精品在线观看| 久久久久九九精品影院| 一本久久精品| 深爱激情五月婷婷| 国产精品国产三级国产av玫瑰| 国产av在哪里看| 国产午夜福利久久久久久| 日本熟妇午夜| 青春草视频在线免费观看| 女人被狂操c到高潮| 日本一二三区视频观看| 超碰av人人做人人爽久久| 高清日韩中文字幕在线| 日本免费在线观看一区| 亚洲,欧美,日韩| 天堂网av新在线| 国产单亲对白刺激| 禁无遮挡网站| 国产成人a∨麻豆精品| 国产精品精品国产色婷婷| 久久精品影院6| 99热网站在线观看| 亚洲成人精品中文字幕电影| 纵有疾风起免费观看全集完整版 | 国产亚洲精品久久久com| 精品免费久久久久久久清纯| 国产黄a三级三级三级人| 色综合亚洲欧美另类图片| av播播在线观看一区| 国产午夜福利久久久久久| 亚洲经典国产精华液单| 一个人看视频在线观看www免费| 麻豆一二三区av精品| 乱码一卡2卡4卡精品| 久久精品国产亚洲网站| 久久久色成人| 性插视频无遮挡在线免费观看| 日韩中字成人| 久久欧美精品欧美久久欧美| 美女脱内裤让男人舔精品视频| 精品少妇黑人巨大在线播放 | 99久久中文字幕三级久久日本| 91av网一区二区| av在线观看视频网站免费| 寂寞人妻少妇视频99o| 黄色日韩在线| 免费看光身美女| 亚洲性久久影院| 麻豆一二三区av精品| 一级爰片在线观看| 国产精品永久免费网站| 久热久热在线精品观看| 两个人视频免费观看高清| 校园人妻丝袜中文字幕| 在线观看美女被高潮喷水网站| 噜噜噜噜噜久久久久久91| 国产精品人妻久久久影院| 久久婷婷人人爽人人干人人爱| 免费看a级黄色片| 一区二区三区高清视频在线| 九九在线视频观看精品| 岛国毛片在线播放| 97超碰精品成人国产| av专区在线播放| 国产精品麻豆人妻色哟哟久久 | 久久精品国产亚洲网站| 水蜜桃什么品种好| 国内精品宾馆在线| av国产久精品久网站免费入址| 视频中文字幕在线观看| 久久综合国产亚洲精品| 久久久久久大精品| 国产精品三级大全| 嫩草影院新地址| 国产精品爽爽va在线观看网站| 99久久中文字幕三级久久日本| 色噜噜av男人的天堂激情| 日韩制服骚丝袜av| av在线天堂中文字幕| 国产亚洲最大av| 国产极品天堂在线| 亚洲欧洲国产日韩| 丝袜美腿在线中文| 国产成人aa在线观看| 国产又黄又爽又无遮挡在线| 亚洲成av人片在线播放无| 免费观看在线日韩| 色噜噜av男人的天堂激情| 天堂√8在线中文| 国产视频首页在线观看| 亚洲av男天堂| 免费观看精品视频网站| 色视频www国产| 99久国产av精品| 欧美激情久久久久久爽电影| 日本与韩国留学比较| 最近最新中文字幕免费大全7| 一级二级三级毛片免费看| 一本一本综合久久| 九九爱精品视频在线观看| 久久这里有精品视频免费| 网址你懂的国产日韩在线| 亚洲精品乱码久久久久久按摩| 五月伊人婷婷丁香| 亚洲国产欧美人成| 中文字幕熟女人妻在线| 乱系列少妇在线播放| 啦啦啦观看免费观看视频高清| 三级男女做爰猛烈吃奶摸视频| 中文欧美无线码| 亚洲av成人av| 18禁在线无遮挡免费观看视频| 久久久久性生活片| 日韩欧美国产在线观看| 日韩大片免费观看网站 | 欧美日本视频| 色网站视频免费| 男人舔女人下体高潮全视频| 噜噜噜噜噜久久久久久91| 亚洲国产精品成人久久小说| 在线免费十八禁| 久久久久久国产a免费观看| 18禁在线播放成人免费| 欧美区成人在线视频| 自拍偷自拍亚洲精品老妇| 色吧在线观看| 精品欧美国产一区二区三| 国产色爽女视频免费观看| h日本视频在线播放| 男人舔奶头视频| 黄片wwwwww| 亚洲第一区二区三区不卡| 亚洲国产欧美在线一区| 国产亚洲午夜精品一区二区久久 | 麻豆成人午夜福利视频| 又爽又黄a免费视频| 桃色一区二区三区在线观看| 嫩草影院新地址| 亚洲欧美清纯卡通| 能在线免费观看的黄片| 成年免费大片在线观看| 嘟嘟电影网在线观看| 蜜桃久久精品国产亚洲av| 精品人妻一区二区三区麻豆| 精品国内亚洲2022精品成人| 国产午夜精品一二区理论片| 一个人看视频在线观看www免费| 亚洲色图av天堂| 寂寞人妻少妇视频99o| 久久欧美精品欧美久久欧美| 3wmmmm亚洲av在线观看| av免费在线看不卡| 色哟哟·www| 免费观看性生交大片5| 亚洲精品国产av成人精品| 精品人妻熟女av久视频| 欧美3d第一页| 亚洲天堂国产精品一区在线| 日韩一区二区视频免费看| 一个人看视频在线观看www免费| 国产高清不卡午夜福利| 天堂中文最新版在线下载 | 国产伦精品一区二区三区视频9| 亚洲精品色激情综合| 狂野欧美激情性xxxx在线观看| 久久韩国三级中文字幕| 国产真实乱freesex| 午夜福利成人在线免费观看| 久久久精品大字幕| 在线播放无遮挡| 国产精品一区二区在线观看99 | 国产色爽女视频免费观看| 日日摸夜夜添夜夜添av毛片| 久久久久性生活片| 好男人在线观看高清免费视频| 久久久久性生活片| 欧美成人午夜免费资源| 色5月婷婷丁香| 黄色日韩在线| 婷婷色av中文字幕| 男女边吃奶边做爰视频| 美女xxoo啪啪120秒动态图| 亚洲高清免费不卡视频| 乱系列少妇在线播放| 亚洲美女搞黄在线观看| 欧美一级a爱片免费观看看| 熟妇人妻久久中文字幕3abv| 黄色日韩在线| 日韩人妻高清精品专区| 看非洲黑人一级黄片| 国产成人精品婷婷| 日本免费a在线| 精品欧美国产一区二区三| 久久精品国产99精品国产亚洲性色| 久久久a久久爽久久v久久| h日本视频在线播放| 国产一区二区三区av在线| 亚洲av成人av| 日本爱情动作片www.在线观看| 国产精品熟女久久久久浪| 欧美xxxx性猛交bbbb| 精品久久久久久成人av| a级一级毛片免费在线观看| 欧美高清成人免费视频www| 亚洲经典国产精华液单| 午夜福利高清视频| 少妇被粗大猛烈的视频| 97在线视频观看| av国产久精品久网站免费入址| 国产中年淑女户外野战色| av黄色大香蕉| 国产伦在线观看视频一区| 成年女人看的毛片在线观看| 亚洲欧美精品专区久久| 97超视频在线观看视频| 搡老妇女老女人老熟妇| 99久国产av精品国产电影| 如何舔出高潮| 成人午夜精彩视频在线观看| 夫妻性生交免费视频一级片| 亚洲精品乱码久久久久久按摩| 亚洲伊人久久精品综合 | 中国国产av一级| 久久久久九九精品影院| 啦啦啦啦在线视频资源| 亚洲三级黄色毛片| 亚洲色图av天堂| 国产精品国产三级专区第一集| 最近最新中文字幕免费大全7| 观看美女的网站| 中文乱码字字幕精品一区二区三区 | kizo精华| 精品一区二区三区人妻视频| 日本wwww免费看| 听说在线观看完整版免费高清| 97热精品久久久久久| 午夜爱爱视频在线播放| 国产久久久一区二区三区| 国产色婷婷99| 波野结衣二区三区在线| 蜜臀久久99精品久久宅男| 亚洲自偷自拍三级| 青青草视频在线视频观看| 国产精品熟女久久久久浪| 麻豆精品久久久久久蜜桃| 可以在线观看毛片的网站| 日本黄色视频三级网站网址| 日韩中字成人| 欧美性猛交╳xxx乱大交人| 午夜精品在线福利| 欧美极品一区二区三区四区| 麻豆成人av视频| 只有这里有精品99| 国产精品三级大全| 在线免费十八禁| 国产毛片a区久久久久| 久久久久久国产a免费观看| 欧美3d第一页| 精品不卡国产一区二区三区| 少妇被粗大猛烈的视频| 中国国产av一级| 国产成人aa在线观看| 国产免费又黄又爽又色| 免费av不卡在线播放| eeuss影院久久| 日韩成人av中文字幕在线观看| 少妇熟女欧美另类| 成人午夜精彩视频在线观看| 国产成人精品久久久久久| 日韩制服骚丝袜av| 久久6这里有精品| 特大巨黑吊av在线直播| 在线播放无遮挡| 亚洲激情五月婷婷啪啪| 精品久久国产蜜桃| 久久久久网色| 日本一本二区三区精品| 国产精品一区二区在线观看99 | 中文字幕av在线有码专区| 亚洲中文字幕一区二区三区有码在线看| 最新中文字幕久久久久| 99九九线精品视频在线观看视频| 国产真实乱freesex| 久久久精品大字幕| 国产精品久久久久久久电影| 亚洲av电影不卡..在线观看| 丝袜喷水一区| 亚洲色图av天堂| eeuss影院久久| 最近中文字幕高清免费大全6| 三级国产精品片| 联通29元200g的流量卡| 亚洲第一区二区三区不卡| 久久亚洲精品不卡| 国产高清国产精品国产三级 | 韩国高清视频一区二区三区| 国产午夜精品论理片| 村上凉子中文字幕在线| 国产精品女同一区二区软件| 国产精品一二三区在线看| 色5月婷婷丁香| 91aial.com中文字幕在线观看| 一级毛片久久久久久久久女| 国产精品久久电影中文字幕| 男人舔奶头视频| 男插女下体视频免费在线播放| 久久久久免费精品人妻一区二区| 国产成年人精品一区二区| 老司机福利观看| 波多野结衣高清无吗| 亚洲五月天丁香| 国产色婷婷99| 国产免费福利视频在线观看| 青春草亚洲视频在线观看| 欧美丝袜亚洲另类| 免费一级毛片在线播放高清视频| 日本黄大片高清| 欧美性猛交╳xxx乱大交人| 能在线免费观看的黄片| 国产伦一二天堂av在线观看| 精品国产三级普通话版| 日韩高清综合在线| 尾随美女入室| 在线a可以看的网站| 久久久成人免费电影| 最近中文字幕高清免费大全6| 欧美极品一区二区三区四区| 国产黄片美女视频| 成人国产麻豆网| 禁无遮挡网站| 天堂网av新在线| 日韩av不卡免费在线播放| 亚洲国产欧美人成| 免费在线观看成人毛片| 伊人久久精品亚洲午夜| www日本黄色视频网| 毛片一级片免费看久久久久| 精品人妻一区二区三区麻豆| 寂寞人妻少妇视频99o| 九色成人免费人妻av| 国产片特级美女逼逼视频| 国产淫语在线视频| 国产黄片美女视频| 日韩三级伦理在线观看| 成人性生交大片免费视频hd| 亚洲,欧美,日韩| 免费电影在线观看免费观看| 中文字幕精品亚洲无线码一区| 网址你懂的国产日韩在线| 亚洲最大成人av| 欧美高清性xxxxhd video| 日本黄色视频三级网站网址| 精品久久国产蜜桃| a级毛色黄片| 国产探花极品一区二区| 少妇丰满av| 2021少妇久久久久久久久久久| 欧美激情国产日韩精品一区| 亚洲欧美成人综合另类久久久 | 中文资源天堂在线| 91久久精品电影网| 在线观看美女被高潮喷水网站| 亚洲美女搞黄在线观看| 两个人的视频大全免费| 69人妻影院| 欧美97在线视频| 国产一区二区三区av在线| 一区二区三区免费毛片| 日韩一区二区视频免费看| eeuss影院久久| 99久国产av精品国产电影| 免费看光身美女| 久久久久久大精品| 国产日韩欧美在线精品| 男女下面进入的视频免费午夜| 桃色一区二区三区在线观看| 欧美三级亚洲精品| 18禁裸乳无遮挡免费网站照片| 91狼人影院| 国产黄a三级三级三级人| 91精品国产九色| 亚洲av日韩在线播放| 欧美一区二区国产精品久久精品| 亚洲欧美一区二区三区国产| 内射极品少妇av片p| 久久久久久久久大av| 美女高潮的动态| 人体艺术视频欧美日本| 激情 狠狠 欧美| 免费一级毛片在线播放高清视频| 国产精品一及| 国产单亲对白刺激| 一区二区三区免费毛片| 青春草视频在线免费观看| 久久久久久久久大av| 国产在视频线在精品| 国产成人免费观看mmmm| 中文字幕人妻熟人妻熟丝袜美| 亚洲国产精品专区欧美| 国产精品蜜桃在线观看| 久久欧美精品欧美久久欧美| 亚洲欧美日韩高清专用| 熟女电影av网| 两个人视频免费观看高清| 中国美白少妇内射xxxbb| 亚洲欧洲日产国产| 大又大粗又爽又黄少妇毛片口| 亚洲伊人久久精品综合 | 青春草视频在线免费观看| 国产亚洲91精品色在线| 国产大屁股一区二区在线视频| 岛国毛片在线播放| 欧美日韩一区二区视频在线观看视频在线 | 天堂√8在线中文| 内地一区二区视频在线| 国产av在哪里看| 久久精品夜色国产| 欧美三级亚洲精品| 女人十人毛片免费观看3o分钟| 伦精品一区二区三区| 国产成人精品婷婷| 又黄又爽又刺激的免费视频.| 欧美精品一区二区大全| av女优亚洲男人天堂| 永久网站在线| 1024手机看黄色片| 亚洲第一区二区三区不卡| 亚洲最大成人手机在线| av.在线天堂| 禁无遮挡网站| 免费av不卡在线播放| 一区二区三区免费毛片| 国产老妇女一区| 精品免费久久久久久久清纯| 日韩成人伦理影院| 久久久久久大精品| 亚洲在线自拍视频| 中文欧美无线码| 免费观看的影片在线观看| 亚洲国产日韩欧美精品在线观看| 国产白丝娇喘喷水9色精品| 亚洲欧美日韩东京热| 菩萨蛮人人尽说江南好唐韦庄 | 久久这里有精品视频免费| 亚洲国产欧洲综合997久久,| 极品教师在线视频| 久久久久久久亚洲中文字幕| 国产不卡一卡二| 国产真实乱freesex| 国内精品一区二区在线观看| 九色成人免费人妻av| 精品久久久久久久久久久久久| 国产成人免费观看mmmm| 丝袜喷水一区| 丰满人妻一区二区三区视频av| 久久人妻av系列| 五月玫瑰六月丁香| 久久久久久久亚洲中文字幕| 国产成人免费观看mmmm| 国产av一区在线观看免费| 国内少妇人妻偷人精品xxx网站| 99久久无色码亚洲精品果冻| 色综合色国产| 免费观看性生交大片5| 国产白丝娇喘喷水9色精品| 国产精品女同一区二区软件| 熟妇人妻久久中文字幕3abv| 乱人视频在线观看| 99久久人妻综合| 国产av在哪里看| 国产黄色视频一区二区在线观看 | 啦啦啦观看免费观看视频高清| 亚洲国产日韩欧美精品在线观看| 国产av不卡久久| 天堂网av新在线| av免费在线看不卡| 女人被狂操c到高潮| 人人妻人人澡欧美一区二区| 国产视频内射| 91午夜精品亚洲一区二区三区| 乱系列少妇在线播放| 身体一侧抽搐| 禁无遮挡网站| av在线蜜桃| 欧美色视频一区免费| 亚洲欧美精品自产自拍| 久久国内精品自在自线图片| 亚洲色图av天堂| 丝袜美腿在线中文| 免费看光身美女| 亚洲欧美日韩卡通动漫| 成年版毛片免费区| 日韩av在线大香蕉| 伦理电影大哥的女人| 日本爱情动作片www.在线观看| 人人妻人人澡人人爽人人夜夜 | 男女下面进入的视频免费午夜| 欧美成人免费av一区二区三区| 黄片wwwwww| 久久草成人影院| 亚洲av中文av极速乱| 国产成人精品婷婷| 免费看美女性在线毛片视频| 亚洲av中文字字幕乱码综合| 久久久久久大精品| 日韩成人伦理影院| 亚洲aⅴ乱码一区二区在线播放| 看黄色毛片网站| 国产高清国产精品国产三级 | 午夜免费男女啪啪视频观看| 日韩三级伦理在线观看| 成人午夜精彩视频在线观看| 少妇丰满av| 色尼玛亚洲综合影院| 婷婷六月久久综合丁香| 国产91av在线免费观看| 草草在线视频免费看| 亚洲人成网站高清观看| 欧美性猛交黑人性爽| 内射极品少妇av片p| 欧美成人a在线观看| 精品国产露脸久久av麻豆 | 九色成人免费人妻av| 男女那种视频在线观看| 日本午夜av视频| 亚洲美女搞黄在线观看| 亚洲综合色惰| 国产日韩欧美在线精品| 久久人人爽人人爽人人片va| 久久这里有精品视频免费| 亚洲av电影在线观看一区二区三区 | 日韩欧美精品v在线| 99久久人妻综合| 亚洲自偷自拍三级| 麻豆一二三区av精品| videossex国产| 国产午夜精品久久久久久一区二区三区| 久久久精品大字幕| 一二三四中文在线观看免费高清| 午夜日本视频在线| 丝袜喷水一区| 岛国在线免费视频观看| 日韩av在线免费看完整版不卡| 国产在视频线在精品| 免费观看人在逋| 亚洲精品aⅴ在线观看| av线在线观看网站| 美女xxoo啪啪120秒动态图| 国产免费福利视频在线观看| 成年av动漫网址| 亚洲精品国产成人久久av| 白带黄色成豆腐渣| 午夜福利视频1000在线观看| av在线蜜桃| 啦啦啦啦在线视频资源| 精品国产三级普通话版| videos熟女内射| 欧美精品国产亚洲| 免费人成在线观看视频色| av.在线天堂| 久久久久久伊人网av| 国产 一区 欧美 日韩| АⅤ资源中文在线天堂| 熟妇人妻久久中文字幕3abv| 日韩高清综合在线| 男人舔奶头视频| 高清毛片免费看| av又黄又爽大尺度在线免费看 | 岛国毛片在线播放| 毛片女人毛片| 村上凉子中文字幕在线| 91精品一卡2卡3卡4卡| 日本爱情动作片www.在线观看|