• <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 ?

    Micrometer-sized NiOOH hierarchical spheres for enhanced degradation of sulfadiazine via synergistic adsorption and catalytic oxidation in peroxymonosulfate system

    2022-06-18 03:00:44CongLyuLuZhangDanHeBoyuanSuYingLyu
    Chinese Chemical Letters 2022年2期

    Cong Lyu, Lu Zhang, Dan He, Boyuan Su, Ying Lyu,*

    a Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130026, China

    b Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130026, China

    c Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, United States

    ABSTRACT As an antibiotic, sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) have significant potential for the degradation of antibiotics.However, there are multiple restrictions including non-specifically binding to target contaminants, which would deplete oxidation capacity, and lacking energy effectiveness due to inefficient utilization of reactive oxygen species (ROS).To overcome these obstacles, we adopted the “bait-hook & destroy” strategy in this study.Herein, we synthesized a novel micrometer-sized NiOOH hierarchical spheres assembled from nanosheets, which have relatively large specific surface areas and yield specified cavities to “bait-hook” sulfadiazine and PMS onto the surface cavities.This process was further conductive to effective generation of ROS and subsequently“destruction” of sulfadiazine with elevated mass transformation rate.20.4% of sulfadiazine can adsorb to NiOOH surface in less than 30 min (0.0051 min-1), and then sulfadiazine was completely degraded in 90 min intervals in the NiOOH/PMS system.The degradation rate constant (k = 0.0537 min-1) was about 5.3, 2.5 and 2.2 times higher than that in Ni2O3/PMS, NiO/PMS and Ni(OH)2/PMS system, respectively.This was ascribed to the synergistic catalytic oxidation and adsorption process occurred on the surface of NiOOH.Appreciably, there were both non-radicals (1O2) and radicals (O2·- and SO4·-) involved in the NiOOH/PMS system, and 1O2 was distinguished as the dominated ROS for degradation of sulfadiazine.This study provides a novel strategy via synergistic adsorption and catalytic oxidation, and indicates that the micrometer-sized NiOOH hierarchical sphere as heterogeneous catalyst is an attractive candidate for potential application of the SR-AOPs technology in water treatment.

    Keywords:Nickel oxyhydroxide Peroxymonosulfate Sulfate radical Singlet oxygen Sulfadiazine

    Sulfadiazine has attracted wide-spread attention since it is extensively applied as an antibiotic pharmaceutical in both veterinary and human medicine, and it can pose serious threats to human well-being and ecosystems [1,2].Conventional wastewater disposal systems, which typically based on the biological treating method,perform poorly on sulfadiazine removal due to the high toxicity and poor biodegradability of sulfadiazine [3,4].As reported, sulfate radical (SO4·-) based advanced oxidation processes (SR-AOPs)could be regarded as competent, environmentally friendly, and reliable assistants to completely remove antibiotic pharmaceuticals[5,6].As such, SO4·-is usually obtained by activating peroxymonosulfate (PMS) [7] and persulfate (PS) [8] in association with ultraviolet [9], heating [10], cavitation [11], microwaves [12], transition metals [3], and so on.Due to the asymmetric molecular structure and low activation energy, PMS is relatively easier to be activated than PS [13].While compared with other energy-based activation methods, transition metals activation is a much simpler attribute to its lower energy consumption and cost-effectiveness [14,15].

    Cobalt ion (Co2+) has proven to be the best PMS activator [16].Unfortunately, the rather low recycling rate of catalysts in the homogeneous systems significantly inhibits further development[17,18], and the leaching Co2+can hold critical cytotoxicity to ecosystem and human health [19].Thus, environmental-friendly heterogeneous catalysts, such as Ni, Fe or Mn-based materials in PMS activation, have the potential to overcome limitations [20-22].Particularly, nickel (Ni) is considered as one of the most abundant elements on the earth and is of less toxic than other transitional metals [23].Ni-based heterogeneous catalysts, such as NiO [24],Ni(OH)2[25] and Ni2O3[26], were proven to be efficient PMS activators in the SR-AOPs system.The redox cycle of Ni2+/Ni3+can improve the highly efficient PMS activation and enhance the generation of reactive oxygen species (ROSs) Eqs.1 and 2.

    However, in the PMS system, target contaminants cannot be effectively removed by ROSs since only a small fraction of ROSs can end up reacting the target contaminants, while the partial of ROSs are either scavenged by background constituents (e.g., NOM, bicarbonate, Cl-etc.) or undergoing fast self-decay [27].Several researchers emphasized the “bait-hook & destroy” strategy to ameliorate the ROS production and utilization, as well as the degradation effect of contaminants [28,29].Compared with the exclusive adsorption strategy and SR-AOP strategy, the “bait-hook & destroy” strategy could not only pre-concentrate target contaminants from the solution, and further decompose themin-situ, into lowor non-toxic products [30].The ideal catalyst can be used as the“hook” in providing elevated adsorption affinity for sulfadiazine and conduct sulfadiazine accessible to ROSs generation sites, which would facilitate concerning contaminants onto catalyst surface for the following degradation [31,32].Furthermore, adequate catalytic activity for the PMS activation process could also help to form ROSs.And subsequently ROSs can efficiently react with the adsorbed contaminants, which are referred to as the “destroy” process and elevate the mass transformation rate of catalyst on its surface.Therefore, there is urgently demanded in developing a novel Ni-based heterogeneous catalyst, which can utilize the “bait-hook& destroy” strategy to degrade sulfadiazine.

    Nickel oxyhydroxide (NiOOH) has drawn extensive attention as a revolutionary catalyst, and exhibits prominent adsorption capacity owing to its magnificent characteristics, including notable adsorption capacity, robust electron transfer rate, and sufficient catalytic active sites [33].It is worth noting that the redox potential of Ni3+/Ni2+(2.0 V) is higher than PMS (1.8 V) [34], indicating that NiOOH has substantial application potential for PMS activation.However, since the surface of NiOOH is hydrophilic, it has a poor affinity for sulfadiazine.To offset its limitation, we attempted to regulate the size, morphology, and microstructures of NiOOH through chemical precipitation processes [35].

    In this study, we applied micrometer-sized NiOOH hierarchical spheres preparedviachemical precipitation method [33], and it exhibits remarkable adsorption capacity and catalytic oxidation competence in the PMS system.Micrometer-sized NiOOH hierarchical spheres, which assembled from nanosheets, have large specific surface areas and produce specified cavities to adsorb sulfadiazine and PMS onto the NiOOH surface.This process was further conducive to the effective generation of ROS and subsequently degrading process of sulfadiazine.Furthermore, the underlying mechanism of sulfadiazine degradation was investigated by quenching tests, X-ray photoelectron spectroscopy (XPS) and electron spinresonance spectroscopy (ESR) analysis.

    The main reagents, preparation, and characterization of NiOOH,experimental procedure, and analysis methods are exhibited in the Supporting information.The X-ray diffraction (XRD) patterns(Fig.1a) showed that there are diffraction peaks at 12.6°, 25.5°,37.6°, 42.7°, 51.0° and 66.0°, corresponding to the (003), (006),(102), (105), (108) and (110) (PDF #06-0075), respectively.The peaks of impurities were not detected in XRD patterns, indicating that NiOOH microparticles synthesized through chemical precipitation processes are of stable crystal formation.Energy dispersive spectrometer (EDS) image (Fig.S1 in Supporting information) exhibited that the quantity ratio of nickel atoms to oxygen atoms was about 1:2, which is unanimous about the atomic quantity ratio of nickel and oxygen in NiOOH.Fig.1b reveals the constituent nanosheets and surface morphology of the synthesized NiOOH.It has the morphology of micrometer-sized hierarchical spheres assembled from nanosheets, which endows it a larger specific surface area and thereby provides abundant catalytic active sites [33].NiOOH has a rather larger specific surface area (35.2 m2/g) compared to other nickel-based catalysts (nanosized Ni(OH)2, 20.9 m2/g) (Table S1 in Supporting information), hence enhancing the surface contact among the sulfadiazine, PMS and NiOOH, exposing more catalytic sites, and increasing the utilization of ROS [36].According to the FTIR spectrum (Fig.1c), the strong and sharp band centered at 567 cm-1represents the movement of hydrogenbonded linkages Ni-O-H and to the stretching vibration of Ni3+-O.The board band at 3450 cm-1, which is congruous with the characteristic of the hydroxyl group, indicates the presence of hydroxyl(-OH) [37-39].Thus, we could confirm that NiOOH was purely synthesized in this study.The synthesized NiOOH samples displayed type IV isotherms, which reveals that it has a representative mesoporous structure [40].As show in Fig.1d, the maximum observation pore size of NiOOH catalyst distribution is 22.35 nm.In addition, the average pore size (15.8 nm) and total pore volume (0.14 cm3/g) of the NiOOH were calculated by Barret-Joyner-Halenda(BJH) simulation (Table S1).It is worth noting that the absorption of sulfadiazine is available, since the pore diameters of NiOOH are significantly larger than sulfadiazine (14.9 × 6.31 × 4.86) [41].

    Fig.1.Characterizations of NiOOH: (a) XRD spectrum, (b) SEM image, (c) FT-IR spectrum and (d) N2 adsorption-desorption curves and pore size distribution of NiOOH.

    The adsorption of NiOOH on P MS activation for sulfadiazine degradation was evaluated.It can be seen from Fig.2a that 23.2%of sulfadiazine can be adsorbed on the NiOOH surface and the calculated saturated adsorption capacity (qe) of sulfadiazine is 11.6 mg/g.46.3% of sulfadiazine was removed within 90 min, implying that the catalytic oxidation process occurred for sulfadiazine degradation.Notably, the synergistic adsorption and catalytic oxidation removal rate of sulfadiazine (0.0537 min-1) was 2.65 times greater than the total contribution of adsorption and catalytic oxidation (0.0051 + 0.0096 = 0.0147 min-1) (Fig.2b).The removal rate of sulfadiazine was increased significantly may attribute to the enrichment of sulfadiazine onto the surface of NiOOHviathe hydrogen bonding (OH···N), and the effective utilization of ROS.As illustrated in Fig.2c, in 90 min reaction, sulfadiazine was completely degraded in 90 min intervals in the NiOOH/PMS system, nevertheless, only 59%, 84% and 90% degradation were accomplished in the Ni2O3/PMS, Ni(OH)2/PMS and NiO/PMS system, respectively.Furthermore, based on the first-order kinetic model, the degradation efficiency of sulfadiazine (0.0537 min-1) in NiOOH/PMS system was about 5.3, 2.5 and 2.2 times higher than that in Ni2O3/PMS,NiO/PMS and Ni(OH)2/PMS system (Fig.2d).Conclusively, NiOOH exhibited much higher catalytic performance for PMS activation than Ni2O3, NiO and Ni(OH)2.

    Fig.2.Adsorption and catalytic oxidation of different catalysts towards sulfadiazine.Degradation kinetics (a, c) and reaction rate (b, d) constants of sulfadiazine in different catalytic PMS system.Conditions: [sulfadiazine] = 10 mg/L, [PMS] = 0.2 mmol/L,[catalysts] = 0.2 g/L, pH 7, T = 20 °C.

    In particular, the fitting correlation coefficient of the quasi-firstorder kinetic model is higher (R2= 0.9833) than quasi-secondorder kinetic model (R2= 0.9463), indicating that sulfadiazine was adsorbed onto NiOOHviathe formation of hydrogen bonds(O-H···N) between the amino group (-NH) of sulfadiazine and hydroxy (-OH) of NiOOH [42,43] (Fig.S2 in Supporting information).The effects of operation parameters like temperature, sulfadiazine doses, PMS doses, NiOOH doses, background constituents(e.g., NOM, bicarbonate, Cl-etc.), and the rate constant (k) of the NiOOH/PMS system were shown in Figs.S3-S5 (Supporting information).TOC removal rate during the sulfadiazine degradation in NiOOH/PMS system was investigated in Fig.S6 (supporting information).After 90 min, with the complete degradation of sulfadiazine, the removal ratio of TOC increased up to 59.9%, suggesting that more degradation intermediates of sulfadiazine were further completely degraded.More importantly, NiOOH has good stability and recyclability under the initial condition of neutral pH, and it is an attractive candidate for PMS activation to degrade antibiotic pharmaceuticals, as a result of Fig.S7 (Supporting information).

    The XPS spectra of NiOOH before and after the catalytic reaction were favorable to evaluate the role of the O and Ni species in the PMS activation.The peaks of Ni 2p at 855.4 eV and 856.4 eV were represented Ni(II) and Ni(III), respectively [44] (Fig.3a).After the reaction, the peak area of Ni(III) peak was decreased from 100.0%to 33.9%, while the peak area of Ni(II) peak was increased from 0% to 66.1%, which indicates that Ni(III) was reduced to Ni(II) during the reaction.The existence of Ni(II) on the highly hydroxylated surface of NiOOH is beneficial to the formation of Ni-OH+active species, which can enhance PMS activation to produce SO4·-and other active oxygen species for sulfadiazine degradation.The peaks of O 1s performed at 533.0 eV, 531.3 eV and 529.1 eV (Fig.3b),which was ascribed to adsorbed oxygen (Oabs), hydroxyl oxygen(Ni-OH) and lattice oxygen (Ni-O), respectively.Specifically, the Ni-O content hardly changed after the reaction, whereas the amounts of Ni-OH increased and the amounts of Oabsdecreased.It was ascribed to the formation more of Ni-OH+species on the NiOOH surface (Table S2 in Supporting Information).Taken together, cycling of Ni valance and formation of Ni-OH+provided a good explanation for the mechanism of PMS activationviaNiOOH.

    To determine the role of various ROS in sulfadiazine degradation, FFA, EtOH, TBA andp-BQ were used as quenchers of1O2,SO4·-,·OH and O2·-to perform the quenching reactions [45], respectively (Fig.3c).Detailed discussion is presented in the supplement information.In order to further identify the various ROS in the NiOOH/PMS system and verify the results of the quenching experiment discussion, DMPO and TEMP were added to conduct the characterization of ESR.Under the secondary redox condition,DMPO can react with ROS to generate adducts, such as DMPO-·OH,DMPO-SO4·-and DMPO-O2·-, while TEMP can react with1O2to generate TEMP-1O2, which resulted in the detection of characteristic peaks on the ESR spectrum [46].The strong ESR signal shown in the Fig.3d was DMPO-·OH, which with a peak-to-height ratio of 1:2:2:1, simultaneously, the low peaks were most likely to be DMPO-SO4·-[47].Apparently, four characteristic peaks were conducted in Fig.3e, which are most likely to be DMPO-O2·-[48].In addition, Fig.3f illustrated a typical TEMP-1O2signal, which performed as a three-equal-intensity-line in ESR pattern with the relative intensity of 1:1:1 [49].Consistent with the quenching experiment results, there were both non-radicals (such as1O2) and radicals (O2·-and SO4·-) occurred in the NiOOH/PMS system, and1O2was distinguished as the dominated ROS [50].

    Fig.3.High-resolution XPS spectra of (a) Ni 2p and (b) O 1s before and after the catalytic oxidation process.Quenching tests and ESR spectrum in the “NiOOH activated PMS” system: (c) The effect of different quenchers on the sulfadiazine degradation in the NiOOH/PMS system and the ESR spectrum of (d) SO4·- and ·OH, (e) O2·- and (f)1O2 in the NiOOH/PMS system.Conditions: [sulfadiazine] = 10 mg/L, [PMS] = 0.2 mmol/L, [NiOOH] = 0.2 g/L, [FFA] = [p-BQ] = 10 mmol/L, [TBA] = [EtOH] = 100 mmol/L,pH 7, T = 20 °C.

    The degradation intermediates were detected through LC-MSMS, and seventeen degradation intermediates were observed, and the details are exhibited in Fig.S8 and Table S4 (Supporting information).Practicable pathways of the degrading reaction were proposed in Fig.S9 (Supporting Information).In the first route,the hydrogen-nitrogen bonds of sulfadiazine were stroked by ROS(SO4·-, O2·-and1O2) and hydroxylation reaction happened, resulting in the creation of intermediate compound 17 withm/z283.52 [51].In the second route, the Nitrogen-Carbon bond of sulfadiazine was stroked, and then form the intermediate compound 15 withm/z235.37.Subsequently, the generation of intermediate compound 12 withm/z199.00 derived from the cleavage of pyrimidine ring, owing to the instability of nitrogen-carbon bonds [52].In the third pathway, sulfadiazine experiences sulfur dioxide extrusion to yield intermediate compound 11 withm/z186.66.In the fourth route, the cleavage of the neighboring sulfur-nitrogen bondsviaROS result in intermediate compound 8 withm/z173.21, and intermediate 8 may hydroxylate instantly and converted to intermediate 5 withm/z111.83 [51].Every single determined intermediate may further degrade in the following reaction by ROS, bring about the generation of aliphatic carboxylic acid, and eventually degrade to CO2and H2O [53].

    In accordance with preceding experimental findings, the synergism between the catalytic oxidation and the adsorption process on the NiOOH surface could depict in Fig.4.Micrometersized NiOOH hierarchical spheres used nanosheets as components,which contribute to the extensive specific surface area, and this feature can improve the adsorption of sulfadiazine and PMS.The NiOOH can be used as the “hook” in providing elevated adsorption affinity for sulfadiazine and conducting sulfadiazine accessible to ROSs generation site, which would facilitate concerning sulfadiazine onto NiOOH surface for the following degradation.Furthermore, the hydrogen bonding (O···N) formed between the surface hydroxyl group of NiOOH and the amide group of sulfadiazine could accelerate the absorption of sulfadiazine Fig.4b).Referring to XPS characterization, quenching experiment, and ESR characterization, NiOOH could concisely activate PMS through non-radical and free radical pathways, as shown in Fig.4c.The ROS producedviaPMS activation by NiOOH, including SO4·-, O2·-and1O2, can be effectively utilized to degrade sulfadiazine (Eqs.1-12).

    Fig.4.The mechanism of sulfadiazine degradation in the NiOOH/PMS system.The“bait-hook & destroy” strategy (a) combined with sulfadiazine adsorption (b) and ROS generation (c) for sulfadiazine degradation.

    Micrometer-sized hierarchical spheres assembled from nanosheets provide abundant catalytic active sites in enriching sulfadiazine and PMS, and then ROS can be effectively utilized to accelerate the sulfadiazine degrading process in the NiOOH/PMS system.Therefore, sulfadiazine might be effectively degraded in the NiOOH/PMS system through the synergism between the catalytic oxidation and the adsorption process.

    In summary, a micrometer-sized NiOOH hierarchical sphere assembled from nanosheets with a large specific surface area has been successfully synthesizedviathe chemical precipitation method.Herein, we adopted the “bait-hook & destroy” strategy to enrich sulfadiazine and PMS onto the surface of NiOOH, and then ROS can be effectively generated and utilized for sulfadiazine degradation.Particularly, both radicals and non-radicals occurred in the PMS activation, in which1O2might play an important role in sulfadiazine degradation.Overall, the micrometer-sized NiOOH hierarchical sphere can be an attractive candidate as heterogeneous catalyst for PMS activation.This study provides a novel strategyviasynergistic adsorption and catalytic oxidation for SR-AOPs system in water treatment.

    Declaration of competing interests

    The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

    Acknowledgments

    The present work was funded by the National Key R&D Program of China (No.2018YFC0406503), the National Natural Science Foundation of China (No.52070086), the Natural Science Foundation of Jilin Provincial Science & Technology Department (No.20200403034SF) and the Open Project Program of Engineering Research Center of Groundwater Pollution Control and Remediation,Ministry of Education.

    Supplementary materials

    Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.cclet.2021.07.012.

    考比视频在线观看| 99re6热这里在线精品视频| 国产精品久久久久久久久免| 老司机在亚洲福利影院| 久久久久精品国产欧美久久久 | 亚洲国产精品一区二区三区在线| kizo精华| 亚洲国产精品一区二区三区在线| 极品人妻少妇av视频| 一边亲一边摸免费视频| 一本大道久久a久久精品| 妹子高潮喷水视频| 欧美成人午夜精品| 麻豆精品久久久久久蜜桃| 少妇猛男粗大的猛烈进出视频| 伦理电影免费视频| 亚洲精品乱久久久久久| 精品一区在线观看国产| 亚洲四区av| 欧美日韩亚洲高清精品| 欧美人与善性xxx| 最近最新中文字幕大全免费视频 | 国产黄频视频在线观看| 高清av免费在线| 亚洲 欧美一区二区三区| 大片免费播放器 马上看| 国产精品嫩草影院av在线观看| 麻豆精品久久久久久蜜桃| av在线老鸭窝| 看十八女毛片水多多多| 最黄视频免费看| 精品一区二区免费观看| 91精品伊人久久大香线蕉| 下体分泌物呈黄色| 国产在线一区二区三区精| 久久久欧美国产精品| 国产高清不卡午夜福利| 亚洲色图 男人天堂 中文字幕| 成人三级做爰电影| 日本爱情动作片www.在线观看| 久久久久精品性色| 女人高潮潮喷娇喘18禁视频| 不卡视频在线观看欧美| 亚洲av日韩在线播放| 成人国产麻豆网| 制服人妻中文乱码| 九色亚洲精品在线播放| 精品一品国产午夜福利视频| 国产免费福利视频在线观看| 女人精品久久久久毛片| 亚洲综合精品二区| 新久久久久国产一级毛片| 不卡视频在线观看欧美| 美女主播在线视频| 国产av国产精品国产| 天堂俺去俺来也www色官网| 精品视频人人做人人爽| 天天操日日干夜夜撸| 视频区图区小说| 中文字幕最新亚洲高清| 一级a爱视频在线免费观看| 男人舔女人的私密视频| 亚洲国产精品999| 永久免费av网站大全| 日本vs欧美在线观看视频| 黄色怎么调成土黄色| 卡戴珊不雅视频在线播放| 国产99久久九九免费精品| 自拍欧美九色日韩亚洲蝌蚪91| 日韩av免费高清视频| 中文字幕色久视频| 观看av在线不卡| av福利片在线| 久久天躁狠狠躁夜夜2o2o | 久久韩国三级中文字幕| 麻豆乱淫一区二区| 日韩欧美一区视频在线观看| 电影成人av| 大码成人一级视频| 超碰成人久久| 美女午夜性视频免费| 99国产综合亚洲精品| 操出白浆在线播放| av卡一久久| 在线亚洲精品国产二区图片欧美| 国产一区二区激情短视频 | 精品福利永久在线观看| 99热网站在线观看| 天天躁日日躁夜夜躁夜夜| 久久精品久久久久久久性| 男人舔女人的私密视频| 国产一区二区激情短视频 | 亚洲 欧美一区二区三区| 老司机亚洲免费影院| 亚洲av综合色区一区| 久久 成人 亚洲| 老司机亚洲免费影院| 国产精品免费视频内射| 久久精品熟女亚洲av麻豆精品| 蜜桃在线观看..| 五月开心婷婷网| 18在线观看网站| 国产亚洲最大av| a 毛片基地| av在线老鸭窝| av.在线天堂| 亚洲av成人精品一二三区| 日韩成人av中文字幕在线观看| 99久国产av精品国产电影| 如何舔出高潮| 午夜免费男女啪啪视频观看| 十八禁人妻一区二区| svipshipincom国产片| av女优亚洲男人天堂| 日韩中文字幕欧美一区二区 | 看十八女毛片水多多多| 久久久亚洲精品成人影院| 亚洲av男天堂| 日本vs欧美在线观看视频| 久久亚洲国产成人精品v| 午夜精品国产一区二区电影| 国产精品免费视频内射| 午夜日韩欧美国产| 两个人看的免费小视频| 亚洲精品国产色婷婷电影| 亚洲精品av麻豆狂野| 亚洲四区av| 99热全是精品| 熟妇人妻不卡中文字幕| 亚洲少妇的诱惑av| 激情视频va一区二区三区| 91精品伊人久久大香线蕉| 国产av国产精品国产| 国产精品嫩草影院av在线观看| 在线 av 中文字幕| 999精品在线视频| 99久久人妻综合| 亚洲第一青青草原| 国产一区二区激情短视频 | 国产亚洲午夜精品一区二区久久| 久久精品久久久久久噜噜老黄| 国产伦人伦偷精品视频| 久久精品人人爽人人爽视色| 国产免费福利视频在线观看| 久久ye,这里只有精品| 婷婷色av中文字幕| 性高湖久久久久久久久免费观看| 久久久国产一区二区| 婷婷色综合www| 免费日韩欧美在线观看| 婷婷色av中文字幕| 人人妻人人澡人人爽人人夜夜| 一本色道久久久久久精品综合| a 毛片基地| 亚洲久久久国产精品| 欧美日韩一级在线毛片| 欧美国产精品一级二级三级| 久久人人97超碰香蕉20202| 免费女性裸体啪啪无遮挡网站| 精品一区在线观看国产| 国产野战对白在线观看| 国产精品成人在线| 亚洲综合精品二区| 不卡视频在线观看欧美| 欧美中文综合在线视频| 老熟女久久久| 欧美日韩成人在线一区二区| 又黄又粗又硬又大视频| 亚洲精华国产精华液的使用体验| 国产精品亚洲av一区麻豆 | 中文字幕人妻熟女乱码| 欧美日韩av久久| 亚洲国产精品999| 菩萨蛮人人尽说江南好唐韦庄| 在线 av 中文字幕| 91精品三级在线观看| 亚洲国产av影院在线观看| 久久久久网色| 黄色视频不卡| www.熟女人妻精品国产| 国产日韩欧美亚洲二区| 91aial.com中文字幕在线观看| 人妻人人澡人人爽人人| 99国产精品免费福利视频| 日韩制服骚丝袜av| 国产亚洲一区二区精品| 成人毛片60女人毛片免费| 日韩成人av中文字幕在线观看| 在线观看人妻少妇| 天天操日日干夜夜撸| 成人国产麻豆网| 黄色怎么调成土黄色| 欧美国产精品一级二级三级| 天堂8中文在线网| 亚洲国产欧美网| 黄网站色视频无遮挡免费观看| 亚洲精品一区蜜桃| a级片在线免费高清观看视频| 日本av免费视频播放| 一二三四中文在线观看免费高清| 免费少妇av软件| 欧美日韩成人在线一区二区| 国产片特级美女逼逼视频| 精品少妇黑人巨大在线播放| 大码成人一级视频| av线在线观看网站| 亚洲熟女精品中文字幕| 日韩成人av中文字幕在线观看| 国产精品一区二区精品视频观看| 日韩 欧美 亚洲 中文字幕| 精品视频人人做人人爽| avwww免费| 90打野战视频偷拍视频| 亚洲精品日韩在线中文字幕| 熟女少妇亚洲综合色aaa.| 男人爽女人下面视频在线观看| 天天躁狠狠躁夜夜躁狠狠躁| 99精国产麻豆久久婷婷| 久久久久久久久免费视频了| tube8黄色片| 一区二区三区精品91| av卡一久久| 热99久久久久精品小说推荐| 十分钟在线观看高清视频www| 欧美成人午夜精品| 男的添女的下面高潮视频| 91精品国产国语对白视频| 国产免费又黄又爽又色| 国产一区二区在线观看av| 免费黄色在线免费观看| 在线天堂最新版资源| 伦理电影免费视频| 国产精品久久久av美女十八| 亚洲欧洲国产日韩| 激情视频va一区二区三区| 免费女性裸体啪啪无遮挡网站| 黄色怎么调成土黄色| 久久久国产欧美日韩av| 一区在线观看完整版| 日韩欧美精品免费久久| www.av在线官网国产| svipshipincom国产片| 伊人久久国产一区二区| 日本色播在线视频| 狂野欧美激情性bbbbbb| 中文字幕另类日韩欧美亚洲嫩草| 日韩成人av中文字幕在线观看| 精品国产一区二区三区四区第35| 亚洲国产av新网站| 18禁动态无遮挡网站| 一级,二级,三级黄色视频| 一区二区三区乱码不卡18| 熟女av电影| 一本色道久久久久久精品综合| 国产一级毛片在线| 欧美亚洲 丝袜 人妻 在线| 2021少妇久久久久久久久久久| 亚洲成av片中文字幕在线观看| 熟女少妇亚洲综合色aaa.| 亚洲av成人不卡在线观看播放网 | 人体艺术视频欧美日本| 丁香六月欧美| 国产毛片在线视频| 亚洲欧洲日产国产| 国产免费又黄又爽又色| 18禁裸乳无遮挡动漫免费视频| 亚洲精品国产区一区二| 亚洲精品,欧美精品| 亚洲精品日本国产第一区| 美女高潮到喷水免费观看| 精品一区在线观看国产| 久久精品aⅴ一区二区三区四区| 日韩制服骚丝袜av| 18禁观看日本| 日本av免费视频播放| 日韩 亚洲 欧美在线| 欧美激情高清一区二区三区 | 欧美激情高清一区二区三区 | 制服丝袜香蕉在线| 日韩,欧美,国产一区二区三区| 亚洲久久久国产精品| 观看av在线不卡| 99久久99久久久精品蜜桃| 亚洲国产精品国产精品| 免费女性裸体啪啪无遮挡网站| 国产精品三级大全| 久久久精品区二区三区| 国产男女超爽视频在线观看| 自拍欧美九色日韩亚洲蝌蚪91| 一级a爱视频在线免费观看| 高清视频免费观看一区二区| 中文字幕人妻熟女乱码| 天天躁日日躁夜夜躁夜夜| 久久精品aⅴ一区二区三区四区| 黄片无遮挡物在线观看| 少妇猛男粗大的猛烈进出视频| 国产又爽黄色视频| 亚洲精品视频女| av国产精品久久久久影院| 国产一区有黄有色的免费视频| 亚洲激情五月婷婷啪啪| 亚洲精品av麻豆狂野| 日韩视频在线欧美| xxx大片免费视频| av在线app专区| 99精品久久久久人妻精品| 日韩中文字幕欧美一区二区 | 欧美日韩亚洲国产一区二区在线观看 | 国精品久久久久久国模美| a级片在线免费高清观看视频| 国产男女内射视频| 精品一区二区三卡| 大片电影免费在线观看免费| 国产日韩欧美亚洲二区| 亚洲av男天堂| 午夜福利视频在线观看免费| 国产精品亚洲av一区麻豆 | www.精华液| 亚洲av成人不卡在线观看播放网 | 欧美亚洲 丝袜 人妻 在线| 欧美日韩av久久| 国产成人精品久久久久久| 好男人视频免费观看在线| 看免费成人av毛片| 亚洲 欧美一区二区三区| 欧美黑人欧美精品刺激| 亚洲情色 制服丝袜| 久久精品aⅴ一区二区三区四区| 大码成人一级视频| 青春草视频在线免费观看| 桃花免费在线播放| 欧美av亚洲av综合av国产av | 午夜免费观看性视频| 一本色道久久久久久精品综合| 久久精品国产a三级三级三级| 日本午夜av视频| 亚洲成人一二三区av| 大香蕉久久成人网| 曰老女人黄片| 男的添女的下面高潮视频| 老司机亚洲免费影院| 天堂中文最新版在线下载| 天天躁日日躁夜夜躁夜夜| 免费高清在线观看日韩| 国产免费视频播放在线视频| 国产精品二区激情视频| 日韩中文字幕视频在线看片| 韩国高清视频一区二区三区| 亚洲成色77777| 国产男女内射视频| 如何舔出高潮| 亚洲国产精品一区二区三区在线| 国产视频首页在线观看| 久久久久久久大尺度免费视频| 波野结衣二区三区在线| 自拍欧美九色日韩亚洲蝌蚪91| 精品国产超薄肉色丝袜足j| 久久青草综合色| 免费少妇av软件| 午夜av观看不卡| 老司机亚洲免费影院| 啦啦啦 在线观看视频| 一本—道久久a久久精品蜜桃钙片| 日日爽夜夜爽网站| 99久久人妻综合| 十八禁人妻一区二区| 亚洲欧美清纯卡通| 久久亚洲国产成人精品v| 亚洲一级一片aⅴ在线观看| 一级黄片播放器| 99国产综合亚洲精品| 人人妻人人添人人爽欧美一区卜| 国产又爽黄色视频| 99香蕉大伊视频| 国产黄色视频一区二区在线观看| 五月开心婷婷网| 熟女少妇亚洲综合色aaa.| 飞空精品影院首页| 亚洲精品aⅴ在线观看| 9色porny在线观看| 国产亚洲av片在线观看秒播厂| av网站免费在线观看视频| 亚洲精品久久午夜乱码| avwww免费| 免费在线观看黄色视频的| 黄色视频在线播放观看不卡| 女人久久www免费人成看片| 免费av中文字幕在线| 99久久人妻综合| 制服诱惑二区| 国产片特级美女逼逼视频| 五月开心婷婷网| 久久午夜综合久久蜜桃| 丝袜喷水一区| 成人黄色视频免费在线看| 女性被躁到高潮视频| 午夜福利免费观看在线| 久久久久人妻精品一区果冻| 精品亚洲成a人片在线观看| 青草久久国产| 日韩 亚洲 欧美在线| 免费女性裸体啪啪无遮挡网站| 国精品久久久久久国模美| 国产精品久久久人人做人人爽| 亚洲精品乱久久久久久| 久久精品熟女亚洲av麻豆精品| 国产亚洲午夜精品一区二区久久| 国产不卡av网站在线观看| 两个人看的免费小视频| 五月开心婷婷网| 99九九在线精品视频| 国产精品av久久久久免费| 不卡av一区二区三区| 永久免费av网站大全| 一级a爱视频在线免费观看| 久久99精品国语久久久| 飞空精品影院首页| av片东京热男人的天堂| 国产淫语在线视频| 国产视频首页在线观看| 亚洲国产日韩一区二区| 女人爽到高潮嗷嗷叫在线视频| 精品国产一区二区三区久久久樱花| 一本久久精品| 亚洲国产欧美一区二区综合| 国产无遮挡羞羞视频在线观看| 中文字幕人妻熟女乱码| 在线观看人妻少妇| 夫妻午夜视频| 久久久久精品人妻al黑| 咕卡用的链子| 纵有疾风起免费观看全集完整版| 青春草国产在线视频| 国产一区二区三区av在线| 女人被躁到高潮嗷嗷叫费观| 日韩不卡一区二区三区视频在线| 另类精品久久| 操出白浆在线播放| 亚洲伊人色综图| 免费不卡黄色视频| 日韩一区二区视频免费看| 色婷婷av一区二区三区视频| 在线观看免费视频网站a站| 亚洲av电影在线观看一区二区三区| 日本黄色日本黄色录像| 亚洲国产欧美网| 天堂中文最新版在线下载| 国产黄色视频一区二区在线观看| 成人手机av| 国产精品蜜桃在线观看| 中文字幕人妻熟女乱码| videos熟女内射| 又粗又硬又长又爽又黄的视频| 国产不卡av网站在线观看| 亚洲欧美一区二区三区黑人| 99精品久久久久人妻精品| 久久久精品区二区三区| 国产精品 国内视频| 久久精品国产综合久久久| 国产探花极品一区二区| 多毛熟女@视频| 国产日韩欧美在线精品| av片东京热男人的天堂| 丝瓜视频免费看黄片| 在线看a的网站| 天天躁日日躁夜夜躁夜夜| 久久精品人人爽人人爽视色| av在线播放精品| 欧美日本中文国产一区发布| 黄片播放在线免费| 欧美老熟妇乱子伦牲交| 国产精品一区二区在线不卡| 久久天堂一区二区三区四区| 国产精品三级大全| 日本黄色日本黄色录像| 国产精品久久久久成人av| 久久久久久久久久久久大奶| 妹子高潮喷水视频| 一级毛片 在线播放| 成人午夜精彩视频在线观看| 高清不卡的av网站| 久久99一区二区三区| 99九九在线精品视频| 看十八女毛片水多多多| 又黄又粗又硬又大视频| 亚洲精品日韩在线中文字幕| 亚洲精品中文字幕在线视频| 亚洲一级一片aⅴ在线观看| 赤兔流量卡办理| 久久久久久久久免费视频了| 美女脱内裤让男人舔精品视频| 国产精品久久久久久精品电影小说| 两性夫妻黄色片| 新久久久久国产一级毛片| svipshipincom国产片| 亚洲国产日韩一区二区| 免费日韩欧美在线观看| 国产精品一国产av| 国产精品麻豆人妻色哟哟久久| 国产精品一区二区在线不卡| 欧美最新免费一区二区三区| 亚洲欧美精品综合一区二区三区| 别揉我奶头~嗯~啊~动态视频 | 激情视频va一区二区三区| av福利片在线| 久久狼人影院| 天美传媒精品一区二区| 精品免费久久久久久久清纯 | 黄色视频不卡| 中文乱码字字幕精品一区二区三区| 91国产中文字幕| 高清在线视频一区二区三区| 成人影院久久| 色网站视频免费| 97人妻天天添夜夜摸| 欧美日韩一级在线毛片| 国产淫语在线视频| 日日爽夜夜爽网站| 亚洲av欧美aⅴ国产| 久久久久久久大尺度免费视频| 亚洲av福利一区| 国产探花极品一区二区| 五月天丁香电影| 日本午夜av视频| 国产又爽黄色视频| 免费观看性生交大片5| 亚洲七黄色美女视频| 国产精品一二三区在线看| 免费女性裸体啪啪无遮挡网站| 久久人人爽人人片av| 国产一区二区在线观看av| 亚洲人成网站在线观看播放| netflix在线观看网站| 欧美日韩亚洲综合一区二区三区_| 日韩免费高清中文字幕av| 欧美日韩亚洲综合一区二区三区_| 人妻人人澡人人爽人人| 中文字幕人妻丝袜制服| 又黄又粗又硬又大视频| 久久人妻熟女aⅴ| 日本欧美国产在线视频| 午夜福利在线免费观看网站| 大片免费播放器 马上看| videosex国产| 99久久99久久久精品蜜桃| www.熟女人妻精品国产| videosex国产| 亚洲精品成人av观看孕妇| 日本vs欧美在线观看视频| 亚洲人成网站在线观看播放| 亚洲国产最新在线播放| 青草久久国产| 欧美97在线视频| 久久人人爽av亚洲精品天堂| 中文字幕人妻丝袜一区二区 | 久久久精品免费免费高清| 国产人伦9x9x在线观看| 亚洲在久久综合| 国精品久久久久久国模美| 久久久国产精品麻豆| 国产免费一区二区三区四区乱码| 久久精品人人爽人人爽视色| av卡一久久| 国产精品一区二区在线观看99| 大片免费播放器 马上看| 黑丝袜美女国产一区| 99久久99久久久精品蜜桃| 国产伦人伦偷精品视频| 久久久久精品性色| 又大又爽又粗| 日韩中文字幕欧美一区二区 | bbb黄色大片| 亚洲av成人不卡在线观看播放网 | 日本av免费视频播放| 亚洲欧美色中文字幕在线| 久久青草综合色| 国产女主播在线喷水免费视频网站| 国产欧美日韩一区二区三区在线| 国产成人啪精品午夜网站| 亚洲成色77777| 欧美国产精品va在线观看不卡| 精品国产乱码久久久久久小说| 成年动漫av网址| 9191精品国产免费久久| 大香蕉久久成人网| 精品国产一区二区三区四区第35| av国产精品久久久久影院| 日韩一本色道免费dvd| 亚洲精品一区蜜桃| 国产日韩一区二区三区精品不卡| 久久精品国产亚洲av高清一级| 男人舔女人的私密视频| av一本久久久久| 欧美日韩亚洲综合一区二区三区_| 啦啦啦啦在线视频资源| 国产男女内射视频| 国产免费现黄频在线看| 久久人人爽人人片av| 18禁裸乳无遮挡动漫免费视频| 九草在线视频观看| 99热全是精品| 中文字幕色久视频| 伦理电影大哥的女人| 秋霞在线观看毛片| 777米奇影视久久| 女性生殖器流出的白浆| 天堂俺去俺来也www色官网| av网站在线播放免费| 成人亚洲精品一区在线观看| 一区二区三区激情视频| 国产一区亚洲一区在线观看| 久久久国产精品麻豆| 国产乱来视频区| 午夜激情久久久久久久| 人人妻人人澡人人爽人人夜夜|