• <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 ?

    Analysis of Dry Fermentation Process for Treating Food Waste

    2014-10-30 07:33:18ATTAEWUSIAmaXiangyuMAZonghuWANGLi

    ATTA-EWUSI Ama, Lü Xiang-yu, MA Zong-hu, WANG Li

    (1.University of Cape Coast,Cape Coast 00233,Ghana;2.Shenyang University of Chemical Technology,Shenyang 110142,China;3.China Huadian Engineering CO.,LTD.,Beijing 100160,China)

    Food waste is the domestic waste of residents living consumption of life,and it easy to be rotten extremely,diffuses fetid and spreads bacteria and viruses.The production of food waste in China has over 6 000 000 tons every year.With the larger population density in adding the meal time concentrated and waste serious,the food waste production is larger.While due to the cafeteria mismanagement,lots of food waste are used to feed pigs and produce cooking oil.It has a strong impact on our health.

    Food waste accounts for a high proportion of municipal solid waste in Asian countries,Visvanathan et al[1]reported the wet weight ratio of several compositions of municipal solid waste in Asian countries as shown in Fig.1.Degrade food waste has a crucial role in handing municipal waste.

    Fig.1 Materials'wet weight ratio of municipal solid waste in Asia countries

    1 Determination of Food Waste Components

    The food waste main ingredients include rice,vegetables,flour food,meat,bone,animal and plant oil,from the chemical composition's point of view,it has starch,cellulose,protein,lipid and inorganic salt[2].As the food waste composition is complex,its material properties are varied.

    1.1 Materials

    The sampling materials of food waste are taken from the restaurant at every Monday for many weeks and sampling times at half an hour after dinner as shown in Fig.2.Stir evenly before sampling in the food waste tank and jetting-out the tons,chopsticks,plastic bags and so on.Smash the food waste into 2~5 mm using food grinder and stir evenly.

    Fig.2 Experiment material

    1.2 Test Items and Method

    All test items use standard methods,the results as shown in Table 1.

    Table 1 The main project measuring method and evidence of food waste

    1.3 Food Waste Properties Analysis

    From outside,the food waste of breakfast main include egg shells,pickles,porridge,steamed stuffed buns,deep-fried dough sticks,deep-fried dough cakes and so on,the lunch and the dinner almost similar,which also include rice,noodle,vegetables,meat and so on.By contrast,the breakfast,lunch and dinner contain more oil and salt.

    1.3.1 Changes of TS,VS,TC,TN and C/N

    Carbon source and nitrogen source are necessary for microbial growth and development,and TS,VS,TC,TN and C/N play an important role in fermentation.

    Cho et al[3]reported that a text about methane yields of cooked meat,cellulose,boiled rice,fresh cabbage and mixed food waste,with the same TS from 15%to 30%,were 482,356,294,277 and 472 mL/g VS added respectively,and anaerobic biodegradability based on the stoichiometric methane yield were 82% ,92% ,72% ,73%and 86%,respectively.

    Hashimoto[4]reported at both mesophilic(35℃)and thermophilic(55℃).The batch tests could smoothly start-up with 0.49 m3/g VS fed.While thermophilic operation was not stable at an effluent substrate concentration of 62.5 m3/kg VS.Chea Eliyan[5]found that as the VS increased,the bio-gas production decreased.The methane bio-gas production rate of 140.35 L/kg VS when reactor loading rate at 2 kg/m3d.However,when loading was increased to 2.5 kg/m3d,the significant deterioration of biogas composition as well as production was only 62.55 L/kg VS.

    C/N make a very important effect on anaerobic digestion.The most suitable C/N proportion(molar ratio)for anaerobic digestion is(10~20)∶1,Polprasert[6]also gave an optimum(C/N)ratio(molar ratio)about(25 ~30)∶1,which is considered suitable for an anaerobic digester.If the C/N proportion too high might be due to acid accumulation and ammonia inhibition when proportion low.If the C/N of material is not suitable,we can mix food waste with other materials,and there are some materials C/N ratio as follows Table 2.

    Table 2 C/N ratio of some materials

    1.3.2 Inorganic Salt Ions

    Food waste contains many complicated nutrients,there is more amount of salt.While the amount of salt might affect performance of anaerobic digestion,so we determine the water-solubility salt.Some studies indicated that it made no difference for methane bacteria under low Na+、Ca2+、C1-concentration.The salt content of food waste of breakfast,lunch and dinner was shown in Table 3.High concentration has clear evidence to restrain the growing of methane bacterial.The inoculation sludge was taken from process maturity anaerobic reaction tank,bacterial domestication as well,so it's feasible for food waste digestion.

    From the result of the analysis about food waste in Table 4 shown,there are abundant nutriments in food waste and C/N、VS/TS rate are all in the appropriate rang,and inorganic salt concentration also haven't reached the degree of inhibition.Comprehensive analysis of the food waste has enormous potential for anaerobic digestion.

    Table 3 The salt content of the food waste

    Table 4 The TS、VS、TC、kjeldahl nitrogen-N、TN of the food waste and the C/N、TS/VS

    Table 4 The TS、VS、TC、kjeldahl nitrogen-N、TN of the food waste and the C/N、TS/VS

    Notes:B—breakfast;L—lunch;D—dinner.

    Item w(TS)/% w(VS)/%w(VS/TS)/%w(TC)/% w(KN)/% w(NO-3-N)/% w(TN)/% w(C/N)/%1 2 3 55 L 30.05 25.12 83.60 30.85 2.77 0.022 7 2.79 13.06 D 28.33 22.80 80.57 30.34 2.45 0.027 7 2.48 14.23 B 34.70 25.10 72.33 23.83 2.03 0.009 8 2.13 13.B 48.12 36.46 75.77 28.46 1.61 0.012 2 1.62 18.18 L 33.45 27.70 82.81 32.10 2.68 0.019 5 2.70 12.88 D 30.80 24.53 81.55 27.48 2.34 0.037 9 2.38 12.57 B 38.32 29.20 76.20 27.00 1.85 0.010 4 1.86 14.71 53 L 40.55 33.28 82.07 34.21 2.06 0.015 6 2.08 18.46 D 32.20 26.15 82.30 31.76 2.46 0.040 2 2.50 12.

    2 Dry Fermentation and Factors

    Dry fermentation,one of the most efficient and productive treatment technologies has received significant attention from researchers.Dry fermentation means organic solid concentration between 20%to 30%,and methane fermentation under no or little flow water condition.Contrast with the wet anaerobic digestion there are no or little fresh water by dry anaerobic digestion,it is only saving water but also save cost for digestive residue dehydration.Therefore dry anaerobic digestion has more high organic loading and bio-gas production efficiency.

    Food waste has abundant organic materials and water,using food waste as matrix for anaerobic digestion not only reduce waste emission but also provide cleaner energy.Zhang et al[7]sampled 500 food waste point location for investigation and bio-gas production study,find food waste is suitable matrix for anaerobic digestion,it has high biodegradability and methanogenesis performance.As shown in Table 5.

    Table 5 Several performance data of digestion for food waste and other solid[8]

    2.1 Temperature

    The optimum temperature is important for microorganism growth and metabolism,it's also important factor for enzyme activity.Generally,thermophilic fermentation and mesophilic fermentation are used for degradation waste.Though thermophilic fermentation have some advantages such as quick response,short digest time,high biogas production and so on.Baere[9]claimed that when thermophilic dry fermentation occurred and became attractive due to higher gas production and pathogen killed-off.A report shown that at a temperature of 35℃,the methane yield was increased by 43%compared to 25 ℃ .Chae et al[10].reported that the bio-gas composition differed according to digestion temperature.Methane contents in the biogas were 65.3%,64.0%and 62.0%at 35℃,30℃ and 25℃,respectively.In view of the geographical environment and climate conditions in northern China,thermophilic fermentation might increase fermentation costs.While mesophilic fer-mentation digests process stability,need less energy consumption,higher treatment ability and more mature technology.It's more suitable for northern Chinese food waste digestion.

    2.2 Hydrogen Concentration(pH)

    The activity of microorganisms is affected by pH value,so pH value affects the whole process of anaerobic digestion.In single-phase anaerobic process,as acid production and methane production in the same reactor,general pH range between 6.4~7.2 is most suitable for the anaerobic digestion process.Mace et al[11]reported at the range of 7.0 to 7.2 bacteria shows the highest performance.When the pH is too low,can make the acid producers occur irreversible inhibition,thus affect the entire digestive process.Lay et al reported that a pH less than 6.1 or more than 8.3 will cause bad performance,even failure of a digester.In two-phase anaerobic digestion process,acidification reactor can regulate the pH value for choosing particular acid producer microbial populations,thus to control acid producing approach and the subsequent methanogenesis process.The growths of methanogens have influenced by the pH value,too high or too low pH value will reduce the active of methanogens,and even kill them.

    2.3 Solid Holdup

    Dry anaerobic fermentation solid content rate can be raised to 20% ~40%,studies had shown that the initial use higher Total Solid(TS)concentration of food waste as anaerobic fermentation raw materials,in the early reaction the solid-phase hydrolysis acidification rapidly,a large number of Volatile Fatty Acids(VFA)can be produced and inhibit hydrolysis-acidification phase and subsequent methane-producing,even affected the speed and stability of the anaerobic fermentation seriously.Forster-Carneiro et al[12],using food waste as raw materials for dry fermentation experiments found that the TS was 20%,and the sludge was 30%,the yield of methane gas rate is 0.49 L·g-1VS.

    2.4 Ratio of Inocula

    The acidification phenomenon of food waste anaerobic digestion might due to the rate of hydrolysis acidification and methane-producing phase mismatch;anaerobic fermentation inocula not only provide a microbial but also plays an important role in regulating acid-base balance.Angelidaki[13]reported it is very important to find appropriate inocula containing the necessary bacteria for the degradation process to proceed,and another important factor is the amount of inocula.Studies had found that mesophilic fermentation under the condition of inoculation proportion between 10∶90 to 15∶85(volume ratio)could be starting and running normally,while when inoculation proportion over 50∶50(volume ratio)the volatile solid(VS)degradation rate and the methane production rate high-efficiency.Mesophilic fermentation in a ratio inocula of 90∶10(volume ratio),volatile solid degradation rate was 99%,the volatile solid methane-producing rate up to 519.3 mL/g,methane production rate can reach 94.5%.

    2.5 Ammonia Nitrogen

    Generally believes that mass concentration below 200 mg/L of ammonia nitrogen is good for anaerobic process,because nitrogen is one of the important nutrients in anaerobic microorganisms.And Gerardi[14]reported that ammonia concentration more than 1 500 mg·L-1at high pH may result into digester failure.Chynoweth and Pullammanappali[15]reported that the concentration of NH4-N between 200 to 1 000 mg·L-1had no adverse effect on digestion,while the concentration above 3 000 mg·L-1,it had toxic for bacteria.Ammonia inhibition concentration range is wide,cause methane production fell into 50%(half inhibition)of mass concentration range is 1.7~14 g·L-1.The effect of ammonia-nitrogen/ammonia in anaerobic digester was summarized in Table 6.Much higher concentrations could be accepted through acclimation.Ammonia inhibition concentration of significant differences can be attributed to the matrix,the inoculation sludge,environmental conditions,and the domestication time difference.

    Table 6 Effect of ammonia-nitrogen/ammonia in an anaerobic digester

    3 Dry Fermentation Kinetics Analysis

    In the 1970s,Bryant discovered originally referred to as“the methane-producing bacteria bacterium”is composed by two kinds of bacteria,one bacterial oxidation acetic acid into ethanol and H2,and another kind of bacteria use H2,CO2and acetic acid generate CH4.Thus he puts forward the theory of anaerobic digestion for three stages,namely hydrolysis-fermentation stage,producing hydrogen-production acetate stage and methaneproducing phase.First of all,through the fermentation of bacteria produce ethanol,propionic acid,butyric acid,lactic acid and so on.Schieder et al[16]found that hydrolysis is often the slowest and limiting-step in anaerobic degradation process for solid substrate.Mata-Alvarez claimed that the hydrolysis is considered to be the key step in the biodegradation of complex wastes.Then through the production of acetic,acid bacteria degradation functions to generate acetic acid,H2and CO2.Schink found that the accumulation of product such as lactate,ethanol,propionate,butyrate and higher volatile fatty acids(VFAs)is the bacteria's response to increased hydrogen concentration.Last by methane bacteria use materials converted to CH4and CO2eventually.

    3.1 Anaerobic Microbe Growth Dynamics

    Microbial growth of six typical periods for:delay phase, acceleration phase, logarithmic phase,deceleration phase,stagnation and death phase.

    In the logarithmic phase of growth rate dX/dt,growth rate μ and the biomass X has relationship as follows:

    μ is restricted production such as carbon source,nitrogen source.

    This is the Monod equation,[S]is the concentration of free organic substrate in reactor,the maximum growth rate of microbesm μmand the difference constant Kshas relationships as follows:the research has shown that the hydrolysis acidification phase and the degradation of propionic acid,butyric acid and the acetic acid reaction of methane bacteria ofpseudo-first-order kinetic model(Monod equation).

    The growth rate of cells equation as follows:

    rxis the absolute rate of cell growth;cxis the cell concentration.

    Two parameters of Monod equation are Ksand μm,respectively.Several kinds of common microorganisms'Ksand μm.were shown in Table 7.

    Table 7 Several kinds of common microorganisms'Ksand μm

    Later,people consider some of the specific problems of facts,such as matrix lack.So some deformation equation occur as follows[17-18]:

    Smis the threshold concentration;D is the actual growth rate;m is maintenance rate.

    The dynamics of death is represented mathematically as a decay of the population Kd[X].Incorporating Monod's concept and the kinetics of death into equation follows.

    [X]is total concentration of organisms in reactor.

    The rate of decrease of the concentration of the substrate is proportional to the rate of increase of the concentration of the organisms.The rate of decrease of the substrate is the equation.

    [K]is rate constant;U is the reciprocal of Y.

    In some cases,Monod equations become no longer applicable,such as high cell density.As a result,people have otherunstructured model(Table 8)is put forward.

    Table 8 Some unstructured model

    Teissier equation was considered as pure empirical formula;Moser equation described the high series reaction substrate consumption;Contois equation described in the high densityofcell growth;Blackman equation reflected in addition to the bottom store there may be other limiting factors;Logistic law belonged to the logic equations,it integrated said because of the lack of nutrients and toxic metabolite accumulation and cell concentration on the negative effectsofcell growth rate.

    3.2 Substrate Consumption Dynamics

    The substrate utilization rate or substrate decrease rate can be modeled with the following expression.

    d[S]/dt is the rate of formation.

    When matrix inhibited by its own bio-degradation,the Monod model above becomes unsatisfactory.In this case,someone made the following equation after their research.

    In some case,the effect of the cell growth is by a variety of substrates at the same time,its means the influence is also different.If there are two limiting substrate influence cellspecific growth rate at the same time,expressed by the following equation.

    μmis the maximum specific growth rate when the two substrates also enough;Ks1、Ks2is the two substrates saturated coefficient.

    If there are n kinds of restrictive substrates.

    If the two substrates can be used at the same time,and also can be substituted.

    μm1、μm2is the maximum specific growth rate at the two substrates,respectively.

    For n kinds of restrictive substrates.

    For more complex cases,the substrates can be divided into two kinds:one kind is necessary to cell growth,if lack of them,a cell cannot grow;another kind is promote cell growth,it can improve the specific growth rate of cells.

    [SI]is the promote cell growth substrate concentration;[SE]is the substrate concentration necessary to cell growth;μm0is the maximum specific growth rate when the promote growth substrates does not exist.

    3.3 Product Inhibition Growth Dynamics

    When microbial growth inhibited by its metabolites,expressed by the dynamics equations as follows:

    Kifor response inhibition constant,[P] is product concentration.

    Bryant is indicted that produce hydrogen-acetic-acid bacteria generate hydrogen increase hydrogen partial pressure suppresses the production of acetic-acid bacteria metabolic activity,if a large number of hydrolysis acid accumulation will lead to methane-producing bacteria activity decrease and even kill the bacteria.So build a new reactor online monitoring system to realize the real-time control of the reaction,ensure the anaerobic digestion progress smoothly.

    Some of the main empirical formulas is as follows.

    Aiba et al:

    KPIis the product inhibition constant.

    Hinshelwood:

    kPis the product inhibition rate constant.

    Levenspeil:

    [Pm]is the product concentration when the cells stop growing;n is the product toxicity indexis the apparent maximum specific growth rate.

    From Levenspiel equation,when [P] =[Pm]=0,cell stop growth,and when[P]=0,μm=

    4 Conclusions

    Food waste output increased dramatically in recent years.Its proportion of household waste becomes more and vaster,and organic matter content in the food waste is higher and the composition is more and more complex.Food waste dry anaerobic fermentation for waste reduction,harmless and recycling is great significance.Focus on the colder winter in northern China and low rate of gas,this article first analyzes the using probability of the food waste,and then sets about experimental study,optimizes the fermentation equipment and heating preservation method as the reference of the northern city life on the dry fermentation of the food waste.

    [1] Visvanathan C,Trankler J,Joseph K,et al.Municipal Solid Waste Management in Asia:Asian Regional Research Program on Environmental Technology(ARRPET)[M].Pathum Thani:Asian Institute of Technology Publication,2004:34-36.

    [2] You Y,Ren N Q,Wang A J,et al.Use of Waste Fermenting Liquor to Produce Bioflocculants with I-solated Strains[J].International Journal of Hydrogen Energy,2008,33(13):3295-3301.

    [3] Cho J K,Park S C.Biochemical Methane Potential and Solid State Anaerobic Digestion of Korean Food Wastes[J].Bioresource Technology,1995,52(3):245-253.

    [4] Hashimoto A G.Thermophilic and Mesophilic Anaerobic Fermentation of Swine Manure[J].Agric Wastes,1983,6(3):175-191.

    [5] Chea Eliyan.Anaerobic Digestion of Municipal Solid Waste in Thermophilic Continuous Operation[J/OL].(2007-04-27).http://www.faculty.ait.ac.th/visu/Data/AIT-Thesis/Master%20Thesis%20final/chea%20combined.pdf.

    [6] Polprasert C.Organic Waste Recycling Technology and Management[M].America:John Wiley &sons,1996:78-80.

    [7] Zhang R H,EI-Mashad H M,Hartman K,et a1.Characterization of Food Waste as Feedstock for Anaerobic Digestion[J].Bioresource Technology,2007,98(4):929-935.

    [8] Jay Chand Shiv.Techno-economic Feasibility Evaluation of Conversion of Food Waste toEnergy Through Anaerobic Digestion and Gasification[EB/OL].(2009-08-10).http://www.uea.ac.uk/env/all/teaching/eiaams/pdf_dissertations/2009/Shiv_Jay.pdf.

    [9] De Baere L.Anaerobic Digestion of Solid Waste:State-of-the-art[J].Water Science and Technology,2000,41(3):283-290.

    [10] Chae K J,Jang A,Yim S K,et al.The Effect of Digestion Temperature and Temperature Shock on the Biogas Yields from the Mesophilic Anaerobic-digestion of Swine Manure[J].Bioresour Technol,2008,99(1):1-6.

    [11] Mace S,Bolzonella D,Cecchi F,et al.Comparison of the Biodegradability of the Grey Fraction of Municipal Solid Waste of Barcelona in Mesophilic and Thermophilic Conditions[J].Water Science and Technology,2000,48(4):21-28.

    [12] Forste-Carneiro T,Pérez M,Remero L I.Influence of Total Solid and Inoculum Concents on Performance of Anaerobic Reactors Treating Food Waste[J].Bioresource Technology,2008,99(15):6994-7002.

    [13] Jantsch T G,Angelidaki I,Schmidt J E,et al.Anaerobic Biodegradation of Spent Sulphite Liquor in a UASB Reactor[J].Bioresource Technology,2002,84(1):15-20.

    [14] Gerardi M.The Microbiology of Anaerobic Digesters[M].New Jersey:John Wiley and sons,Inc.,2003:186-189.

    [15] Chynoweth D P,Pullammanappallil P.Microbiology of Solid Waste[M].New york:Anaerobic Digestion of Solid Waste,1996:71-77.

    [16] Schieder D,Schneider R,Bischof F.Thermal Hydrolysis(TDH)as a Pretreatment Method for the Digestion of Organic Waste[J].Water Science and Technology,2000,41(3):181-187.

    [17] Goudar C,Strevett K,Grego J.Competitive Substrate Biodegradation During Surfactant-enhanced Remediation[J].Journal of Environmental Engineering,1999,125(12):1142-1148.

    [18] Goudar C T,Ganji S H,Pujar B G,et al.Substrate Inhibition Kinetics of Phenol Biodegradation[J].Water Environment Research,2000,72(1):50-55.

    肉色欧美久久久久久久蜜桃| 亚洲欧美一区二区三区国产| 久久久午夜欧美精品| 80岁老熟妇乱子伦牲交| 韩国高清视频一区二区三区| 日本vs欧美在线观看视频 | 久久99热6这里只有精品| 爱豆传媒免费全集在线观看| 久久精品国产a三级三级三级| 精品少妇久久久久久888优播| 国产伦精品一区二区三区视频9| 精品国产露脸久久av麻豆| 赤兔流量卡办理| 亚洲精品456在线播放app| 亚洲高清免费不卡视频| 日韩在线高清观看一区二区三区| 人人妻人人添人人爽欧美一区卜| 黑丝袜美女国产一区| 中文字幕亚洲精品专区| 久久 成人 亚洲| 制服丝袜香蕉在线| 2021少妇久久久久久久久久久| 这个男人来自地球电影免费观看 | a级一级毛片免费在线观看| 妹子高潮喷水视频| av不卡在线播放| 久久午夜综合久久蜜桃| 免费观看av网站的网址| 亚洲av成人精品一区久久| 日韩熟女老妇一区二区性免费视频| 日韩精品有码人妻一区| 观看免费一级毛片| 最近手机中文字幕大全| 五月玫瑰六月丁香| 久久久久久久久久久久大奶| 97超碰精品成人国产| 免费看日本二区| 一区二区三区免费毛片| 亚洲内射少妇av| 国产精品无大码| 亚洲成色77777| 老司机亚洲免费影院| 日本猛色少妇xxxxx猛交久久| 女人久久www免费人成看片| 五月天丁香电影| 大片电影免费在线观看免费| 熟女电影av网| 中文资源天堂在线| 乱人伦中国视频| 婷婷色av中文字幕| 国产高清国产精品国产三级| 色网站视频免费| 日韩欧美精品免费久久| 国产亚洲欧美精品永久| .国产精品久久| 久久精品熟女亚洲av麻豆精品| 欧美丝袜亚洲另类| 国产精品一区www在线观看| 亚洲va在线va天堂va国产| 日日爽夜夜爽网站| av一本久久久久| 亚洲国产精品专区欧美| av卡一久久| 中文资源天堂在线| 少妇 在线观看| av卡一久久| 国产成人免费观看mmmm| 国产在线免费精品| 久热久热在线精品观看| 久久国内精品自在自线图片| 日韩精品有码人妻一区| 午夜福利网站1000一区二区三区| 国产精品99久久久久久久久| 另类亚洲欧美激情| 精品久久久噜噜| 国产精品久久久久久精品古装| 人妻人人澡人人爽人人| 人妻人人澡人人爽人人| 99久久中文字幕三级久久日本| 亚洲人成网站在线播| 久久ye,这里只有精品| 日韩av在线免费看完整版不卡| 伊人久久精品亚洲午夜| 国产欧美日韩精品一区二区| 亚洲成人一二三区av| 插阴视频在线观看视频| a级毛片免费高清观看在线播放| 亚洲精品乱久久久久久| 22中文网久久字幕| 亚洲国产精品999| 久久久久久久国产电影| 久久久久网色| 成人特级av手机在线观看| 又大又黄又爽视频免费| 久久女婷五月综合色啪小说| 中国美白少妇内射xxxbb| 精品久久久噜噜| 观看免费一级毛片| 97精品久久久久久久久久精品| 亚洲精品国产色婷婷电影| 在线天堂最新版资源| 另类精品久久| 18禁在线无遮挡免费观看视频| 天美传媒精品一区二区| 欧美日韩视频精品一区| 日韩欧美 国产精品| 三级国产精品欧美在线观看| 亚洲电影在线观看av| 国产成人精品福利久久| 日本黄色日本黄色录像| 中国美白少妇内射xxxbb| 日韩一区二区视频免费看| 午夜老司机福利剧场| 国产精品免费大片| 日本与韩国留学比较| 国产成人一区二区在线| 欧美3d第一页| 午夜福利视频精品| 欧美另类一区| 欧美精品一区二区免费开放| 看十八女毛片水多多多| 国产伦在线观看视频一区| 日韩成人伦理影院| 另类亚洲欧美激情| 赤兔流量卡办理| 人人妻人人看人人澡| 亚洲丝袜综合中文字幕| 久久人人爽人人片av| 国产精品女同一区二区软件| 国产精品不卡视频一区二区| 午夜视频国产福利| 色94色欧美一区二区| 人妻夜夜爽99麻豆av| 80岁老熟妇乱子伦牲交| 麻豆成人午夜福利视频| 欧美性感艳星| 久久人人爽人人爽人人片va| 国产 一区精品| 国内少妇人妻偷人精品xxx网站| 国产av精品麻豆| 亚洲经典国产精华液单| 日本黄色日本黄色录像| 性高湖久久久久久久久免费观看| 成人综合一区亚洲| 美女视频免费永久观看网站| 最后的刺客免费高清国语| 高清不卡的av网站| 亚洲av福利一区| 成人国产麻豆网| 欧美精品一区二区免费开放| 免费看日本二区| 下体分泌物呈黄色| 麻豆成人午夜福利视频| 一本久久精品| 亚洲欧洲日产国产| 我的女老师完整版在线观看| 欧美日韩在线观看h| 国产精品偷伦视频观看了| 黑丝袜美女国产一区| 欧美日本中文国产一区发布| 蜜桃在线观看..| 亚洲无线观看免费| 伊人久久精品亚洲午夜| 国产高清不卡午夜福利| 亚洲av日韩在线播放| 国产亚洲5aaaaa淫片| 国产熟女午夜一区二区三区 | 欧美成人午夜免费资源| 2021少妇久久久久久久久久久| 青春草亚洲视频在线观看| 久久久久久久久大av| 日本色播在线视频| 亚洲第一区二区三区不卡| 国产成人一区二区在线| 三级经典国产精品| kizo精华| 欧美激情国产日韩精品一区| 伊人久久精品亚洲午夜| 波野结衣二区三区在线| 日本黄大片高清| 久久久久久久久久久久大奶| 国产一区二区三区av在线| 国产极品粉嫩免费观看在线 | 国产高清不卡午夜福利| 狂野欧美激情性bbbbbb| 在线观看三级黄色| 26uuu在线亚洲综合色| 中文欧美无线码| 欧美日韩精品成人综合77777| 欧美日韩一区二区视频在线观看视频在线| 久久精品国产亚洲av涩爱| 免费看不卡的av| 赤兔流量卡办理| 国产又色又爽无遮挡免| 日韩在线高清观看一区二区三区| 两个人免费观看高清视频 | 天天躁夜夜躁狠狠久久av| 国产男女超爽视频在线观看| 亚洲在久久综合| 18禁动态无遮挡网站| 亚洲av综合色区一区| 国产视频内射| 高清毛片免费看| 精品一品国产午夜福利视频| 99re6热这里在线精品视频| 亚洲成人av在线免费| 一级毛片黄色毛片免费观看视频| 欧美人与善性xxx| 成人午夜精彩视频在线观看| 特大巨黑吊av在线直播| 蜜桃久久精品国产亚洲av| 一级av片app| 国产片特级美女逼逼视频| 下体分泌物呈黄色| 热re99久久精品国产66热6| 成年av动漫网址| av线在线观看网站| 国产色婷婷99| 国产成人一区二区在线| 天堂中文最新版在线下载| 亚洲精品自拍成人| 午夜福利,免费看| 人妻制服诱惑在线中文字幕| 18+在线观看网站| 日韩电影二区| 亚洲性久久影院| 成人午夜精彩视频在线观看| 亚洲无线观看免费| 两个人免费观看高清视频 | 亚洲精品,欧美精品| 高清黄色对白视频在线免费看 | 亚洲精品国产av成人精品| 51国产日韩欧美| av线在线观看网站| 日韩欧美一区视频在线观看 | 国产日韩一区二区三区精品不卡 | 精品国产一区二区三区久久久樱花| 色5月婷婷丁香| 热99国产精品久久久久久7| 中文欧美无线码| 中文字幕亚洲精品专区| 高清在线视频一区二区三区| 成人综合一区亚洲| 久久av网站| 久久久国产精品麻豆| 国产精品一区二区性色av| 亚洲av国产av综合av卡| 国产极品粉嫩免费观看在线 | www.av在线官网国产| 亚洲成色77777| 亚洲一区二区三区欧美精品| 国产真实伦视频高清在线观看| 最新的欧美精品一区二区| 69精品国产乱码久久久| 九九久久精品国产亚洲av麻豆| 日本wwww免费看| 一级毛片电影观看| 亚洲四区av| 亚洲精品国产av蜜桃| 国产又色又爽无遮挡免| 午夜福利在线观看免费完整高清在| 国产免费一级a男人的天堂| 亚洲电影在线观看av| 全区人妻精品视频| 中文欧美无线码| 最新中文字幕久久久久| 激情五月婷婷亚洲| 观看美女的网站| av在线播放精品| 欧美3d第一页| 日韩在线高清观看一区二区三区| 大话2 男鬼变身卡| 亚洲伊人久久精品综合| 美女xxoo啪啪120秒动态图| 水蜜桃什么品种好| 伊人久久国产一区二区| 国产在线免费精品| 国产亚洲5aaaaa淫片| 女人精品久久久久毛片| 久久久久精品久久久久真实原创| 亚洲精品,欧美精品| 美女主播在线视频| 亚洲欧洲国产日韩| 日本av手机在线免费观看| 青青草视频在线视频观看| 少妇猛男粗大的猛烈进出视频| 王馨瑶露胸无遮挡在线观看| 青春草国产在线视频| 女的被弄到高潮叫床怎么办| 老司机影院成人| 如何舔出高潮| 蜜桃在线观看..| 欧美日韩一区二区视频在线观看视频在线| 2022亚洲国产成人精品| 少妇的逼好多水| 五月天丁香电影| 欧美精品高潮呻吟av久久| 人人妻人人澡人人爽人人夜夜| 欧美日韩视频精品一区| 在线观看国产h片| 男人和女人高潮做爰伦理| 妹子高潮喷水视频| 成年女人在线观看亚洲视频| 丝袜在线中文字幕| 超碰97精品在线观看| 国产中年淑女户外野战色| 内地一区二区视频在线| 久久av网站| 久久久久久久久久久久大奶| 七月丁香在线播放| 国产免费视频播放在线视频| 色视频www国产| 秋霞伦理黄片| h日本视频在线播放| 街头女战士在线观看网站| 欧美少妇被猛烈插入视频| 婷婷色综合www| 欧美 日韩 精品 国产| av专区在线播放| 在线看a的网站| 美女主播在线视频| 成人特级av手机在线观看| 亚洲婷婷狠狠爱综合网| 少妇熟女欧美另类| 亚洲三级黄色毛片| 亚洲久久久国产精品| 街头女战士在线观看网站| 亚洲av电影在线观看一区二区三区| 欧美xxxx性猛交bbbb| 国产在线男女| 国产精品无大码| 亚洲欧洲精品一区二区精品久久久 | 亚洲欧美日韩卡通动漫| 国国产精品蜜臀av免费| 国产精品99久久99久久久不卡 | 久久精品久久精品一区二区三区| 男人和女人高潮做爰伦理| 亚洲av综合色区一区| 久久久久国产精品人妻一区二区| 性色av一级| 欧美丝袜亚洲另类| 免费在线观看成人毛片| 三级国产精品片| 亚洲精品成人av观看孕妇| 国产日韩欧美亚洲二区| av线在线观看网站| videos熟女内射| 免费观看av网站的网址| 22中文网久久字幕| 黄片无遮挡物在线观看| 夫妻午夜视频| 国产免费视频播放在线视频| 久久久久久久精品精品| 我要看日韩黄色一级片| 一本久久精品| 黄色视频在线播放观看不卡| 亚洲av不卡在线观看| 日韩电影二区| 青春草视频在线免费观看| 熟女av电影| 国产有黄有色有爽视频| 精品人妻偷拍中文字幕| 久久99蜜桃精品久久| 哪个播放器可以免费观看大片| 国产精品成人在线| 中国三级夫妇交换| 久久人人爽av亚洲精品天堂| 婷婷色综合www| 在线免费观看不下载黄p国产| 老女人水多毛片| 久久精品国产亚洲av涩爱| 我的老师免费观看完整版| 一级片'在线观看视频| 国产综合精华液| 欧美精品亚洲一区二区| 麻豆成人av视频| 日本黄大片高清| 久久久午夜欧美精品| av免费观看日本| 草草在线视频免费看| 欧美精品国产亚洲| 黑人猛操日本美女一级片| 黄色怎么调成土黄色| 亚洲四区av| 欧美3d第一页| 国产一区二区三区综合在线观看 | 久久久欧美国产精品| 大香蕉久久网| 纵有疾风起免费观看全集完整版| 国产一区二区在线观看av| 久久 成人 亚洲| 久久国内精品自在自线图片| 亚洲国产最新在线播放| 黄色视频在线播放观看不卡| 国产精品蜜桃在线观看| 精品人妻熟女毛片av久久网站| 精品国产露脸久久av麻豆| 深夜a级毛片| 国产亚洲欧美精品永久| 我要看黄色一级片免费的| 99久久人妻综合| 少妇被粗大的猛进出69影院 | 欧美丝袜亚洲另类| 亚洲久久久国产精品| 久久久久久久久久久免费av| 国产 一区精品| 成人国产av品久久久| 麻豆精品久久久久久蜜桃| 纯流量卡能插随身wifi吗| 黄色配什么色好看| 中文天堂在线官网| 极品人妻少妇av视频| 国产综合精华液| 天堂8中文在线网| 秋霞在线观看毛片| 成人美女网站在线观看视频| 久久人妻熟女aⅴ| 少妇被粗大猛烈的视频| 嫩草影院新地址| 男人狂女人下面高潮的视频| 97超碰精品成人国产| 精品久久久噜噜| 亚洲久久久国产精品| 永久免费av网站大全| 如日韩欧美国产精品一区二区三区 | 亚洲欧美精品自产自拍| 九九久久精品国产亚洲av麻豆| 亚洲色图综合在线观看| 韩国高清视频一区二区三区| 亚洲av成人精品一区久久| 看十八女毛片水多多多| 日韩中字成人| 狂野欧美激情性xxxx在线观看| 简卡轻食公司| 亚洲av成人精品一区久久| 人体艺术视频欧美日本| 又大又黄又爽视频免费| 欧美少妇被猛烈插入视频| 日韩av免费高清视频| 视频中文字幕在线观看| 狂野欧美白嫩少妇大欣赏| 午夜视频国产福利| 菩萨蛮人人尽说江南好唐韦庄| 狂野欧美激情性bbbbbb| 久久久久久久久久久免费av| 日韩制服骚丝袜av| 毛片一级片免费看久久久久| 成人特级av手机在线观看| 99九九在线精品视频 | videos熟女内射| 亚洲国产精品999| 在线观看av片永久免费下载| 777米奇影视久久| 曰老女人黄片| 亚洲国产精品国产精品| 九草在线视频观看| 少妇高潮的动态图| av播播在线观看一区| 高清av免费在线| 一区二区三区乱码不卡18| 麻豆成人午夜福利视频| 免费黄色在线免费观看| 中文字幕久久专区| 肉色欧美久久久久久久蜜桃| 国产成人精品婷婷| 好男人视频免费观看在线| 欧美丝袜亚洲另类| 日韩电影二区| 全区人妻精品视频| 最黄视频免费看| 久久ye,这里只有精品| 在线观看美女被高潮喷水网站| 在现免费观看毛片| 亚洲av在线观看美女高潮| 国产在线视频一区二区| 日日啪夜夜撸| 丰满迷人的少妇在线观看| 99热全是精品| 久久av网站| 哪个播放器可以免费观看大片| 在线观看国产h片| 色视频www国产| 成年人免费黄色播放视频 | 午夜福利网站1000一区二区三区| 亚洲av二区三区四区| 欧美日韩亚洲高清精品| 黄色配什么色好看| 日本av免费视频播放| 亚洲精品久久午夜乱码| 久热久热在线精品观看| 黄色一级大片看看| 99热网站在线观看| 日韩免费高清中文字幕av| 美女中出高潮动态图| 亚洲欧美精品自产自拍| 日韩大片免费观看网站| 色婷婷久久久亚洲欧美| 美女视频免费永久观看网站| 亚洲人成网站在线观看播放| 国产午夜精品久久久久久一区二区三区| 高清不卡的av网站| 国产高清三级在线| 国产永久视频网站| 亚洲国产精品一区三区| 在线观看www视频免费| 伊人久久精品亚洲午夜| 免费不卡的大黄色大毛片视频在线观看| av女优亚洲男人天堂| 午夜视频国产福利| 免费观看a级毛片全部| 国产男女内射视频| 热re99久久精品国产66热6| 另类亚洲欧美激情| 亚洲欧美精品自产自拍| 狂野欧美激情性xxxx在线观看| 亚洲人与动物交配视频| 尾随美女入室| 如日韩欧美国产精品一区二区三区 | 男女免费视频国产| 国产 一区精品| 美女福利国产在线| 黑人巨大精品欧美一区二区蜜桃 | 亚洲美女搞黄在线观看| 精品亚洲成a人片在线观看| 欧美最新免费一区二区三区| 日韩精品有码人妻一区| 亚洲精品国产av成人精品| 国产91av在线免费观看| 大陆偷拍与自拍| 成人国产av品久久久| av视频免费观看在线观看| 久久免费观看电影| 午夜免费鲁丝| 久久精品国产亚洲av天美| 国产成人精品久久久久久| 丰满乱子伦码专区| 人妻系列 视频| 内射极品少妇av片p| 亚洲av男天堂| 最近2019中文字幕mv第一页| a级一级毛片免费在线观看| 男女啪啪激烈高潮av片| 国国产精品蜜臀av免费| 成年人午夜在线观看视频| 亚洲精品国产av蜜桃| 少妇裸体淫交视频免费看高清| 免费看av在线观看网站| 日韩熟女老妇一区二区性免费视频| 狂野欧美激情性bbbbbb| 少妇丰满av| 五月天丁香电影| 在线观看一区二区三区激情| 亚洲国产精品专区欧美| 少妇猛男粗大的猛烈进出视频| 极品少妇高潮喷水抽搐| 我的老师免费观看完整版| 一本久久精品| 91精品一卡2卡3卡4卡| 精品一区二区免费观看| 中文字幕精品免费在线观看视频 | 啦啦啦啦在线视频资源| 人人妻人人澡人人爽人人夜夜| av国产精品久久久久影院| 免费黄频网站在线观看国产| 国产黄频视频在线观看| 国产高清有码在线观看视频| 熟女av电影| 美女国产视频在线观看| 在线免费观看不下载黄p国产| 在线播放无遮挡| 国产成人免费观看mmmm| 黄色视频在线播放观看不卡| 亚洲性久久影院| 亚洲精品色激情综合| 欧美xxxx性猛交bbbb| 国产精品.久久久| 国产亚洲欧美精品永久| 国产无遮挡羞羞视频在线观看| 永久网站在线| 噜噜噜噜噜久久久久久91| 欧美成人精品欧美一级黄| 免费大片黄手机在线观看| 少妇人妻久久综合中文| 久久久久网色| 精品国产露脸久久av麻豆| 国产精品一区二区在线不卡| 亚洲美女搞黄在线观看| 欧美三级亚洲精品| 美女内射精品一级片tv| 日韩精品免费视频一区二区三区 | 一个人看视频在线观看www免费| 女人精品久久久久毛片| 久久久久国产精品人妻一区二区| 精品熟女少妇av免费看| 久久99热这里只频精品6学生| tube8黄色片| 深夜a级毛片| 亚洲精品中文字幕在线视频 | 高清黄色对白视频在线免费看 | 啦啦啦啦在线视频资源| 女性生殖器流出的白浆| 伦理电影免费视频| 97超碰精品成人国产| 黑人高潮一二区| 国产精品久久久久久久久免| 婷婷色综合大香蕉| 国产精品一二三区在线看| 精品国产露脸久久av麻豆| 午夜免费鲁丝| 久久鲁丝午夜福利片| 丰满乱子伦码专区| 亚洲精品一区蜜桃| 亚洲一级一片aⅴ在线观看| 欧美日韩亚洲高清精品| 亚洲电影在线观看av|