• <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 ?

    Effective purification of oily wastewater using lignocellulosic biomass:A review

    2022-07-11 03:38:32MengWngHsuShengTsiChofnZhngChengyuWngShihHsinHo
    Chinese Chemical Letters 2022年6期

    Meng Wng,Hsu-Sheng Tsi,Chofn Zhng,Chengyu Wng,Shih-Hsin Ho,?

    a State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150001,China

    b Laboratory for Space Environment and Physical Sciences,Harbin Institute of Technology,Harbin 150001,China

    c Key Laboratory of Bio-based Material Science &Technology (Northeast Forestry University),Ministry of Education,Harbin 150040,China

    Keywords:Lignocellulosic biomass Superwetting Oily wastewater Wastewater treatment Oil-water separation

    ABSTRACT Due to the frequent occurrence of oil spills and the large-scale production of oily wastewater,the treatment of oily sewage has become an important issue for sustainable development.Recently,materials prepared from lignocellulosic biomass (LCB) for oil-water separation have been found to be effective due to their high separation efficiency,good recyclability,and superior sustainability.However,few reviews have focused on the advantages and limitations of LCB for sewage treatment.This review summarizes the performance of modified LCB in oily wastewater treatment,in terms of the advanced modification methods applied and the structural dimensions of LCB materials according to the principle of superwetting oil-water separation.Research on the preparation technologies,separation mechanisms,and treatment efficiency of different LCB materials are briefly summarized,along with the characteristics of different LCB material types for oily wastewater treatment.Finally,the future prospects and challenges faced in the development of LCB materials are discussed.

    1.Introduction

    The increasing global demand for energy,along with rapid social and economic development,has resulted in a continual increase in the discharge of oily industrial wastewater and domestic sewage in recent years [1,2].Human survival and the health of most habitats worldwide are dependent in some manner on ocean ecosystems and therefore,oil spills or the release of untreated oily wastewater is a critical issue for marine ecosystem[3,4].Oily wastewater and oil spills introduce toxic compounds into terrestrial and marine environments,threatening species from every level of the trophic system from the bottom (e.g.,algae) to the top (e.g.,mammal),including humans.The improper handling of oil-water mixtures causes significant harm to both the waterbody and the surrounding ecological environment [5–8].Therefore,the materials and technologies applied to oily wastewater treatment are receiving increased research attention and development.

    Oily wastewater can be categorized as a simple oil-water mixture (oil-water stratification),a highly dispersed (uniform) mixture,or a miscible (homogeneous phase) mixture,according to its macroscopic physical state [9,10].The primary oil pollutants in domestic and industrial sewage are the lipids formed from biological fats and petroleum,respectively,including fatty acids,fats,waxes,and other similar substances.Crude oil is a mixture containing water,which is mainly composed of alkanes,cycloalkanes,aromatics,and unsaturated hydrocarbons [11,12].In addition to the pollution caused by oil itself,various pollutants dissolved in oil can also induce serious toxic effects,such as organic pesticides,polycyclic aromatic hydrocarbons,aromatic hydrocarbons,polychlorinated biphenyls,and dyes [13,14].The traditional treatment technologies used for oily wastewater treatment generally adopt physical methods such as gravity sedimentation and coarse-grained oil removal.More sophisticated treatment methods utilize physical (air flotation and filtration),chemical (flocculation and chemical oxidation),and biological (active sludge and biofilms) methods[15,16].However,these traditional methods are time-consuming,labor-intensive,and incur high operational costs.Furthermore,the additional use of fillers such as flocculants,produces secondary pollution and results in the need for stringent control mechanisms[17].

    Degradable lignocellulosic biomass (LCB) material has exhibited good potential for practical application for the purification of oily wastewater [18,19].It is attractive to use LCB as a promising candidate material for the purification of oily wastewater [20,21].The different components and structures of LCB are powerful modification platforms for technological development,which can be selectively modified according to specific requirements,allowing an advanced level of oily wastewater treatment that achieves effective separation and purification.A wide variety of functional materials have been manufactured for oily wastewater treatment;however,few review articles are available on the application of LCB in this field.In this review,we summarize the latest research progress in the preparation of materials from LCB for oily wastewater treatment.The mechanism of action and the wettability of LCB materials which are beneficial for oily wastewater treatment are discussed initially,followed by the advantages and disadvantages of their application for oily wastewater treatment,in view of the structures and compositions of LCB.Based on this,new methods of LCB material modification for oily wastewater treatment were reviewed,summarizing the oil-water separation efficiency and recycling performance of LCB materials with 0-dimensional (0D)powder,2-dimensional (2D) membrane,and 3-dimensional (3D)structures.In particular,the emerging materials,derived from LCB and exhibiting special wettability performance for oily wastewater treatment are discussed,demonstrating the relationship between the material structure and oil-water separation efficiency.Finally,the potential for large-scale application of LCB materials is summarized.By assessing the existing methods of LCB material preparation,this review is intended to provide clear information about the latest technological developments on the use of LCB biomass materials for oily wastewater treatment,and provide reference material for scientists investigating how to achieve optimized,low-cost biomass capable of high efficiency oil-water separation.

    2.The mechanism of superwettability for oily wastewater treatment

    Adjusting the wettability of materials is an effective method to improve oil absorption capability [22,23].Materials with superhydrophobic and superlipophilic properties can simultaneously repel the water phase and make it easier for the oil phase to diffuse,absorb and penetrate substances,achieving oil-water separation [24].The wettability of materials is affected by the surface roughness and chemical composition.Fig.1a presents a schematic of the effect of contact angle (CA).The wetting system can theoretically be divided into three-phase gas/liquid/solid and liquid/liquid/solid systems according to the different media in contact with the functional surface,according to Young’s equation (Eq.1) [25]:

    Fig.1.Schematic diagram of three-phase wetting system.(a) Schematic of the contact angle.(b) Wenzel model.(c) Cassie model.(d) The transitional state between Wenzel’s and Cassie’s states.(e) Schematic of the contact angles of liquid 1 in air.(f)Schematic of the contact angles of liquid 2 in air.(g) Three-phase system of liquid 1 in liquid 2.(h) Underoil superhydrophobic surface.(i) Underwater superoleophobic surface.

    where,γSV,γSLandγLVrepresent the surface tensions of solidgas,solid-liquid,and gas-liquid interfaces,respectively.Young’s equation is only applicable for smooth,non-deformed,and ideal isotropic surfaces,while for the non-ideal solid surfaces,the Wenzel equation must be applied (Eq.2) [26]:

    where,θr,θandrrepresent the apparent contact angle,balanced contact angle,and roughness,respectively.Wenzel model is shown in Fig.1b.Considering the non-ideality of solid surfaces,Eq.2 was optimized,assuming that the material surface consists of two substances (1 and 2) as shown in Fig.1c,with the intrinsic contact angles of substance 1 and 2 beingθ1andθ2,respectively.Therefore,the Cassie-Baxter equation was proposed (Eq.3) [27]:

    wheref1andf2represent the surface area fractions of two substances on the solid surface (f1+f2=1).When the solid surface possesses strong hydrophobicity,the droplets would have nonwetting contact with the solid surface (Fig.1d),withf1andf2defined as the surface area fractions of liquid-solid and dropletair pore contacts (f1+f2=1),respectively.The CA between droplet and the air is 180° and therefore,Eq.3 can be developed to form Eq.4 as follows:

    According to Eq.4,the hydrophobicity of the material is enhanced with an increase inf2.The wettability of the material surface,therefore,can be reasonably designed according to the Cassie-Baxter equation (Eq.3) in order to endow materials with the superwettability required for effective oil-water separation [28,29].For the liquid/liquid/solid three-phase wetting system,L1,L2,S,andVare expressed as the liquid phase 1,liquid phase 2,ideal solid surface,and gas phase,respectively.Schematics of the CA in different three-phase systems are shown in Fig.1e (liquid 1 in air),Fig.1f (liquid 2 in air),and Fig.1g (liquid 1 in liquid 2).Introducing the Young’s equation (Eq.1) into this three-phase system generates Eqs.5-7 as follow:

    Combining Eqs.5-7 results in Eq.8 as follows:

    where,theθ1,θ2andθ3individually represent the CA of liquid 1 to the solid surface in air,the CA of liquid 2 to the solid surface in air,and the CA of liquid 1 to the ideal solid surface in a liquid/liquid/solid three-phase system.Eq.8 can describe the wetting behavior of smooth,non-deformed,and isotropic ideal surfaces in a liquid/liquid/solid three-phase system,withθ3calculated fromθ1andθ2,as the liquid phases are known [30,31].

    For the wettability model of liquid/liquid/solid three-phase systems with a rough surface,the Cassie-Baxter equation (Eq.3)should be introduced into the system for derivation.The state of rough solid surfaces in the liquid phase can be regarded as a binary composite interface formed between one liquid and the solid surface,resulting in the contact state between the other liquid and the solid surface being referred to as the Cassie state.In this case,f1is defined as the surface area fraction of contact between one liquid and the solid,whilef2is defined as the surface area fraction of contact between the other liquid and the solid(f1+f2=1),with the CA of the droplet to another liquid phase considered to be 180°.Thus,the wettability equation for the liquid/liquid/solid three-phase system with a rough surface can be obtained,as shown in Eq.(9):

    where,θ′3represents the CA of liquid 1 to the rough solid surface in the system [32,33].

    The above equations illustrate the theoretical wettability of three-phase systems.Materials selectively absorb water or oil on their surface as they possess higher hydrophilicity and oleophobicity or lipophilicity and hydrophobicity,respectively,resulting in oil-water separation.In liquid/liquid/solid three-phase systems,the underoil superhydrophobic (Fig.1h) and the underwater superoleophobic surfaces (Fig.1i) are the two surfaces with mutually contradictory wettability characteristics,which depend on an exact match of the materials surface geometry and chemistry[34–36].Generally,the oil-water separation effect can only be achieved when the material surfaces show the opposite wettability for water/oil.The superhydrophobic/superlipophilic surfaces are conducive for oil filtration and absorption,while the underoil superhydrophobic and the underwater superoleophobic surfaces possess more comprehensive oil-water separation ability,the former and the latter are mainly used to separate water-in-oil and oil-inwater mixtures,respectively.In the next section,we will elaborate on various new modification methods for LCB,so that the readers can quickly understand the methods based on reasonable adjustment of the wettability of LCB for the oily wastewater treatment.

    3.The use of LCB as an applied material for oily wastewater treatment

    3.1.LCB components and pretreatment methods

    3.1.1.LCB components

    LCB is a main component of plant resources and its effective utilization is an important way of developing environmentally sustainable industrial practices,as the biomass resource LCB usually has surplus availability [37].LCB is composed of cellulose,hemicellulose,and lignin as its three major components,with the proportion of cellulose being the highest (35%?50%).Cellulose is a polymer (up to 10,000 units) that is connected linearlyvia β?1,4 glycosidic linkages [38].Glucose molecules contain a large number of intramolecular and intermolecular hydrogen bonds,which result in the cellulose compound being difficult to degrade.Meanwhile,the large number of hydroxyl groups (?OH) endow the LCB surface with high activity and surface energy.Hemicellulose is an amorphous polysaccharide compound that contains various unit compositions including xylose,glucose,mannose,galactose,and arabinose,along with other types of structural units.The number of sugar units in hemicellulose ranges from 100 to 200,resulting in its molecular weight being far lower than that of cellulose [39].The hemicellulose component acts as a binder between cellulose and lignin,improving the rigidity of the biomass overall[40].In contrast,lignin has a 3D-grid polymeric structure without a fixed shape,in which the basic unit is composed of methoxylated phenylpropanoid units including sinaphyl,coniferyl,andpcoumaryl alcohols [41,42].Cellulose and hemicellulose can tightly combine with lignin to form lignocellulose.These components provide plants with the strength and hardness required to resist external forces,while also forming a protective layer to prevent external microbial degradation of polysaccharides [43].

    3.1.2.A brief description about pretreatment of LCB

    LCB must be pretreated before functionalization.Generally,the pretreatment includes physical,chemical,physicochemical,and biological methods.The particle size and degree of polymerization of the LCB material largely depend on the pretreatment methods applied.[44–46].Physical pretreatment methods are generally used to reduce the size of biomass,increase the specific surface area and pore size,or reduce the crystallinity and polymerization degree of cellulose.Chemical treatment is mostly performed using acids,alkalis,organic solvents,or co-solvents,which are capable of selectively removing the main structural components [47,48].Physicochemical approaches include steam explosion,ammonia fiber explosion (AFEX),and liquid hot water (LHW) methods [49,50].Biological pretreatment allows lignin to be specifically degraded and obtains the corresponding products [51].

    3.2.Advantages of LCB application for oily wastewater treatment

    The recent rapid development of biomass energy technologies and bionics has provided new ideas for the invention of lowcost materials capable of high efficiency oily wastewater treatment[20,52].The complete separation of oil-water mixtures using LCB materials without the consumption of any external energy,has become a key research focus.

    The linear molecular structure of cellulose (β-D-glucopyranose,(C6H10O5)n),is the main component of LCB and is,therefore,diffi-cult to dissolve using common polar and non-polar solvents as the chemical bonds are not easily broken.The strong hydrogen bonding is attributed to the large number of hydroxyl functional groups(?OH) on the surface of cellulose,which make LCB inherently hydrophilic,enabling it to chemically react with different functional groups.The main ?OH functional group reactions of LCB include oxidation to aldehyde groups (?CHO),oxidation to carboxyl groups(?COOH),hydroxyl group substitution reactions,alcoholysis with alkoxy groups to form new alkoxy bonds,condensation reactions with phenolic and melamine resins,hydrogen bonding,coordination,electrostatic,and van der Waals interactions.The interconnected lignin,cellulose,and hemicellulose compounds in LCB form a lignin-carbohydrate complex,providing mechanical strength and forming the internal structure of LCB materials.Furthermore,the lignin in LCB contains active groups such as aromatic,phenolic hydroxyl,alcoholic hydroxyl,carbonyl,methoxy,carboxyl groups,and conjugated double bonds,capable of selective functional group chemical reactions [53].Therefore,suitable reactions can be selected to facilitate the addition or removal of specific functional groups on LCB,supporting further functionalization.For example,the use of different long-chain silanes for hydrolysis and grafting onto the surface of LCB,allows precise control over the wettability of LCB,endowing it with the characteristics required for oily wastewater treatment [54,55].In addition,the 3D pore structure of the original LCB material makes it suitable as a natural filter and filler material [56,57].Due to the 3D network structure of LCB,there are an abundance of controllable factors (pretreatment modification,pore shape,length,diameter,etc.),allowing the 3D channels of LCB to be filled using functional particles and surface modifications [58].

    4.Advanced LCB modification techniques for oily wastewater treatment

    LCB has the advantages of excellent sustainability,degradability,and an abundance of natural resources,resulting in it becoming a sustainable development research hotspot.The different potential wettability characteristics and multilayer structures of LCB materials are the main factors contributing to the oil-water separation capability.In order to improve the efficiency of oil-water separation,the selection of suitable LCB material modification methods has been found to be the key factor.

    4.1.Dip coating

    Dip coating is an effective method for superwetting oily wastewater treatment,in which the pretreated LCB substrate is fully immersed into a solution containing micro/nano particles,a low surface energy substance,or a mixture of both,forming an LCB structure with low surface energy and achieving superwettability.The micro/nano particles commonly used to construct micro-nano surface structures include SiO2,TiO2,ZnO,carbon materials,and metal nanoparticles [59].Generally,the low surface energy substances used include fluorine-containing silanes,fluorine-containing resins,silicone resins,and fluorine-free longchain silanes.Wanget al.immersed wood in a mixed solution of zinc acetate and triethylamine,modifying the wood with stearic acid to obtain a stable superhydrophobic surface with a water contact angle (WCA) of up to 151° [60].Furthermore,modifying wood using potassium methyl siliconate (PMS) and controlling the dipping conditions,resulted in the formation of superhydrophobic wood with a WCA of 153° [61].Rahmanet al.constructed micronano structures on a fabric surface by enzymatic hydrolysis and then treated it using the polydimethylsiloxane (PDMS) dip coating method [62].Superhydrophobic cellulosic biomass could be obtained by optimizing the treatment conditions.In practice,the effectiveness of the dip coating method is limited due to the fragile adhesion between the micro-nano structure and the LCB substrate surface,affecting the stability and recyclability of the modified LCB material,although this limitation can be overcome using other methods and techniques.Overall,the dip coating technique is simple to implement and provides a convenient method for achieving superwettability of LCB and other materials [63,64].

    4.2.Spray coating

    The spray coating technique atomizes raw materials and applies them to the substrate surface through a spray gun or an atomizer,avoiding the limitations of the substrate and efficiently accomplishing coating on a large-scale.Hydrophobic silica nanoparticles dispersed in a solution can be sprayed on tape to prepare a multifunctional superhydrophobic surface,using a simple and practical method [65].Xieet al.first utilized polydopamine (PDA) coating to generate a double-sided superhydrophilic surface on a regenerated cellulose (RC) membrane,then spraying superhydrophobic attapulgite (SOATP) onto one of the surfaces to finally obtain a membrane with opposing characteristics on each side [66].This modified RC membrane achieved efficient oil-water separation of up to 99%.Shanget al.produced a superhydrophobic cotton fabric by spraying it with a solution composed of the oligomer and hydrophobic SiO2nanoparticles [67].Due to its excellent superhydrophobicity and superlipophilicity,the functional cotton fabric effectively separated a variety of oil-water mixtures and emulsions with ultrahigh efficiency and reusability,with the separation efficiency remaining above 99.990% after 30 separation cycles.The spray coating method can effectively construct micro-nano structures on the surface of various complex substrates,although these structures can easily be damaged.Another key limitation is that spray coating cannot be applied to the modification of 3D micro/mesoporous internal structures [68].

    4.3.Chemical vapor deposition (CVD)

    In the chemical vapor deposition (CVD) method,precursors are reacted and the products are deposited on the substrate to form multifunctional nanomaterial coatings.CVD coating can be used to efficiently modify LCB and other substrates for oily wastewater treatment.Ultra-light cellulose aerogel can be modified by CVD to become hydrophobic,resulting in a capability for oil absorption,with high surface and internal hydrophobicity [69].Zhanget al.conducted a comprehensive study on the CVD of SiO2on sootcoated copper mesh and prepared a network of SiO2nanofibers with superhydrophobicity and superlipophilicity,offering a solution for the treatment of oily wastewater [70].Similarly,silk fabric was enzymatically etched using the CVD process,achieving stable oil-water separation performance [71].Furthermore,an oil-water separation aerogel with thermal management function was fabricatedviaCVD modification by Zhuet al.using a top-down strategy to combine balsa wood,PDMS,and carbon nanotubes (CNTs) [72].The photothermal effect of CNTs promotes rapid volatilization of the absorbed oil and due to the automatically continuous output path,oil absorption by the superhydrophobic CNTs/wood aerogel does not become saturated,providing a novel system for the development of functional materials capable of oily wastewater treatment.

    4.4.Sol-gel technique

    The sol-gel method incorporates precursors into solution and gel states,then processes them to form a composite solid [73].Briefly,the preparation process hydrolyzes the precursor to form a solution and then forms a compound with the substrate to generate the functional material.For example,a hydrophobic cellulose membrane was modified with hexadecyltrimethoxysilane (HDTMS)by Medina-Sandovalet al.,using a SiO2sol-gel method,achieving the separation of immiscible oil-water mixtures at an efficiency of over 99% and remaining effective (separating a water/oil (1:1)emulsion) after 18 cycles of reuse [74].Through a one-step solgel strategy,Xieet al.utilized sol-gel strategy for the hydrolysis and polycondensation of tetraethylorthosilicate (TEOS) and hexadecyltrimethoxysilane (HDTMS),preparing a superhydrophobic cellulose membrane (SOCM) with nano-micro structures and a low surface energy,achieving a separation efficiency of over 98% for various oil-water mixtures and exhibiting good stability and recyclability [75].Using a simple vapor-liquid sol-gel method,underoil superhydrophobic and underwater superoleophobic fabrics with excellent durability were prepared by Chenet al.,effectively separating heavy oil/water,light oil/water,water-in-oil (W/O),oil-in-water(O/W) emulsions,and immiscible organic solvents [76].Overall,the sol-gel technique provides a foundation for the preparation of multifunctional materials for use in oil-water separation.

    4.5.Other advanced modification techniques

    Due to recent technological progress,novel LCB modification methods and LCB smart materials are likely to be applied to the oily wastewater treatment,especially techniques forming smart materials with self-healing properties,catalytic activity,photothermal performance,and multi-functionality.

    Caoet al.developed a carbon black membrane (CBM) with a layered structure and suitable chemical composition,exhibiting excellent multiphase emulsion separation performance due to its underwater superoleophobicity and underoil superhydrophobicity [77].Using a process based on dual-function aqueous suspensions,a superhydrophobic nanocellulose fiber (SHNCF) aerogel was developed by Wanget al.,achieving high capacity oil absorption (13.03–32.95 g/g),with efficiently continuous oil-water separation [78].Although materials with special wettability have been proven capable of oil-water separation,they can easily be polluted by oil during practical application.The preparation of materials capable of catalytic degradation or intelligent wettability conversion is a promising solution to overcome this limitation.Yanget al.proposed a fluorine-free strategy for the modification of superhydrophobic cotton with TiO2nanoparticles,generating a cotton fabric capable of self-cleaningviasuperhydrophobicity and photocatalytic degradation,with an oil-water separation efficiency of>99.0% maintained after 7 cycles of reuse [79].Chenet al.fabricated a smart fabric coating based on pH-responsive and UVcurable polyurethane,which endowed the fabric with wettability characteristics switching from superhydrophobic to underwater superoleophobic with changing pH conditions [80].The smart Janus membrane has shown much promise for application in oily wastewater treatment,exhibiting different wettability characteristics on both sides and effectively separating various emulsions and oil-water mixtures.Lehtinenet al.prepared a Janus filter by spraying polydimethylsiloxane (PDMS) on one side of cotton fabric and treating the other side with dimethylaminoethyl methacrylate(DMAEMA) [81].Due to the demulsification,the Janus fabric can achieve a high rate of oil-water separation (4.9×10?4mL/s).Despite significant progress in the development of intelligent materials for oily wastewater treatment,their use in large-scale applications remains a significant challenge.

    Fig.2.Schematic diagram of the process of LCB used in oily wastewater treatment after refining and advanced modification techniques.

    These various techniques of advanced modification applied to LCB for oily wastewater treatment are summarized in Fig.2.The different modification methods and corresponding key findings are summarized in Table 1.By comparing the effect of different modification methods,this review summarizes key references for the practical application of modified LCB materials in oily wastewater treatment.

    Table 1 Comparison of different modification methods and corresponding key findings.

    5.Construction of 0D,2D and 3D-LCB materials for oily wastewater treatment

    Different types of LCB materials exhibit specific characteristics for oily wastewater treatment due to varying structures and wettability behaviors.As a basis for representative comparison,the dimensions of materials are used as the discussion standard: 0DLCB modified powders,2D-LCB membranes,and 3D-LCB structures with continuous channels for oily wastewater treatment.

    5.1.0D-LCB materials for oily wastewater treatment

    The mature LCB powder materials used in oily wastewater treatment include superhydrophobic-superlipophilic (waterremoving) and superhydrophilic-underwater superoleophobic (oilremoving) powders.Using sawdust as a raw material,a superhydrophobic and superoleophilic oil sorbent LCB was designed by Zanget al.,combining sawdust fibers with SiO2particles and self-assembly octadecyltrichlorosilane (OTS) monomers[82].The WCA and oil contact angle (OCA) of sawdust oil absorbents were 153° and ~0°,respectively,exhibiting an excellent oil absorption capacity of 14.4 g/g.In order to improve the oil absorption and recycling capacity of LCB powders,hollow spherical ZnO particles and HDTMS were deposited on the surface of corn straw powdersviachemical hydrophobic modification,effectively improving surface roughness and reducing the surface free energy of corn straw fibers [83].The WCA and OCA of the corn straw oil absorbent were 155° and~0°,respectively,achieving an absorption capacity of 20.4 g/g,resulting in high efficiency oil removal (99%?100%).Similarly,Xuet al.fabricated a novel superhydrophobic/superoleophilic corn straw fiber using the impregnation method,achieving excellent superhydrophobicity (WCA ~152°) and superlipophilicity (OCA ~0°),with the modified corn straw fiber exhibiting an oil absorption capacity of up to 27.8 g/g [84].Furthermore,the WCA and OCA remained unchanged after 150 days of storage under ambient temperature and humidity conditions.Overall,the corn straw oil absorbent has high potential for use in the treatment of oily wastewater,due to its good environmental stability and high efficiency oilwater separation capability.Hydrophobic wood powders modified with ZnO nanoparticles can effectively treat oily wastewater,with modified wood flour shown to possess excellent stability with a WCA and OCA of 156° and 0°,respectively [85].The oil absorption capacity of modified wood flour was 20.81 g/g,with an oil absorption efficiency ranging from 98% to 100%.A key advantage is that modified wood flour can be recycled after removal of the absorbed oil.Therefore,the superior oil-water separation efficiency and environmental durability of the modified wood flour greatly enhance its commercial applicability and feasibility.The composite modification of LCB with a variety of nanoparticles is an important method for improving the capability for oily wastewater treatment.Similarly,through the composite modification of LCB with ZnO/SiO2and octyltriethoxysilane (OTES),a superhydrophobicsuperoleophilic corn straw material was fabricated for the separation of oil from liquid mixtures,achieving absorption capacities for crude and bean oils of 20.05 and 22.50 g/g,respectively[86].Although LCB powdered materials possess high oil absorption and oil removal efficiencies,they remain limited by their capacity for recycling and reuse.Diet al.designed Fe3O4/sawdust composites (HFSCs) capable of high efficiency oil-water separation(up to 99%) [87].It is of note,that the oil-absorbing composites of LCB were easily separated magnetically,allowing the oil-absorbed Fe3O4/sawdust to be collected using a magnet and reused after treatment.Recyclability,cost-effectiveness,and environmental impact are the important evaluation criteria for the selection of materials for use in oily wastewater treatment.Overall,0D-LCB materials have been shown to exhibit great potential for application in the treatment of oily wastewater.

    5.2.2D-LCB materials for oily wastewater treatment

    Oil-water mixtures can be passed through 2D-LCB membranes modified by superwettable materials to achieve complete oily wastewater treatment.The separation efficiency,flux,stability,cost,and sustainability of LCB membranes are the key parameters for assessing whether they can be applied in practice.Therefore,establishing simple preparation processes,low-cost raw materials,excellent separation efficiency,and high membrane strength,requires the further exploration of materials such as LCB composites for use in filter membranes.Yuet al.prepared a corn straw powder-nylon 6,6 membrane (CSPNM) using the phase-inversion method,achieving superhydrophilicity and underwater superoleophobicity [88].After 20 separation cycles,the oil rejection rate remained>99.50%,with a flux of 1561.09 L m?2h?1,indicating that the CSPNM possessed good reuse capability and environmental stability.A similar nylon membrane coated with a superhydrophilic/underwater superoleophobic cellulose-starch-silica (CSS)composite was designed by Zhanget al.,exhibiting a WCA and underwater OCA of 0° and 159.5°,respectively [89].The membrane possessed a mixture flux of 31,847 L?1m?2h?1bar?1and after 100 cycles,the separation efficiency remained above 97%,with the membrane able to be maintained for at least 24 h under extreme environmental conditions (pH 4–10),exhibiting high removal flux,good stability,and reusability.The separation of twophase oil-water mixtures under laboratory conditions is idealized,while three-phase or more complex light oil/water/heavy oil mixtures are more representative of real wastewater conditions.Using the strategy of continuous gravity separation of three-phase oilwater mixtures,a dually prewetted LCB membrane with underwater superoleophobicity and underoil superhydrophobicity,has been shown to possess superior oil-water separation capabilities [90].A superamphiphilic waste corn straw powder (CSP)-coated fabric(CSPF) was designed by spraying CSP and polyurethane (PU) solutions onto cotton fabrics.The CSPF was dually prewetted using water and oil (DCSPF) to form a water-containing region (WCR)and an oil-containing region (OCR),respectively,in which the oil and water were selectively passed through the WCR or OCR to separate the three-phase oil-water mixtures.The average fluxes of water,light oil,and heavy oil in the DCSPF were ~3.8,~8.9 and~13.3 L m?2s?1,respectively,with a three-phase mixture separation efficiency of over 97% maintained after 50 separation cycles.The Janus membrane with asymmetric surface properties was also found to perform very well in oily wastewater treatment.Utilizing cellulose and Ag nanoparticles,a double-sided Janus composite membrane (JCM) was fabricated by Lvet al.,with both superhydrophilic and superhydrophobic properties [91].The separation fluxes of oil-in-water and water-in-oil emulsions in the JCM were 640 L m?2h?1and 323.04 L m?2h?1,respectively,with the separation efficiency exceeding 96%.At present,the trend in development of 2D-LCB materials for oily wastewater treatment has shifted from single-to multi-functional modifications and from single emulsion to multiphase emulsion treatments,supporting the development of low-cost,readily available,environmentally friendly,and sustainable materials.Therefore,further studies are required in order to transition from laboratory research to industrial applications.

    5.3.3D-LCB materials for the oily wastewater treatment

    The high porosity,suitable pore sizes and compressibility of 3D-LCB porous oil-absorbing materials make them suitable for application in oily wastewater treatment.Due to the complexity and diversity of oily wastewater,there is an urgent need to develop low-energy and high-efficiency 3D-LCB materials for oily wastewater treatment.Yanget al.performed controlled dissolution treatment using raw cotton,freeze-drying the product to develop a cellulose sponge with excellent underwater superoleophobicity [92].The oil-water separation efficiency and flux of the 3D cellulose sponge were 99.2% and up to 485 L m?2h?1,respectively.Sawdust waste can also be used for oily wastewater treatment [93].A 3D liquefied-larch-based polymer foam (LLBPF) with a honeycomb interconnected structure and its carbonized product,LLB-CF,were prepared using larch sawdust waste as the raw material.The unique 3D structure endowed LLB-PF/CF with a high abundance of pores,hydrophobicity,and superoleophilicity.The absorption of tetrachloromethane and epoxidized soybean oil by LLB-PF and LLB-CF reached 88-fold and 153-fold greater than their own weight,respectively.A balsa wood sponge with the fluoroalkyl silane modified reduced graphene oxide (FrGO@WS) was produced by Huanget al.for oily wastewater treatment,achieving an oil-water separation efficiency of 99.0%due to its hydrophobicity (WCA=145°) and longitudinal channels [94].In addition,F-rGO@WS possesses electric-heating performance,resulting in a 10-fold higher heavy oil and water separation rate under a voltage of 20 V,significantly enhancing its capability for the treatment of complex oily wastewater.Similarly,innovative 3D-LCB aerogels have shown great potential for oily wastewater treatment,with cellulose aerogels (CEA) and aerogels coated with Cu nanoparticles (Cu/CEA) possessing high oil absorption capabilities (67.8–164.5 g/g) [95].Cu/CEA can quickly separate oil-water mixtures with a high separation efficiency of>97%,while also exhibiting good recyclability (>10 times)making it a promising material for practical application.Menget al.constructed a lignin-based carbon aerogel enhanced by graphene oxide (LCAGO),resulting in synergistic superhydrophobicity and good mechanical properties for oily wastewater treatment [96].The oil absorption capacity of LCAGO was 32–34 g/g,making it suitable for use in environmental remediation.The combination of wood pulp cellulose nanofibers (CNF) and three silane modifiers,resulted in the fabrication of a novel hydrophilic and oleophobic composite aerogel,which achieved a good absorption capacity of 11.5 g/g.After 5 absorption-regeneration cycles,the oil absorption capability of the modified aerogels remained at 10 g/g,with its rugged compression performance and excellent water resistance being beneficial for practical industrial applications [97].Yuanet al.utilized natural sisal cellulose as a raw material,using carbonization and MnO2self-assembly to prepare a hierarchical biomass carbon@SiO2@MnO2(HBCSM) aerogel with a high specific surface area and good mechanical flexibility [98].The WCA of the HBCSM aerogel was 155°,resulting in a large absorption capacity for different oils and organic solvents (60–120 g/g).Furthermore,the HBCSM aerogel remained effective for more than 9 cycles of reuse,making it a promising candidate material for oily wastewater treatment.LCB porous oil-absorbing materials are a promising development in the field of oily wastewater treatment due to their unique 3D structures,with the research focus now aimed at developing environmentally friendly,economical,and low-energy consuming 3D-LCB materials for oily wastewater treatment.

    Factors such as separation efficiency,separation quality,and recyclability determine the potential for practical application of LCB materials.A comparison of the parameters of 0D-,2D-and 3D-LCB materials for oily wastewater treatment is shown in Table 2.Overall,selecting LCB materials with an appropriate structure for oily wastewater treatment according to the actual treatment conditions is the key to achieving optimal treatment performance.

    Table 2 Comparison of the oily wastewater treatment parameters of 0D-,2D-,3D-LCB materials.

    6.Current challenges and future prospects

    The diversity and biocompatibility of the natural components of LCB,provide biomass materials with inherent advantages and potentially transformative characteristics.Taking LCB biomass as raw materials possesses the advantages of being green and sustainable.They are nontoxic after degradation and capable of avoiding secondary pollution effectively.In addition,LCB biomass is economically feasible,and most of them are waste resources such as wood flour and corn stalk.Therefore,the use of LCB to prepare oil-water separation materials not only meets the needs of environmental protection but also the requirements of low cost.However,despite the achievements made in the preparation,microscopic morphology,chemical structure,and composition of LCB materials,there remain various limitations and deficiencies,as shown in Fig.3.The challenges include single functions,poor stability and circulation,low efficiency oil-water separation,and high environmentalimpact modification processes.Therefore,developing strategies for the conversion of LCB components into the materials capable of high efficiency oil-water separation is essential,particularly simple strategies to adjust the morphology of LCB materials from 0D fibers,2D membranes to 3D structures for oily wastewater treatment.

    Fig.3.The advantages and disadvantages of LCB in wastewater treatment applications.

    The recycling and regeneration capabilities of materials for oily wastewater treatment are of great significance to their practical application.Due to the high recycling cost and complex recycling processes,most 0D-LCB powder absorbents are difficult to use repeatedly.In contrast,2D-LCB membranes rarely involve recovery problems,but they are often used in the later stages of water treatment processes,as membrane filtration requires high water quality and large impurities may damage the membrane.In particular,in filtration membranes for the separation of oil-water emulsions,if the emulsion enters the 2D membrane together with a large amount of un-emulsified water or oil,a serious decline in flux will occur in the membrane [99].3D-LCB materials are suitable for oily wastewater treatment due to their abundance of interconnected pores or channels [100].Whether LCB materials can be used industrially for oily wastewater treatment is a main factor in the evaluation of their practical value.It is essential to develop sustainable LCB materials with catalytic properties such as visible light catalysis,electrocatalysis,and advanced oxidation for oily wastewater treatment,overcoming the limitations of singleperformance separation materials.

    A comprehensive technical and economic sustainability analysis should be conducted to determine the optimal LCB pretreatment methods and modification routes,to achieve high-efficiency oily wastewater treatment.It is of note,that most of the chemicals used in wettability modification are not environmentally friendly and in particular,fluorine-free modifiers should be selected for use in the modification process [101–103].Separation efficiency,recyclability,and cost are the preferred evaluation criteria for LCB materials usable in industrial and domestic oily wastewater treatment.The ideal intelligent sewage separation systems are easy to repair itself after being damaged and capable of treating composite pollutants.The characteristics of rapid degradation and selfdecontamination of intelligent systems will enable the treated wastewater to meet the qualified standards,which possess the advantages of low cost,high separation efficiency,easy self-cleaning,and low labor cost.The cost optimization of the intelligent system should be operated in accordance with the process and technical requirements.Controlling the cost of raw materials and optimizing the design and structure of the LCB treating medium can improve separation efficiency and quality.A cost-benefit calculation system should be established to optimize the treatment process to improve the economic benefits of the intelligent system.More efforts should be made to analyze the mechanism of biomass materials for removal of complex pollutants in sewage on the basis of ensuring the effect of oil-water separation [104,105].Therefore,there is a strong need to develop LCB materials with different dimensions and structures,in order to meet the actual requirements of different field applications.

    Fig.4.The development prospect of LCB in wastewater treatment applications.

    At present,most of the materials used in oily wastewater treatment reported in the literature have been non-renewable materials [106].Fig.4 highlights the development prospects of LCB for wastewater treatment applications.From the perspective of sustainable development,some important aspects need to be considered during the deployment of LCB materials for oily wastewater treatment:

    (1) In the utilization of a certain component of LCB,it is necessary to develop efficient separation processes to achieve environmentally friendly and low-cost separation.

    (2) Further research is needed to explore the internal relationship between the mechanical properties of LCB-2D/3D porous materials and their structure.LCB materials should be optimized to allow the sustainable recycling of oil and water resources.

    (3) LCB materials are susceptible to damage after repeated use and mechanical abrasion,resulting in a reduction or even loss of separation efficiency.The construction of sustainable and recyclable superwetting LCB materials for oily wastewater treatment materials remains a key problem that needs to be solved.

    (4) The design of LCB materials capable of simultaneously treating oily wastewater and pollutants on a large scale remains a challenge,especially the large-scale treatment of organic dyes,heavy metal ions,pesticides,antibiotics and other pollutants.

    (5) The construction and development of multifunctional,intelligent sewage separation systems using LCB are essential,with self-healing capabilities and multiple response mechanisms (such as temperature,light,electric,pH,and magnetic responses).

    7.Conclusions

    The application of LCB materials has become an attractive solution for oily wastewater treatment,although there are still some shortcomings that must be overcome.In order to effectively separate and purify oily wastewater,it is necessary to develop sustainable and multifunctional LCB materials.Multi-dimensional wastewater treatment and purification system utilizing LCB is a key trend in sustainable development,requiring thorough evaluation for effective large-scale application.Considering the feasibility of taking LCB as raw materials to build the sewage treatment system with cost optimization,treatment efficiency,and recyclability,which is conducive to the develop a high-efficiency intelligent sewage treatment system.Ultimately,the current research indicates that these materials are promising for sustainable oily wastewater treatment and that further development of LCB materials will overcome the present challenges and limitations.

    Declaration of competing interest

    The authors declare no conflict of interest.

    Acknowledgments

    This work was financially supported by the National Natural Science Foundation of China (No.51961165104) and the Project of Thousand Youth Talents.

    亚洲avbb在线观看| 国产成人福利小说| 岛国在线免费视频观看| 午夜精品久久久久久毛片777| 免费看日本二区| 日韩大尺度精品在线看网址| 国产老妇女一区| 又粗又爽又猛毛片免费看| 3wmmmm亚洲av在线观看| 免费大片18禁| 色吧在线观看| 欧美黑人巨大hd| 啦啦啦啦在线视频资源| 亚洲午夜理论影院| 精品人妻偷拍中文字幕| 国产男人的电影天堂91| 欧美黑人巨大hd| 最新在线观看一区二区三区| 尾随美女入室| 亚洲精品一卡2卡三卡4卡5卡| 欧美激情国产日韩精品一区| 免费无遮挡裸体视频| 在线观看66精品国产| 国产精品福利在线免费观看| 综合色av麻豆| 亚洲国产色片| 午夜精品一区二区三区免费看| 亚洲性久久影院| 少妇高潮的动态图| 大型黄色视频在线免费观看| 高清日韩中文字幕在线| a在线观看视频网站| 女的被弄到高潮叫床怎么办 | 两个人的视频大全免费| 天堂√8在线中文| 中国美女看黄片| 精品日产1卡2卡| 在线播放无遮挡| 国产精品久久久久久亚洲av鲁大| 中文字幕熟女人妻在线| 成年免费大片在线观看| 韩国av一区二区三区四区| 又粗又爽又猛毛片免费看| 久久人人爽人人爽人人片va| 精品一区二区三区视频在线| 中文字幕久久专区| 久久精品人妻少妇| 久久久久久大精品| 中文字幕精品亚洲无线码一区| 亚洲在线自拍视频| 日本免费一区二区三区高清不卡| 久久精品综合一区二区三区| 免费在线观看成人毛片| 搡老熟女国产l中国老女人| 欧美+亚洲+日韩+国产| 国产成年人精品一区二区| 亚洲精品影视一区二区三区av| 成年免费大片在线观看| 久久久久国产精品人妻aⅴ院| 国产精品福利在线免费观看| 日日干狠狠操夜夜爽| 美女高潮的动态| 日韩在线高清观看一区二区三区 | 一边摸一边抽搐一进一小说| 国产aⅴ精品一区二区三区波| 免费av不卡在线播放| av国产免费在线观看| 我要看日韩黄色一级片| 久久久国产成人精品二区| 亚洲av中文字字幕乱码综合| 亚洲精品一区av在线观看| 国国产精品蜜臀av免费| 欧美色欧美亚洲另类二区| 看片在线看免费视频| 一区二区三区高清视频在线| a级毛片免费高清观看在线播放| 久9热在线精品视频| 中文在线观看免费www的网站| 欧美不卡视频在线免费观看| 91麻豆精品激情在线观看国产| 欧美成人性av电影在线观看| 中文字幕免费在线视频6| 91狼人影院| 此物有八面人人有两片| 日本免费a在线| 性欧美人与动物交配| 伦精品一区二区三区| 人人妻,人人澡人人爽秒播| 亚洲国产欧美人成| 女人被狂操c到高潮| 免费av观看视频| 波多野结衣高清无吗| 国产精品爽爽va在线观看网站| 美女 人体艺术 gogo| 看片在线看免费视频| 国产乱人视频| 校园人妻丝袜中文字幕| 亚洲美女搞黄在线观看 | 国产不卡一卡二| 日本爱情动作片www.在线观看 | 特级一级黄色大片| 亚洲美女视频黄频| 日韩亚洲欧美综合| 午夜免费男女啪啪视频观看 | 亚洲狠狠婷婷综合久久图片| 精品午夜福利视频在线观看一区| 欧美不卡视频在线免费观看| 国产精品人妻久久久影院| 亚洲av免费高清在线观看| 亚洲欧美日韩高清在线视频| 日韩欧美国产一区二区入口| 日韩av在线大香蕉| 天堂网av新在线| 日本黄大片高清| 亚洲18禁久久av| 最近在线观看免费完整版| 国内精品久久久久精免费| 国产高清视频在线播放一区| 免费大片18禁| 尤物成人国产欧美一区二区三区| 999久久久精品免费观看国产| 久久人人爽人人爽人人片va| 亚洲一区高清亚洲精品| 婷婷精品国产亚洲av| 99久久精品热视频| 亚洲欧美日韩高清专用| 日日摸夜夜添夜夜添av毛片 | 日本三级黄在线观看| 女同久久另类99精品国产91| 有码 亚洲区| 日韩 亚洲 欧美在线| 麻豆一二三区av精品| 大型黄色视频在线免费观看| 免费人成视频x8x8入口观看| 黄色欧美视频在线观看| 亚洲真实伦在线观看| 露出奶头的视频| 日本黄色片子视频| 亚洲专区国产一区二区| 五月玫瑰六月丁香| 国产视频内射| 中文亚洲av片在线观看爽| 国产精品,欧美在线| 精品一区二区三区视频在线| 可以在线观看毛片的网站| 国内少妇人妻偷人精品xxx网站| 亚洲av日韩精品久久久久久密| 欧美色欧美亚洲另类二区| 欧美精品啪啪一区二区三区| 欧美黑人欧美精品刺激| 最新在线观看一区二区三区| 久久香蕉精品热| 亚洲熟妇熟女久久| 三级毛片av免费| 国产伦一二天堂av在线观看| 少妇人妻一区二区三区视频| 午夜福利视频1000在线观看| a级一级毛片免费在线观看| 久久欧美精品欧美久久欧美| 色播亚洲综合网| 天堂网av新在线| 男人舔奶头视频| 男女之事视频高清在线观看| 黄色丝袜av网址大全| 永久网站在线| 日本a在线网址| 九九爱精品视频在线观看| 国产视频一区二区在线看| 国产成人福利小说| 亚洲avbb在线观看| 久久久久久九九精品二区国产| 听说在线观看完整版免费高清| 男人狂女人下面高潮的视频| 国产精品国产高清国产av| 丰满的人妻完整版| 亚洲成人久久爱视频| 成人永久免费在线观看视频| 亚洲精品色激情综合| 国产成人aa在线观看| 久久久久久久久久成人| 久久精品国产清高在天天线| 一进一出抽搐动态| 国产黄片美女视频| or卡值多少钱| 国产 一区 欧美 日韩| 欧美一区二区精品小视频在线| 亚洲性夜色夜夜综合| 特大巨黑吊av在线直播| 1000部很黄的大片| 69av精品久久久久久| 精品久久久久久久久久免费视频| 国产精品福利在线免费观看| 成年人黄色毛片网站| 在线播放无遮挡| 国产精品av视频在线免费观看| 国内精品宾馆在线| 久久久久久久久久成人| 亚洲av免费在线观看| bbb黄色大片| 久久久久国产精品人妻aⅴ院| 亚州av有码| 欧美丝袜亚洲另类 | 一个人观看的视频www高清免费观看| 久久精品国产鲁丝片午夜精品 | 免费看日本二区| 网址你懂的国产日韩在线| 少妇的逼好多水| 欧美中文日本在线观看视频| 日本黄色视频三级网站网址| 欧美性猛交╳xxx乱大交人| 亚洲图色成人| 最好的美女福利视频网| 桃红色精品国产亚洲av| 国产精品乱码一区二三区的特点| 深夜精品福利| 特大巨黑吊av在线直播| 在线观看av片永久免费下载| 日韩高清综合在线| 亚洲,欧美,日韩| www.色视频.com| 中文字幕精品亚洲无线码一区| 网址你懂的国产日韩在线| 有码 亚洲区| 成人亚洲精品av一区二区| 国产高潮美女av| 成人午夜高清在线视频| 日日摸夜夜添夜夜添小说| 精华霜和精华液先用哪个| 午夜精品在线福利| 亚洲最大成人中文| 亚洲国产欧美人成| 十八禁国产超污无遮挡网站| 久久国产乱子免费精品| 51国产日韩欧美| 成人高潮视频无遮挡免费网站| 在线免费观看的www视频| 成人鲁丝片一二三区免费| 欧美三级亚洲精品| 少妇猛男粗大的猛烈进出视频 | 女的被弄到高潮叫床怎么办 | 中出人妻视频一区二区| 午夜福利高清视频| 嫁个100分男人电影在线观看| 国产伦在线观看视频一区| 91麻豆精品激情在线观看国产| 日本撒尿小便嘘嘘汇集6| 在线天堂最新版资源| 久久久精品欧美日韩精品| 十八禁国产超污无遮挡网站| 日本 av在线| 午夜激情欧美在线| 99久久久亚洲精品蜜臀av| 国产高清有码在线观看视频| 看片在线看免费视频| 国产免费av片在线观看野外av| 久99久视频精品免费| 久久久久国产精品人妻aⅴ院| 99在线人妻在线中文字幕| 校园春色视频在线观看| 美女大奶头视频| 国产欧美日韩一区二区精品| 国产精品亚洲一级av第二区| 校园人妻丝袜中文字幕| 日日摸夜夜添夜夜添av毛片 | 搡老熟女国产l中国老女人| 免费不卡的大黄色大毛片视频在线观看 | 精品久久久久久久久久久久久| 舔av片在线| 18禁黄网站禁片午夜丰满| 国内久久婷婷六月综合欲色啪| 欧美三级亚洲精品| a级毛片免费高清观看在线播放| 麻豆精品久久久久久蜜桃| 免费一级毛片在线播放高清视频| 两性午夜刺激爽爽歪歪视频在线观看| 亚洲精品亚洲一区二区| a级毛片免费高清观看在线播放| 真人一进一出gif抽搐免费| 国产精品永久免费网站| 亚洲最大成人中文| 无遮挡黄片免费观看| 国内毛片毛片毛片毛片毛片| 国产在线男女| 窝窝影院91人妻| 午夜福利在线观看免费完整高清在 | 国产一区二区激情短视频| 久9热在线精品视频| 欧美最黄视频在线播放免费| 日本-黄色视频高清免费观看| 日韩欧美三级三区| 午夜免费激情av| 久久精品国产亚洲av天美| 看十八女毛片水多多多| 国产一区二区三区av在线 | 欧美人与善性xxx| 大型黄色视频在线免费观看| 亚洲熟妇中文字幕五十中出| 男插女下体视频免费在线播放| 日本在线视频免费播放| 成人高潮视频无遮挡免费网站| 村上凉子中文字幕在线| 九色成人免费人妻av| videossex国产| 免费看av在线观看网站| 国产伦在线观看视频一区| 在线观看av片永久免费下载| 国产私拍福利视频在线观看| 听说在线观看完整版免费高清| 午夜激情福利司机影院| 亚洲人成网站高清观看| 三级男女做爰猛烈吃奶摸视频| 久久精品人妻少妇| 亚洲熟妇熟女久久| 欧美成人一区二区免费高清观看| 欧美3d第一页| 欧美最黄视频在线播放免费| 在线观看免费视频日本深夜| av天堂在线播放| АⅤ资源中文在线天堂| 色播亚洲综合网| 久久久久久久亚洲中文字幕| 国产免费一级a男人的天堂| 99九九线精品视频在线观看视频| 成人av在线播放网站| 国内精品久久久久精免费| 伦理电影大哥的女人| 午夜福利18| 美女高潮喷水抽搐中文字幕| 亚洲av第一区精品v没综合| 久久久色成人| 成人综合一区亚洲| 成人国产综合亚洲| av在线蜜桃| 88av欧美| 热99re8久久精品国产| 搡老熟女国产l中国老女人| 亚洲精品在线观看二区| 国产免费av片在线观看野外av| 日本免费a在线| bbb黄色大片| 中文字幕久久专区| 亚洲电影在线观看av| 精品人妻视频免费看| 日韩欧美三级三区| 亚洲精华国产精华精| 亚洲精品乱码久久久v下载方式| 成人精品一区二区免费| h日本视频在线播放| 亚洲乱码一区二区免费版| 亚洲无线在线观看| 欧美色视频一区免费| 尤物成人国产欧美一区二区三区| .国产精品久久| 色噜噜av男人的天堂激情| or卡值多少钱| 国产欧美日韩一区二区精品| 最近最新中文字幕大全电影3| 欧美日韩综合久久久久久 | 色哟哟·www| 给我免费播放毛片高清在线观看| 黄色欧美视频在线观看| 永久网站在线| 天堂√8在线中文| 亚洲精华国产精华精| 亚洲avbb在线观看| 国产精品一区二区三区四区免费观看 | 色av中文字幕| 国内精品一区二区在线观看| 亚洲精品亚洲一区二区| 乱人视频在线观看| 国产日本99.免费观看| av在线亚洲专区| 欧美又色又爽又黄视频| 噜噜噜噜噜久久久久久91| 麻豆国产av国片精品| 国内精品久久久久精免费| 亚洲一区二区三区色噜噜| 五月玫瑰六月丁香| 午夜福利视频1000在线观看| 日本一本二区三区精品| 国产极品精品免费视频能看的| 国产精品国产三级国产av玫瑰| 亚洲欧美清纯卡通| 精品久久久噜噜| 97碰自拍视频| 日日干狠狠操夜夜爽| 中出人妻视频一区二区| 国产精品一区二区三区四区免费观看 | 十八禁国产超污无遮挡网站| 成人特级黄色片久久久久久久| 欧美黑人欧美精品刺激| 51国产日韩欧美| 国产伦精品一区二区三区四那| 亚洲成人精品中文字幕电影| 最近中文字幕高清免费大全6 | a级一级毛片免费在线观看| av在线观看视频网站免费| 69人妻影院| 国内久久婷婷六月综合欲色啪| 国产高清三级在线| 三级男女做爰猛烈吃奶摸视频| 少妇的逼好多水| 免费看av在线观看网站| 国产精品1区2区在线观看.| 久久久久久久久久黄片| 国产美女午夜福利| 欧美精品啪啪一区二区三区| 国产私拍福利视频在线观看| 能在线免费观看的黄片| 黄色欧美视频在线观看| 亚洲乱码一区二区免费版| 18禁在线播放成人免费| 亚洲av电影不卡..在线观看| 久久香蕉精品热| 国产精品人妻久久久影院| 日本撒尿小便嘘嘘汇集6| 两性午夜刺激爽爽歪歪视频在线观看| 久久久久久伊人网av| 男人和女人高潮做爰伦理| 色综合婷婷激情| 3wmmmm亚洲av在线观看| 午夜老司机福利剧场| 精品国内亚洲2022精品成人| 欧美又色又爽又黄视频| 久久6这里有精品| 十八禁国产超污无遮挡网站| 大型黄色视频在线免费观看| 午夜亚洲福利在线播放| 国产aⅴ精品一区二区三区波| 国产高潮美女av| 亚洲av日韩精品久久久久久密| 亚洲美女搞黄在线观看 | h日本视频在线播放| 国产成年人精品一区二区| 国产日本99.免费观看| 韩国av一区二区三区四区| 九九久久精品国产亚洲av麻豆| 亚洲av免费高清在线观看| 国产伦一二天堂av在线观看| 久久精品国产亚洲av香蕉五月| 亚洲人与动物交配视频| 又黄又爽又免费观看的视频| 国产精品免费一区二区三区在线| 别揉我奶头~嗯~啊~动态视频| 伊人久久精品亚洲午夜| 免费av毛片视频| 成人二区视频| 亚洲成人免费电影在线观看| 国产国拍精品亚洲av在线观看| 精品久久久久久久末码| 黄色欧美视频在线观看| av在线观看视频网站免费| 国产精品久久视频播放| 国产高清三级在线| 欧美日本亚洲视频在线播放| 日日干狠狠操夜夜爽| 日本一本二区三区精品| 亚洲乱码一区二区免费版| 欧美xxxx黑人xx丫x性爽| 亚洲中文日韩欧美视频| 国产一区二区在线观看日韩| 精品欧美国产一区二区三| 不卡视频在线观看欧美| 国产精品,欧美在线| 在线免费观看不下载黄p国产 | 我要搜黄色片| 久久久久久久亚洲中文字幕| 大型黄色视频在线免费观看| 亚洲黑人精品在线| 亚洲三级黄色毛片| 国产一区二区在线观看日韩| 久9热在线精品视频| 少妇熟女aⅴ在线视频| 国产成年人精品一区二区| 麻豆av噜噜一区二区三区| 国产黄片美女视频| 露出奶头的视频| 又爽又黄a免费视频| 亚洲精品一区av在线观看| 国产精华一区二区三区| 搡老熟女国产l中国老女人| 免费电影在线观看免费观看| 真人一进一出gif抽搐免费| 熟妇人妻久久中文字幕3abv| 亚洲熟妇中文字幕五十中出| 精品午夜福利视频在线观看一区| 99久久久亚洲精品蜜臀av| videossex国产| 国产伦在线观看视频一区| 国产精品,欧美在线| 久久精品国产99精品国产亚洲性色| 身体一侧抽搐| 99国产精品一区二区蜜桃av| 亚洲av中文字字幕乱码综合| 国产精品,欧美在线| 亚洲欧美精品综合久久99| 日本免费一区二区三区高清不卡| 亚洲精品影视一区二区三区av| 亚洲中文日韩欧美视频| 精品一区二区免费观看| 夜夜夜夜夜久久久久| 日本黄大片高清| 久久亚洲真实| 精品久久久久久久人妻蜜臀av| 国产精品久久久久久精品电影| 韩国av在线不卡| 99久久久亚洲精品蜜臀av| 久久天躁狠狠躁夜夜2o2o| 欧美日韩国产亚洲二区| 国产国拍精品亚洲av在线观看| 精品久久久久久久久久久久久| 深夜a级毛片| 18禁黄网站禁片午夜丰满| 日韩中文字幕欧美一区二区| 嫩草影院新地址| 亚洲av中文字字幕乱码综合| 我的女老师完整版在线观看| 如何舔出高潮| 波多野结衣高清无吗| 真人一进一出gif抽搐免费| 免费无遮挡裸体视频| 国产精品女同一区二区软件 | 日韩欧美三级三区| 欧美国产日韩亚洲一区| 亚洲国产精品sss在线观看| 国产美女午夜福利| 亚洲国产高清在线一区二区三| 欧美黑人巨大hd| 欧美激情久久久久久爽电影| 丰满乱子伦码专区| 高清在线国产一区| 精品久久久久久,| 国产成人aa在线观看| 日本与韩国留学比较| 国产成人影院久久av| 国内精品一区二区在线观看| 成人特级av手机在线观看| 久久人妻av系列| 久久精品夜夜夜夜夜久久蜜豆| 国产视频内射| 国产高潮美女av| 久久久久九九精品影院| 老熟妇乱子伦视频在线观看| 欧美一区二区亚洲| 精品久久久久久久久久免费视频| 久久精品久久久久久噜噜老黄 | 18禁裸乳无遮挡免费网站照片| 搡老熟女国产l中国老女人| 国产国拍精品亚洲av在线观看| 久久精品国产鲁丝片午夜精品 | 久久九九热精品免费| 伊人久久精品亚洲午夜| 最近视频中文字幕2019在线8| 国产精品野战在线观看| 99在线人妻在线中文字幕| 久久国产精品人妻蜜桃| 国产免费av片在线观看野外av| 国产精品久久久久久久久免| 两个人的视频大全免费| 国产精品久久视频播放| 免费看光身美女| 亚洲狠狠婷婷综合久久图片| 国产高清三级在线| 色综合亚洲欧美另类图片| 亚洲av电影不卡..在线观看| 自拍偷自拍亚洲精品老妇| 免费在线观看成人毛片| 嫩草影视91久久| 国产精品嫩草影院av在线观看 | 午夜影院日韩av| 很黄的视频免费| 又粗又爽又猛毛片免费看| 国产人妻一区二区三区在| 亚洲中文字幕日韩| 国产成人影院久久av| .国产精品久久| 天天躁日日操中文字幕| 少妇高潮的动态图| 亚洲七黄色美女视频| 日韩,欧美,国产一区二区三区 | 免费大片18禁| 韩国av一区二区三区四区| 日韩强制内射视频| 国产精品人妻久久久久久| АⅤ资源中文在线天堂| 亚洲在线观看片| 国产亚洲91精品色在线| 大又大粗又爽又黄少妇毛片口| 国产精品,欧美在线| 老师上课跳d突然被开到最大视频| 日韩欧美一区二区三区在线观看| 别揉我奶头 嗯啊视频| 久久久成人免费电影| 99久久成人亚洲精品观看| 久久久成人免费电影| 老女人水多毛片| 久久久久久伊人网av| 中文字幕人妻熟人妻熟丝袜美| 国产私拍福利视频在线观看| 日本三级黄在线观看| www日本黄色视频网| 国产视频内射| 精品人妻偷拍中文字幕| 午夜福利视频1000在线观看| 欧美激情国产日韩精品一区| 欧美日韩中文字幕国产精品一区二区三区| 国内久久婷婷六月综合欲色啪| www.色视频.com| 色尼玛亚洲综合影院| 他把我摸到了高潮在线观看| 国产久久久一区二区三区| 3wmmmm亚洲av在线观看| 两人在一起打扑克的视频| 日韩欧美国产一区二区入口| 非洲黑人性xxxx精品又粗又长|