• <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.

    香蕉精品网在线| 国产精品人妻久久久影院| 亚洲精品色激情综合| 国产av一区二区精品久久| 又大又黄又爽视频免费| 精品一区二区三卡| 久久精品夜色国产| 亚洲一码二码三码区别大吗| 久久久精品免费免费高清| a级毛片黄视频| 欧美亚洲 丝袜 人妻 在线| 国产毛片在线视频| 日日啪夜夜爽| 在现免费观看毛片| 国产免费视频播放在线视频| 一二三四在线观看免费中文在 | 成人亚洲精品一区在线观看| 久久久精品免费免费高清| 亚洲人成网站在线观看播放| 在线精品无人区一区二区三| 亚洲国产精品一区二区三区在线| 亚洲av电影在线进入| 交换朋友夫妻互换小说| 日韩熟女老妇一区二区性免费视频| 香蕉丝袜av| 久久人妻熟女aⅴ| 久久人妻熟女aⅴ| 亚洲激情五月婷婷啪啪| 久久久久久久久久久免费av| 精品熟女少妇av免费看| 久久久精品免费免费高清| kizo精华| 九九在线视频观看精品| 久久精品人人爽人人爽视色| 亚洲精品一二三| 九九爱精品视频在线观看| 久久国内精品自在自线图片| 高清黄色对白视频在线免费看| av视频免费观看在线观看| 精品一区二区三区视频在线| 亚洲精品久久午夜乱码| 宅男免费午夜| 亚洲美女搞黄在线观看| 日韩免费高清中文字幕av| 国产成人a∨麻豆精品| 日韩成人av中文字幕在线观看| 大片免费播放器 马上看| 婷婷色综合www| 超碰97精品在线观看| 高清欧美精品videossex| 亚洲欧美中文字幕日韩二区| 中文字幕av电影在线播放| 中文乱码字字幕精品一区二区三区| 成年人午夜在线观看视频| 水蜜桃什么品种好| 国产无遮挡羞羞视频在线观看| 亚洲av在线观看美女高潮| 精品一品国产午夜福利视频| 九九在线视频观看精品| 黄片无遮挡物在线观看| 精品久久国产蜜桃| 国产av国产精品国产| 久久国内精品自在自线图片| 欧美另类一区| 国产精品久久久久成人av| av国产精品久久久久影院| 亚洲精品国产av成人精品| 日韩免费高清中文字幕av| 在线免费观看不下载黄p国产| 久久久久久久大尺度免费视频| 9热在线视频观看99| 韩国高清视频一区二区三区| 少妇的逼水好多| 久久女婷五月综合色啪小说| 午夜日本视频在线| 又粗又硬又长又爽又黄的视频| 久久97久久精品| 欧美性感艳星| 久久这里只有精品19| 精品人妻偷拍中文字幕| 亚洲中文av在线| 亚洲国产精品国产精品| 国产精品蜜桃在线观看| 欧美精品亚洲一区二区| 七月丁香在线播放| 性高湖久久久久久久久免费观看| 2022亚洲国产成人精品| 成人毛片60女人毛片免费| 亚洲第一区二区三区不卡| 国产 一区精品| 中文精品一卡2卡3卡4更新| 一个人免费看片子| 秋霞伦理黄片| 国产黄色免费在线视频| xxx大片免费视频| 在线 av 中文字幕| 91在线精品国自产拍蜜月| 久久久久网色| 国产亚洲精品第一综合不卡 | 成人黄色视频免费在线看| 亚洲国产欧美在线一区| 一本久久精品| 自线自在国产av| 人人妻人人爽人人添夜夜欢视频| 1024视频免费在线观看| 桃花免费在线播放| 久久国产亚洲av麻豆专区| 亚洲国产色片| 日本91视频免费播放| 不卡视频在线观看欧美| 男人操女人黄网站| 人人澡人人妻人| 亚洲高清免费不卡视频| 建设人人有责人人尽责人人享有的| 精品99又大又爽又粗少妇毛片| 成年动漫av网址| 免费av不卡在线播放| 一区二区三区精品91| 国产精品国产三级国产av玫瑰| 在线观看美女被高潮喷水网站| 亚洲四区av| 高清毛片免费看| 亚洲精华国产精华液的使用体验| 18在线观看网站| 一级毛片 在线播放| 久久精品久久精品一区二区三区| 婷婷色av中文字幕| 久久精品熟女亚洲av麻豆精品| 色94色欧美一区二区| 两性夫妻黄色片 | 天堂8中文在线网| 亚洲国产精品成人久久小说| 亚洲少妇的诱惑av| 精品少妇黑人巨大在线播放| 丝袜人妻中文字幕| 日本av免费视频播放| 少妇的逼好多水| 精品少妇内射三级| av电影中文网址| 久久热在线av| 国产一区二区在线观看av| 日本-黄色视频高清免费观看| 黄色配什么色好看| 日韩,欧美,国产一区二区三区| 欧美97在线视频| 欧美精品高潮呻吟av久久| 97精品久久久久久久久久精品| 欧美人与性动交α欧美软件 | 自线自在国产av| 日韩 亚洲 欧美在线| 在现免费观看毛片| 又黄又粗又硬又大视频| 成人无遮挡网站| 国产精品嫩草影院av在线观看| 99热全是精品| 国产不卡av网站在线观看| 狠狠婷婷综合久久久久久88av| 观看av在线不卡| 精品一区在线观看国产| 午夜老司机福利剧场| 欧美成人午夜免费资源| 五月开心婷婷网| 亚洲精品aⅴ在线观看| 亚洲欧洲国产日韩| 人人澡人人妻人| 九色亚洲精品在线播放| 黑人巨大精品欧美一区二区蜜桃 | 香蕉丝袜av| 国产国语露脸激情在线看| 9色porny在线观看| 丝袜美足系列| 亚洲精品456在线播放app| 午夜视频国产福利| 久久精品久久久久久久性| 久久99一区二区三区| 狠狠婷婷综合久久久久久88av| 不卡视频在线观看欧美| 伦理电影大哥的女人| 99re6热这里在线精品视频| 女性生殖器流出的白浆| 在线观看免费日韩欧美大片| 如日韩欧美国产精品一区二区三区| 五月伊人婷婷丁香| 欧美人与性动交α欧美精品济南到 | 欧美bdsm另类| 日韩av在线免费看完整版不卡| 亚洲成国产人片在线观看| 王馨瑶露胸无遮挡在线观看| 香蕉精品网在线| 久久这里有精品视频免费| 你懂的网址亚洲精品在线观看| 久久久久精品久久久久真实原创| 最近中文字幕高清免费大全6| 韩国av在线不卡| 久久国产精品男人的天堂亚洲 | 久久国产亚洲av麻豆专区| 日韩 亚洲 欧美在线| 一区二区日韩欧美中文字幕 | 大香蕉久久网| 国产国语露脸激情在线看| 狂野欧美激情性xxxx在线观看| 国精品久久久久久国模美| 啦啦啦啦在线视频资源| 精品人妻在线不人妻| 美女脱内裤让男人舔精品视频| av福利片在线| av在线播放精品| 丝袜在线中文字幕| 色网站视频免费| 国产欧美日韩综合在线一区二区| 精品少妇久久久久久888优播| 国产精品99久久99久久久不卡 | av片东京热男人的天堂| 在线观看免费高清a一片| 亚洲美女搞黄在线观看| 亚洲人成77777在线视频| av.在线天堂| 亚洲国产精品专区欧美| 亚洲欧美清纯卡通| 亚洲欧美色中文字幕在线| 精品国产一区二区三区久久久樱花| 日韩制服骚丝袜av| 午夜91福利影院| av线在线观看网站| 国产精品一区二区在线观看99| 久久久久精品久久久久真实原创| 18禁在线无遮挡免费观看视频| 久久精品国产a三级三级三级| 久久女婷五月综合色啪小说| 五月玫瑰六月丁香| 免费黄色在线免费观看| 深夜精品福利| 亚洲av成人精品一二三区| 毛片一级片免费看久久久久| av在线app专区| 久久精品国产亚洲av涩爱| 一区在线观看完整版| 91在线精品国自产拍蜜月| 九九爱精品视频在线观看| 久久女婷五月综合色啪小说| 久久久久视频综合| 夜夜骑夜夜射夜夜干| 日日啪夜夜爽| 男的添女的下面高潮视频| 中文字幕人妻熟女乱码| 在线观看免费高清a一片| 自线自在国产av| 国产探花极品一区二区| 日本午夜av视频| 久久韩国三级中文字幕| 91成人精品电影| 满18在线观看网站| 国产国拍精品亚洲av在线观看| 女性被躁到高潮视频| 成人综合一区亚洲| 国产女主播在线喷水免费视频网站| 国产极品粉嫩免费观看在线| 国产视频首页在线观看| 999精品在线视频| 欧美激情极品国产一区二区三区 | 亚洲成人手机| 欧美日韩亚洲高清精品| 狠狠婷婷综合久久久久久88av| 久久久久视频综合| 99热全是精品| 18禁国产床啪视频网站| 2022亚洲国产成人精品| 欧美性感艳星| 欧美成人午夜免费资源| 大话2 男鬼变身卡| 免费久久久久久久精品成人欧美视频 | 香蕉国产在线看| 两个人看的免费小视频| 久久精品国产a三级三级三级| 欧美精品一区二区免费开放| 少妇 在线观看| 永久网站在线| 午夜老司机福利剧场| 亚洲国产日韩一区二区| 美女xxoo啪啪120秒动态图| tube8黄色片| 人人妻人人澡人人看| 久久精品久久久久久久性| 欧美精品人与动牲交sv欧美| 国语对白做爰xxxⅹ性视频网站| 免费少妇av软件| 亚洲一码二码三码区别大吗| 国产亚洲最大av| 999精品在线视频| 看十八女毛片水多多多| 精品久久国产蜜桃| 久久久久久人妻| 亚洲国产看品久久| 色吧在线观看| a级毛色黄片| 欧美激情极品国产一区二区三区 | 国产精品国产三级国产专区5o| 热99久久久久精品小说推荐| 欧美人与性动交α欧美精品济南到 | 欧美xxxx性猛交bbbb| 一级爰片在线观看| freevideosex欧美| 美女福利国产在线| 欧美97在线视频| 欧美亚洲 丝袜 人妻 在线| 97在线视频观看| 天堂俺去俺来也www色官网| 国产一区二区激情短视频 | 亚洲,一卡二卡三卡| 丰满饥渴人妻一区二区三| 高清视频免费观看一区二区| 成人国产麻豆网| 黑人猛操日本美女一级片| 男男h啪啪无遮挡| 国产亚洲精品第一综合不卡 | 亚洲国产av新网站| 美女视频免费永久观看网站| 日本-黄色视频高清免费观看| 欧美国产精品一级二级三级| 18禁动态无遮挡网站| 国产成人精品在线电影| 免费久久久久久久精品成人欧美视频 | 久久午夜综合久久蜜桃| 高清毛片免费看| 中文天堂在线官网| 国产综合精华液| 久久久久久久大尺度免费视频| 色网站视频免费| 多毛熟女@视频| 丝瓜视频免费看黄片| 你懂的网址亚洲精品在线观看| 一本—道久久a久久精品蜜桃钙片| 老司机亚洲免费影院| 日韩欧美一区视频在线观看| 久久99精品国语久久久| 国产av国产精品国产| 国产一区有黄有色的免费视频| 成人毛片60女人毛片免费| 精品少妇久久久久久888优播| av在线app专区| a级毛片在线看网站| 丰满迷人的少妇在线观看| 极品少妇高潮喷水抽搐| 日韩人妻精品一区2区三区| 国产精品女同一区二区软件| 女人被躁到高潮嗷嗷叫费观| 狠狠婷婷综合久久久久久88av| 伦理电影免费视频| 日日啪夜夜爽| 在线精品无人区一区二区三| 看非洲黑人一级黄片| 2021少妇久久久久久久久久久| 欧美丝袜亚洲另类| 国产av精品麻豆| 少妇的丰满在线观看| 一区二区三区四区激情视频| 亚洲av在线观看美女高潮| 亚洲天堂av无毛| 国产精品久久久久成人av| 亚洲,欧美,日韩| 精品久久蜜臀av无| 18禁观看日本| 91午夜精品亚洲一区二区三区| 日日摸夜夜添夜夜爱| 久热这里只有精品99| 搡女人真爽免费视频火全软件| 最近的中文字幕免费完整| 免费看光身美女| 黑人高潮一二区| 黄色 视频免费看| 欧美xxⅹ黑人| 啦啦啦中文免费视频观看日本| 精品国产一区二区三区四区第35| 精品国产乱码久久久久久小说| 性色av一级| 亚洲欧美精品自产自拍| 国产在视频线精品| 永久网站在线| 国产精品99久久99久久久不卡 | 精品人妻在线不人妻| 日本午夜av视频| 国产精品久久久久久精品电影小说| 国产毛片在线视频| 秋霞伦理黄片| 男人操女人黄网站| 久久精品夜色国产| 午夜日本视频在线| 亚洲av免费高清在线观看| 亚洲久久久国产精品| 日韩三级伦理在线观看| 晚上一个人看的免费电影| 成人毛片a级毛片在线播放| 国精品久久久久久国模美| 精品人妻在线不人妻| 国产一区二区在线观看av| 韩国av在线不卡| 人人妻人人澡人人爽人人夜夜| 欧美精品av麻豆av| 精品亚洲成a人片在线观看| 成人毛片60女人毛片免费| 免费大片18禁| 成人综合一区亚洲| 日韩不卡一区二区三区视频在线| 久久人人爽人人片av| 免费女性裸体啪啪无遮挡网站| 男女国产视频网站| 精品亚洲乱码少妇综合久久| 人成视频在线观看免费观看| 国产视频首页在线观看| 国产色婷婷99| 精品国产乱码久久久久久小说| 97精品久久久久久久久久精品| 在线天堂最新版资源| 黄片播放在线免费| 涩涩av久久男人的天堂| 国产一区二区三区综合在线观看 | 妹子高潮喷水视频| 精品国产一区二区三区久久久樱花| 丰满迷人的少妇在线观看| 精品国产一区二区三区四区第35| 如日韩欧美国产精品一区二区三区| 日日爽夜夜爽网站| 80岁老熟妇乱子伦牲交| 日本猛色少妇xxxxx猛交久久| 好男人视频免费观看在线| 亚洲伊人色综图| 国产一区二区三区av在线| 欧美 日韩 精品 国产| 国产麻豆69| 91成人精品电影| 久久人人爽人人爽人人片va| 亚洲,欧美精品.| 91在线精品国自产拍蜜月| 国产精品一区二区在线观看99| 婷婷色综合www| 亚洲av欧美aⅴ国产| 麻豆乱淫一区二区| av福利片在线| 亚洲国产毛片av蜜桃av| www.熟女人妻精品国产 | 欧美性感艳星| 成人亚洲精品一区在线观看| 我要看黄色一级片免费的| av网站免费在线观看视频| 麻豆精品久久久久久蜜桃| 如日韩欧美国产精品一区二区三区| 熟妇人妻不卡中文字幕| 中文精品一卡2卡3卡4更新| 久久毛片免费看一区二区三区| 视频中文字幕在线观看| 国产av精品麻豆| 国产精品久久久久久精品电影小说| 咕卡用的链子| av.在线天堂| 国产精品99久久99久久久不卡 | 人人妻人人澡人人爽人人夜夜| 免费观看性生交大片5| 色94色欧美一区二区| 久久国内精品自在自线图片| 2022亚洲国产成人精品| 久久人人97超碰香蕉20202| 亚洲av.av天堂| 精品一区二区三卡| 人人澡人人妻人| 久久女婷五月综合色啪小说| 亚洲国产色片| 男人操女人黄网站| 久久久a久久爽久久v久久| 午夜激情久久久久久久| 中国美白少妇内射xxxbb| xxxhd国产人妻xxx| 狠狠婷婷综合久久久久久88av| 亚洲人与动物交配视频| 久久精品国产自在天天线| 国产日韩欧美亚洲二区| 一级片'在线观看视频| 亚洲,欧美精品.| 久久青草综合色| 色网站视频免费| 中文乱码字字幕精品一区二区三区| 久久免费观看电影| 午夜精品国产一区二区电影| 亚洲av福利一区| 国产又色又爽无遮挡免| 中文字幕av电影在线播放| 精品熟女少妇av免费看| 黄网站色视频无遮挡免费观看| 国产熟女午夜一区二区三区| 欧美精品高潮呻吟av久久| 成人影院久久| 国产白丝娇喘喷水9色精品| 久久国内精品自在自线图片| freevideosex欧美| 亚洲伊人色综图| 男女边吃奶边做爰视频| 久久久久精品人妻al黑| av不卡在线播放| 大香蕉久久成人网| 纯流量卡能插随身wifi吗| 18禁裸乳无遮挡动漫免费视频| 久久久欧美国产精品| 一二三四中文在线观看免费高清| 永久免费av网站大全| 激情视频va一区二区三区| 国产成人91sexporn| 国产av一区二区精品久久| 日日摸夜夜添夜夜爱| 久久99一区二区三区| 成人二区视频| 日韩制服骚丝袜av| 久久毛片免费看一区二区三区| 国产免费视频播放在线视频| av网站免费在线观看视频| 国产精品蜜桃在线观看| 黑人高潮一二区| 一本一本久久a久久精品综合妖精 国产伦在线观看视频一区 | 韩国av在线不卡| 久久久久久久久久久免费av| 青青草视频在线视频观看| 欧美激情 高清一区二区三区| 精品久久国产蜜桃| 另类亚洲欧美激情| 黑人猛操日本美女一级片| 赤兔流量卡办理| 黑人欧美特级aaaaaa片| 亚洲,欧美精品.| 色视频在线一区二区三区| 十八禁网站网址无遮挡| 看免费av毛片| 国产在线视频一区二区| 亚洲 欧美一区二区三区| 欧美日本中文国产一区发布| 最近中文字幕高清免费大全6| 国产欧美亚洲国产| 毛片一级片免费看久久久久| 国产高清不卡午夜福利| 夜夜骑夜夜射夜夜干| 在线看a的网站| 亚洲国产精品成人久久小说| 精品人妻偷拍中文字幕| 秋霞在线观看毛片| 亚洲精品久久久久久婷婷小说| 51国产日韩欧美| 最新的欧美精品一区二区| 欧美成人午夜精品| 亚洲色图 男人天堂 中文字幕 | 国产在线一区二区三区精| 精品国产一区二区久久| 新久久久久国产一级毛片| 91久久精品国产一区二区三区| 亚洲经典国产精华液单| 一边摸一边做爽爽视频免费| 成人国语在线视频| 人妻 亚洲 视频| 成人18禁高潮啪啪吃奶动态图| 捣出白浆h1v1| 国语对白做爰xxxⅹ性视频网站| 制服丝袜香蕉在线| 人妻少妇偷人精品九色| 一区在线观看完整版| 精品视频人人做人人爽| av卡一久久| 一级,二级,三级黄色视频| 亚洲国产精品国产精品| 久久人人爽av亚洲精品天堂| 亚洲av日韩在线播放| 狂野欧美激情性bbbbbb| 中文欧美无线码| 国产深夜福利视频在线观看| 亚洲精品乱久久久久久| 日韩欧美一区视频在线观看| 中文字幕最新亚洲高清| 夫妻性生交免费视频一级片| 韩国高清视频一区二区三区| 亚洲av福利一区| 少妇高潮的动态图| 97人妻天天添夜夜摸| 少妇人妻 视频| 在线观看免费视频网站a站| 黄色毛片三级朝国网站| 亚洲av国产av综合av卡| 久久精品国产a三级三级三级| 成人漫画全彩无遮挡| videosex国产| 九色亚洲精品在线播放| 桃花免费在线播放| 国产伦理片在线播放av一区| 中文字幕精品免费在线观看视频 | av在线app专区| 欧美性感艳星| 永久网站在线| 18禁动态无遮挡网站| 亚洲欧洲日产国产| 亚洲av电影在线进入| 亚洲欧美中文字幕日韩二区| 搡女人真爽免费视频火全软件| 尾随美女入室| 欧美国产精品va在线观看不卡| 国产国语露脸激情在线看| 宅男免费午夜| 成年人午夜在线观看视频| 菩萨蛮人人尽说江南好唐韦庄| 欧美+日韩+精品| 97人妻天天添夜夜摸| 99久久中文字幕三级久久日本| 捣出白浆h1v1| 免费黄色在线免费观看| 国产一区亚洲一区在线观看| 九草在线视频观看| 人妻系列 视频| 大片电影免费在线观看免费| 久久国产精品大桥未久av| 欧美亚洲日本最大视频资源| 久久久精品94久久精品| 免费观看在线日韩|