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Some zwitterionic surfactants exhibit upper critical solution temperature (UCST) in aqueous solutions. For the zwitterionic surfactant solution mixed with cellulase, when its temperature is below UCST, the cellulase can be recovered by coprecipitation with zwitterionic surfactant. In this work, 3-(Hexadecyldimethylammonio) propanesulfonate (SB3-16) was selected to enhance the enzymatic hydrolysis of lignocelluloses and recover the cellulase. After adding 2 mmol/L of SB3-16, the enzymatic digestibility of eucalyptus pretreated by dilute acid (Eu-DA) and by sulfite (Eu-SPORL) increased from 27.9% and 35.1% to 72.6% and 89.7%, respectively. The results showed that SB3-16 could reduce the non-productive adsorption of cellulase on hydrophobic interface, while it did not significantly inhibit the activity of cellulase. For the solution contained 1 wt% SB3-16 and 200 mg protein/L CTec2 cellulase, 55.2% of protein could be recovered by cooling. The filter paper activity of the recovered cellulase was 1.93 FPU/mg protein, which was 95.8% of its initial activity. [ABSTRACT FROM AUTHOR]

[Display omitted] Cellulase was recycled by using pH-UCST-type LSB, and the process is sustainable while realizing the value-added utilization of industrial lignin. • LSB showed a pH-UCST-sensitive response and was recyclable. • Cellulase was efficiently recycled at higher pH by using LSB. • The value-added utilization of enzymatic hydrolysis lignin was realized. Recycling cellulase can reduce the cost of lignocellulosic enzymatic hydrolysis. Here, a lignin-grafted sulfobetaine (LSB) was first synthesized by grafting sulfobetaine (SB) on enzymatic hydrolysis lignin (EHL). LSB had a sensitive response of pH and temperature. LSB dissolved under the conditions of lignocellulosic enzymatic hydrolysis (pH 5.0, 50 °C). After hydrolysis, LSB co-precipitated with cellulase when lowering pH of the hydrolysate to 4.0 and cooling to 25 °C. When 3.0 g/L LSB-100 was added to the hydrolysis system of corncob residue (CCR), 70 % of amount of cellulase was saved. LSB had a remarkable response and stronger cellulase recovery capacity. This was attributed that carboxylate radical in LSB was protonated, and positive and negative ions of SB associated to form salt at 25 °C. This work provides a new idea for reducing the cost for preparing fermentable sugars from lignocellulose, and increasing the added value of EHL. [ABSTRACT FROM AUTHOR]

Five Lignin/Polyethylene Glycol (L-PEG) film-forming agents with different lignin contents were prepared using industrial Alkali Lignin (AL) and Polyethylene Glycol (PEG) as the main raw materials. FI-IR and 1H NMR analysis demonstrated the introduction of large amounts of polyethylene chains in lignin molecules. The prepared L-PEGs could be dispersed in water to form a stable nanoemulsion with a particle size of 131–232 nm and a zeta potential of − 27.22~− 38.64 mV. After L-PEGs drying into film, the obtained films can swell rapidly in water, with a swelling rate of 183.3–257.6%. The swollen wet film dissolved slowly in water with a dissolution rate of 42.3–57.1% in 14 days. The 5% flowable concentrate for seed coating (FS) of chlorantraniliprole was prepared by using L-PEG as a film-forming agent. The storage stability at elevated temperature experiment showed that the FS had good storage stability. The coating experiment showed that the FS had good coating performance, with film forming time less than 4 min, coating uniformity higher than 93.3%, and shedding rate lower than 7.67%. The pot experiment showed that the germination percentage of coated maize (Zea mays L.) seeds increased from 86.67% to over 93.33%, which could promote the growth of seedlings. [Display omitted] • Lignin/polyethylene glycol (L-PEG) film-forming agent were synthesized from alkali lignin and polyethylene glycol. • L-PEG film could rapidly swell in water with 183.3–257.6% swelling rate, but dissolve very slowly in water. • The germination percentage of maize seeds was increased from 86.67% to above 93.33% after the FS coating prepared from L-PEG. [ABSTRACT FROM AUTHOR]

Highlights: [•] A modified lignosulfonate GCL4-1 improves stability of DMM suspension significantly. [•] GCL4-1 fraction with Mw of 10,000–30,000 has strongest dispersive ability. [•] Dispersive ability of GCL4-1 is contributed to sulfonated degree and adsorbed amount. [•] GCL4-1 fraction with largest Mw has strongest adsorption, but may cause flocculation. [ABSTRACT FROM AUTHOR]

Abstract: As a plasticizer and retarder, calcium lignosulfonate (CL) frequently leads to quick set of Portland cement containing anhydrite. For exploring the cause of this problem, the hydration characteristics of the tricalcium aluminate–anhydrite system in the saturated calcium hydroxide solution with and without CL were researched from two aspects: the compositions of liquid phases and the formations of hydration products. Results show that the CL can promote the formation of ettringite, which induces a significant decrease in sulfate ion concentration at the initial time of hydration. The size of ettringite crystals becomes large in the presence of CL, which seems to be related to a decrease in calcium sulfate saturation ratio. It can be deduced that the quick set in the presence of CL is mainly caused by the accelerated reaction between the tricalcium aluminate and the anhydrite at the initial time of hydration. [Copyright &y& Elsevier]

Synopsis: The facile method to prepare novel all-lignin microcapsules (ALMC) was presented. [Display omitted] • Lignin particles (LPs) were used to prepare oil-in-water Pickering emulsions. • 1,6-dibromohexane or epichlorohydrin in the oil phase crosslinked the LPs to form dense capsule wall. • The ALMC showed good sustained release performance and excellent anti-photolysis performance. Lignin based microcapsules are highly attractive for protect easy photolysis substances. However, so far, all-lignin microcapsules prepared with water-soluble lignin are not satisfactory in terms of wall thickness and mechanical properties. Herein, we fabricated a novel all-lignin microcapsules (ALMC) by using 1,6-dibromohexane or epichlorohydrin to crosslink lignin particles adsorbed at the Pickering emulsion droplets interface. 1, 6-Dibromohexane demonstrated a stronger cross-linking activity than epichlorohydrin, and could be used in less dosage and at lower temperatures. The shell thickness of ALMC was about 300 nm. Further analysis confirmed that the shell had a double-layer structure, the outer layer was rough and shrinking and the inner layer was smooth and dense. ALMC can be used to encapsulate hydrophobic substances, and a photosensitive pesticide avermectin (AVM) was chosen to be sealed as model object. The AVM-encapsulated ALMC showed ideal sustained-release performance, namely releasing slowly in the early stage without affecting the overall release. After 70 h of UV irradiation, 93.7 % of AVM was retained, while the original AVM without encapsulation almost all of them was photodegraded, which means that the ultraviolet absorption property of lignin provides excellent protection for the core materials. [ABSTRACT FROM AUTHOR]

• Lignin-based surfactants LC and LCQ with various isoelectric points were synthesized. • The effect and mechanism of the pI of LCQ on the enzymatic hydrolysis were studied. • The SED of Eu-SPORL increased from 35.2% to 95.3% by adding LCQ-40. • LCQ could be efficiently recovered for the excellent pH-response performance. The isoelectric point (pI) of lignin-based surfactant is an important factor in the enhancement on the enzymatic hydrolysis of lignocellulose. In this work, lignin carboxylate (LC) and quaternary ammonium lignin carboxylates (LCQ-x, x%: the mass ratio of quaternizing agent to enzymatic hydrolysis lignin) with different isoelectric points were synthesized. LC or LCQ-x with pI significantly lower or higher than 4.8 reduced the non-productive adsorption of cellulase on lignin, but for the significant inhibitory effect on cellulase activity, their enhancements on the enzymatic hydrolysis of lignocellulose were not remarkable. However, LCQ-x with pI around 4.8 preserved the cellulase activity, and significantly reduced the non-productive adsorption of cellulase, therefore remarkably enhanced the enzymatic hydrolysis. 2 g/L LC, LCQ-40 (pI = 5.0) and LCQ-100 (pI = 9.2) increased the enzymatic digestibility of pretreated eucalyptus from 35.2% to 53.4%, 95.3% and 60.4% respectively. In addition, for the excellent pH-response performance, LCQ could be efficiently recovered after enzymatic saccharification. [ABSTRACT FROM AUTHOR]

In this work, sulfomethylated lignin (SAL) was firstly synthesized using alkali lignin (AL) as raw materials, and then grafted with pyrrolidone as adsorption groups to prepare sulfomethylated lignin grafted by pyrrolidone (SALN). Results showed that SALN had a lower sulfonic group content than SAL but additionally contained 0.79 mmol/g of pyrrolidone groups. SAL and SALN were separately used as dispersants to prepare 20 wt% of cobalt blue nano pigment paste, and the minimum particle size of 82 nm and 52 nm was achieved when the dispersant dosage was 10 wt% and the grinding time was 4 h. After 7 days of thermal storage at 60 °C, the particle size of nano pigment paste prepared by SALN nearly remained unchanged, but that prepared by SAL increased from 82 nm to 285 nm, and there was obvious precipitation. Therefore, the thermal storage stability of cobalt blue nano pigment paste prepared by SALN was much better than that of SAL. Adsorption isotherm and infrared spectra experimental results indicated a firm multi-point anchoring complexing adsorption was formed between the pyrrolidone group of SALN and Co–O on cobalt blue surface, which made SALN not easy to desorb during collisions caused by Brownian motions. SAL was adsorbed through –C(=O)O−, and thus easy to desorb. Therefore, the stability of the nano pigment paste prepared by SALN was superior to that of SAL. [ABSTRACT FROM AUTHOR]

Abstract: Different lignosulfonate (LS) samples were prepared via a three-step method and were characterized by FT-IR, UV, GPC and functional groups measurement. FT-IR and UV spectra confirmed the prepared samples had typical characteristics of lignin materials. GPC and functional groups measurement results indicated the samples had different molecular mass (M w), but same quantities of sulfonic groups (S). The influence of M w of LS on the resulting surface charges of dimethomorph particles via adsorption was further investigated. The results indicated that the adsorption isotherms of LS on dimethomorph surfaces belonged to L-type and the adsorption capacity (q m) increased with increasing M w. However, the non-linear correlation between zeta potentials with the products of S and adsorption amount (SA) indicated SA did not positively improve the surface charges expectedly. Based on the analysis, an adsorption confirmation was proposed allowing prediction of the relation between M w and surface charge efficiency of LS for solid particles. [Copyright &y& Elsevier]

[Display omitted] • This work successfully synthesizes high concentration PCEs at room temperature via a photoinitiated one-pot method. • The high concentration PCEs prepared by a photoinitiated one-pot method have reasonable structure and good dispersion performance. • The conversion rate and molecular weight of PCEs increase with the reaction concentration in a photoinitiated one-pot method. Polycarboxylate superplasticizers (PCEs) are primarily liquid products (40 wt%) with narrow application range, which incur high transportation and storage costs. However, the high reaction viscosity makes it challenging to produce high concentration PCEs. In our study, high concentration PCEs are successfully synthesized by a photoinitiated one-pot method at room temperature. The results show that the reaction viscosity of photoinitiation is slightly higher than that of traditional initiation systems, but the photoinitiated reaction remains stable and controllable, with no occurrence of violent polymerization. The impact of varying reaction concentrations on the polymerization rate, molecular structure, and properties of PCEs has been studied under the photoinitiated one-pot method. The results indicate that an increase in reaction concentration leads to a rise in polymerization rate, molecular weight, and molecular gyration radius of the polymers. The conversion rate of the macromonomer exceeds 80%, while the polydispersion index (PDI) for molecular weight is below 2 with a narrow distribution. Furthermore, the monomer polymerization ratio of the product remains close to the feeding ratio at different reaction concentrations. Finally, it is observed that PCEs with a high concentration of 80 wt% exhibit favorable dispersion, rheology and adsorption properties. This study presents a new method for synthesizing high concentration PCEs using photoinitiation. [ABSTRACT FROM AUTHOR]

Open shell-core structure is crucial for light absorption, photogenerated carrier dynamics and mass transfer in photocatalytic processes. However, the preparation of open shell-core structures is rarely reported. Hence, ZnIn 2 S 4 hemisphere-wrapped TiO 2 nanoparticles (Ti-ZIS) shell-core heterojunctions were successfully prepared through a N, N-Dimethylformamide (DMF)-assisted solvothermal process for outstanding photocatalytic performances. Among them, CO gas generated by DMF decomposition helps ZIS to form hollow structure, while TiO 2 nanoparticles are generated based on the interference of dimethylamine generated by DMF decomposition with its crystal growth. The research show that the shell-core structure increases the specific surface area (124.9 m2/g), shorten the migration distance of electron and hole pairs, and promotes light absorption. Additionally, the transfer process of photogenerated carriers have been changed and accelerated via the built-in electric field, thereby enhancing the photocatalytic reaction. The experimental results show that the Ti-ZIS shell-core heterojunction exhibits excellent photocatalytic hydrogen evolution (28.0 mmol/h/g with Pt as cocatalyst and 7.4 mmol/h/g without cocatalyst) than those of other state-of-the-art ZIS-based noble metal or without cocatalysts reported recently, and lignin degradation (76.7% within 120 min). The removal rates of chemical oxygen demand (COD) and total organic carbon (TOC) are 72.1% and 49.4%, respectively. [ABSTRACT FROM AUTHOR]

Effects of nonionic surfactants on enzymatic hydrolysis of Avicel at different agitation rates and solid loadings and the mechanism were studied. Nonionic surfactants couldn’t improve the enzymatic hydrolysis efficiency at 0 and 100 rpm but could enhance the enzymatic hydrolysis significantly at high agitation rate (200 and 250 rpm). Cellulase was easily deactivated at high agitation rate and the addition of nonionic surfactants can protect against the shear-induced deactivation, especially when the cellulase concentration was low. When 25 mg protein/L of cellulase solution was incubated at 200 rpm for 72 h, the enzyme activity increased from 36.0% to 89.5% by adding PEG4600. Moreover nonionic surfactants can compete with enzyme in air-liquid interface and reduce the amount of enzyme exposed in the air-liquid interface. The mechanism was proposed that nonionic surfactants could enhance the enzymatic hydrolysis of Avicel by reducing the cellulase deactivation caused by shear force and air-liquid interface. [ABSTRACT FROM AUTHOR]

Polyvinylpyrrolidone (PVP) is an antifouling polymer to resist the adsorption of protein on solid surface. Effects of PVP on the enzymatic hydrolysis of pretreated lignocelluloses and its mechanism were studied. Adding 1 g/L of PVP8000, the enzymatic digestibility of eucalyptus pretreated by dilute acid (Eu-DA) was increased from 28.9% to 73.4%, which is stronger than the classic additives, such as PEG, Tween and bovine serum albumin. Compared with PEG4600, the adsorption of PVP8000 on lignin was larger, and the adsorption layer was more stable and hydrophilic. Therefore, PVP8000 reduced 73.1% of the cellulase non-productive adsorption on lignin and enhanced the enzymatic hydrolysis of lignocelluloses greatly. [ABSTRACT FROM AUTHOR]

Lignin is a future feedstock for the production of low molecular weight aromatics, and hydrogenolysis is probably the most promising process for lignin depolymerization. Effect of the benzylic alcohol group, aromatic methoxyl and phenolic hydroxyl groups on the hydrogenolysis of β -O-4 bonds in lignin model compounds was investigated in Pd/C hydrogenolysis system. It was found that the β -O-4 bonds in compounds with no a benzylic alcohol group were cleaved directly and quickly to form two aromatic monomers in near-quantitative yield. However, both dehydrogenation and dehydroxylation occurred for the model compounds containing a benzylic alcohol group, and resulted in more complicated products distribution. The dehydrogenation of a benzylic alcohol group hindered the cleavage of β -O-4 bonds to form aromatic monomer products. The results also indicated that both the aromatic methoxyl and phenolic hydroxyl groups had no impact on products distribution. The aromatic methoxyl group in non-phenolic and phenolic compounds promoted the cleavage of β -O-4 bonds, while the phenolic hydroxyl group had a slightly negative impact on cleavage of β -O-4 bonds. [ABSTRACT FROM AUTHOR]

A new two-step lignin depolymerization strategy was developed, in which the benzylic alcohols in lignin was methylated under microwave irradiation, followed by a hydrogenolysis for the cleavage of β O 4 bond with Pd/C as the catalyst. The results showed that an efficient and selective catalytic methylation of benzylic alcohols was achieved with various lignin model compounds, and the acidic environment promoted the methylation of benzylic alcohol. Methylation of benzylic alcohol increased the β O 4 bond cleavage rate by 55.9%, and improved products selectivity. Preliminary study of lignin depolymerization illustrated that methylation pretreatment of benzylic alcohols facilitated lignin depolymerization to produce aromatic monomers and reduced the oxygen content of aromatic monomers. [ABSTRACT FROM AUTHOR]

Two pretreatment methods to overcome recalcitrance of lignocelluloses, sulfite pretreatment (SPORL) and dilute acid (DA), were conducted to pretreat softwood masson pine and hardwood eucalyptus for enzymatic hydrolysis. In the presence of corresponding pre-hydrolysates, adding moderate cetyltrimethylammonium bromide (CTAB) could enhance the enzymatic hydrolysis of the SPORL-pretreated substrates, but had no enhancement for the DA-pretreated substrates. The results showed that sodium lignosulfonate (SL) in pre-hydrolysates and CTAB together had a strong enhancement on the enzymatic hydrolysis of lignocelluloses. The compound of commercial lignosulfonate SXSL and CTAB (SXSL-CTAB) could enhance the substrate enzymatic digestibility (SED) of SPORL-pretreated masson pine from 27.1% to 71.0%, and that of DA-pretreated eucalyptus from 37.6% to 67.9%. The mechanism that CTAB increased the adsorption of SL on lignin to form more effective steric hindrance and reduced the non-productive adsorption of cellulase on lignin by neutralizing the negative charge of SL was proposed. [ABSTRACT FROM AUTHOR]

Effect of the molecular structure of lignosulfonate-based polyoxyethylene ether (LS-PEG) on the enzymatic hydrolysis of Avicel and corn stover was investigated. With the increase of PEG contents and M w of LS-PEG, glucose yield of corn stover increased from 16.7% to 51.9%. When LS-PEG was compounded with cationic surfactant cetyltrimethylammonium bromide (CTAB), the enhancement of glucose yield of corn stover was further increased from 45.3% to 62.8%. Sulfonic group of LS-PEG preferentially interacted with quaternary ammonium group of CTAB by the electrostatic attraction to form a similar non-ionic surfactant CTAB-LS-PEG. CTAB-LS-PEG showed electrically neutral and more hydrophobic, and blocked more nonproductive adsorption of cellulase on the lignin. Therefore, CTAB-LS-PEG enhanced enzymatic hydrolysis efficiency of lignocelluloses more significantly. The understanding developed in this study can help to develop potential approaches and strategies for effective application of lignosulfonate to improve bioconversion of lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

Sodium lignosulfonate (SXSL) and long-chain fatty alcohols (LFAs) could enhance the enzymatic hydrolysis of xylan, and the compound of SXSL and LFAs have synergies on the enzymatic hydrolysis. SXSL shows a strong enhancement in buffer pH range from 4.0 to 6.0. The enhancement increased with the SXSL dosage and the xylanase loading. The cellulose and lignin in corncob substrate could not only adsorb xylanase nonproductively, but also seriously reduce the accessibility of xylanase on xylan to impede the enzymatic hydrolysis of xylan. Cellulase could break the plant cell wall structure of corncob and make additives work better. The xylose yield of corncob at 72 h increased from 59.4% to 73.7% by adding the compound of 5 g/L SXSL and 0.01% (v/v) n -decanol, which was higher than that without cellulase and additives by 30.7%. Meanwhile, the glucose yield at 72 h of corncob increased from 45.8% to 62.3%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Indium sulfide with indium defects and hydrophobic surface is prepared. • Defect is important for the induction of CTAB. • The hydrophobic indium sulfide enhances the adsorption of lignin and oxygen. • In x S 3 -C exhibits good activity under low visible light (80 mW⋅cm−2, 5 W LED). • The degradation pathway of lignosulfonate was proposed by HPLC-MS. Lignin is difficult to be degraded due to its complex structure and hydrophobicity. Herein, we report an effective strategy to degrade lignin by defective indium sulfide with the hydrophobic surface (In x S 3 -C). In x S 3 -C is synthesized by a one-pot hydrothermal method with the assistance of CTAB. The optimal photocatalyst (In 0.75 S 3 -C) exhibits great adsorption capacity and degradation efficiency for lignosulfonate. The degradation rate of lignosulfonate achieves 90% after irradiating by visible light for 30 min, representing nearly 80 times higher activity than the commercial photocatalyst (P25). The great photocatalytic performance of In 0.75 S 3 -C is ascribed to the enhanced adsorption of lignosulfonate and oxygen, which facilitates intimate contact and mass transfer. Furthermore, TG-DSC, FTIR, UV–vis DRS and TRPL demonstrate that the defects are important for the introduction of CTA+, as well as enhance visible light absorption and the separation of photogenerated carriers. Combined with HPLC-MS analysis, a possible degradation pathway of lignosulfonate is proposed. [ABSTRACT FROM AUTHOR]

Abstract: This article studied the effect of molecular weight of sulphonated acetone-formaldehyde condensate (SAF) on the adsorption and dispersion properties in cementitious system. SAF was separated into four different molecular weight fractions using ultrafiltration membranes. The adsorption behaviors were investigated by measuring the adsorption amount, zeta potential, and thickness of the adsorbed films obtained from various SAF fractions. Results show that the SAF fraction with a higher molecular weight has larger adsorption amount, higher absolute value of zeta potential, and thicker adsorbed film, which induces better dispersibility of the corresponding cement paste. An adsorption model of SAF on cement surface is presented. The SAF fraction with a higher molecular weight is more likely to twist and be adsorbed on cement particles through “loop and tail” adsorption. On the contrary, SAF fraction with a lower molecular weight tends to be adsorbed on cement particles through “flat train” adsorption. [Copyright &y& Elsevier]

Abstract: The effect of the molecular weight of sulfanilic acid-phenol-formaldehyde condensate (SPF) on the properties of cementitious system was investigated. It is found that SPF with the molecular weight of 35,000 Dalton (Da) gives a good adsorption capacity on the surface of the cement particles, hence a larger zeta potential to cement particles and a good fluidity to the cement paste. In addition, this fraction has a high chelating capacity to calcium in the cement slurry, causing a long retardation of the cementitious system. However, the fractions of a high molecular weight (42,000 Da, and 45,000 Da) exhibit lower bleed water as a percentage of total mix water (BWP). It can be deduced that there is an ideal molecular weight for the best performances of the superplasticizer investigated, which can be used for optimizing the technical parameters in the preparation. [Copyright &y& Elsevier]

Abstract: A new type of water-soluble polymer, sulphonated acetone–formaldehyde resin (SAF), was developed as dispersant for the preparation of highly-loaded coal water slurry (CWS). In this study, in order to evaluate the practical use in industry, the SAF and a naphthalene sulfonate formaldehyde condensate are used to prepare CWS using four Chinese coals with different coalification degrees. The evaluation of the properties of CWS shows that SAF has better ability in reducing CWS viscosity at lower dosage than naphthalene sulfonate formaldehyde condensate, and that the CWS prepared from SAF has excellent stability within 48h and exhibits shear-thinning apparent viscosity/shear rate behavior at lower dosage. Based on the results, the SAF is an effective and promising dispersant for highly-loaded CWS. [Copyright &y& Elsevier]

• Lignin-based hollow carbon (LHC) with opening structure was first prepared. • Hollow carbon was obtained with a facile EISA and carbonization process. • ZnO was immobilized on the exterior and interior surface of LHC by in-situ growth. • LHC endowed ZnO with improved optical absorption and separation of charge carriers. • ZnO/LHC presented excellent photocatalytic activity and recyclability. Enzymatic hydrolysis lignin (EHL), an industrial waste, is mainly used as a low-grade combustible energy source. Design and preparation of high value-added materials with EHL is still a challenge. Demonstrated here in was the first application of EHL as the precursor for preparing a lignin-based hollow carbon (LHC) with opening structure based on a facial self-assembly and carbonization process. ZnO nanoparticles can be uniformly immobilized on the exterior and interior surface of LHC due to rich oxygen-containing functional groups and opening structure, and composite (ZnO/LHC) was obtained. The ZnO/LHC presented high photocatalytic degradation rate of ciprofloxacin and photocatalytic H 2 evolution rate, which were about 2.0 times and 1.8 times that of pure ZnO, respectively. The enhancement can be attributed to the electronic interaction between ZnO and LHC, endowing ZnO extended photoabsorption region and enhanced separation of hole-electron pairs. Moreover, the hollow and opening structure offered photocatalyst fast substance transfer, abundant active sites and high light-harvesting. Besides, the recyclability of ZnO was also improved after the introduction of LHC. Our study not only opens up new avenues for the high value-added application of EHL, but also offers a simple strategy to promote the practical use of ZnO photocatalyst. [ABSTRACT FROM AUTHOR]

• Highly recyclable SC was used in lignocellulosic enzymatic hydrolysis. • Using SC to enhance cellulase recovery through ingenious pH regulation. • SC increased the sugar yield of Eu-DA by 95.5% and save at least 40% cellulase. Most additives that capable of enhancing enzymatic hydrolysis of lignocellulose are petroleum-based, which are not easy to recycle with poor biodegradability. In this work, highly recyclable and biodegradable sodium caseinate (SC) was used to enhance lignocellulosic hydrolysis with improved cellulase recyclability. When the pH decreased from 5.5 to 4.8, more than 96% SC could be precipitated from the solution and recovered. Adding SC increased enzymatic digestibility of dilute acid pretreated eucalyptus (Eu-DA) from 39.5% to 78.2% under Eu-DA loading of 10 wt% and pH = 5.5, and increase cellulase content in 72 h hydrolysate from only 15.2% of the original to 60.0%, which facilitated the recovery of cellulases through re-adsorption by fresh substrates. With multiple cycles of re-adsorption, application of SC not only increased the sugar yield of Eu-DA by 95.5%, but also reduced cellulase loading by 40%. [ABSTRACT FROM AUTHOR]