Advanced Treatment of Papermaking Wastewater by Heterogeneous Fenton Process with Iron Sludge-based Catalyst

LUO Qing,XUE Wei,ZHANG Anlong,ZONG Xiaoning,JING Tianhao,SONG Gang

2022,41(5):1-7.DOI:10.11980/j.issn.0254-508X.2022.05.001

Iron sludge-based catalysts were prepared via high temperature pyrolysis， with sludge from papermaking wastewater treated by Fenton oxidation as raw material， and compounded with fly ash， coal sludge and sodium carboxymethyl cellulose. The effects of iron sludge-based catalyst on the treatment of wastewater during heterogeneous Fenton advanced treatment were studied with effluent of secondary sedimentation tank of waste papermaking as the target pollutant， and CODCr removal rate and color removal rate as the evaluation indexes. The results showed that the specific surface area of iron sludge-based catalyst was 230 m2/g. When the initial pH value of the reaction system was 2.5， the dosage of catalyst was 15 g/L， m（CODCr）∶m（H2O2） was 1∶1.5， and the reaction time was 100 min， the removal rate of CODCr was 66.7%， the removal rate of color was higher than 80%， and the sludge yield was 91%~94% lower than that of homogeneous Fenton.

[Abstract] [PDF]

Preparation and Properties Characterization of Thin-layer Deinking Paper Sludge-based Activated Carbon with a High Mesopore Ratio

DAI Yuzhuo,JI Xingxiang,TIAN Zhongjian,MA Hao,ZHANG Fengshan,FANG Guigan

2022,41(5):8-16.DOI:10.11980/j.issn.0254-508X.2022.05.002

The preparation of deinking paper sludge-based activated carbon （DPS-AC） with a thin-layer and high mesopores ratio structure by using deinking paper sludge （DPS） as raw material， via twice deashing with hot water and hydrochloric acid pickling， KOH activation， and ball milling assistance was discussed in this study. The results showed that the optimal process conditions for the preparation of DPS-AC were that hot water pretreatment and acid washing treatment for two deashing， KOH solution concentration of 6.5 mol/L， solid-liquid ratio of 1∶2， carbonization temperature of 750℃， time of 90 min， and 250 r/min intermittent ball milling for 180 min. The DPS-AC prepared under these conditions had an iodine adsorption capacity of 657.50 mg/g， a methylene blue adsorption capacity of 230.69 mg/g， a specific surface area of 595.138 m2/g， a total pore volume of 0.646 cm3/g， an average pore diameter of 4.339 nm， and mesoporous well-developed structure.

[Abstract] [PDF]

Study on Using Chitosan/Polyvinyl Alcohol to Improve the Water Vapor and Oxygen Barrier Properties of Paper-based Materials

LIU Xiaofei,ZHANG Xue,ZHAO Yumeng,CHENG Yun,HU Xiaoli,ZHANG Hongjie

2022,41(5):17-24.DOI:10.11980/j.issn.0254-508X.2022.05.003

In this paper， the application effect of chitosan and polyvinyl alcohol in improving the barrier properties of paper-based materials for water vapor （polar gas） and oxygen （non-polar gas） was studied. The effects of different mass ratios of chitosan/polyvinyl alcohol and different compounding methods （blending and layering） on the water vapor and oxygen barrier properties， mechanical properties and coating stability of paper-based materials were studied. The results showed that as the mass ratio of chitosan/polyvinyl alcohol decreased， the water vapor barrier properties of paper-based materials gradually increased， while the oxygen barrier properties gradually decreased. Compared with the chitosan/polyvinyl alcohol blending-coated paper， the chitosan/polyvinyl alcohol layering-coated paper had lower water vapor and oxygen transmission ratio. When the mass ratio of chitosan and polyvinyl alcohol was 1∶1， the water vapor and oxygen transmission rate of chitosan/polyvinyl alcohol layering-coated paper were 9.36 g/（m2·d） and 31.93 cm3/（m2·d）， respectively. Compared with the pure chitosan-coated paper， the water vapor transmission rate was reduced by about 92%. Compared with the chitosan/polyvinyl alcohol blending-coated paper， the water vapor and oxygen transmission rate were reduced by about 68% and 67%， respectively.

[Abstract] [PDF]

Effect of FeSiAl Size on Static and Dynamic Magnetic Properties of Paper-based Composites

YANG Dong,HU Jinwen,LIU Sicheng,ZHAO Xiaojiao,JU Wenbo,WANG Yi,LIU Zhongwu,LONG Jin,HU Jian

2022,41(5):25-31.DOI:10.11980/j.issn.0254-508X.2022.05.004

Paper-based composites （PBCs） were prepared by wet papermaking forming technology with FeSiAl sheets and aramid fibers. The effect of FeSiAl size on the static and dynamic magnetic properties of PBCs was discussed. The results showed that FeSiAl exhibited a unique layered arrangement structure due to the wet papermaking forming process and its high aspect ratio， resulting a significant magnetic anisotropy of PBCs， of which the obvious differences existed in in-plane and out-of-plane hysteresis loops. The results of the simulated impact method showed that with the increase of FeSiAl size， the coercivity of PBCs decreased and the complex permeability increased significantly. When the average particle size of FeSiAl increased from 14 μm to 116 μm， the coercivity of PBCs decreased from 3.47 Oe to 2.31 Oe， and the complex permeability changed from 13.55~9.01 j to 18.04~22.01 j （110 MHz）.

[Abstract] [PDF]

Effect of Beating Degree and Fiber Ratio on Properties of Surface Layer Fiber Sheets of Liquid Packaging Paper Board

LU Shiqiang,CHEN Jianyun,CHEN Ting,XU Huiyu,LUO Yuying

2022,41(5):32-36.DOI:10.11980/j.issn.0254-508X.2022.05.005

The effects of different beating degree and fiber ratio on properties of surface layer fiber sheets of liquid packaging paper board were studied by the actual production technology of liquid packaging paper board， including tensile index， tear index， burst index， stiffness， bulk and bonding force. The adaptability in processing applications was also studied by crease testing. The results showed that the optimization of the beating process was better than the increase in the softwood pulp ratio in terms of the improvement in strength properties of liquid packaging paperboard surface layer fiber sheets. When the softwood wood pulp and hardwood pulp ratio was 1∶1， the tear index reached maximum of 13.4 mN·m²/g with beating degree of 22ºSR， the stiffness reached maximum of 85.9 mN·m with beating degree of 25ºSR， the burst index and tensile index reached maximum of 5.82 kPa·m²/g and 68.2 N·m/g， respectively， with beating degree of 29ºSR. The crease testing results exhibited the better results under this condition.

[Abstract] [PDF]

Study on Improving Strength Properties of OCC Reconstituted Paper with Pectinase and Laccase/Glutamic Acid System

CHEN Yingjia,MA Yongwen,WANG Xianghuai,XU Chaofeng,ZHANG Fengshan,XU Yinchuan,WAN Jinquan

2022,41(5):37-45.DOI:10.11980/j.issn.0254-508X.2022.05.006

The improvement of strength performance of old corrugated cardboard （OCC） reconstituted paper by pectinase and laccase/glutamic acid pretreatment system was studied. The results showed that pectinase and laccase/glutamate acid pretreatment could significantly improve the strength properties of OCC reconstituted paper. The optimized process conditions via response surface method were that pectinase dosage of 3.5 U/g， laccase dosage of 12.2 U/g， pectinase treatment time of 62 min， laccase treatment time of 160 min. Compared with untreated OCC reconstituted paper， the relative content of C1 of OCC reconstituted paper pretreated under the optimized process conditions was decreased by 26.2%， whereas the relative content of C2， C3 and O/C increased by 15.0%， 11.2% and 27.9%， respectively. The tensile strength， burs strength， tear strength and the ring compression strength of OCC reconstituted paper pretreated under the optimized process conditions were increased by 24.7%， 33.7%， 25.5% and 31.1%， respectively. The pectinase and laccase/glutamate acid pretreatment could degrade lignin and produce more hydroxyl groups.

[Abstract] [PDF]

Preparation and Properties Analysis of Superhydrophobic Paper-based Material

WU Xiangnan,YANG Jun,HAN Yingying,MA Chao,ZHAO Huifang,SHA Lizheng

2022,41(5):46-51.DOI:10.11980/j.issn.0254-508X.2022.05.007

In this study， the original paper was prepared by internal sizing and pretreated with citric acid （CA） to improve its surface activity， then coated by cellulose nanofibril/titanium dioxide （CNF/TiO2） suspension to improve its surface roughness. Finally， the superhydrophobic paper-based material was prepared via impregnated into alkyl ketene dimer （AKD） emulsion to improve its hydrophobicity. The results showed that the surface activity of paper was significantly improved by CA pretreatment， giving a higher TiO2 retention for the paper， and made it easier to achieve the required surface roughness of the superhydrophobic paper-based material. The prepared superhydrophobic paper-based material had a contact angle of 153.8°， which met the requirements of superhydrophobic materials， and also showed good self-cleaning ability.

[Abstract] [PDF]

Study on Deacidification and Reinforcement of Aged Paper by Nanocellulose Collaborated in-situ Synthesized Calcium Carbonate

QI Shi,REN Junli,CAO Xian,HE Bei,FAN Huiming

2022,41(5):52-58.DOI:10.11980/j.issn.0254-508X.2022.05.008

A protection method for deacidification and reinforcement of aged paper by synthesized calcium carbonate in-situ and collaborated nanocellulose was proposed. The effects of different treatment methods and nanocellulose concentration on properties of aged paper were discussed. The results showed that the paper was treated by pressure atomization of 0.1 mol/L calcium propionate and 0.1 mol/L sodium carbonate aqueous solution to synthesize calcium carbonate in the paper in-situ for deacidification. Then the paper was enhanced by 1 wt% nanocellulose. After treatment， the pH value of the aged paper sample reached 8.40， the alkaline reserve was about 245 mmol/kg， the tensile index and the folding endurance increased by 19% and 109%， respectively， compared with the untreated sample. The treated paper also had excellent anti-aging and mold resistance.

[Abstract] [PDF]

Extraction and Characterization of Cellulose from Corn Straw Bark and Pith

LI Mengyang,LI Mingxin,ZHANG Tao,XIANG Yuzhou,YUE Jinquan

2022,41(5):59-64.DOI:10.11980/j.issn.0254-508X.2022.05.009

Corn straw was used as raw material to study the properties of cellulose in the bark and pith of corn straw. The purified cellulose from corn straw bark and pith was obtained by extracting the bark and pith with benzene-ethanol， respectively， and further removing lignin with sodium chlorite under acidic environment， and finally removing pentosane by potassium hydroxide. The results showed that the fiber bundles in the straw bark were more neatly and tightly arranged， and the chemical fractions of straw bark and pith were similar. The yield of purified cellulose from corn straw bark and pith were 38.9% and 38.2%， respectively， of which the α-cellulose content was 87.5% and 82.4%， respectively， and most of pentosane and lignin were removed. The crystalline structure of purified cellulose from straw bark and pith was still cellulose type I. Compared with corn straw bark and pith before purification， the crystallinity of purified cellulose increased from 51.2% and 30.4% to 67.7% and 42.1%， respectively. The starting and maximum decomposition temperatures of purified cellulose were increased compared with those of straw bark and pith， and the thermal stability was better than that of corn straw bark and pith.

[Abstract] [PDF]

Optimized Power Configuration and Control Method of Variable Reduction Ratio Rewinder Retiring Roller Motor

MA Huihai,WANG Tengda,MENG Yanjing,CHAI Dexi

2022,41(5):65-69.DOI:10.11980/j.issn.0254-508X.2022.05.010

In view of the contradiction between the demand for torque at large roll diameter and the demand for rotational speed at small roll diameter of the rewinder retiring roller， resulting in excess of motor power configuration， the variable reduction ratio design and power configuration model were proposed. Firstly， the optimization scheme and principle of variable reduction ratio structure were analyzed. Then， the power configuration method was analyzed and the corresponding parameters were calculated， followed by the system working process and reduction ratio switching control process were explained. Finally， the effects of energy saving and cost reduction of variable reduction ratio were explained. Compared with the traditional fixed reduction ratio structure， this program reached the purpose of configuration optimizing， resource and cost saving.

[Abstract] [PDF]

Carbon Emission, Carbon Capture and Utilization Technologies of Kraft Pulping Enterprises

SONG Jiayi,FAN Zhongqiu,LI Chenxi,LIU Liqin,CAO Haibing,CHENG Zhengbai,ZOU Xuejun,LIU Hongbin,AN Xingye

2022,41(5):70-79.DOI:10.11980/j.issn.0254-508X.2022.05.011

The emission sources of CO2 during the pulp production process of kraft pulping enterprises were first introduced in this paper. The overall carbon footprint of “forest-pulp integration” enterprises was further analyzed， followed by reviewing the accounting methods of greenhouse gas emissions and introducing the research progress of CO2 capture and utilization technologies in kraft pulping enterprises. The technologies mainly included the lignin production from black liquor via acid precipitation process， the production of precipitated calcium carbonate， the extraction of Tall oil， and the production of lignin nanoparticles， etc. Finally， the possibility of combining kraft pulping enterprises with biorefinery enterprises to further reduce the carbon emission was discussed.

[Abstract] [PDF]

Advances in the Application of Transparent Wood-based Functional Composites

LIN Tao,ZHANG Cong,YIN Xuefeng,WU Xiaoyu,WEI Xiaoyao

2022,41(5):80-87.DOI:10.11980/j.issn.0254-508X.2022.05.012

Wood is a renewable， green and degradable natural material with a wide range of sources， low thermal conductivity， excellent mechanical properties and complex hierarchical structure， so it can be widely used in the fields of building and furniture. At present， there are many research on wood-based functional composites， of which the wood-based material functionalization need to modify original wood first， and then further functionalization. The relevant research results of wood with new applications in different fields through physical and chemical treatments based on wood transparency were summarized in this paper， and the unsolved problems in industrialization of transparent wood-based functionalized composites were analyzed.

[Abstract] [PDF]

Thermally Conductive Paper (Films): A Review

JIA Chengying,LIU Wen,ZHU Yangyang,ZHU Jinghang,SHI He,JI Jianfeng,LI Hongkai

2022,41(5):88-97.DOI:10.11980/j.issn.0254-508X.2022.05.013

The heat dissipation problem of electronic products is increasing， and it has attracted wide spread attention to thermal management in the electronic field. Flexible and thermally conductive materials have the characteristics of excellent toughness， elasticity， thermal conductivity and flexibility， etc. It can be applied in flexible electronic devices， light and thin electronic devices， batteries and other fields to help solve the heat dissipation problems. Paper or film is flexibl, e， simple to produce and the thickness is adjustable， which is a kind of wonderfully flexible and thermally conductive materials. The research progress of thermally conductive paper （film） in recent years was reviewed in this paper. The thermally conductive papers with different substrates were summarized and introduced. The preparation methods， thermal conductivity， measurement for the thermal conductivity and mechanical properties of the cellulose-based paper and film was highlight and discussed.

[Abstract] [PDF]

Research Progress of Nanocellulose-based Electrode in Supercapacitors

LIU Shuaibiao,YANG Jianheng,WU Chaojun,YU Dongmei,CHEN Yehong

2022,41(5):98-107.DOI:10.11980/j.issn.0254-508X.2022.05.014

Nanocellulose exhibits the high mechanical strength， low density， and has many chemically modified hydroxyl functional groups on its surface. Therefore， it becomes the ideal material for assembling high-performance supercapacitor electrodes. In this review， the main mechanisms of soft material and carbon-based composite electrodes prepared by using nanocellulose combined with some active materials， such as conductive polymer and transition metal oxide， etc.， were introduced. Then the assembling methods including the freeze drying， carbonization， in situ polymerization， filtration and coating， were discussed in detail. In addition， the mechanical and electrochemical performances of nanocellulose-based supercapacitor electrodes were compared and analyzed. Finally， the potential application of nanocellulose-based electrodes in supercapacitors were prospected.

[Abstract] [PDF]

Development Status and Trend Analysis of Molded Fiber Products Industry

2022,41(5):108-116.DOI:10.11980/j.issn.0254-508X.2022.05.015

The development history， main products categories of molded fiber products were introduced. The policies of plastic limit/ban at home and abroad were summarized. The development status and trend， major manufactures at home and abroad， as well as scientific and technological innovation of molded fiber products industry were analyzed. Finally， the development suggestions of molded fiber products industry were put forward.

[Abstract] [PDF]

Thinking and Reconstitution of Practical Teaching Mode in Universities under Post-Epidemic Era

WANG Wenliang,LUO Qing,LI Xinping,YOU Xiangyu,XUE Bailiang

2022,41(5):117-121.DOI:10.11980/j.issn.0254-508X.2022.05.016

Practical teaching in university is vital to develop students’ abilities of engineering thinking and innovation consciousness. Taking the light chemical engineering of Shaanxi University of Science and Technology as an example， the characteristics of the practical teaching mode in universities under the post-epidemic era were analyzed in this paper. Many key issues such as the matching of the practical teaching concept with the requirements of the new situation and the connection between the multiple links of the practical teaching system were put forward. Combined with the professional certification standards of engineering education and the concept of new engineering construction， three major models had been formed， including the "strong + weak" practice link classification training system， the online and offline mixed practice teaching concept， and the intelligent practice teaching platform. Through the research and practice of practical teaching models in universities under the post-epidemic era， the aim of this work was to train the model for engineering education professional certification and a practical teaching system that met the requirements of new engineering disciplines， and develop excellent engineering talents with the abilities of diversification and innovation.

[Abstract] [PDF]