The 5-5′ type lignin substructure is very stable during kraft pulping and it is difficult to degrade in the treatment of wastewater from pulping. However, phenolic 5-5′ can polymerize by laccase. In order to understand the co-polymerization between 5-5′ type lignin model and p-hydroxycinnamic acid in existence of laccase to provide the theoretic basis for the development of precipitation and flocculation of the lignin in effluent from pulping process, the polymerization reaction between p-hydroxycinnamic acid and a lignin model compound of phenolic 5-5′ type lignin model compound, i.e. dehydrodiacetovanillione, catalyzed by laccase was studied .Gel permeation chromatography (GPC) was used to analyze the molecular weights of the polymerization products. FT-IR and NMR spec-troscopy were employed to determine the chemical structure of the polymer obtained. The result indicates that dehydrodivanillyl alcohol can polymerize with p-hydroxycinnamic acid catalyzed through dehydrogenation. While GPC determination indicated the molecular weight Mn increased from 306 to 2106. The linking ways of structure units were mainly though β-O-4、α-O-4、β-β structures.

Unbleached softwood kraft pulp was treated with a biomimetic bleaching system, i.e. Co-salen system comprised of Co (Ⅱ)salen, pyridine, hydrogen peroxide, oxygen (Co-salen system) and the changes of kappa number, brightness of the pulp after biomimetic treatment were analyzed. It was found that Co-salen system had a limited ability to decrease kappa number and increase brightness. The result illustrated that the Co-salen system was not effective in lignin macromolecule. However, biomimetc process oxidized a part of lignin to be carbonyl compounds which was easy to be degraded and dissolved during alkali extraction and hydrogen peroxide bleaching. Consequently, this work provides a convictive information about Co-salen biomimetic delignification system that could be applied to industrial bleaching.

The CODCr of mixed wastewater from CMP of wheat straw is removed evidently by biomimetic treatment,and the removal of CODCr can reach more than 60%.Bio degradable property of the mixed wastewater is improved through the removal of lignin,and it creates condition for subsequent treatment of poor degradable wastewater.Fe-carboxyl acid complexes have stable characteristics and low price,and can simulate the function of lignin peroxidase very well.The best condition of wastewater treatment is as follows.Fe-CA 10 mg/L wastewater,the pH of original wasterwater is adjusted to neutral,the temperature of wastewater is 30℃,H2O2 0.15 g/L,Al2(SO4)3 0.4 g/L,sedimentation time 6 h.

Under the laccase catalysis,the water soluble lignin in APMP effluent and its derivatives were polymerized with p-hydroxycinnamic acid to form high molecule hydrophobic lignin polymer which will be removed by sedimentation.The results of the experiment indicate that addition of p-hydroxycinnamic acid could effectively remove soluble lignin and its derivatives in the effluent under the reaction of laccase.The optional effluent treatment condition:p-hydroxycinnamic dosage 0.066 g/L,laccase dosage 14.82 IU/L,temperature 25℃,reaction time 1h.The removal rate of lignin reached 73.9%,the removal rate of CODCr was 69.1%and the chroma removal rate was 86.7%respectively.

The compositive wastewater of papermaking was disposed by biomimetic coagulation method,it's CODCr can be reduced evidently.The removal of CODCr can reach more than 65%.Fe-carboxyl acid complexes has stable characteristics and low price,and can simulate the function of lignin peroxidase very well.The best conditions of wastewater treatment were as follow: Fe-CA 10mg/L wastewater,the pH of original wasterwater was adjusted to neutral,the temperature 30℃,H2O2 0.15g/L,Al2(SO4)3 0.4g/L,sedimentation time 6h.

Cu-salen system comprised of Cu-salen, pyridine, hydrogen peroxide, oxygen was used to investigate the bleaching of softwood CTMP pulp. The effect of Cu-salen dosage, NaOH dosage, reaction temperature and reaction time on brightness of the pulp before pretreatment and after bleaching was probed. The fi ndings indicate that the Cu-salen biomimetic system has a desirable effect on the pretreatment of softwood CTMP.

An investigation to the bleaching of softwood CTMP treated with a Co-salen biomimetic system comprised of Co-salen, pyridine, hydrogen peroxide and oxygen was made and the change of brightness of the pulp during the bleaching process was investigated. The findings indicated that Co-salen biomimetic system had a better effect on the treatment of softwood CTMP. The effect on brightness of NaOH dosage, H2O2 dosage and Co-salen dosage was also investigated.

Co-salen biomimetic delignification system has been proved to be a promising method. In order to understand the mechanism of delignification with Co-salen system, guaiacylglycerol-beta-guaiacyl ether and milled wood milled lignin (MWL) from aspen were treated with the biomimetic system using Co(II)-salen, pyridine, hydrogen peroxide and oxygen. GC-MS analysis was used to investigate the change of the chemical structure of the beta-O-4 type model Compound and the MWL during the treatment. The results showed that Co-salen type biomimetic system bad strong ability in degradation of phenolic type beta-O-4 model compound. After degradation, a series of low molecular aromatic compounds containing carboxyl, hydroxyl and carbonyl groups were produced. It is Suggested that the following reactions were caused by the Co-salen system: ether-bond cleavage, alkyl-aryl cleavage and C(beta)-C(gamma) cleavage. After MWL was treated, the content of hydroxyl and carboxyl groups increased. Some low molecule compounds as syringaldehyde and vanillin were produced. The results could prove that the oxidation of side chain lead to the cleavage of the linkage between the units of lignin substructure.

Isotope(deuterium oxide,D2O)tracer method was used to trace the water content in cut tobacco in order to reveal the variation of water transfer in the course of tobacco processing.The cut tobacco obtained from each stage of the processing was dried in a vacuum oven to remove all of the water.It was then loaded into the vacuum line assembly(VLA)in which the same mass of deuterium oxide(D2O)was injected.The diffused D2O was absorbed by the dried tobacco till in equilibrium.The D2O at different stages of the processing were then extracted with the VLA,respectively.The D2O extract was derivatized with acetic anhydride,and analysed by GC-MS to obtain the mole ratio of CH3COOD to CH3COOH,through which the mole ratio of D2O/H2O was obtained.The amount of water lost at each stage of the processing was confirmed.It was found that the loss occurred mainly in the parching process.The result may be useful for the optimization of cut tobacco processing.

A biomimetic degradation investigation on β-O-4 lignin model compound triploid of populus tomentosa milled wood lignin ( MWL) was carried out with Cu-salen biomimetic system composed of Cu-salen and pyridine and the structural changes of β-O-4 type model compound and MWL during the reaction was analyzed with GC-MS. The investigation indicated that Cu-salen type biomimetic system has strong degradation ability to MWL phenolic β-O-4 type model compound and a series of aromatic low molecular aromatic compounds containing hydroxy, aldehyde group and carbonyl groups is produced after degradation. From the structure of the reaction products, it is suggested that the major degradation track were β-O-4 ether-bond cleavage, Cα-Cβ bond cleavage, alkyl-aryl bond cleavage and aromatic ring opening. Some MWL turned into such low molecular compounds as syringaldehyde and vanillin, which indicates that the oxidation of side chain led to the cleavage of the linkage between the units of lignin substructure.

The research status and development trend of biomimetic delignification catalyzed by metal com- plexes were reviewed.Effects of porphyrins and nonporphyrins metal complexes used as biomimetic cata- lysts for delignification were evaluated.The application perpective of biomimetic delignification catalyzed by metal complexes was also prospected.Metalloporphyrins complexes had attracted much interest because of their high catalytic activity under relatively mild condition.This kinds of central metal irons of porphyrins also influenced the catalytic activity of delignification.Metalloporphyrins complexes are difficult to be used in practice because of their high cost.Non porphyrins metal complexes such as metallophthalocyanines,Gif systems,Shiffbase complexes,etc.are being paid more attention due to their high catalytic activity,selectiv- ity and easy synthesis,i.e.Co-salen biomimetic delignification system has been proved to be an efficient bleaching method.

The application of Co-salen-flocculation in dealing with effluent with high COD from pulp and papermaking industry has a very good function for the organic matter in catalysis and oxidation.The removal of CODCr can reach more than 50%.Large amount of the removal of lignin from waste water can improve the character of biochemistry of the temperature,making it easier for the following treatment.