改进型气升式反应器中白腐菌降解碱木素

设计了一种白腐菌糙皮侧耳高效降解废水中碱木素的改进型气升式反应器,研究了内套管的开孔高度与脱色率的关系,并采用分批进料方式考察了改进后反应器中白腐菌对碱木素的降解效果。实验结果表明：反应器内套管的最佳开孔高度为45 cm;改进后反应器的漆酶酶活、COD去除率、脱色率分别最高达到了89.33 U/L、87.3%和81.39%,较改进前分别相对提高了17.5%、43.3%和39.6%。     

一株吡啶降解菌的筛选及其降解性能

以吡啶为唯一碳源,从焦化厂活性污泥中分离得到一株对吡啶具有高效降解能力的菌株B1,对其进行了菌种鉴定。通过单因素实验研究了菌株B1适宜的降解条件,对反应过程进行了动力学拟合,并考察了菌株B1对焦化废水中吡啶的降解效果。实验结果表明:菌株B1为革兰氏阴性菌,属于不动杆菌属(Acinetobacter sp.);菌株B1适宜的降解条件为降解温度30℃、初始pH为7、摇床转速150 r/min;菌株B1对吡啶的降解过程符合零级反应动力学模型,当初始吡啶质量浓度为300 mg/L时,降解速率常数最高达到21.103 mg/(L·h);用菌株B1对初始吡啶质量浓度为430 mg/L的实际焦化废水处理74 h后,吡啶降解率可达74.26%。     

Fenton试剂催化氧化法处理模拟酸性红B染料废水

采用Fenton试剂催化氧化处理用酸性红B配制的模拟偶氮染料废水,考察了影响处理效果的主要因素,并探讨了酸性红B降解的动力学.实验结果表明,Fenton试剂催化氧化处理酸性红B废水的最佳工艺条件为:H2O2加入量49.0 mmol/L,Fe2+加入量2.0 mmol/L,反应温度25℃,初始废水pH 3～6.在此最佳工艺条件下反应5min时,酸性红B去除率为99.8％,COD去除率为62.3％;反应60 min后,酸性红B去除率为99.9％,COD去除率为80.0％.Fenton试剂催化氧化降解酸性红B的反应符合二级反应动力学规律.     

膨胀颗粒污泥床反应器在低温低浓度下的动力学研究

在考虑膨胀颗粒污泥床(EGSB)反应器的反应动力学、水力动力学和热动力学特点的基础上,建立了EGSB反应器在低浓度下的基质降解动力学模型,求出EGSB反应器在进水COD450m g/L、35,15℃(与35℃同样的液体上升流速)和15℃(提高液体上升流速至最佳)3种运行条件时的速率常数分别为3.91×102,1.07×102,2.54×102d-1。用A rrhenius方程分析了温度对速率常数的影响,计算出EGSB反应器在提高液体上升流速前后的活化能分别为4.897×104J/m o l和1.197×104J/m o。l低温使速率常数明显降低,但液体上升流速的提高却能显著提高速率常数,降低活化能。     

Cu2+-Mn2+-H2O2体系催化氧化降解罗丹明B

研究了Cu2＋-Mn2＋-H2O2体系催化氧化降解染料罗丹明B的效果。实验结果表明,Cu2＋-Mn2＋-H2O2体系的罗丹明B降解率比H2O2体系、Mn2＋-H2O2体系和Cu2＋-H2O2体系有显著提高,反应120rain后罗丹明B降解率接近100％。对于Cu2＋-Mn2＋-H2O2体系,最佳罗丹明B降解条件：溶液pH为5,反应温度为45℃,质量浓度为10mg／L的罗丹明B溶液体积100mL,浓度为0．01mol／L的硫酸铜溶液加入量5．0mL,浓度为0．01moVL的硫酸锰溶液加入量3．0mL,体积分数为30％的H2O2溶液加入量1．5mL。在此条件下罗丹明B降解的反应速率常数最大,为0．04228min-1,其拟合相关系数为0．99912。罗丹明B降解符合一级动力学模型。     

不同光照度下活性艳红X-3B的光催化降解动力学研究

以活性艳红X-3B为模型化合物，以TiO2为光催化剂，研究了不同光照度下污染物的多相光催化降解动力学。结果表明，活性艳红X-3B的光催化降解动力学符合Langmiur—Hinshelwood动力学模型，其中的表观反应速率常数(k)随入射光照度的增加而增大，吸附平衡常数(KA)却随入射光照度的增加而减小，在实验的光照度范围内，k和KA^-1与光照度的平方根成比。     

4株正十六烷降解菌的降解能力及代谢动力学特性

从处理采油废水的活性污泥中分离出4株产生物表面活性剂的正十六烷高效降解菌。菌株A14和B45为非脱羧勒克菌（Leclercia adecarboxylata）,菌株C28和A27为肠杆菌（Enterobacter sp.）。在NaCl质量浓度15~25 g/L、pH 6.0~7.0、接种量10%（φ）,培养温度37 ℃,摇床转速160 r/min、正十六烷体积分数0.30%的条件下降解16 d后,菌株A14、B45、C28和A27的正十六烷降解率分别为93.7%,87.8%,73.3%,65.7%。4株菌所产生的生物表面活性剂均为磷脂类表面活性剂。菌体生长满足逻辑斯蒂模型,正十六烷的降解满足一级反应动力学模型。菌株C28、A27的生长速率快于菌株A14、B45,菌株A14、B45的正十六烷降解速率快于菌株C28、A27。     

Na_5[Ce(ZrMo_(11)O_(39))]·xH_2O杂多酸盐的光催化降解性能

采用傅立叶变换红外光谱仪和X射线衍射仪对自制的Keggin型结构的Na5[Ce(ZrMo11O39)]·xH2O杂多酸盐进行了表征,并研究了Na5[Ce(ZrMo11O39)]·xH2O杂多酸盐对模拟酸性绿B印染废水的光催化降解效果。实验结果表明:合成的杂多酸盐具有Keggin型结构;在模拟酸性绿B印染废水初始质量浓度为10mg/L、初始pH为6、杂多酸盐加入量为0.8g/L的条件下,光照160min后模拟印染废水中酸性绿B的降解率达79.49%。动力学分析结果表明,降解反应符合一级反应动力学模型。     

镰刀菌HJ01对对氯苯酚的降解特性

采用实验室分离的一株镰刀菌HJ01,以对氯苯酚(4-CP)为降解底物,以蔗糖为外加碳源,考察了蔗糖质量浓度、降解温度、初始pH对4-CP降解效果的影响,初步探讨了镰刀菌HJ01对4-CP的降解动力学和降解机理.实验结果表明:该菌株能以4-CP为惟一碳源和能源生长;在外加蔗糖为碳源,蔗糖质量浓度为3 g/L、降解温度为30℃、初始pH为8的条件下,50 mg/L4-CP能在6 d内被完全降解.以4-CP为惟一碳源和外加蔗糖下的降解动力学分别符合Haldane模型和一级动力学方程.     

蒙脱石基絮凝剂处理染料废水

采用先酸活化蒙脱石、再加碱聚合的方法制备了蒙脱石基絮凝剂（PMT）,用于去除染料废水的TOC和色度。实验结果表明：PMT处理2BLN分散蓝、KNR活性艳兰、X-3B活性艳红模拟染料废水的最佳加入量分别为0．30。0．30,0．25g／L。在此最佳条件卜,2BLN分散蓝、KNR活性艳兰和X-3B活性艳红模拟染料废水的TOC去除率分别为77．0％,89．2％,39．5％,脱色率分别为41．2％,43．1％,57．4％。PMT对KNR活性艳兰和2BLN分散蓝实际染料废水的TOC去除率高于聚合氯化铝（PAC）和聚合硫酸铁（PFS）,分别为91．6％和88．4％。但PMT对X-3B活性艳红实际染料废水的TOC去除率及对3种实际废水的脱色率均低于PAC和PFS。     

Infrared and nuclear magnetic resonance evidence of degradation in thermoplastics based on forest products

The degradation of lignin-(1-phenylethylene) graft copolymers (lignin-styrene graft copolymers) by white rot basidiomycete fungi was followed by monitoring aromatic absorption bands by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The FTIR of the graft copolymers shows a series of characteristic absorbance peaks from multi-substituted aromatic rings and a strong poly(1-phenylethylene) (polystyrene) absorbance peak from monosubstituted aromatic rings. Subtraction of copolymer spectra taken before incubation from spectra taken after 50 days of incubation with the four tested fungi shows the loss of functional groups from the copolymer. NMR spectra also show reduction of aromatic ring resonances from the copolymer and incorporation of peaks from fungi as a result of incubation with fungi. The biodegradation tests were run on lignin-(1-phenylethylene) graft copolymers which contained 10.3, 32.2, and 50.4% of lignin. The polymer samples were incubated with the white rot fungiPleurotus ostreatus, Phanerochaete chrysosporium, andTrametes versicolor, and the brown rot fungusGleophyllum trabeum. White rot fungi degraded the plastic samples at a rate that increased with increasing lignin content in the copolymer sample. Both poly(1-phenylethylene) and lignin components of the copolymer were readily degraded. Observation by scanning electron microscopy of incubated copolymers showed a deterioration of the plastic surface. The brown rot fungus did not affect any of these plastics, nor did any of the fungi degrade pure poly(1-phenylethylene).Paper presented at the Bio/Environmentally Degradable Polymer Society—Second National Meeting, August 19–21, 1993, Chicago, Illinois.     

Evaluation of white‐rot fungi for the remediation of creosote‐contaminated soil

Application of fungal‐based bioaugmentation was evaluated for the remediation of creosote‐contaminated soil at a wood‐preserving site in West Virginia. Soil at the site contained creosote‐range polycyclic aromatic hydrocarbons (PAHs) at concentrations in some areas that exceed industrial risk‐based levels. Two white‐rot fungi (Pleurotus ostreatus and Irpex lacteus) were evaluated for remediation effectiveness in a two‐month bench‐scale treatability test. Both fungi produced similar results, with up to 67.3 percent degradation of total PAHs in 56 days. Pilot‐scale testing was performed at the site using Pleurotus ostreatus grown on two local substrate mixtures. During the 276‐day field trial, total PAHs were degraded by up to 93.2 percent, with all individual PAHs except one achieving industrial risk‐based concentrations. It was recommended that fungal‐based remediation be applied to all contaminated soil at the site. © 2002 Wiley Periodicals, Inc.     

Biodegradation of Polyaromatics Synthesized by Peroxidase-Catalyzed Free-Radical Polymerization

Polymers formed from peroxidase-based free-radical polymerization reactions were characterized for rates of mineralization against lignin and humic acid controls. Degradation studies were carried out in soil systems over 202 days and cumulative net CO₂ was determined. Whereas mineralization of the humic acid and alkali lignin controls totaled ca. 20% at the end of the test exposure, there was essentially no net mineralization of the hydrolytic lignin control. Mineralization of the test samples totaled 5% for poly(p-ethylphenol) and 11% for poly(m-cresol). At the same time, mineralization of the poly(p-phenyl phenol) totaled 64%. Conversely, the readily biodegradable polymers cellulose and PHB reached values of 91 to 97% in less than 60 days. Our data suggest that the mineralization kinetics of the enzymatically derived polyaromatics mimic those of the naturally occurring heteropolymers.     

Polylactic Acid Composites Utilising Sequential Surface Treatments of Lignocellulose: Chemistry,Morphology and Properties

Polylactic acid (PLA)—maple fibre composites have been synthesised using a series of sequentially modified cellulose fibres (namely alkylation followed by either acetylation or silanation). Confirmations of the sequential modifications were made using Fourier Transform Infrared Spectroscopy and Inductively Coupled Plasma—Atomic Emission Spectroscopy and the new surface morphologies analysed using Scanning Electron Microscopy. The key advantage of the use of sequential treatments (with initial alkali treatment) was the allowance for direct grafting of suitable chemical groups onto the cellulose in the fibre due to the removal of lignin, hemicellulose and other surface impurities. However, a balance was found to exist between alkali exposure time, concentration and resulting fibre integrity. The conditions used resulted in a loss in fibre weight, fibre moisture content and tensile strength. Sequential treatments with acetylation or silane resulted in a 15–21% strength recovery from that of the alkali treated composite. Factors that influenced this recovery in strength were the improved fibre-polymer interface, namely the hydrophilic balancing of the fibres and this further affected the thermal-hydrolysis of the PLA during composite fabrication.     

A Two-Step Chemical Process for the Extraction of Cellulose Fiber and Pectin from Mulberry Branch Bark Efficiently

In this work, a two-step method for the extraction of pectin and cellulose fiber from mulberry branch bark, a by-product of sericultural industry, was described. The method was based on the acid extraction of pectin and subsequently alkali treatment for obtaining cellulose fibers. The obtained pectin was high purity with the total galacturonic acid content of 85.46% ± 2.76% and the degree of esterification of 71.13% ± 1.67%. The chemical composition analysis, FTIR spectroscopy, XRD and TG analysis were used to characterize the cellulose fiber at different processing stages. After the two-step chemical process, the cellulose content was increased from 37.38% in original bark to 92.60% in cellulose fiber. The FTIR spectra revealed the removal of pectin, hemicelluloses and lignin from the bark by acid extraction and alkali treatment. The XRD and TG results indicated that the obtained cellulose fibers were with the increased crystallinity and thermal stability, whose crystallinity and degradation temperature were 86.36% ± 5.56% and 355 °C, respectively. This work may provide a new approach for high utilization of mulberry branch bark.     

Isolation of a fungus from denitrifying activated sludge that degrades highly chlorinated dioxins

 This article reports the potential of denitrifying activated sludge to degrade highly chlorinated dioxins, especially from a (landfill) leacheate treatment plant in Japan, and the isolation from this denitrifying activated sludge of a microorganism able to degrade highly chlorinated dioxins. Using a 700-ml bioreactor, denitrifying activated sludge was cultivated under denitrifying conditions by adding 2.0 ng of a mixture of 4- to 8-chlorinated dioxins from fly ash. The dioxin contents of the sample, effluent, and medium before and after cultivation were measured by gas chromatography–mass spectrometry (GC–MS). After 7 days cultivation, about 90% of added dioxins were lost (average percentage of isomer depletion). A dioxin-degrading microorganism was isolated from the activated sludge. Lignin was added to the medium as a color indicator of aromatic compound degradation, and the lignin-decolorizing microorganisms in the denitrifying activated sludge were screened. Some strains were isolated, and one major isolated fungus, strain 622, decolorized lignin effectively. Strain 622 was identified as an Acremonium sp. from its morphological characteristics. It could decolorize lignin by 24% under paraffin-sealed anaerobic conditions. After the cultivation of strain 622 with a 2 ng/ml mixture of 4- to 8-chlorinated dioxins for 1 day, 82% (average for individual isomers) of the added 4- to 8-chlorinated dioxins had been degraded. Added octachlorodibenzo-p-dioxin (OCDD, 100 ng) was degraded under aerobic conditions after 8 h of incubation. During this process, heptachlorodibenzo-p-dioxin was produced and appeared to be a degradation product of OCDD. 1- or 2-hydroxydibenzo-p-dioxin from OCDD was also identified as the degradation product by GC–MS. These results indicated that OCDD was degraded to the nonchlorinated dibenzo-p-dioxins through dechlorination by Acremonium sp. strain 622. Received: October 12, 2001 / Accepted: March 11, 2002     

A Novel and Formaldehyde-Free Preparation Method for Lignin Amine and Its Enhancement for Soy Protein Adhesive

In this work, a novel two-step process to prepare primary lignin amine was developed. The lignin used in this study was obtained from the residue of cellulosic sugar fermentation for bioethanol (referred as “lignin”). The lignin was initially oxidized through Fenton oxidation. The oxidized lignin was further converted to lignin amine by reductive amination. Ammonia was used in the second step leading to give the highly active primary lignin amine. The oxidation and reduction exhibited relatively high yields of 80.0 and 91.2 % respectively. For comparison, lignin was partially depolymerized via mild hydrogenolysis and then the partial depolymerized lignin was also converted to lignin amine using the same method. The obtained lignin amines were characterized in detail using elemental analysis, proton nuclear magnetic resonance (¹H NMR), and Fourier transform infrared spectroscopy (FTIR). Further, modification of soy protein adhesive by lignin amine was exemplified in wood bonding, and the results indicated that addition of lignin amine greatly increased water resistance of soy protein adhesives.     

木质素活性炭的制备及其对硝基苯的吸附

利用工业碱木质素分别经KOH及H3PO4活化制备两种木质素活性炭（KAC和PAC）,并用于模拟硝基苯废水的处理。采用SEM和IR等手段对木质素活性炭进行了表征。考察了木质素活性炭加入量、废水pH、吸附时间等因素对硝基苯吸附量的影响。表征结果显示,KAC具有丰富的孔结构,PAC表面含有多种功能基团。实验结果表明： 在吸附温度298 K、初始硝基苯质量浓度250 mg/L、木质素活性炭加入量1.0 g/L、废水pH 3、吸附时间24 h的条件下,KAC及PAC对硝基苯的吸附量分别为237.8 mg/g和211.9 mg/g,去除率分别达到91%和84%; KAC及PAC对硝基苯的吸附过程符合拟二级动力学方程,吸附等温线满足Langmuir等温吸附方程;当解吸剂的V（乙醇）∶V（去离子水）=9时,在PAC和KAC上吸附的硝基苯的解吸率分别达到99%和93%;木质素活性炭重复使用5次后,KAC和PAC对硝基苯的吸附量分别为115.4 mg/g和130.7 mg/g。     

Structural Differences Between Lignin Model Polymers Synthesized from Various Monomers

In a plant cell wall, lignin is synthesized from several monomeric precursors, combined in various ratios. The variation in monomer type and quantity enables multifunctional role of lignin in plants. Thus, it is important to know how different combinations of lignin monomers impact variability of bond types and local structural changes in the polymer. Lignin model polymers are a good model system for studies of relation between variations of the starting monomers and structural variations within the polymer. We synthesized lignin model polymers from three monomers, CF??based on coniferyl alcohol and ferulic acid in monomer proportions 5:1 and 10:1 (w/w), CP??based on coniferyl alcohol and p-coumaric acid in proportion 10:1 (w/w) and CA??based on pure coniferyl alcohol. We studied structural modifications in the obtained polymers, by combining fluorescence microscopy and spectroscopy, FT-IR and Raman spectroscopy, in parallel with determination of polymers?? molecular mass distribution. The differences in the low M _w region of the distribution curves of the 10:1 polymers in comparison with the CA polymer may be connected with the increased content of C=C bonds and decreased content of condensed structures, as observed in FT-IR spectra and indicated by the analysis of fluorescence spectra. The 5:1 CF polymer contains a different type of structure in comparison with the 10:1 CF polymers, reflected in its simpler M _w distribution, higher homogeneity of the fluorescence emitting structures and in the appearance of a new high-wavelength emission component. We propose that this component may originate from ??-conjugated chains, which are longer in this polymer. The results are a contribution to the understanding of the involvement of structural variations of lignin polymers in the cell wall structural plasticity.