Chemical characterization and sorption capacity measurements of degraded newsprint from a landfill

Newsprint samples collected from 12-16 ft (top layer (TNP)), 20-24 ft (middle layer (MNP)), and 32-36 ft (bottom layer (BNP)) below the surface of the Norman Landfill (NLF) were characterized by infrared (IR) spectroscopy, cross-polarization, magic-angle spinning 13C nuclear magnetic resonance (CP-MAS 13C NMR) spectroscopy, and tetramethylammonium hydroxide (TMAH) thermochemolysis gas chromatography/mass spectrometry (GC/MS). The extent of NLF newsprint degradation was evaluated by comparing the chemical composition of NLF newsprint to that of fresh newsprint (FNP) and newsprint degraded in the laboratory under methanogenic conditions (DNP). The O-alkyl/alkyl, cellulose/lignin, and lignin/resin acid ratios showed that BNP was the most degraded, and that all three NLF newsprint samples were more degraded than DNP. 13C NMR and TMAH thermochemolysis data demonstrated selective enrichment of lignin over cellulose, and TMAH thermochemolysis further exhibited selective enrichment of resin acids over lignin. In addition, the crystallinity of cellulose in NLF newsprint samples was significantly lower relative to that of FNP and DNP as shown by 13C NMR spectra. The yield of lignin monomers from TMAH thermochemolysis suggested that hydroxyl groups were removed from the propyl side chain of lignin during the anaerobic decomposition of newsprint in the NLF. Moreover, the vanillyl acid/aldehyde ratio, which successfully describes aerobic lignin degradation, was not a good indicator of the anaerobic degradation of lignin on the basis of the TMAH data. The toluene sorption capacity increased as the degree of newsprint degradation increased or as the O-alkyl/alkyl ratio of newsprint decreased. The results of this study further verified that the sorbent O-alkyl/ alkyl ratio is useful for predicting sorption capacities of natural organic materials for hydrophobic organic contaminants.     

Pleurotus mushrooms. Part III. Biotransformations of natural lignocellulosic wastes: commercial applications and implications

Species of Pleurotus are endowed with the capacity to degrade unfermented natural lignino-cellulosic wastes. From the time the substrate is spawned until the end of cropping, there occurs a spectrum of qualitative and quantitative changes in the various substrate constituents, viz., cellulose, hemicellulose, lignin, sugars, amino acids, phenols, ash, nitrogen, etc. In general, cellulose, hemicellulose, and lignin are degraded, solubility of the substrate is increased, phenolic content is decreased, sugar and amino acid contents are increased, as is the ash content due to a constant utilization of the organic matter. The ability of Pleurotus to effect these degradative changes is discussed under both sterile (monoculture) and nonsterile culturing conditions. The enzymatic aspects affecting these various chemical changes in the lignino-cellulosic substrates are brought out. The various commercial applications and implications of the spent substrate, such as use as an upgraded form of ruminant feed, production of biogas, manufacture of paper/cardboard, recycling into Agaricus compost, garden fertilizer, production of single cell proteins, etc., are critically evaluated.     

Influence of rhamnolipids and triton X-100 on the desorption of pesticides from soils

A rhamnolipid biosurfactant mixture produced by P. aeruginosa UG2 and the surfactant Triton X-100 were tested for their effectiveness of enhancing the desorption of trifluralin, atrazine, and coumaphos from soils. Sorption of both surfactants by the soils was significant and adequately described by the Langmuir-type isotherm. Values of maximum sorption capacity (Qmax) and Langmuir constant (Klang) did not correlate with the amount of soil organic matter. Our results indicate that clay surfaces play an important role in the sorption of surfactants. When surfactant dosages were high enough to reach soil saturation and maintain an aqueous micellar phase, pesticide desorption was only enhanced. At dosages below soil saturation, surfactants sorbed onto soil, increasing its hydrophobicity and enhancing the sorption of the pesticides by a factor of 2. Similar values of water-soil partition coefficients (Ksol*) for aged and fresh added pesticides to soils indicate that the aging process used did not significantly after the capability of either surfactant to desorb the pesticides. A model able to estimate equilibrium distributions of organic compounds in soil-aqueous-micellar systems was tested against experimental results. The determined organic carbon partition coefficients, Koc values, indicate that, on a carbon normalized basis, sorbed Rh-mix is a much better sorbent of pesticides than TX-100 or soil organic matter. These results have significant implications on determining the effectiveness of surfactants to aid soil remediation technologies.     

嗜碱性木素降解菌降解能力的初步研究

通过比较不同嗜碱细菌对麦草中木素、纤维素和半纤维素的降解率, 并比较不同菌株的产酶及酶活情况, 筛选出了木素降解能力较强, 而纤维素和半纤维素降解能力相对较弱的嗜碱性木素降解菌。在ｐＨ≈１０－４的条件下培养８ｄ 后, 菌株６ 降解了３２－３７％ 的麦草木素, 而纤维素和半纤维素分别降解了２１－４８％ 和２２－６９％ 。这与其产酶情况基本一致, 该菌株的酶活最高, 分别为ＭｎＰ２７１－３０Ｕ／Ｌ和ＬｉＰ４１－９４Ｕ／Ｌ。     

Phenanthrene sorption by aliphatic-rich natural organic matter

Contaminant sorption, an important process that may limit bioavailability, hinder remediation, encourage environmental persistence, and control mobility in the environment, has been the focus of numerous studies. Despite these efforts, the fundamental understanding of sorptive processes in soil and sedimentary environments has not been resolved. For instance, many have suggested that contaminants, such as polycyclic aromatic hydrocarbons (PAHs), solely interact with aromatic domains of organic matter. Until now, studies have neglected the aliphatic components that are known to be a recalcitrant and significant part of soil and sedimentary organic matter (SOM). In this investigation, the sorption of phenanthrene to several aliphatic-rich SOM samples was measured. The samples included the following: SOM precursors (algae, degraded algae, cellulose, collagen, cuticle, and lignin), two kerogen samples, and a highly aromatic humic acid. All samples were characterized by cross polarization magic angle spinning carbon-13 (CPMAS 13C) NMR and carbon, hydrogen, and nitrogen analysis. Batch experiments demonstrated that the highest organic carbon normalized sorption coefficients (Koc values) were obtained with the Pula kerogen sample (log Koc = 4.88) that only contains 6.5% aromatic carbon. Other aliphatic-rich samples, namely the Green River kerogen, degraded algae, and collagen samples produced comparable log Koc values (4.64, 4.66, and 4.72, respectively) to that of the highly aromatic humic acid (log Koc = 4.67). Phenanthrene uptake was the least for cellulose and lignin, two major soil components. A comparison of phenanthrene Koc values and paraffinic carbon content revealed a positive correlation (Koc = 798 +/- 96.1 * paraffinic carbon (%), r2 = 0.56) and indicates that amorphous polymethylene carbon is an important consideration in phenanthrene sorption. This study establishes that aliphatic SOM domains have a strong affinity for phenanthrene and likely, other PAHs. Therefore, aliphatic structures, that are an important component of SOM, require more attention in the examination of sorption processes in terrestrial and sedimentary environments.     

白腐菌对稻草秸秆中木质纤维素降解规律的研究

通过对傅里叶变换红外光谱(FTIR)谱图的分析和木质纤维素组分含量变化的测定,研究了3株白腐菌在50天培养期内降解稻草中木质纤维素的规律。结果表明,3株白腐菌对稻草秸秆中木质纤维素的降解具有一定的顺序和选择性,先降解半纤维素和木质素,再同时降解半纤维素、纤维素和木质素。从降解比例来看,白腐菌对半纤维素和木质素具有很好的降解优势,对半纤维素有较好的降解选择性。     

Hydration of natural organic matter: effect on sorption of organic compounds by humin and humic acid fractions vs original peat material

Natural organic matter (NOM) hydration is found to change activity-based sorption of test organic compounds by as much as 2-3 orders of magnitude, depending on the compound and the specific NOM sorbent. This is demonstrated for sorption on humin, humic acid, and the NOM source material. Hydration assistance in organic compound sorption correlates with the ability of the sorbate to interact strongly with hydrated sorbents, demonstrating the important role of noncovalent polar links in organizing the sorbent structure. Differences in hydration effect between the sorbents are caused mainly by differences in compound-sorbent interactions in the dry state. For a given compound, hydration of the sorbent tends to equalize the sorption capability of the three sorbents. No correlation was found between the strength of sorbate-sorbent interactions or the type of sorbate functional groups and the extent of sorption nonlinearity. Sorption nonlinearity compared over the same sorbed concentration range is greater on the original NOM than on either of the two extracted fractions. In elucidating sorption mechanisms on hydrated NOM, it is important to explicitly consider the participation of water molecules in organic compound interactions in the NOM phase.     

Evaluation of pretreatment with Pleurotus ostreatus for enzymatic hydrolysis of rice straw

The effects of biological pretreatment of rice straw using four white-rot fungi (Phanerochaete chrysosporium, Trametes versicolor, Ceriporiopsis subvermispora, and Pleurotus ostreatus) were evaluated on the basis of quantitative and structural changes in the components of the pretreated rice straw as well as susceptibility to enzymatic hydrolysis. Of these white-rot fungi, P. ostreatus selectively degraded the lignin fraction of rice straw rather than the holocellulose component. When rice straw (water content of 60%) was pretreated with P. ostreatus for 60 d, the total weight loss and the degree of Klason lignin degraded were 25% and 41%, respectively. After the pretreatment, the residual amounts of cellulose and hemicellulose were 83% and 52% of those in untreated rice straw, respectively. By enzymatic hydrolysis with a commercial cellulase preparation for 48 h, 52% holocellulose and 44% cellulose in the pretreated rice straw were solubilized. The net sugar yields based on the amounts of holocellulose and cellulose of untreated rice straw were 33% for total soluble sugar from holocellulose and 32% for glucose from cellulose. The SEM observations showed that the increase in susceptibility of rice straw to enzymatic hydrolysis by pretreatment with P. ostreatus is caused by partial degradation of the lignin seal. When the content of Klason lignin was less than 15% of the total weight of the pretreated straw, enhanced degrees of enzymatic solubilization of holocellulose and cellulose fractions were observed as the content of Klason lignin decreased.     

彩色胶印新闻纸酶—超声波协同脱墨的研究

进行了酶与超声波协同作用对彩色胶版印刷新闻纸脱墨的研究.实验结果表明,超声波协同酶预处理对彩色胶印新闻纸的脱墨效率有很大的提高,处理后浆的白度比空白试样提高5%ISO.虽然酶和超声波的处理会在一定程度上降低纤维粗度和纤维长度,但对纸张的强度影响很小.研究发现,超声波的主要作用是提高了酶对纤维表面碳水化合物的水解速度,因而有利于油墨的脱除.     

不同方法提取的橄榄果渣纤维素的性质表征

以橄榄果渣为原料,采用碱液浸提法从橄榄果渣中提取纤维素(初始纤维素),用2 mol/L HCl和H2SO4溶液水解初始纤维素,得到橄榄渣微晶纤维素(MCC).测定初始纤维素与微晶纤维素的持水力、持油力和膨胀力.通过差示扫描量热仪(DSC)、傅里叶红外光谱仪(FTIR)、X射线衍射仪(XRD)、场发射扫描电镜(SEM)和...     

Chemical composition of some forages and various residues from feeding value determinations

NDF, ADF, ‘cellulose’ and IVOMD residues, from feeding value determinations, were prepared from some forages, including straw, alkali-treated straw, grass and lucerne samples. The crude protein, cellulose, hemicellulose, uronic acid, Klason lignin, lignin and ash contents of these residues and the corresponding original forage samples were determined together with the relative composition of the neutral sugar constituents after acid hydrolysis. Cellulose, hemicellulose and Klason lignin were the main components in the NDF fractions but substantial amounts of crude protein (1–6%) also remained. Cellulose and Klason lignin were the main components in the ADF fractions, but 7–14% of the fractions was hemicellulose and 1–4% crude protein. Cellulose was the main component in the ‘cellulose’ fractions, but they also contained 8–13% hemicellulose, 2–7% Klason lignin and 2–11% ash. The composition of the IVOMD residues showed that cellulose and hemicellulose had been dissolved to about the same amounts (70–80%) and that most of the Klason lignin remained.     

Oil is a sedimentary supersorbent for polychlorinated biphenyls

The often-observed enhanced sorption of hydrophobic organic chemicals (HOCs) to sediments is frequently attributed to the presence of soot and soot-like materials. However, sediments may contain other hydrophobic phases, such as weathered oil residues. Previous experiments have shown that these residues can be efficient sorbents for certain PAHs. In this study we investigated sorption of PCBs to sediments contaminated with different concentrations and types of oils, and from that derived oil-water distribution coefficients (Koil). Sorption of PCBs to both fresh and weathered oils was proportional to sorbate hydrophobicity, and no effects of PCB planarity were observed. Furthermore, the experiments demonstrated that different oils sorbed PCBs similarly and extensively (Koil up to 108.3 for PCB 169), and that weathering caused an almost 2-fold increase in sorption of the lower chlorinated PCBs. Koil values indicated that at the PCB equilibrium concentrations tested (pg-ng/L range), for many congeners weathered oil is a stronger sorbent than pure soot and soot-like materials. Due to attenuation of adsorption to the latter materials in sediments (caused by competitive adsorption with organic matter), sedimentary weathered oil will therefore, if present as a separate phase, defeat sedimentary soot, coal, and charcoal as PCB sorbent in most cases. Consequently, weathered oil probably is the ultimate sedimentary sorbent for PCBs and should be included in HOC fate models.     

Lignin Interaction with Cellulase during Enzymatic Hydrolysis

The conversion of lignocellulosic biomass into biofuels or biochemicals typically involves a pretreatment process followed by the enzyme-catalyzed hydrolysis of cellulose and hemicellulose components to fermentable sugars. Many factors can contribute to the recalcitrance of biomass, e.g., the lignin content and structure, crystallinity of cellulose, degree of fiber polymerization, and hemicellulose content, among others. However, nonproductive binding between cellulase and lignin is the factor with the greatest impact on enzymatic hydrolysis. To reduce the nonproductive adsorption of enzymes on lignin and improve the efficiency of enzymatic hydrolysis, this review comprehensively summarized the progress that has been made in understanding the interactions between lignin and enzymes. Firstly, the effects of pretreatment techniques on lignin content and enzymatic hydrolysis were reviewed. The effects of lignin content and functional groups on enzymatic hydrolysis were then summarized. Methods for the preparation and characterization of lignin films were assessed. Finally, the methods applied to characterize the interactions between lignin and cellulase were reviewed, and methods for decreasing the nonproductive binding of enzymes to lignin were discussed. This review provides an overview of the current understanding of how lignin hinders the enzymatic hydrolysis of lignocellulosic biomass, and provides a theoretical basis for the development of more economical and effective methods and additives to reduce the interaction of lignin and enzymes to improve the efficiency of enzymatic hydrolysis.     

木质素与半纤维素对稻草秸秆酶解的影响

分别采用稀酸和酸碱顺序两种方法处理稻草秸秆,20 FPU/g(底物干重)的纤维素酶、底物质量浓度为80 g/L,45℃酶解72 h。结果表明,木质素与半纤维素对纤维素转化为葡萄糖都有较大影响,稀酸处理的秸秆酶解纤维素转化率(43.4%,葡萄糖质量浓度24.1 g/L)是未处理秸秆(16.8%,葡萄糖质量浓度6.2 g/L)的2.6倍,而酸碱顺序处理的秸秆(60.6%,葡萄糖质量浓度47.7 g/L)则是未处理秸秆的3.6倍。采用上述两种方法处理秸秆后,秸秆木质素和半纤维素被移去,秸秆结构发生改变,从而秸秆纤维更易受纤维素酶的攻击,并且秸秆木质素和半纤维素质量分数越低,纤维素的酶解得率就越高。     

Effect of surfactants on the survival and sorption of viruses

There is an increasing concern about the protection of groundwater from contamination by enteric viruses and the prevention of outbreaks of waterborne diseases. Knowledge of survivability and transport of viruses from their point of origin is necessary to determine their potential effects on the neighboring groundwater systems. The distribution of virus is, in turn, dependent on the physical and chemical compositions of the surrounding soil and subsurface systems. For the present study, we have determined the effects of different surfactants (cationic, anionic, nonionic, and biological) and natural organic matter (NOM) on bacteriophages. Results indicated that surfactants and NOM adversely affect phage survival in binary systems, with surfactants being the most harmful. Studies with ternary systems also showed that the presence of surfactants reduced sorption of phages on sorbents either by occupying available sorption sites on the sorbent material or by displacing the sorbed phages from the sorbent surface. Water contact angles of the selected phages and different sorbent surfaces have been measured. Experimental data demonstrated that the sorption of hydrophobic viruses was favored by hydrophobic sorbents, while the sorption of hydrophilic viruses was favored by hydrophilic sorbents.     

Photosensitized oxidation of substituted phenols on aluminum phthalocyanine-intercalated organoclay

Bentonite modified with cationic surfactant, cetyltri-methylammonium bromide (CTMA), was an effective sorbent for organic pollutants in water. To make the sorbent recyclable, aluminum phthalocyanine (AIPc), a representative photosensitizer for generation of singlet oxygen, was inserted successfully into the interlamellar space of CTMA-modified bentonite. Under visible light (lambda > 450 nm) irradiation, the composite catalyst exhibited a remarkable activity for degradation of the recalcitrant pollutants phenol, 4-chlorophenol, 4-nitrophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol in an aerated aqueous medium. The initial rate of the heterogeneous photoreaction was found to increase with the initial amount of the substrate sorption onto the catalyst, the kinetics following the Langmuir-Hinshelwood equation. Loading of AIPc into the organoclay led to slight expansion of the clay basal spacings from 1.82 to 2.15 nm, but the sorption capacity was decreased notably. The optimal loading of AIPc was about 0.25 wt %. The result demonstrates thatthe surfactant-modified bentonite not only offers a hydrophobic zone for enrichment of organic contaminants but also provides a flexible environment for destruction of the sorbed pollutants by singlet oxygen generated in situ. It was noted, however, that during four repeated experiments, both the sorption and the degradation rate of 2,4,6-trichlorophenol were gradually decreased, due to some intermediates formed and sorbed onto the catalyst surface.     

低压蒸汽爆破处理对蔗渣浆化学组分的影响

本文对经低压蒸汽爆破处理的蔗渣浆进行了化学组分分析,重点探讨爆破处理后浆料的纤维素、半纤维素和木素含量的变化情况,同时对废液中的还原糖含量和有机酸含量进行了分析.     

Enzymatic effects of Pleurotus ostreatus spent substrate on whole-plant corn silage and performance of lactating goats

Pleurotus ostreatus (oyster mushroom) synthesizes enzymes that degrade lignin, cellulose, and hemicellulose. The objectives of this study were to evaluate the effect of Pleurotus ostreatus spent substrate (POSS) on whole-plant corn silage (WPCS) chemical composition, antioxidant capacity, lignin monomers, and in vitro digestibility, as well as the performance of lactating goats fed corn silage treated with different levels of POSS. In experiment 1, 4 levels of lignocellulolytic enzymes were tested in a complete randomized design: 0, 10, 20, and 30 mg of lignocellulosic enzymes per kilogram of fresh matter, 4 replicates per treatment (vacuum-sealed bags). The bags were opened 60 d after ensiling. In experiment 2, corn silage treated with 3 enzyme levels (0, 10, or 30 mg/kg of fresh matter) was fed to lactating goats as part of the total mixed ration. Nine lactating Saanen goats (62.68 ± 7.62 kg BW; 44 ± 8 d in milk; 2.91 ± 0.81 kg of milk/day, mean ± SD) were assigned to three 3 × 3 Latin squares. Data were analyzed using the GLIMMIX procedure of SAS (version 9.4, SAS Institute Inc.), and means were compared by linear and quadratic orthogonal contrast. In experiment 1, neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, and cellulose quadratically decreased in the WPCS treated with POSS. At the nadir point, POSS decreased NDF by 14.1%, ADF by 19.5%, lignin by 9.07%, and cellulose by 22.1% compared with the untreated silage. Therefore, POSS led to a quadratic increase in in vitro dry matter digestibility of WPCS (+8.88% at the vertex) compared with the untreated silage. In experiment 2, POSS quadratically increased the in vivo total-tract ADF digestibility. Also, the concentration of polyphenols in the milk of goats linearly increased with the addition of POSS, and no differences were observed among treatments for milk yield and composition. In summary, adding 10 mg of lignocellulolytic enzymes from POSS per kilogram of fresh matter of whole-plant corn at ensiling had a more evident reduction in lignin and cellulose concentration, leading to greater in vitro digestibility, as well as greater in vivo ADF digestibility; however, milk yield was not different among treatments.     

NaOH/尿素低温溶解法测定烟梗木质素含量的研究

建立了一种准确测定烟梗木质素含量的新方法。用低温NaOH/尿素水溶液抽提烟梗,采用优化的酸处理条件（硫酸浓度17.5 %、液固比80 mL?g-1、酸解温度100 ℃、酸解时间30 min）打断烟梗中木质素与纤维素等组份之间的化学键,残渣用低温NaOH/尿素水溶液进一步溶解纤维素、半纤维素等天然高分子物质,得到酸不溶木质素。酸溶木质素采用分光光度法在325 nm处测定,酸不溶木质素采用灼烧法测定。本方法RSD小于3%,准确度良好,且减少了有机溶剂预处理和浓硫酸处理,提高了测试的安全性。      

Sorption of aromatic organic contaminants by biopolymers: effects of pH, copper (II) complexation, and cellulose coating

Sorption of hydrophobic organic compounds (HOCs) (i.e., pyrene, phenanthrene, naphthalene, and 1-naphthol) by original and coated biopolymers was examined. Lignin yielded nonlinear isotherms due to its glassy character. Except for pyrene, cellulose showed linear isotherms for other compounds, indicating a partitioning dominant mechanism. Sorption of 1-naphthol by lignin decreased with increasing pH, attributed to both the increased pi e theta-pi e theta repulsion and weakened hydrogen bonds, while the affinity reduction of cellulose for 1-naphthol with increasing pH resulted from only the decrease in H-bonding due to its absence of benzene ring. Complexation of lignin with Cu2+ increased the sorption affinity for phenanthrene (2.6 times) and slightly enhanced its isotherm nonlinearity. For 1-naphthol, lignin-Cu2+ complex had a much higher sorption capacity (7 times)than the original lignin, accompanied bythe increased isotherm nonlinearity. Cellulose-coated lignin showed increased sorption affinity and more pronounced nonlinearity for 1-naphthol than the lignin-Cu2+ complex. In comparison, cellulose coating exhibited little effect on sorption affinity for phenanthrene relative to the lignin-Cu2+ complex. Isotherm nonlinearity of coated lignins increased with increasing cellulose coating, indicating more condensed domains produced, supported by an increase (from 68.9 degrees C for the original lignin to 82.4 degrees C for the highest cellulose coating level) in glass transition temperature (Tg). Results of this study highlightthe importance of structure, polarity, surface O-containing functional groups, and surface charges of biopolymers in controlling HOC sorption.