Improved Denitrification of Municipal Sludge in Biofilm-electrode Reactor

The denitrification of municipal sludge was improved by combining biofilm process with the electro-chemical effect in a single novel reactor. Experiments in this reactorl-electric current 60 mA, hydraulic reten-tion time (HRTs) 6.0h] showed that the removal of CODcr, ammonia nitrogen and total nitrogen in the biofilm-electrode reactor were 2.5%, 1.2%, 14.9%, respectively, higher than those in a traditional biofilm reactor.     

Interactions and Encapsulation of Vitamins C,B3, and B6 with Dendrimers in Water

Titrations of commercial diaminobutane (DAB) and polyamidoamine (PAMAM) dendrimers by vitamins C (ascorbic acid, AA), B₃ (nicotinic acid), and B₆ (pyridoxine) were monitored by ¹H NMR spectroscopy using the chemical shifts of both dendrimer and vitamin protons and analyzed by comparison with the titration of propylamine. Quaternarizations of the terminal primary amino groups and intradendritic tertiary amino groups, which are nearly quantitative with vitamin C, were characterized by more or less sharp variations (Δδ) of the ¹H chemical shift (δ) at the equivalence points. The peripheral primary amino groups of the DAB dendrimers were quaternarized first, but not selectively, whereas a sharp chemical‐shift variation was recorded for the inner methylene protons near the tertiary amines, thereby indicating encapsulation, when all the dendritic amines were quaternarized. With DAB‐G5‐64‐NH₂, some excess acid is required to protonate the inner amino groups, presumably because of basicity decrease due to excess charge repulsion. On the other hand, this selectivity was not observed with PAMAM dendrimers. The special case of the titration of the dendrimers by vitamin B₆ indicates only dominant supramolecular hydrogen‐bonding interactions and no quaternarization, with core amino groups being privileged, which indicates the strong tendency to encapsulate vitamins. With vitamin B₃, a carboxylic acid, titration of DAB‐G3‐16‐NH₂ shows that only six peripheral amino groups are protonated on average, even with excess vitamin B₃, because protonation is all the more difficult due to increased charge repulsion, as positive charges accumulate around the dendrimer. Inner amino groups interact with this vitamin, however, thus indicating encapsulation presumably with supramolecular hydrogen bonding without much charge transfer.     

垃圾渗沥液中难降解有机污染物的Fenton混凝处理

垃圾渗沥水;上流式厌氧污泥床;废水处理;垃圾渗沥液中难降解有机污染物的Fenton混凝处理     

The Role of the Reactor Wall in Hydrothermal Biomass Conversions

The processing of renewable feedstocks to platform chemicals and, to a lesser degree, fuels is a key part of sustainable development. In particular, the combination of lignocellulosic biomass with hydrothermal upgrading (HTU), using high temperature and pressure water (HTPW), is experiencing a renaissance. One of the many steps in this complicated process is the in‐situ hydrogenation of intermediate compounds. As formic acid and related low‐molecular‐weight oxygenates are among the species generated, it is conceivable that they act as a hydrogen source. Such hydrogenations have been suggested to be catalyzed by water, by bases like NaOH, and/or to involve “reactive/nascent hydrogen”. To achieve the temperatures and pressures required for HTU, it is necessary to conduct the reactions in high‐pressure vessels. Metals are typical components of their walls and/or internal fittings. Here, using cyclohexanone as a model compound for more complex biomass‐derived molecules, iron in the wall of high‐pressure stainless steel reactors is shown to be responsible for the hydrogenation of ketones with low‐molecular‐weight oxygenates acting as a hydrogen source in combination with water.     

Characterization of the Insoluble Sludge from the Dissolution of Irradiated Fast Breeder Reactor Fuel

Insoluble sludge is generated in the reprocessing of spent fuel. The sludge obtained from the dissolution of irradiated fuel from the “Joyo” experimental fast reactor was analyzed to evaluate its chemical form. The sludge was collected by the filtration of the dissolved fuel solution, and then washed in nitric acid. The yields of the sludge weight were less than 1% of the total fuel weight. The chemical composition of the sludge was analyzed after decomposition by alkaline fusion. Molybdenum, technetium, ruthenium, rhodium, and palladium were found to be the main constituent elements of the sludge. X-ray diffraction patterns of the sludge were attributable to Mo₄Ru₄RhPd, regardless of the experimental conditions. The concentrations of molybdenum and zirconium in the dissolved fast reactor fuel solutions were low, indicating that zirconium molybdate hydrate is produced in negligible amounts in the process.     

流化床中 CH4/C3H8 自热重整制合成气

 在流化床反应器中, 考察了 Ni/SiO2 催化剂上 CH4 或 CH4-C3H8 临氧 CO2 重整 (自热重整) 制合成气反应性能. 结果表明, 在 CH4-C3H8 混合气自热重整反应中, Ni 粒径较小催化剂的活性和抗积炭性能较高, CH4 和 CO2 转化率分别达 75.5% 和 72.6%. C3H8 比 CH4 更易解离及被氧化, 部分 C3H8 解离出来的中间产物 CHx 物种可与吸附 H 结合为 CH4, 因而降低了 CH4 的表观转化率; CHx 也可与吸附的 CO2 物种反应生成 H2 与 CO, 从而促进了 CO2 的转化.     

Investigation on Electronic Structures and Spectra for the Substituted Fullerene C77B-

1 INTRODUCTION After Guo[1] synthesized and detected C60-nBn and C70-nBn by mass spectra, investigations on fullerenes doped by other atoms became more and more interesting. Andreoni[2] studied the impurity states of the doped fullerenes C59B; Dong[3] calculated the structural and electronic properties of C59B; Wang[4] assessed the stability of heterohedral fullerenes C60-xBx. Lamparth[5] prepared C59N and C69N , and put forward the possible structures for C59N . Sahoo[6] obtained…     

LC Simultaneous Determination of the Free Forms of B Group Vitamins and Vitamin C in Various Fortified Food Products

An LC–UV screening method for simultaneous determination of ascorbic acid (C), and the free forms of thiamine (B₁) riboflavin (B₂), niacin (B₃), pyridoxine (B₆) in enriched food products was developed and validated. The chromatographic separation was accomplished within 18 min using a gradient of water with 0.1% formic acid (pH 2.5) and methanol with 0.1% formic acid on a C₁₈ reverse phase column (5 μm, 150 × 3.2 mm) while detection was performed at two wavelengths (266 and 290 nm). Sample preparation was based on an extraction method originally developed for vitamin C. This procedure besides extracting vitamin C was extended to the extraction of the free forms of vitamins B₁, B_2, B_3, B₆ and B₉. The developed analytical method was successfully applied for the simultaneous determination of the vitamin C content along with the free vitamin B forms of three different enriched food products.     

LC Simultaneous Determination of the Free Forms of B Group Vitamins and Vitamin C in Various Fortified Food Products

An LC–UV screening method for simultaneous determination of ascorbic acid (C), and the free forms of thiamine (B₁) riboflavin (B₂), niacin (B₃), pyridoxine (B₆) in enriched food products was developed and validated. The chromatographic separation was accomplished within 18 min using a gradient of water with 0.1% formic acid (pH 2.5) and methanol with 0.1% formic acid on a C₁₈ reverse phase column (5 μm, 150 × 3.2 mm) while detection was performed at two wavelengths (266 and 290 nm). Sample preparation was based on an extraction method originally developed for vitamin C. This procedure besides extracting vitamin C was extended to the extraction of the free forms of vitamins B₁, B_2, B_3, B₆ and B₉. The developed analytical method was successfully applied for the simultaneous determination of the vitamin C content along with the free vitamin B forms of three different enriched food products.

     

Quantitative Analysis of Previously Identified Propionate-Oxidizing Bacteria and Methanogens at Different Temperatures in an UASB Reactor Containing Propionate as a Sole Carbon Source

Propionate degradation is crucial for maintaining the efficiency and stability of an anaerobic reactor. However, there was little information about the effects of ecological factor on propionate-oxidizing bacteria (POB). In current research, quantitative real-time fluorescence polymerase chain reaction (QPCR) of some identified POB and methanogens with a decrease in temperature in an upflow anaerobic sludge bed (UASB) reactor containing propionate as sole carbon source was investigated. The results showed that there were at least four identified POB, including Pelotomaculum schinkii, Pelotomaculum propionicum, Syntrophobacter fumaroxidans, and Syntrophobacter sulfatireducens, observed in this UASB reactor. Among them, P. schinkii was dominated during the whole operational period. Its quantity was 1.2?×?10⁴ 16S rRNA gene copies per nanogram of DNA at 35 °C. A decrease in temperature from 35 to 30 °C led to P. schinkii to be increased by 1.8 times and then it was gradually reduced with a decrease in temperature from 30 to 25, 20, and 18 °C stepwise. A decrease in temperature from 35 to 20 °C did not make the amount of methanogens markedly changed, but hydrogenotrophic methanogens (Methanospirillum) and acetotrophic methanogens (Methanosaeta) at 18 °C were increased by an order of magnitude and 1.0 time, respectively, compared with other experimental conditions.     

Determination of Vitamins D2 and D3 in Feedingstuffs by High Performance Liquid Chromatography

Abstract

A sensitive and reliable HPLC method for complete separation and quantitation of vitamins D₂ and D₃ in complicated biological mixtures such as feedingstuffs has been developed and described. The method has been applied to the quantitative determination of D₂ and D₃ in feedingstuffs and related matrices at both high premix levels and low feed levels ranging down to a detection limit near 100 IU/1b or 0.22 IU/g sample. The procedures consist of the initial step of sample preparation by extraction; four sample cleanup stages: Sep/Pak/Silica Cartridge Cleanup, Millipore-Teflon Cleanup, Gel Permeation/Sephadex LH-20 Column Cleanup, and HPLC/Partisil-PAC Column Cleanup; and the final step of Reverse-Phase HPLC Separation, Identification, and Quantitation. The analytical Column used was Rainin Accupak 20 cm-3 um C-18 & Guard Columns. The Waters Associates Model 440 Fixed Wavelength UV Detector at 254 nm was used for all measurements. All separations and quantitations were carried out isocratically at room temperature and under subdued lighting. By these procedures, the sensitivity for both D₂ and D₃ is about the same (20 ng), and the resolution is excellent. Normally, the D₂ peak eluted at 30–31 min. and the D₃ peak followed at 2–3 min. later. By using the standard calibration and standard addition methods, the percent recovery ranges from 90.0%–104.8% with the mean value of 97.4%, whereas the accuracy is from 85.3% to 108.9% with the average of 97.8%. The standard deviation is ±5.2% and the coefficient of variation is 5.3%.     

Feasibility of 2,4,6-Trichlorophenol and Malonic Acid as Metabolic Uncoupler for Sludge Reduction in the Sequence Batch Reactor for Treating Organic Wastewater

The activated sludge process generates a large amount of excess sludge as a byproduct, which is one of the most serious challenges in biological wastewater treatment. In the present study, the feasibility of 2,4,6-trichlorophenol (TCP) and malonic acid (MA) as metabolic uncouplers to reduce sludge generation in the sequence batch reactor (SBR) for treating organic wastewater for a long period was studied. The results showed that 2 mg/L TCP could reduce sludge generation by about 47%, while chemical oxygen demand (COD) removal efficiency and sludge settlability were not obviously influenced. Although 10 mg/L MA could also reduce excess sludge production by about 30% while slightly affecting COD removal, it seriously deteriorated sludge settlability. Accordingly, TCP is a better uncoupler for sludge reduction for a longer period in the SBR for treating organic wastewater, and MA can only be used as a short-term or transitional uncoupler. Microscopic and 16S ribosomal deoxyribonucleic acid analyses showed that the microbial population of sludge varied when uncouplers were fed to the activated sludge system. Occurrence of large amounts of filament and the disappearance of protozoa may be the main reason for the aggravation of sludge settlability under uncoupled metabolic conditions caused by MA.     

Primary structure of the alanine subunit of ricin T from the seeds of the Central Asian castor oil plant VI. Tryptic peptides of the cyanogen bromide fragments B-1, B-2, and B-3

Tryptic hydrolysates of cyanogen bromide fragments B-1, B-2, and B-3 have been studied. As a results, 23 tryptic peptides have been isolated and characterized and the primary structures of 22 of them have been established. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 801–806, November–December, 1998.     

Role of the C3-substituted derivatives of cinchonidine in the enantioselective hydrogenation of ethyl pyruvate on Pt-alumina catalyst in AcOH

Summary The enantioselective hydrogenation of ethyl pyruvate (EtPy) was studied on Pt-alumina catalysts modified by C3-substituted cinchonidines (NC, A, B, C1, C2in Fig. 1) and for comparison by DHCDand MeO-DHCDin AcOH. The effect of the C3-substituent on the reaction rate and the enantioselectivity were examined. Using the Engelhard 4759 catalyst under mild experimental conditions (room temperature, hydrogen pressure 1 bar) such as DHCDthe (R)-ethyl lactate formed in excess (e.e.max: 79-91%)</o:p>     

Role of complement anaphylatoxin C3a in photodynamic therapy-elicited engagement of host neutrophils and other immune cells

Tumor treatment by photodynamic therapy (PDT) provokes a host-protective inflammatory and acute-phase response and an immune reaction. Neutrophilia manifested in this context is driven by multiple mediators of neutrophil chemotaxis orchestrated by an activated complement system. Mouse FsaR fibrosarcoma was used in this study to further investigate neutrophilia induced by Photofrin-based PDT. The complement anaphylatoxin C3a was identified as a major chemoattractant in the advanced phase of PDT-induced neutrophilia, because injecting mice with antibodies blocking its receptor C3aR significantly inhibited the increase in neutrophil levels 8 h after PDT. At the same time point, an increased C3aR expression was detected in neutrophils, monocytes and B lymphocytes in the blood of host mice. Peritoneal macrophages and mast cells harvested from treatment-naive mice exhibited elevated C3aR expression after coincubation in vitro for 8 h with PDT-treated FsaR cells. Thus, C3a emerges as one of the key effector molecules engaged in PDT-induced host response.     

HLB number of Vitamins C,E, coenzyme Q10 derivatives and their transportation efficiency into skin

We have been proposing a new delivery system of medicines and supplements. Derivatives of vitamin C, E and coenzyme Q₁₀ were examined regarding the relationship between the hydrophile-lipophile balance (HLB) number and the transdermal transportation efficiency into the skin. Non-invasive vibrational spectroscopies, infrared attenuated total reflection (IR-ATR) and near-infrared diffusive reflection (NIR-DR) methods were used in order to evaluate transported materials in the skin. Vitamin C derivatives of sodium l-ascorbyl-2-phosphate (hereafter abbreviated as APS) and sodium l-ascorbyl-2-phosphate-6-palmitate (APPS) were examined. APPS contains both a hydrophilic group and a hydrophobic group, since APS has been modified to APPS by deriving palmitic acid ester in the 6-OH position. APPS has the value of HLB around 9.0, while APS has that of 20. The iontophoretic efficiency of APPS is higher than APS. Vitamin E derivatives of DL-α-tocopheryl N,N-dimethylglycinate (TDMG) and α-tocopheryl acetate (TA) were examined regarding the transdermal transportation effect. Those HLB numbers are 2.3 and 0, respectively. TA is hydrophobic, while TDMG has a hydrophilic terminal group of dimethylglycine HCl materials. Coenzyme Q₁₀ (CoQ₁₀) is hydrophobic and a portion of benzoquinone is also hydrophobic, thus, HLB = 0. CoQ₁₀ has been modified to a reduced form of CoQ₁₀ (CoH₂Q₁₀) by NaBH₄. CoH₂Q₁₀ has a hydroquinone structure of hydrophilic property and HLB = 3.9. Supersonic perforation transported a greater amount of CoH₂Q₁₀ into the skin than CoQ₁₀. The balance of the hydrophilic group and the hydrophobic group in the transported material is an important factor for the effective transportation into the skin.     

Switching the Statistical C3/C1 Ratio in the Threefold Aromatic Substitution of Tribenzotriquinacenes towards the C3 Isomer

Tribenzotriquinacene (TBTQ) is a bowl‐shaped molecule that has been widely used as a molecular building block in supramolecular and materials chemistry. Especially C₃‐symmetric threefold‐substituted TBTQs are interesting for these purposes. Until now a general and selective synthetic approach to those C₃‐symmetric products was lacking, mainly because the typically used electrophilic aromatic substitution reactions of the parent TBTQ hydrocarbons produce predominantly the C₁ isomer over the C₃ isomer (3:1 statistical ratio). Herein we introduce a threefold borylation of TBTQ with the C₃ isomer as the main product (2.6:1 C₃/C₁ ratio). The borylated TBTQ can be converted in good yields into other C₃‐symmetric TBTQs, thus allowing straightforward synthetic access to new building blocks for supramolecular and materials chemistry.