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Morris I. Schnitzer Carlos M. Monreal Glenn A. Facey Peter B. Fransham 《Journal of environmental science and health. Part. B》2013,48(1):71-77
Fast pyrolysis of chicken manure produced two biooils (Fractions I and II) and a residual char. All four materials were analyzed by chemical methods, 13C and 1H Nuclear Magnetic Resonance Spectrometry (13C and 1H NMR), and Fourier Transform Infrared Spectrosphotometry (FTIR). The char showed the highest C content and the highest aromaticity. Of the two biooils Fraction II was higher in C, yield and calorific value but lower in N than Fraction I. The S and ash content of the two biooil fractions were low. The Cross Polarization Magic Angle Spinning (CP-MAS) 13C NMR spectrum of the initial chicken manure showed it to be rich in cellulose, which was a major component of sawdust used as bedding material. Nuclear Magnetic Resonance (NMR) spectra of the two biooils indicated that Fraction I was less aromatic than Fraction II. Among the aromatics in the two biooils, we were able to tentatively identify N-heterocyclics like indoles, pyridines, and pyrazines. FTIR spectra were generally in agreement with the NMR data. FTIR spectra of both biooils showed the presence of both primary and secondary amides and primary amines as well as N-heterocyclics such as pyridines, quinolines, and pyrimidines. The FTIR spectrum of the char resembled that of the initial chicken manure except that the concentration of carbohydrates was lower. 相似文献
54.
Pentachlorobenzene (PeCB) in simulated flue gas was destructed by a commercial V2O5-WO3/TiO2 catalyst in this study. The effects of reaction temperature, oxygen concentration, space velocity and some co-existing pollutants on PeCB conversion were investigated. Furthermore, a possible mechanism for the oxidation of PeCB over the vanadium oxide on the catalysts was proposed. Results show that the increase of gas hourly space velocity (GHSV) and the decrease of operating temperature both resulted in the decrease of PeCB removal over the catalyst, while the effect of the oxygen content in the range of 5-20% (v/v) on PeCB conversion was negligible. PeCB decomposition could be obviously affected by the denitration reactions under the conditions because of the positive effect of NO but negative effect of NH3. The introduction of SO2 caused the catalyst poisoning, probably due to the sulfur-containing species formed and deposited on the catalyst surface. The PeCB molecules were first adsorbed on the catalyst surface, and then oxidized into the non-aromatic acyclic intermediates, low chlorinated aromatics and maleic anhydride. 相似文献
55.
A novel electrolytic groundwater remediation process, which used the H2 continuously generated at cathode to achieve in situ catalytic hydrodechlorination, was developed for the treatment of 2,4-dichlorophenol (2,4-DCP) in groundwater. Catalytic hydrodechlorination using Pd supported on bamboo charcoal and external H2 showed that 2,4-DCP was completely dechlorinated to phenol within 30 min at pH ? 5.5. In a divided electrolytic system, the catalytic hydrodechlorination of 2,4-DCP in cathodic compartment by H2 generated at the cathode under 20 and 50 mA reached 100% at 120 and 60 min, respectively. Two column experiments with influent pHs of 5.5 (unconditioned) and 2 were conducted to evaluate the feasibility of this process. The 2,4-DCP removal efficiencies were about 63% and nearly 100% at influent pHs of 5.5 and 2, respectively. Phenol was solely produced by 2,4-DCP hydrodechlorination, and was subsequently degraded at the anode. A low pH could enhance the hydrodechlorination, but was not necessarily required. This study provides the preliminary results of a novel effective electrolytic process for the remediation of groundwater contaminated by chlorinated aromatics. 相似文献
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Yoshimitsu?UemuraEmail author Kouichi?Baba Hiroyuki?Ohe Yoshihiro?Ohzuno Yasuo?Hatate 《Journal of Material Cycles and Waste Management》2003,5(2):94-97
A two-stage process for the chemical recycling of plastics is proposed. In this process, which consists of two reactors, plastics are converted into hydrogen and carbon. In the first reactor, plastic chips are thermally decomposed into hydrocarbons. In the second reactor, the hydrocarbons formed in the first reactor are catalytically decomposed into carbon and hydrogen. In this study, in order to obtain basic data for the second reactor, propene was catalytically decomposed in a laboratory-scale spouted-bed reactor (600mm high, 21.6mm internal diameter, made of SUS304). The effect of the type of spouting medium used on the decomposition behavior of propene was investigated using four types of spouting medium (nickel-plated -alumina, palladium-plated -alumina, nickel-impregnated -alumina, and -alumina). The nickel-impregnated -alumina gave the best propene conversion and hydrogen yield. 相似文献
58.
采用消化液硝酸/高氯酸消解法、硝酸-硫酸消解法和微波消解方法消化省沽油,用原子吸收分光光度法测定硒(Se)含量。比较了3种消解方法在测定省沽油中的硒含量。发现微波消解法测定野生省沽油(干菜)中Se含量准确性好、时间段效率高、对环境污染少、操作简单。 相似文献
59.
《环境科学学报(英文版)》2023,35(7):139-151
This study investigated the enhancement effects of dissolved carbonates on the peroxymonosulfate-based advanced oxidation process with CuS as a catalyst. It was found that the added CO32− increased both the catalytic activity and the stability of the catalyst. Under optimized reaction conditions in the presence of CO32−, the degradation removal of 4-methylphenol (4-MP) within 2 min reached 100%, and this was maintained in consecutive multi-cycle experiments. The degradation rate constant of 4-MP was 2.159 min−1, being 685% greater than that in the absence of CO32− (0.315 min−1). The comparison of dominated active species and 4-MP degradation pathways in both CO32−-free and CO32−-containing systems suggested that more CO3•−/1O2 was produced in the case of CO32−deducing an electron transfer medium, which tending to react with electron-rich moieties. Meanwhile, Characterization by X-ray photoelectron spectroscopic and cyclic voltammetry measurement verified CO32− enabled the effective reduction of Cu2+ to Cu+. By investigating the degradation of 11 phenolics with different substituents, the dependence of degradation kinetic rate constant of the phenolics on their chemical structures indicated that there was a good linear relationship between the Hammett constants σp of the aromatic phenolics and the logarithm of k in the CO32−-containing system. This work provides a new strategy for efficient removal of electron-rich moieties under the driving of carbonate being widely present in actual water bodies. 相似文献
60.
The effects of employing activated Al2O3 during the catalytic pyrolysis of waste printed circuit boards (WPCBs) are investigated, focusing on the recycling of light oil. Variations in the pyrolysis process are studied through analysis of the phase distribution, water content and boiling point fractions of the resulting products. Product composition and carbon number distribution are analyzed using gas chromatography techniques. The use of activated Al2O3 increases the light oil fraction and also reduces the quantity of brominated products formed. It was determined that the best yield of light oil and most efficient debromination resulted from catalytic pyrolysis at 600 °C. Applying catalyst-to-feed ratios in the range of 1.0–1.5 also maximizes the yield of light oil. The major oil fraction resulting from catalytic pyrolysis has a boiling point range of 0–250 °C and carbon number range of C6–C9, showing for use as a potential fuel after suitable treatment such as hydrogenation. At a higher catalyst-to-feed ratio of 2.0, activated Al2O3 generates a high proportion of light oil fractions containing a significant quantity of chemicals such as phenol (52.67% at 600 °C), although an overall lower yield of oil is obtained. The oil produced in this manner may also be used as a raw material feedstock for the production of various other useful chemicals. 相似文献