Vacuum ultraviolet (VUV) and ultraviolet (UV)/chlorine processes are regarded as two of many advanced oxidation processes (AOPs). Because of the similar cost of VUV/UV and UV lamps, a combination of VUV and UV/chlorine (i.e., VUV/UV/chlorine) may enhance the removal of organic pollutants in water but without any additional power input. In this paper, a minifluidic VUV/UV photoreaction system (MVPS) was developed for bench-scale experiments, which could emit both VUV (185 nm) and UV (254 nm) or solely UV beams with a nearly identical UV photon fluence. The photon fluence rates of UV and VUV output by the MVPS were determined to be 8.88 × 10 −4 and 4.93 × 10 −5 einstein m −2 s −1 , respectively. The VUV/UV/chlorine process exhibited a strong enhancement concerning the degradation of methylene blue (MB, a model organic pollutant) as compared to the total performance of the VUV/UV and UV/chlorine processes, although the photon fluence of the VUV only accounted for 5.6% of that of the UV. An acidic pH favored MB degradation by the VUV/ UV/chlorine process. The synergistic mechanism of the VUV/UV/chlorine process was mainly ascribed to the effective use of • OH for pollutant removal through formation of longer-lived secondary radicals (e.g.,• OCl). This study demonstrates that the new VUV/UV/chlorine process, as an enhanced AOP, can be applied as a highly effective and energy-saving technology for small-scale water and wastewater treatment.

Methanolysis of an extraction residue (ER) from Xianfeng lignite was carried out to obtain extracts 1−4 (E 1 −E 4 ). The molecular compositions (MCs) of oxygen-containing species (OCSs) in E 1 −E 4 were characterized using negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). In addition, solid-state 13 C nuclear magnetic resonance and X-ray photoelectron spectrometry were used to analyze the carbon types and oxygen functional groups (OFGs) in the ER. The results show that the carbon skeleton structures in the ER are dominated by aliphatic (50.2%) and aromatic (44.9%) carbons. Methylene and methoxy carbons are the most abundant among the aliphatic carbons. Each aromatic cluster contains three rings on average with two substituent groups on each ring. The OFGs in the ER include hydroxy, ether, carbonyl, and carboxyl groups, among which the hydroxy group is the most abundant. The ESI FT-ICR MS analysis shows that the molecular mass distributions of E 1 −E 4 range from 150 to 500 u. The O n (n = 1−6) class species are the predominant OCSs in E 1 −E 4 , with 0−14 double bond equivalent (DBE) values and 9−34 carbon numbers (CNs). The most abundant O n class species in E 1 −E 4 are O 2 , O 2 , O 2 −O 3 , and O 3 , respectively. The OCSs in E 4 contain low abundances of O 1 and O 2 class species but relatively high abundances of O 4 −O 6 class species. In addition, the O n class species in E 4 have narrower ranges of DBE values and CNs than those in E 1 −E 3 . A series of acidic species with different DBE values and CNs are assigned to alkanoic acids, alkanedioic acids, alkanetricarboxylic acids, alkylarenols, alkylarenediols, alkylarenetriols, and alkylarenoic acids. With high resolving power and mass accuracy, ESI FT-ICR MS is an effective technique for characterizing MC of the soluble portion from lignites, which will facilitate producing important chemicals from lignites.

No abstract

No abstract

The structures of typical organic species in Jincheng No. 15 anthracite (J15A) were characterized by solid-state 13 C nuclear magnetic resonance, X-ray photoelectron spectrometry, X-ray diffraction, and Fourier transform infrared spectrometry in combination with gas chromatography/mass spectrometry and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry analyses of the resulting soluble organic species from ruthenium-ion-catalyzed oxidation (RICO) of J15A. The results show that the typical organic species in J15A are condensed aromatics, along with small amounts of methyl group as the dominant side chain on the condensed aromatic rings (CARs) and methylene linkage connecting the CARs. Every aromatic cluster contains five rings on average, and the substituted degree of each aromatic ring is very low. In addition, J15A is rich in peri-condensed aromatics but poor in cata-condensed aromatics and polyaryls. The oxygen functional groups in J15A include C−O and >CO groups. Pyrrolic nitrogen species and arylthiophenes are the main organic nitrogen and sulfur species in J15A, respectively.