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Removal of Hg 0 using two homogeneous Photo-Fenton-Like reactions was first investigated in a photochemical reactor. Effects of process parameters on Hg 0 removal were studied. Free radical and reaction products were analyzed.

The oxidation removal process of nitric oxide (NO) from flue gas using an ultraviolet (UV) light and heat coactivated oxone (potassium peroxymonosulfate, 2KHSO5·KHSO4·K2SO4) system in an UV (254 nm)-impinging stream reactor was studied. The main process parameters (e.g., light intensity, oxone concentration, solution temperature, solution pH, flue gas composition, and flow rate of flue gas and solution), products, mechanism, and kinetics of NO removal were studied. The results show that UV and oxone have a significant synergistic effect for promoting free radical production and improving NO removal. NO removal was improved via increasing the light intensity, oxone concentration, or solution flow rate and was inhibited with increasing the NO concentration, SO2 concentration, or flue gas flow rate. Solution temperature and pH have double impacts on NO removal. UV light activation for oxone is the main source of SO4 – • and •OH. Heat activation for oxone is the complementary source of SO4 – • and •OH. SO4 – • and •OH are the key oxidizing agents and play an important role in NO removal. Oxone plays a complementary role in NO removal. The NO removal process is a fast reaction and meets a total 1.44 order reaction (i.e., 1.0 order for NO and 0.44 order for oxone). The key kinetic parameters of NO removal were also determined.

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The organic and mineral components in two coals and resulting high-temperature ashes with high silicon content were characterized by second-derivative infrared spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD). The infrared spectra of raw coals show weak organic functional groups bands but strong kaolinite bands because of the relatively high silicates content. In contrast, the Raman spectra of raw coals show strong disordered carbon bands but no mineral bands since Raman spectroscopy is highly sensitive to carbonaceous phases. The overlapping bands of mineral components (e.g., calcite, feldspar, and muscovite) were successfully resolved by the method of second-derivative infrared spectroscopy. The results of infrared spectra indicate the presence of metakaolinite in coal ashes, suggesting the thermal transformation of kaolinite during ashing. Intense quartz bands were shown in both infrared and Raman spectra of coal ashes. In addition, Raman spectra of coal ashes show a very strong characteristic band of anatase (149 cm–1), although the titanium oxides content is very low. Combined use of second-derivative infrared spectroscopy and Raman spectroscopy provides valuable insight into the analyses of mineralogical composition. The XRD results generally agree with those of FTIR and Raman spectroscopic analyses.

A phenol-formaldehyde resin (PFR) and a bituminous coal (SH) were pyrolyzed at various temperatures. The structure and the char-NO reactivity were analyzed in order to examine the effect of pyrolysis temperature on the micro-structure of the resulting char and further on the reactivity towards NO. Micro-structure of the char samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy. It was indicated that the micro-structure of PFR char and coal char experienced remarkable changes during pyrolysis, which resulted in the decrease of phenolic OH, aromatic hydrogen and more ordered structure. The pyrolysis temperature showed a weak impact on the reactivity of PFR char but comparatively remarkable impact on that of coal char at lower reaction temperature. Mineral matter in coal char presented a weak effect on the reactivity.