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In recent years, atmospheric composite pollution has become increasingly serious, and accelerating VOC governance has become the focus of and difficulty in atmospheric governance. Volatile organic compounds (VOCs) come from a wide range of sources, and industrial sources are the main source of anthropogenic VOC emissions in China. Chemicals, oil refining, and solvents are three typical VOC-emitting industries, and their control is an important part of accelerating and optimizing VOC governance. It can be controlled by source control, process control, and pipe end treatment; among these, pipe end treatment is divided into recovery technology and destruction technology. In pipeline end treatment, with the key materials of adsorption, absorption, catalytic oxidation, and catalytic combustion, the research and development of adsorbents, absorbents and catalysts has become a hot spot in recent years. This paper summarizes the chemical materials used in typical VOC pipe end-treatment technology (including adsorbents used in the adsorption method, absorbents used in the adsorption method, and catalysts used in the catalytic oxidation and catalytic combustion methods), summarizes the advantages and disadvantages of various materials and their application range, and looks forward to the direction of future developments. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are an important class of environmental pollutants, and there is much interest in China to eliminate such pollutants. Noble metal catalysts have long been a family of catalysts with high efficiency and good low-temperature catalytic activity. As a representative of the noble metals, Pt has been widely used. This paper reviews the research trend of Pt-based catalysts for the catalytic oxidation of VOCs, and it compares several important components of Pt-based catalysts. The size of Pt particles, supported carriers, and reaction mechanism are reviewed. Toluene in VOCs is the main research subject. The activity, stability, water resistance, and selectivity of a series of Pt-based catalysts are summarized. [ABSTRACT FROM AUTHOR]

Exceeding the permitted manganese (Mn2+) and ammonium (NH4+-N) levels is a frequent seasonal occurrence in a water treatment plant in south China. An iron Fe–Mn complex oxide film was found capable of removing more than 95% of Mn2+ and NH4+-N at a water temperature of 20 °C and an alkalinity level of 30 mg/L. It could remove up to 5.5 mg/L of Mn2+ and up to 3.5 mg/L of NH4+-N in a stable manner. Alkalinity is a crucial factor in the removal process. The morphology, elemental composition, and micro-structure of the oxide film were investigated using a scanning electron microscope, an energy-dispersive spectrometer, a Brunauer–Emmett–Teller specific surface-area analyzer, an X-ray diffractometer, and a Fourier-transform infrared spectrometer. The capacity of the Fe–Mn complex oxide film on the surface of the filter medium increased appreciably as its content and specific surface area increased. This research, which provides a theoretical basis for simultaneous manganese and NH4+-N removal by catalytic oxidation, demonstrates an engineering reference value. [ABSTRACT FROM AUTHOR]

In recent years, with the improvement of environmental protection requirements, the Ministry of Environmental Protection of the People's Republic of China has issued relevant pollutant emission standards. The emission requirements for volatile organic compounds (VOCs) have been raised from 25,000 mg/m³ to 120 mg/m³. The eastern coastal areas of China have implemented stricter emission standards. A complete set of VOCs recovery unit was built for the oil and gas produced by volatilization during storage and transporta-tion. Due to certain design defects of the original VOCs recovery device, the VOCs emission in the exhaust gas does not meet the standard requirements, and the mass concentration reaches 3,000~5,000 mg/m³, which can only be discharged after being treated by the catalytic oxidation device. After in-depth analysis of the causes of non-compliance of the exhaust gas of VOCs device, by optimizing the process flow of VOCs recovery device and improving the ratio of adsorbent, the VOCs content of the exhaust gas of VOCs recovery unit can be controlled within 50 mg/m³, which can achieve direct standard discharge, so as to effectively reduce the load of catalytic oxidation device, and fully recover oil and gas hydrocarbon resources, which has good economic and environmental protection value. [ABSTRACT FROM AUTHOR]

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biogas slurry, an inevitable outcome of anaerobic digestion (AD), is a treatment burden for urban environmental management. In this study, two kinds of biogas slurry (slurry J and slurry C), collected from the AD plants in Japan and China, were treated using novel TiZrO 4 @Cu and TiZrO 4 @Cu@SiO 2 multilayered hollow spheres containing Cu sub-nanoclusters as the catalyst. The results showed that the chemical oxygen demand (COD) was removed by 63 % for slurry J and 44 % for slurry C after 5 h. The Cu sub-nanoclusters acted as co-catalysts and active centers, facilitating rapid electron transfer to oxygen molecules and forming highly reactive •O 2 − and •OH species (Use slurry J as the based solution). These free radicals cleaved the interconnecting bonds between benzene rings, disintegrated the ring structure, formed intermediate compounds such as n-hexylic acid, and ultimately mineralized organic pollutants in biogas slurry into CO 2 and H 2 O. At the same time, TiZrO 4 @Cu@SiO 2 had excellent stability due to the protection of the SiO 2 shell and reduced threefold Cu leaching than TiZrO 4 @Cu. The COD removal rate was always 60 % in six cycles in the slurry J. The new catalyst ensured the high performance of catalytic air oxidation at low temperatures, which has significant potential as an environmentally friendly and energy-saving method for organic wastewater treatment. [Display omitted] • Cu sub-nanocluster embedded on the surface of TiZrO 4 hollow sphere was fabricated. • The TiZrO 4 @Cu protected by SiO 2 shell catalytic system had excellent stability. • The mechanism of TiZrO 4 @Cu catalyzing reactions was revealed through LSPR effects. • Cu sub-nanocluster catalyst activated O 2 to form •O 2 − and •OH radicals were proved. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co@NC-catalyzed oxidation rate of magnesium sulfite increased 14 times. • Co@NC has a large pore size and abundant surface reactive oxygen species. • Co-O on the surface of Co@NC dominates the catalytic activity in sulfite oxidation. • An environmentally friendly resource conversion method. Magnesium desulfurization is a wet flue gas desulfurization (WFGD) technology widely used in China, however, the low oxidation rate of magnesium sulfite (MgSO 3), a byproduct of WFGD, causes the subsequent oxidation and crystallization process to require amount energy. Here, we prepared a cobalt-based nitrogen-doped porous carbon catalyst (Co@NC) using ZIF-67 as a precursor for the efficient catalytic oxidation of MgSO 3 generated during magnesium desulfurization. The performance of Co@NC catalysts obtained at an optimal calcination temperature of 650 °C showed that the catalysts with oxidation rates up to 0.1332 mmol·L−1·s−1 of MgSO 3 were considerably better than those previously studied, which outperformed the catalysts described in earlier research by a considerable margin. Further studies revealed that the Co@NC's exceptional catalytic activity was attributed to both its special porous structure and the exposed active Co sites in the organic skeleton. The uniformly dispersed Co species act as the active sites of the Co@NC that can be fully contacted with the reactant. The presence of 0.5 g·L−1 Co@NC increases the MgSO 3 oxidation rate by about 14 times compared to the noncatalytic benchmark. A practical tactic is furnished by this research for energy saving and emission reduction in the WFGD process, especially for the efficient oxidation and resource conversion of the by-product MgSO 3. [ABSTRACT FROM AUTHOR]

Because of the nano-scale tunnel constructed by the active Mn-O octahedron in cryptomelane, cryptomelane-type manganese oxides have high activity in the oxidation of several volatile organic compounds (VOCs). Natural cryptomelane, in the form of supergene oxide manganese ore, carpets much of South China. In the lower part of the Datangpo Formation of Nanhua System on the southeastern Yangtze Platform, cryptomelane is one of the major manganese oxides in black shale of the Xiangtan manganese deposit in this deposit. Formaldehyde is a dominant indoor pollutant among volatile organic compounds (VOCs), and applications of synthetic cryptomelane have been reported to eliminate it. To study the removal capacity of naturally outcropping cryptomelane, representative samples of manganese oxide (the primary mineral component of cryptomelane) from the Xiangtan Mn deposit were analyzed in this study. The chemical composition, crystal structure and micromorphology of the manganese oxide minerals were explored using ICP-AES, XRD, EPMA, SEM and HR-TEM techniques. Fine-grained and poorly crystalline, these minerals consist primarily of cryptomelane, along with minor amounts of pyrolusite, hollandite, lithiophorite, limonite and quartz. Natural cryptomelane is a monoclinic crystal, and its cell parameters are refined. The results of catalytic tests revealed that natural cryptomelane has obvious catalytic activity in the oxidation of formaldehyde in a static environment under room temperature. This study may provide a natural mineral material as an inexpensive and efficient catalyst for the purification of formaldehyde in industrial or indoor air treatment. [ABSTRACT FROM AUTHOR]

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study of copper slag has attracted the attention of scholars from both China and around the world. But few have paid attention to its applications in the simultaneous removal of SO2 and NOx in wet flue gas desulfurization (WFGD), becasue WFGD technique is inappropriate for directly treating NOx owing to the low solubility of NO. This work aims to improve NOx removal efficiency in WFGD technology using copper slag slurry associated with the oxidation of NOx by yellow phosphorus. Different operating conditions, including dispersion of P4, solid‐liquid ratio, initial pH value of copper slag slurry, reaction temperature, oxygen content, and gas flow rate, were compared regarding the efficiency of SO2 and NOx simultaneous removal. The characterizations were carried out on the liquid and solid part of fresh and spent copper slag slurry after filtration. The results indicated that a great amount of metals ions, such as Fe3+ and Zn2+, were leached by reacting with produced acids (H2SO4, HNO3, and H3PO4), which had a liquid‐phase catalytic oxidation on SIV species (SO32−/HSO3−), leading to promotion in absorption for SO2. The copper slag played a significant role in dispersing the yellow phosphorus and promoting ozone generation, thus improving NOx removal efficiency. The reaction pathway can be divided into three parts: (a) ozone generation induced by yellow phosphorus, (b) the oxidation of NO by O3 and then dissolution in aqueous solution, and (c) the dissolution of SO2 and the liquid‐phase oxidation for SO2 through metal ions produced by the reaction between acid and copper slag. [ABSTRACT FROM AUTHOR]

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cooking emission is an important reason for the air quality deterioration in the metropolitan area in China. Transition metal oxide and different loading of manganese oxide supported on cordierite were prepared by incipient wetness impregnation method and were used for non-methane hydrocarbon (NMHC) oxidation in cooking oil fumes (COFs). The effects of different calcination temperature and different Mn content were also studied. The SEM photographs and CO2 temperature-programmed desorption revealed 5 wt% Mn/cordierite had the best pore structure and the largest number of the weak and moderate basic sites so it showed the best performance for NMHC oxidation. XRD analysis exhibited 5 wt% Mn/cordierite had the best dispersion of active phase and the active phase was MnO2 when the calcination temperature was 400℃ which were good for the catalytic oxidation of NMHC. [ABSTRACT FROM AUTHOR]

Due to the long lifespan of thermal oxidizers (over 20 years), outdated facilities might still be operational. However, these oxidizers may not be energy efficient due to the lack of an energy recovery system. Thus, those outdated facilities need to be either retrofitted or replaced to decrease both energy and fuel consumption. In this regard, it is important to systematically assess the costs and environmental impact of the available technological options to promote more informed selection criteria for new oxidizers. Therefore, the environmental and economic performances of a recuperative thermal oxidizer and a catalytic thermal oxidizer were assessed in this study to provide a decision support tool for the selection of new incinerators. These two scenarios have been compared to an outdated thermal oxidizer such as a direct flame incinerator, which was selected as a baseline scenario. The life cycle assessment of the three oxidizers has been performed using SimaPro software according to the ReCiPe method at mid-point level (hierarchist). The main sources of impact for the considered oxidizers are the natural gas needed for the operation of the combustion chamber, electricity and gaseous emissions, including CO 2 , water and residual volatile organic compounds. The results indicated that both alternatives could significantly reduce the overall impact of the thermal oxidation process compared to the baseline case. However, the catalytic oxidation process emerged as the most sustainable technological option due to its lower fuel and electricity requirements. Moreover, the cost analysis of the scenarios considered clearly demonstrated that the catalytic oxidizer could represent the most cost effective alternative. This is due to its lower annual costs, which might offset the higher investment necessary to set-up a catalytic oxidizer within the first year of operation. Image 1 • LCA of three thermal oxidizers for VOCs oxidation are conducted. • Electricity and fossil fuel are the main contributors to the impact of all oxidizers. • RTO and CTO are more sustainable technological option compared to TO • CTO emerged as the most cost effective among the oxidizers considered. [ABSTRACT FROM AUTHOR]

The low-temperature catalytic oxidation of heavy crude oil (Xinjiang Oilfield, China) was studied using three types of catalysts including oil-soluble, water-soluble, and dispersed catalysts. According to primary screening, oil-soluble catalysts, copper naphthenate and manganese naphthenate, are more attractive, and were selected to further investigate their catalytic performance in in situ upgrading of heavy oil. The heavy oil compositions and molecular structures were characterized by column chromatography, elemental analysis, and Fourier transform infrared spectrometry before and after reaction. An Arrhenius kinetics model was introduced to calculate the rheological activation energy of heavy oil from the viscosity-temperature characteristics. Results show that the two oil-soluble catalysts can crack part of heavy components into light components, decrease the heteroatom content, and achieve the transition of reaction mode from oxygen addition to bond scission. The calculated rheological activation energy of heavy oil from the fitted Arrhenius model is consistent with physical properties of heavy oil (oil viscosity and contents of heavy fractions). It is found that the temperature, oil composition, and internal molecular structures are the main factors affecting its flow ability. Oil-soluble catalyst-assisted air injection or air huff-n-puff injection is a promising in situ catalytic upgrading method for improving heavy oil recovery. [ABSTRACT FROM AUTHOR]

Catalytic oxidation is widely used in the treatment of refractory wastewater. However, catalytic oxidation has some problems such as high cost and limited production of radicals. To improve these, in this study, a new process of O 3 /H 2 O 2 /Fe-shavings which coupled catalytic ozonation and Fenton-like oxidation with Fe-shaving wastes reused, was used in the treatment of coking wastewater secondary biochemical effluent (CWSBE). The effects of the environmental conditions on the degradation of CWSBE were studied and the response surface method was used to optimise the parameters. The performances in organic pollutant removal from CWSBE were systematically analysed by a couple of methods such as gas chromatography mass spectrometry and three-dimensional fluorescence. The results showed that macromolecular organics were degraded into small molecules pollutants after treatment by the O 3 /H 2 O 2 /Fe-shavings process. At an ozone concentration of 27.5 mg/L, with the hydrogen peroxide concentration being 10.7 mmol/L, the reaction time 60 min, the initial pH value 3.6, and the pump speed 150 rpm, the COD removal degradation efficiency was 77.5%, and the effluent COD met relevant wastewater discharge standards in China (GB 16171-2012). The mechanism research showed that·OH plays an important role in the degradation of organic pollutants. [Display omitted] • The COD removal efficiency when using the O 3 /H 2 O 2 /Fe-shavings process was 77.5%. • Response surface method was suitable for parameter prediction (R2 Adj >0.97). • The molecular weights of the treated pollutants were majorly <1 kDa (86%). • Fe-shavings improve the concentration of·OH in the O 3 /H 2 O 2 /Fe-shavings process. [ABSTRACT FROM AUTHOR]

In response to extreme environmental conditions, Bactrian camels with largest population in China have evolved with the unique and extraordinary stress-tolerant mechanism in the bodies, in which the most abundantly secreted serum albumins contribute to an important role in diverse physiological activities such as maintaining osmotic pressure and transporting endogenous/exogenous molecules. In this study, we have for the first time purified Chinese Bactrian camel serum albumins (CSA) aimed at exploring their biomedical application. The mass spectrometric as well as structural analysis of CSA have revealed the sequence consensus and alpha-helix abundant structures among its heterologous proteins. Using desolvation methods, CSA-based nanoparticles have been prepared to encapsulate two substrate molecules including Doxorubicin (Dox) and hemin, which confers the versatility of nanocomposite. As drug delivery matrix, the Dox-loaded CSA nanoparticles displayed sustained release behaviors of DOX with the decreased cytotoxicity detected by both CCK-8 assay and real-time cell analysis. The CSA-hemin nanoparticles exhibited superior catalytic activities in the oxidation of Orange II comparable with horse radish peroxidase following a ping-pong mechanism. Furthermore, the constructed CSA-hemin nanoparticles were applied for the spectroscopic detection of H 2 O 2 resulting in a wide linear calibration curve ranging from 5 to 400 μM with a detection limit of 3.32 μM. Unlabelled Image • Chinese Bactrian camel serum albumins (CSA) was purified for biomedical use. • The amino acid sequence of CSA was solved for the first time. • A versatile biocargo of CSA was built for biocatalysis and bioanalysis. [ABSTRACT FROM AUTHOR]

Phosphate removal through in-situ Fe2+ oxidation induced homogenous phosphate precipitation has shown its advantages in municipal wastewater treatment. Its feasibility and suitability for phosphate removal in industrial wastewater with wide-range pH variation like electro-plating wastewater were investigated in bench scale experiments using synthetic wastewater and continuous experiment using real wastewater. Bench scale experiments showed that different Fe2+ oxidation approaches worked well for phosphate removal at varied pH conditions. Sole dosing Fe2+ salt with aeration achieved sound phosphate removal at alkaline condition (pH ≥ 8). At neutral pH (6 < pH < 8), transition metallic ions catalytic oxidation is a suitable alternative. Cu2+ exhibited superior catalytic Fe2+ oxidization over Mn2+, Zn2+, and Ni2+. At acid pH (3.0 ＜ pH ≤ 6.0), Fenton reaction oxidation (H 2 O 2 = 5 mg/L) showed its efficiency. At their corresponding optimal pH conditions and with Fe2+/P ratio of 1.8, dosing sole Fe2+ salt, Cu2+ catalyzed Fe2+ oxidation, and Fe2+/H 2 O 2 treatments can achieve the TP discharge limit of 0.5 mg/L. In a 30-day continuous experiment using real electro-plating wastewater (pH 4.9–5.5), in both direct Fe2+/H 2 O 2 treatment and Cu2+ catalyzed Fe2+ oxidation treatment after wastewater pH being adjusted to 7 effluent TP met China's discharge requirement 0.5 mg/L. • In-situ Fe2+ oxidation induced homogenous precipitation is efficient for P removal. • Phosphate removal efficiency is altered by pH and oxidation approaches. • Sole dosing Fe2+ with aeration has sound phosphate removal at alkaline pH (pH ≥ 8). • Cu2+ catalytic Fe2+ oxidation works well for phosphate removal at pH 6–8. • Fenton reaction oxidation shows efficient phosphate removal at acid pH. [ABSTRACT FROM AUTHOR]

Herein we fabricated the supported single-atom silver catalysts using an in situ molten salt method. The Mn 2 O 3 nanowires supported single-atom silver catalyst (i.e., 0.06 wt% Ag/Mn 2 O 3 ) exhibited excellent catalytic activity for toluene combustion, with the temperatures required for 50 and 90% of toluene conversions being 170 and 205 °C, respectively, at a space velocity of 40,000 mL/(g h). However, the toluene conversion at 205 °C quickly decreased from 90 to 30% within 2.5 h of on-stream reaction. Based on the various characterization results, we found that there were no aggregation of Ag particles, no change in crystal structure of the Mn 2 O 3 nanowire support, and no carbon deposition on the catalyst surface, and the quick deactivation of 0.06 wt% Ag/Mn 2 O 3 was mainly associated with the low oxygen activation ability. The proper CeO 2 addition to the 0.06 wt% Ag/Mn 2 O 3 catalyst was found to not only improve the catalytic activity but also significantly enhance the stability of the catalyst. Toluene conversion at 195 °C over 0.63 wt% CeO 2 -0.06 wt% Ag/Mn 2 O 3 decreased by only 10% in 50 h of on-stream reaction. Because Ag and CeO 2 particles were highly dispersed on the Mn 2 O 3 nanowire support, the oxygen species formed at the surface oxygen vacancies of CeO 2 could efficiently migrate to the active sites (i.e., the interface of Ag-Mn 2 O 3 ) and replenish the surface reactive lattice oxygen species. Thus, the present single-atom silver catalyst is an alternative for commercial noble metal catalysts for the removal of VOCs., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)