In this reported work, lotus leaves‐derived biochar (LBC) was modified using various chemical methods. LBC prepared by different modification methods was used as the carrier for the development of low‐temperature selective catalytic reduction (SCR) catalysts. A comparative study of low‐temperature SCR manganese catalysts based on LBC chemically modified using NaOH, HNO3 and hexadecylcetyltrimethylammonium bromide (CTAB) was performed, revealing different deNOx performance of these catalysts. For the supported catalysts, the 25%Mn/LBC‐OH catalyst appeared to be optimum since it exhibited over 95% NOx conversion at 225 °C with a space velocity of 37 500 h−1. The microstructure, phase composition, redox properties and surface acidity were determined using field emission scanning electron microscopy, Brunauer–Emmett–Teller surface area, X‐ray diffraction, H2‐temperature‐programmed reduction, NH3‐temperature‐programmed desorption, and so forth. The results showed that the excellent SCR performance of 25%Mn/LBC‐OH was closely related to its abundant high valence Mn, suitable surface acidity and high redox capability. More importantly, highly dispersed MnOx easily formed on the surface of the LBC‐OH support, which was the key factor in the excellent catalytic activity of 25%Mn/LBC‐OH catalyst. Furthermore, the highly dispersed 25%Mn/LBC‐OH catalyst also exhibited improved tolerance to SO2 and H2O, making this catalyst a good candidate for reducing the NOx emission from coal‐fired power plants. © 2022 Society of Chemical Industry (SCI).

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The national architectural ceramic industrial center in east China is suffering from serious ambient fine particle pollution. The study reported herein describes an effort to ascertain the degree and sources of the PM2.5 collected at a ceramic industrial base in winter. The major chemical components in PM2.5 were analyzed, including carbonaceous aerosols, water-soluble ions, and inorganic elements. The chemical mass balance (CMB) model, backward trajectory method and potential source contribution function model, etc. were used to track and identify possible sources and contributions of these chemical components in the formation of the PM2.5. The results showed that the average PM2.5 concentration during sampling period was 134 ± 74.7 μg m -3 , which exceeding World Health Organization (WHO)Air Quality Guidelines levels. The dominant components in the PM2.5 at this sampling site were found to be secondary ions (sulfate and nitrate) and carbon fractions.Water-soluble ions and total carbon contributed about 48.7% and 13.9% of the PM2.5 mass, respectively. In addition, the SO4 2-/NO3ratio in the ambient PM2.5 during the sampling period was 1.16, indicating that it was the result of primarily emissions from stationary sources. Furthermore, source apportionment using the CMB model indicated that a ceramic industry source was the main contributor to the PM2.5 mass, which accounted for about 27.9%, and this was followed by secondary formation dust sources, and gasoline/diesel vehicle exhaust emissions and motor vehicle non-exhaust emissions. Based on the backward trajectory analysis and potential source apportionment, it was found that PM2.5 regional transmission existed, but it originated primarily from local sources and surrounding areas. Hence, this study provided a

BACKGROUND: Carbon materials have been regarded as valuable adsorbents for removal of volatile organic compounds (VOCs) owing to their high specific surface area and abundant pore structure. However, the complexity and high cost of the process used to treat the feedstock to produce commercial activated carbon has limited its application. In this reported study, a series of biochar materials was prepared using the KOH modification method employing corn cob as the raw material. The effects of different potassium hydroxide dosages, various activation temperatures and the activator addition method on the structure, physicochemical properties and VOC adsorption performance of the resulting biochars and their structure-activity relationship were systematically studied.RESULTS: Adsorption performance tests and a series of characterization results showed that the CC-3-700 (corn cob/KOH = 1:3, T = 700 °C, two-step dry mixing pyrolysis method) sample had highest toluene dynamic adsorption capacity (up to 573.5 mg g −1 ) compared to the other prepared samples. This result was attributed to the maximum specific surface area (2349 m 2 g −1 ) and pore volume (1.22 cm 3 g −1 ) of this sample. Moreover, the result suggested that the high specific surface area, abundant pore structure and highly disordered non-graphitizable carbon in sample CC-3-700 were the major reasons for its excellent adsorption performance. The results of a multi-component adsorption performance test showed that corn cob biochar had a strong adsorption capacity for toluene when simultaneously exposed to benzene and toluene. CONCLUSION:The results of this study revealed that the corn cob biochar prepared using a two-step roasting method offers good potential prospects for application in the field of VOC pollution control.