Abstract ：

The PdPtVOx/CeO2−ZrO2 (PdPtVOx/CZO) catalysts were obtained by using different approaches, and their physical and chemical properties were determined by various techniques. Catalytic activities of these materials in the presence of H2O or SO2 were evaluated for the oxidation of ethylbenzene (EB). The PdPtVOx/CZO sample exhibited high catalytic activity, good hydrothermal stability, and reversible sulfur dioxide-poisoning performance, over which the specific reaction rate at 160°C, turnover frequency at 160°C (TOFPd or Pt), and apparent activation energy were 72.6 mmol/(gPt⋅sec) or 124.2 mmol/(gPd⋅sec), 14.2 sec−1 (TOFPt) or 13.1 sec−1 (TOFPd), and 58 kJ/mol, respectively. The large EB adsorption capacity, good reducibility, and strong acidity contributed to the good catalytic performance of PdPtVOx/CZO. Catalytic activity of PdPtVOx/CZO decreased when 50 ppm SO2 or (1.0 vol.% H2O + 50 ppm SO2) was added to the feedstock, but was gradually restored to its initial level after the SO2 was cut off. The good reversible sulfur dioxide-resistant performance of PdPtVOx/CZO was associated with the facts: (i) the introduction of SO2 leads to an increase in surface acidity; (ii) V can adsorb and activate SO2, thus accelerating formation of the SOx2− (x = 3 or 4) species at the V and CZO sites, weakening the adsorption of sulfur species at the PdPt active sites, and hence protecting the PdPt active sites to be not poisoned by SO2. EB oxidation over PdPtVOx/CZO might take place via the route of EB → styrene → phenyl methyl ketone → benzaldehyde → benzoic acid → maleic anhydride → CO2 and H2O. © 2023

Keyword ：

Sulfur dioxide resistance Volatile organic compound Supported palladium−platinum−vanadium catalyst Ceria−zirconia Ethylbenzene oxidation

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Abstract ：

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen removal. However, how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application, especially in mainstream wastewater treatment. In this study, the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of bio-carriers. By using ordinary activated sludge, a sequencing batch reactor (SBR) followed by an up-flow anaerobic sludge bed (UASB) was operated at 25 ± 2°C for 214 days. The long-term operation was divided into five phases, in which SBR and UASB were started-up in Phases I and II, respectively. By eliminating oxygen and adjusting the inflow ratios in Phases III-V, advanced nitrogen removal was achieved with the effluent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5% in Phase V. Both in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and anammox. Moreover, 16S rRNA high-throughput sequencing analysis revealed that Candidatus Brocadia was enriched from below the detection limit to in biofilms (0.4% in SBR, 2.2% in UASB) and the floc sludge (0.2% in SBR, 1.3% in UASB), while Thauera was mainly detected in the floc sludge (8.1% in SBR, 8.8% in UASB), which might play a key role in partial denitrification. Overall, this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers, which will improve large-scale application of anammox processes in mainstream wastewater treatment. © 2023

Keyword ：

Enrichment Mainstream wastewater Anammox biomass Partial denitrification Bio-carriers

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Abstract ：

Previous air pollution control strategies didn't pay enough attention to regional collaboration and the spatial response sensitivities, resulting in limited control effects in China. This study proposed an effective PM2.5 and O3 control strategy scheme with the integration of Self-Organizing Map (SOM), Genetic Algorithm (GA) and WRF-CAMx, emphasizing regional collaborative control and the strengthening of control in sensitive areas. This scheme embodies the idea of hierarchical management and spatial-temporally differentiated management, with SOM identifying the collaborative subregions, GA providing the optimized subregion-level priority of precursor emission reductions, and WRF-CAMx providing response sensitivities for grid-level priority of precursor emission reductions. With Beijing-Tianjin-Hebei and the surrounding area (BTHSA, “2 + 26” cities) as the case study area, the optimized strategy required that regions along Taihang Mountains strengthen the emission reductions of all precursors in PM2.5-dominant seasons, and strengthen VOCs reductions but moderate NOx reductions in O3-dominant season. The spatiotemporally differentiated control strategy, without additional emission reduction burdens than the 14th Five-Year Plan proposed, reduced the average annual PM2.5 and MDA8 O3 concentrations in 28 cities by 3.2%–8.2% and 3.9%–9.7% respectively in comparison with non-differential control strategies, with the most prominent optimization effects occurring in the heavily polluted seasons (6.9%–18.0% for PM2.5 and 3.3%–14.2% for MDA8 O3, respectively). This study proposed an effective scheme for the collaborative control of PM2.5 and O3 in BTHSA, and shows important methodological implications for other regions suffering from similar air quality problems. © 2023

Keyword ：

SOM WRF-CAMx PM2.5 and O3 control GA Machine learning Bionic algorithm

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Abstract ：

控制大气中的氮氧化物的排放对环境和健康有着至关重要的作用，应用于NO_(x)去除的技术有很多，其中选择性催化还原技术（NH_(3)-SCR）是去除NO_(x)最有效的技术之一，利用CO去除NO_(x)为烟气脱硝提供了一种简单且低成本的技术（CO-SCR），直接催化分解NO被认为是去除NO_(x)最理想、最环保的技术。Cu离子分子筛作为去除NO_(x)的高效催化剂，具有宽温度窗口和良好的水热稳定性。本文综述了Cu交换分子筛在去除NO领域的研究进展，讨论了Cu离子分子筛在NH_(3)-SCR、CO-SCR以及直接催化分解NO中的应用，着重总结了Cu离子参与去除NO的反应机理，归纳了分子筛中Cu活性位点对性能的影响。此外，还讨论了铜离子分子筛的抗H_(2)O和SO_(2)中毒性能。展望了Cu离子分子筛未来可能的发展方向。

Keyword ：

Cu离子分子筛 NH_(3)-SCR NO直接分解 CO-SCR NO_(x)去除

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Abstract ：

An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5 and O3 compound pollution in China. We estimated the anthropogenic VOC emission inventory in China in 2018 and established a source profile database containing 129 sources based on localized detection and the latest research results. Then, the distribution of the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) for emission sources was analyzed. Moreover, priority control routes for VOC emission sources were proposed for different periods. Anthropogenic VOC emissions in China reached 27,211.8 Gg in 2018, and small passenger cars, industrial protective coatings, biomass burning, heavy trucks, printing, asphalt paving, oil storage and transportation, coking, and oil refining were the main contributors. Industrial protective coatings, small passenger cars, and biomass burning all contributed significantly to OFP and SOAFP. Priority in emission reduction control should be given to industrial protective coatings, small passenger cars, heavy trucks, coking, printing, asphalt paving, chemical fibers, and basic organic chemical sources over the medium and long term in China. In addition, the priority control route for VOC emission sources should be adjusted according to the variations in VOC emission characteristics and regional differences, so as to obtain the maximum environmental benefits. © 2022

Keyword ：

Reactivity Volatile organic compounds Anthropogenic emission inventory Emission projection Priority control route

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以柠檬酸（CA）和聚乙二醇聚丙二醇单甲醚（MPEPPG）为主要反应原料，进行酯化反应合成一种柠檬酸改性低分子量减水剂（LMWS）。通过红外光谱、核磁氢谱和凝胶色谱测试获得合成减水剂的结构参数信息。同时通过动态光散射（DLS）、水泥净浆Zeta电位、减水剂对水泥的吸附性能、水泥净浆凝结时间、水泥水化热、塑性粘度、水泥净浆流动度及混凝土性能等研究对比了相同酸醚比（n(CA):n(MPEPPG) = 1:1），不同分子量LMWS的综合性能。结果表明：相同掺量条件下，分子量适中的LMWS-3显著降低水泥净浆的塑性粘度并延缓水泥的水化进程，具有优异的初始分散和分散保持性能。

Keyword ：

酯化 低分子量减水剂 混凝土 柠檬酸

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A study was conducted on aerosol-radiation interactions over six cities in this region within the 2015–2019 period. WRF-Chem simulations on 2017 showed that based on the six-city average, the aerosol load (PM2.5 concentrations) of 121.9, 49.6, 43.3, and 66.3 µg/m3 in January, April, July, and October, mainly lowered the level of downward shortwave radiation by 38.9, 24.0, 59.1, and 24.4 W/m2 and reduced the boundary layer height by 79.9, 40.8, 87.4, and 31.0 m, via scattering and absorbing solar radiation. The sensitivity of meteorological changes to identical aerosol loads varied in the order July > January > October and April. Then, the cooling and stabilizing effects of aerosols further led to increases in PM2.5, by 23.0, 3.4, 4.6, and 7.3 µg/m3 respectively in the four months. The sensitivity of the effect of aerosols on PM2.5 was greatest in January rather than in July, contrary to the effect on meteorology. Moreover, a negative linear relation was observed between daily BLH reductions and aerosol loads in fall and winter, and between PM2.5 increases and aerosol loads in all seasons. With the PM2.5 pollution improvements in this region, the aerosol radiative forcing was effectively reduced. This should result in daily BLH increases of 10–24 m in fall and winter, and the estimates in Beijing agreed well with the corresponding results based on AMDAR data. Additionally, the reduction in aerosol radiation effects brought about daily PM2.5 decreases of 1.6-2.8 µg/m3, accounting for 7.0%–17.7% in PM2.5 improvements. © 2022

Keyword ：

Boundary layer height (BLH) PM2.5 Radiative forcing Aerosol North China

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Abstract ：

This study employed multispectral techniques to evaluate fulvic acid (FA) compositional characteristic and elucidate its biodegradation mechanisms during partial nitritation (PN) process. Results showed that FA removal efficiency (FRE) decreased from 90.22 to 23.11% when FA concentrations in the reactor were increased from 0 to 162.30 mg/L, and that molecular size, degree of aromatization and humification of the effluent FA macromolecules all increased after treatment. Microbial population analysis indicated that the proliferation of the Comamonas, OLB12 and Thauera exhibit high FA utilization capacity in lower concentrations (<50.59 mg/L), promoting the degradation and removal of macromolecular FA. In addition, the sustained increase in external FA may decrease the abundance of above functional microorganisms, resulting in a rapid drop in FRE. Furthermore, from the genetic perspective, the elevated FA levels restricted carbohydrate (ko00620, ko00010 and ko00020) and nitrogen (HAO, AMO, NIR and NOR) metabolism-related pathways, thereby impeding FA removal and total nitrogen loss associated with N2O emissions. © 2022

Keyword ：

Partial nitritation UV/Vis 3DEEM-PARAFAC Fulvic acid Microbially driven mechanism

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Weld scam tracking is the key technology for achieving automated welding. In this paper, a scam tracking method based on a line array camera and a feature recognition algorithm is constructed to provide gapless seam recognition under laser welding. The workpiece surface image is captured by a line array camera and denoised by mean filtering. By analyzing the gray value of the image, the change in the gray value of the image, the gray gradient of the image, and the width of the weld area, the weld track is identified, and the identification and tracking of the gapless weld are realized. Welding experiments are conducted, and the results show that the error of the weld identification method based on a line array camera is less than 0. 05 mm. Weld seam tracking experiments on welds with different a gap are conducted, and the results show that the proposed method has a good recognition effect for welds with a gap less than 0. 3 mm.

Keyword ：

laser welding gapless weld line array camera laser technique welded identification

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