不同基原秦皮、香豆素单体抗菌作用对比研究

目的研究4种基原秦皮提取物、5种香豆素单体、5种单体混合物、苦枥白蜡树树皮已知香豆素指纹区样品、未知成分指纹区样品的体外抑菌作用。方法采用体外抑菌试验微量定量检测方法，测定最小抑菌浓度及最低杀菌浓度。结果4种基原秦皮苦枥白腊树、尖叶白腊树、白腊树、宿柱白腊树树皮均有明显抑菌、杀菌作用，抑菌强度依次为：宿柱白腊树〉苦枥白腊树〉尖叶白腊树〉白腊树。5种香豆素单体秦皮素、秦皮乙素对9种细菌均有明显抑菌、杀菌作用，秦皮甲素、秦皮苷对金黄色葡萄球菌、表皮葡萄球菌有一定抑菌、杀菌作用，抑菌作用依次为：秦皮素〉秦皮乙素〉秦皮甲素〉秦皮苷〉6，7-二甲氧基-8-羟基香豆素。苦枥白腊树树皮提取物对所试9种细菌均有明显抑菌作用；单体混合物，已知香豆素指纹区样品对金黄色葡萄球菌、表皮葡萄球菌、乙型溶血性链球菌、绿脓杆菌、大肠杆菌、肺炎克雷伯氏菌、卡他菌有明显抑菌作用；未知成分指纹区样品对金黄色葡萄球菌有明显抑菌作用，对表皮葡萄球菌、甲型溶血性链球菌、乙型溶血性链球菌、大肠杆菌、沙门氏菌也有一定抑菌作用。结论秦皮抑菌强弱与已知香豆素成分含量高低基本一致。秦皮中苷元的抑菌作用优于苷，5种香豆素类单体中秦皮素、秦皮乙素抑菌作用最强。     

焚烧飞灰处理技术与资源化利用研究进展

焚烧飞灰中含有可溶盐、重金属、痕量有机物及二恶英等物质,对环境和人体健康造成极大的危害。介绍了目前熔融处理、水泥固化、化学药剂稳定化等处理技术的研究进展,总结了飞灰资源化利用途径,提出了未来研究方向的建议。     

Incense stick ash as a novel and sustainable adsorbent for sequestration of Victoria Blue from aqueous phase

The present investigation assessed the applicability of incense stick ash, a novel and sustainable adsorbent for remediation of Victoria Blue dye from wastewater. Incense stick ash, without any physical and chemical treatment has been applied to investigate the influence of various experimental parameters as pH, loading of adsorbent, concentration, shaking time, temperature and ionic strength on Victoria Blue remediation in a batch operation. Incense stick ash was characterized using BET, DLS, SEM-EDS, FTIR and XRD techniques. BET surface area, pore volume and pore diameter of incense stick ash are obtained as 2.245 m² g^?1, 0.0118 cm³ g^?1 and 21.02 nm, respectively. Average particle size of the adsorbent is obtained as 293.2 nm. Goodness of the fit of isotherm and kinetic model to the reported data was identified based on chi squared and coefficient of determination values. Isotherm and kinetic behavior was best represented by Freundlich and pseudo 2nd order equation, respectively. Boyd model confirmed involvement of film diffusion mechanism along with intra-particle for adsorption of Victoria Blue on incense stick ash. Maximum dye uptake was reported as 105.57 mg g^?1. Thermodynamic study revealed spontaneous and favorable adsorption of Victoria Blue on incense stick ash at higher temperature. The performed elution and subsequent regeneration study implied desorption capability of incense stick ash and its applicability as a fresh adsorbent for further cycle of adsorption. The overall study implied scavenging potential of incense stick ash, a novel and sustainable adsorbent available at zero cost towards Victoria Blue removal.     

Coal fly ash is a major carbon flux in the Chang Jiang (Yangtze River) basin

Fly ash—the residuum of coal burning—contains a considerable amount of fossilized particulate organic carbon (FOC_ash) that remains after high-temperature combustion. Fly ash leaks into natural environments and participates in the contemporary carbon cycle, but its reactivity and flux remained poorly understood. We characterized FOC_ash in the Chang Jiang (Yangtze River) basin, China, and quantified the riverine FOC_ash fluxes. Using Raman spectral analysis, ramped pyrolysis oxidation, and chemical oxidation, we found that FOC_ash is highly recalcitrant and unreactive, whereas shale-derived FOC (FOC_rock) was much more labile and easily oxidized. By combining mass balance calculations and other estimates of fly ash input to rivers, we estimated that the flux of FOC_ash carried by the Chang Jiang was 0.21 to 0.42 Mt C⋅y⁻¹ in 2007 to 2008—an amount equivalent to 37 to 72% of the total riverine FOC export. We attributed such high flux to the combination of increasing coal combustion that enhances FOC_ash production and the massive construction of dams in the basin that reduces the flux of FOC_rock eroded from upstream mountainous areas. Using global ash data, a first-order estimate suggests that FOC_ash makes up to 16% of the present-day global riverine FOC flux to the oceans. This reflects a substantial impact of anthropogenic activities on the fluxes and burial of fossil organic carbon that has been made less reactive than the rocks from which it was derived.

Fossil particulate organic carbon (FOC) is a geologically stable form of carbon that was produced by the ancient biosphere and then buried and stored in the lithosphere; it is a key player in the geological carbon cycle (1–7). Uplift and erosion liberate FOC from bedrock, delivering it to the surficial carbon cycle. Some is oxidized in sediment routing systems, but a portion escapes and can be transported by rivers to the oceans (5, 8–10). Oxidation of FOC represents a long-term atmospheric carbon source and O₂ sink, whereas the reburial of FOC in sedimentary basins has no long-term net effect on atmospheric CO₂ and O₂ (1, 9, 11). Exhumation and erosion of bedrock provide a natural source of FOC (2, 8), which we refer to as FOC_rock. Human activities have introduced another form of FOC from the mining and combustion of coal. Burning coal emits CO₂ to the atmosphere but also leaves behind solid waste that contains substantial amounts of organic carbon (OC) that survives high-temperature combustion (12–14). This fossil-fuel-sourced carbon represents a poorly understood anthropogenic flux in the global carbon cycle; it also provides a major source of black carbon, which is a severe pollutant and climate-forcing agent (12–15).Previous studies sought to quantify black carbon in different terrestrial and marine environments and to distinguish fossil fuel versus forest fire sources (14–18). In this study, we focused on fly ash—the material left from incomplete coal combustion. As a major fossil fuel, coal supplies around 30% of global primary energy consumption (19, 20). Despite efforts to capture and utilize fly ash, a fraction enters soils and rivers; the resulting fossil OC from fly ash (FOC_ash) has become a measurable part of the contemporary carbon cycle (14). FOC_ash is also referred to as “unburned carbon” in fly ash (21–25); it provides a useful measure of combustion efficiency and the quality of fly ash as a building material (e.g., in concrete) (23–26). Industrial standards of FOC_ash content in fly ash have been established for material quality assurance (23, 24, 26, 27). However, the characteristics and fluxes of FOC_ash released to the environment, and how these compare to FOC_rock from bedrock erosion, remain less well understood.To fill this knowledge gap, we examined the Chang Jiang (Yangtze River) basin in China—a system that allowed us to evaluate the influence of FOC_ash on the carbon cycle at continental scales. In the 2000s, China became the largest coal-consuming country in the world, with an annual coal consumption of over 2,500 Mt, equating to ∼50% of worldwide consumption (19, 20, 28). Coal contributed over 60% of China’s national primary energy consumption through the 2000s. A significant portion of this coal (approximately one-third) was consumed in the Chang Jiang (CJ) basin, where China’s most populated and economically developed areas are located (29). Significant amounts of fly ash and FOC_ash continue to be produced and consumed in the CJ basin. To determine the human-induced FOC_ash flux, we investigated the FOC_ash cycle in the CJ basin. We characterized OC in a series of samples including fly ash, bedrock sedimentary shale, and river sediment through multiple geochemical analyses. We then estimated the CJ-exported FOC_ash flux and evaluated how human activities modulated FOC transfer at basin scales. We found that in the CJ basin, coal combustion and dam construction have conspired to boost the FOC_ash flux and reduce the FOC_rock flux carried by the CJ; as a result, these two fluxes converged over an interval of 60 y.     

四川市售白芍饮片质量调研

目的:调研四川市售白芍饮片质量。方法:随机采购四川市售白芍饮片16批,参照现行2010版药典的规定,测定饮片水分、总灰分、水溶性浸出物,并采用HPLC法测定芍药苷含量。结果:16批次白芍饮片中仅3批次芍药苷的量符合药典规定,9批次水分符合药典规定。结论:白芍饮片存在的质量问题主要是芍药苷含量和水分含量不合格。针对导致白芍药材或饮片质量问题的多种原因,药品监督管理部门应加强监督管理,规范饮片市场。     

The Correlation of Temperature-Mineral Phase Transformation as a Controlling Factor of Thermal and Mechanical Performance of Fly Ash-Based Alkali-Activated Binders

This research focuses on an evaluation of mineral phase and structure transformations in Class F fly ash-based geopolymer systems. The research also studies the strength response of geopolymers when exposed to temperatures between 25 and 800 °C. The purpose of this research is to understand the processes that occur in alkali-activated systems within a wide range of high-working temperatures. The XRD, SEM, and DTA/TG analyses performed for the alkali-activated compositions after exposure to different temperatures confirmed a direct correlation of structural transformations with strength performance. The detrimental effect of sodium hydrocarbonate Na₃(HCO₃)(CO₃) 2H₂O or trona contained in one of the fly ash products was observed for the corresponding alkali-activated composite under high-temperature exposure between 600 and 800 °C. It was also detected that a high-temperature interval of 400–800 °C created favorable conditions that helped to form nanosized nepheline crystals and an additional vitreous substance that also contributed to a denser alkali-activated matrix.     

A Study on the Utilization of Coal Fly Ash Derived Grog in Clay Ceramics

Grog is an additive material that plays important roles in ceramic making. It improves the fabrication process of green bodies as well as the physical properties of fired bodies. Few low-cost materials and wastes have found their application as grog in recent years, thus encouraging the replacement of commercial grogs with cost-saving materials. Coal fly ash, a combustion waste produced by coal-fired power plant, has the potential to be converted into grog owing to its small particle sizes and high content of silica and alumina. In this study, grog was derived from coal fly ash and mixed with kaolin clay to produce ceramics. Effects of the grog addition on the resultant ceramics were investigated. It was found that, to a certain extent, the grog addition reduced the firing shrinkage and increased the total porosity of the ceramics. The dimensional stability of the ceramics at a firing temperature of 1200 °C was also not noticeably affected by the grog. However, the grog addition in general had negative effects on the biaxial flexural strength and refractoriness of the ceramics.     

Evaluation of Hybrid Melamine and Steel Fiber Reinforced Geopolymers Composites

This study investigated the influence of the steel and melamine fibers hybridization on the flexural and compressive strength of a fly ash-based geopolymer. The applied reinforcement reduced the geopolymer brittleness. Currently, there are several types of polymer fibers available on the market. However, the authors did not come across information on the use of melamine fibers in geopolymer composites. Two systems of reinforcement for the composites were investigated in this work. Reinforcement with a single type of fiber and a hybrid system, i.e., two types of fibers. Both systems strengthened the base material. The research results showed the addition of melamine fibers as well as steel fibers increased the compressive and flexural strength in comparison to the plain matrix. In the case of a hybrid system, the achieved results showed a synergistic effect of the introduced fibers, which provided better strength results in relation to composites reinforced with a single type of fiber in the same amount by weight.     

Hardening Slurries with Fluidized-Bed Combustion By-Products and Their Potential Significance in Terms of Circular Economy

Hardening slurries (water-bentonite-binder mixtures) constitute a well-established material used broadly, i.a., for cut-off walls in civil and water engineering. Although they usually contain Portland cement, similar to common concrete, their properties differ greatly, mostly due to a much higher water content. This characteristic of hardening slurries creates unique opportunities for the utilization of significant quantities of industrial by-products that are deemed problematic in the concrete industry. This article investigates the effect of the addition of by-products of fluidized-bed combustion of hard, brown coal and municipal sewage sludge, as well as ground granulated blast furnace slag, on the properties of slurries. Unconfined compressive strength tests, as well as mercury porosimetry, scanning electron microscopy, and X-ray diffraction analyses were performed. The results suggest that it is possible to design hardening slurry mixes of desired properties, both in liquid and solid state, containing at least 100–300 kg/m³ of industrial waste. This includes cement-free slurries based entirely on industrial by-products as binders. In addition, the analyzed slurries exhibited good chemical resistance to landfill eluates, at the same time effectively immobilizing heavy metals. It was concluded that hardening slurry technology can ensure the safe deposition of significant amounts of waste that would be otherwise difficult to manage, thus contributing to the circular economy concept.