Ambient PM 2.5 was sampled in three indoor environments (a common office, a photocopy room and a student dormitory) and one outdoor environment (a rooftop) on a campus of Nanchang University in Nanchang city, China, on June 5-20, 2009. Analysis by ion chromatograph showed the indoor-outdoor differences and relationships of water-soluble ions. The indooroutdoor distributions indicated that chemicals and household garbage contributed most to the generation of water-soluble ions indoors. The indoor-outdoor relationships of water-soluble ions in PM 2.5 in the common office and student dormitory were unrelated or weak, which indicated that the ions were produced indoors rather than carried in from outdoors. Correlations between various water-soluble ions in indoor and outdoor PM 2.5 are discussed here, and it is suggested that the photocopier machine contributed little to the water-soluble ions indoors. Ion balance calculations indicated that the anions and cations in the photocopy room and outdoor environment shared an origin, but part of the anions and cations in the common office room and student dormitory originated indoors. The linear regression slopes (anion/cation) are all lower than 1, with the anion deficits probably affected by the absence of data on F

Carbon-based catalytic materials have received significant attention for low temperature flue gas denitrification (DeNO x ) process, due to their physicochemical properties and ease of modification. To improve the DeNO x efficiency, preparation of biochar catalyst supports was conducted that included the acid treatment of the agricultural wastes rice straw, corn cobs and lotus leaves. Taguchi experimental design (3 4 ) was employed to screen suitable carbon materials and optimize the preparation parameters of the biochar. All of the acid-modified and unmodified samples were evaluated to determine their performance and they were characterized by using SEM, BET and FT-IR analysis. The experimental and characterization results showed that acid modification of the biochars improved their DeNO x performance, which may have been due to the changes in the physical and chemical properties of the carbon material following the acid treatment. The optimum combination in the acid modification procedure was found to be the use of lotus leaf carbon treated with an acid/mass ratio of 1.50 and a pyrolysis temperature of 800°C. The biochar prepared using these optimum preparation parameters were then employed as a carrier to support an active catalyst component (MnO x ). The lotus leaf biochar supported 10 wt% manganese catalyst prepared using ultrasonic impregnation method exhibited nearly 90% NO x conversion at 250°C at a high space velocity of 45, 000 -1 , and it exhibited strong resistance to H 2 O. Additional studies showed that higher redox capacity and suitable surface acidity were two of the deciding factors in the improved low temperature SCR performance of the 10% Mn/LBC catalysts.

A quasi-static experimental program of light-gauge steel keel gypsum board partition walls (LSKGBPW) was carried out to evaluate the seismic damage phenomena, failure mechanisms, and fragility. The 15 specimens in five groups were designed per current Chinese codes and engineering practice. Then, three damage states were defined based on the damage and repair measures, and the fragility data of each group were presented, providing basic data for the estimation of seismic damage and consequential loss of nonstructural components.

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PM2.5 samples were collected for 15 consecutive days in a rural area in Shandong from January to February 2022. The carbon components and water-soluble ions in PM2.5 were measured, and the distribution characteristics and sources of the carbonaceous aerosols were analysed. It was found that the concentrations of PM2.5 in the region were high in winter (55.79–236.11 μg/m³). Organic carbon (OC) and elemental carbon (EC) accounted for 11.61% and 4.57% of PM2.5, respectively. The average concentrations of OC (19.01 μg/m³) and EC (7.49 μg/m³) in PM2.5 were high. The mean value of secondary organic carbon (SOC), estimated by the minimum R squared (MRS) method, was 14.76 μg/m3, accounting for a high proportion of OC (79.41%). Four OC fractions (OC1, OC2, OC3, and OC4) were significantly correlated with SOC, indicating that the OC components contained a large amount of SOC. OC3, OC4, EC1, and OC2 dominated (accounting for 80% of TC) among the eight carbon fractions. Water-soluble organic carbon (WSOC, 12.82 μg/m³) and methanol-soluble organic carbon (MSOC) (16.28 μg/m³) accounted for 67.47% and 84.99% of OC, respectively, indicating that SOC accounted for a high proportion of OC. The proportion of eight water-soluble ions in PM2.5 was 47.48%. NH4+ can neutralise most of the SO42− and NO3−, forming (NH4)2SO4 and NH4NO3, while Cl− mainly exists in the form of KCl and MgCl2. The ratios of some typical components showed that PM2.5 was not only affected by local combustion sources, but also by mobile sources. The cluster analysis results of the backward trajectory model showed that primary and secondary sources in Shandong Province had a great impact on PM2.5 (64%). The analysis results of the positive matrix factorisation (PMF) model showed that the sources of PM2.5 in the region included mobile sources, primary combustion sources, secondary sources, and dust sources, among which secondary sources contributed the most (60.46%).