Physiochemical properties, heavy metal leaching characteristics and reutilization evaluations of solid ashes from municipal solid waste incinerator plants.

A clear understanding of the physicochemical, compositional, morphological properties and heavy metal leaching behaviours of municipal solid waste (MSW) incinerated fly ash (FA) and bottom ash (BA) are essential to guide their respective re-utilizations. In this study, FA and BA collected from three MSW incinerator plants located in Xiamen were systematically exploited. Results indicated that FA in the three plants exhibited more porous structures than BA, and the particle sizes of FA and BA were 45-295 µm and >3000 µm, respectively. However, both ashes showed similar main mineralogical crystalline phases of Ca(OH)2, CaCO3 and SiO2, indicative of high feasibilities in manufacturing cement, bricks or construction materials. Additionally, the heavy metal migration of MSW into leachate, flue gas, FA and BA were all specifically measured in this study to provide full data analyses and in-depth understandings of heavy metal migrations, manifesting that the heavy metals of MSW majorly migrated into the FA and BA with clearly discrepant metal ratios and only a very small fraction migrated into the leachate and flue gas. To maximumly reuse both FA and BA, importantly, the green degree and cost-benefit analysis methods were integrated into this study to evaluate their re-utilization alternatives on environmental impacts and economic benefits, and results implied that FA was beneficial for re-utilizing as aggregates in bricks while BA was optimum as paving materials. This study provides overall systematic perspectives on guiding the re-utilization of FA/BA from the MSW incinerators and also considers their environmental and economic benefits for future long-term management.

Iron-Catalyzed Dearomatization of Biaryl Ynones with Aldehydes via Double C-H Functionalization in Eco-Benign Solvents: Highly Atom-Economical Synthesis of Acylated Spiro[5.5]trienones.

The multiple C-H bonds of biaryl ynones render the 6-exo-trig regioselective C-H activation dearomatization to spiro[5.5]trienones challenging since the competing reactions of C-H bonds on Ar1 or the ortho-C-H bonds on Ar3 may result in 5-exo-trig cyclization to indenones or 6-exo-trig ortho-dearomatization, respectively. We here report an unprecendented dearomatization of biaryl ynones with aldehydes via double C-H functionalization where a regiospecific remote unactivated para-C-H functionalization of biaryl ynones efficiently furnishes acylated spiro[5.5]trienones. This cascade cyclization features a green catalyst and solvent and high atom- and step-economy.

Comparison of Pediatric Forearm Fracture Fixation Between Single- and Double-Elastic Stable Intramedullary Nailing.

The purpose of this study was to evaluate and compare the outcome of single- and double-elastic stable intramedullary nailing (ESIN) for the treatment of pediatric both-bone forearm fractures. We retrospectively analyzed 49 children with both-bone forearm fractures treated with ESIN. Twenty-four patients were treated with single-ESIN (S-ESIN) to fixate the radius only, and the other 25 patients were treated with double-ESIN (D-ESIN) to fixate the radius and ulna. The duration of surgery, times of fluoroscopy, cost of hospitalization, period of castoff, union time, radiographic outcomes, clinical results, and postoperative complications were compared. The duration of surgery, times of fluoroscopy, and cost of hospitalization were significantly lower in the S-ESIN group; however, the average period of castoff was longer in the S-ESIN group. The incidence of delayed union of the ulna was significantly higher in the D-ESIN than in the S-ESIN group. Although the mean angulation deformity of the ulna in the S-ESIN group was significantly larger than in the D-ESIN group, both of them were acceptable (<10 degrees). Despite this, there was no difference in the loss of forearm motion and complication rates between the 2 groups. In conclusion, our data suggest that S-ESIN to fixate the radius alone remains an equally effective fixation method in the pediatric population compared with both-bone fixation and is our treatment of choice.