Non-negligible environmental risks of typical hazardous trace elements in wastes from Chinese coal-fired industrial boilers.

Coal-fired industrial boilers (CFIBs) that provide heat for industrial production operate to produce large quantities of wastes containing hazardous trace elements (HTEs), threatening the quality of the environment. Based on the established facility-level material flow inventory of five typical HTEs (Hg, As, Cd, Cr, and Pb) of Chinese CFIBs in 2020, we explored the enrichment characteristics and environmental risks of HTEs in wastes at the regional scale from the perspective of substance flow and enrichment levels. Results showed that the shares of HTEs entering the waste stream were 2.

Tracking the flows of Hg, As, Cd, Cr, and Pb in Chinese coal-fired industrial boilers.

Coal-fired industrial boilers (CFIBs) are critical anthropogenic contributors of heavy metals (HMs) because of their high coal consumption and complicated air pollution control facilities (APCDs). This study explored the flows of Hg, As, Cd, Cr, and Pb in CFIBs at regional scale by establishing a boiler-level HMs inflow-outflow inventory. The results indicate that large-capacity CFIBs (≥ 65 t/h) are the leading contributors to HMs inflows.

High-precision spatio-temporal variations and future perspectives of multiple air pollutant emissions from Chinese biomass-fired industrial boilers.

Biomass-fired industrial boilers (BFIBs) are one of the neglected and important anthropogenic sources of air pollutants. A comprehensive boiler-based emission inventory of multiple air pollutants from BFIBs in China in 2020 was first developed based on the activity level database and updated emission factors. Results showed that national emissions of air pollutants from BFIBs in 2020 were estimated to be 11.

Refined assessment and decomposition analysis of carbon emissions in high-energy intensive industrial sectors in China.

Carbon emissions from high-energy intensive industrial sectors are the focus of this study due to the huge energy consumption of these sectors. A refined carbon emission inventory of Chinese high-energy intensive industrial sectors in 2020 was first developed at the point source level. The results showed that coal-fired power plants (CFPPs) were the leading contributors to carbon emissions, followed by iron and steel smelting (ISS) and cement production (CMP).

Application of loofah and insects in a bio-trickling filter to relieve clogging.

Bio-trickling filters (BTFs) use an inert filler to purify pollutants making them prone to clogging due to bacterial accumulation. To investigate the performance of a non-inert filler in BTF and its cooperation with insects to relieve clogging, a vertical BTF was constructed with a loofah/Pall ring/polydimethylsiloxane composite filler and selected bacteria to purify toluene. The BTF was started up within 17 d and restarted within 3 d after starvation for 12-16 d.

Distribution, chemical fractionation, and potential environmental risks of Hg, Cr, Cd, Pb, and As in wastes from ultra-low emission coal-fired industrial boilers in China.

This study conducted a comprehensive investigation of the distribution, chemical fractionation, and potential environmental risks of Hg, Cd, Cr, Pb, and As in waste based on new data from five ultra-low emission (ULE) coal-fired industrial boilers (CFIBs). The results showed that fly ash was enriched with Cd, Pb, As, and Hg, while its Cr contents were not invariably higher than those of slag. Fly ash was the predominant output flow for Hg, Cd, Cr, Pb, and As in the tested ULE boilers, with higher proportions of HTEs in the fly ash and lower proportions of HTEs in the flue gas than in the non-ULE boilers.

Unit-based emissions and environmental impacts of industrial condensable particulate matter in China in 2020.

The emission of condensable particulate matter (CPM) and its environmental impacts are arousing concern in China with the effective control of filter particulate matter (FPM). This study established an up-to-date and unit-based CPM emission inventory for industrial sectors and systematically evaluated the effects of CPM on primary and secondary PM in China. In 2020, the national CPM emissions total for industrial sectors was estimated to be 0.

Identification of NO hotspots from oversampled TROPOMI NO column based on image segmentation method.

Satellite-based measures of NO have become increasingly available for resolving the limitation on insufficient spatial and temporal coverage of ground-level monitoring networks. Oversampled NO column density can obtain more detailed features of NO column with a spatial resolution as high as 2 km × 2 km, while it is still challenging to identify hotspots of NO pollution plume in city-scale due to background interference. In this study, we proposed a method for detecting the NO hotspot grids from oversampled satellite NO column based on the image segmentation method, and identifying major source types using Term frequency-inverse document frequency (TF-IDF).

Highly-resolved spatial-temporal variations of air pollutants from Chinese industrial boilers.

Industrial boilers are a significant anthropogenic source of air pollutant emissions. In this study, a county-based atmospheric emission inventory of particulate matter (PM), PM, PM, SO, NOx, organic carbon (OC) and elemental carbon (EC) from industrial boilers over mainland China in 2017 was developed for the first time, based on county-level activity data from ~61,000 coal-fired industrial boilers (CFIBs), ~44,000 biomass-fired industrial boilers (BFIBs), ~71,000 gas-fired industrial boilers (GFIBs) and ~9300 oil-fired industrial boilers (OFIBs), updated emission factors (EFs) and air pollution control device (APCD) efficiencies. The total national PM, PM, PM, SO, NOx, OC and EC emissions from industrial boilers in 2017 were estimated to be 1,240, 347, 761, 1,648, 1,340, 13.

Measure-specific environmental benefits of air pollution control for coal-fired industrial boilers in China from 2015 to 2017.

From 2015 to 2017, China took strong air pollution control measures (APCMs) for coal-fired industrial boilers (CFIBs), including eliminating CFIBs, promoting clean fuels, and updating air pollution control devices (APCDs). Based on the industrial boiler's emission inventory of air pollutants, measure-specific emission reductions from 2015 to 2017 was estimated in this study. Besides, the measure-specific environmental benefits of unit emission reduction on concentration and deposition flux were systematically evaluated by WRF-CMAQ model.

Refined spatio-temporal emission assessment of Hg, As, Cd, Cr and Pb from Chinese coal-fired industrial boilers.

Coal-fired industrial boilers (CFIBs) are a significant source of trace metals (TMs) emissions, due to its large number and widespread industry application. In this study, a highly resolved of county-based atmospheric emission inventory of Hg, As, Cd, Cr and Pb for Chinese CFIBs in 2017 is established firstly based on integrated source-specific information of both activity level and air pollution control devices (APCDs) from ~61,000 CFIBs in mainland China. Our results estimated that the total emissions of Hg, As, Cd, Cr and Pb from national CFIBs in 2017 were about 25.

[Evaluation of oral midazolam conscious sedation in different age groups in pediatric dentistry].

Objective: To summarize the effect of oral midazolam sedation in a group of uncooperative patients in pediatric dentistry and analyze the influence of age on treatment results and safety.

Methods: Oral midazolam conscious sedation (dosages range: 0.50 - 0.