Identification of mercury species in coal combustion by-products from power plants using thermal desorption-atomic fluorescence spectrometry on-line coupling system.

Along with the environmental protection policies becoming strict in China, the air pollution control devices (especially selective catalytic reduction (SCR)) are widely equipped in coal-fired power plants. The installation and run of these devices will inevitably affect mercury (Hg) species distribution in coal fired by-products such like fly ash (FA) and gypsum. In this work, a new on-line coupling system based on atomic fluorescence spectrometry (AFS) with a home-made chromatographic workstation was successfully developed to identify Hg species through thermal programmed desorption (TPD).

Gaseous Arsenic Capture in Flue Gas by CuCl-Modified Halloysite Nanotube Composites with High-Temperature NO and SO Resistance.

Gaseous arsenic emitted from coal combustion flue gas (CCFG) causes not only severe contamination of the environment but also the failure of selective catalytic reduction (SCR) catalysts in power plants. Development of inexpensive and effective adsorbents or techniques for the removal of arsenic from high-temperature CCFG is crucial. In this study, halloysite nanotubes (HNTs) at low price were modified with CuCl (CuCl-HNTs) through ultrasound assistance and applied for capturing AsO(g) in simulated flue gas (SFG).

Distribution and chemical speciation of arsenic in different sized atmospheric particulate matters.

The distribution and chemical speciation of arsenic (As) in different sized atmospheric particulate matters (PMs), including total suspended particles (TSP), PM, and PM, collected from Baoding, China were analyzed. The average total mass concentrations of As in TSP, PM, and PM were 31.5, 35.

Preparation of halloysite nanotubes-encapsulated magnetic microspheres for elemental mercury removal from coal-fired flue gas.

Halloysite nanotubes (HNTs) as a natural and inexpensive clay mineral with hollow nanotubular structures, good biocompatibility and active surfaces have been ubiquitously applied in many fields. In this work, a novel multifunctional core-shell sorbent based on HNTs, CuCl-HNTs encapsulated magnetic microspheres (SiO@FeO), was successfully fabricated and applied for Hg removal from flue gas with good performance for the first time. The core-shell structure prevented the composites from aggregating but kept their magnetism, which enabled the adsorbents being easily separated for reuse by an external magnetic field.

Synergistic effects of Fe-Mn binary oxide for gaseous arsenic removal in flue gas.

High-efficient and economic sorbents are highly desired for arsenic (As) emission control in flue gas from coal-fired power plant. A series of Fe-Mn binary oxides were prepared by a facile method, and their behaviors for gaseous arsenic removal in flue gas were investigated. The binary oxide exhibited a remarkable synergistic effect for arsenic removal compared with Mn or Fe monometallic oxide.

Fractions of arsenic and selenium in fly ash by ultrasound-assisted sequential extraction.

Sequential extraction has been validated as an effective method to assess the fractions of elements in fly ash. However, the time consumption and high labor costs limit the application of the conventional sequential extraction (CSE) for fast screening of elemental fractions in fly ash. In this study, two ultrasound-assisted sequential extraction (UASE) methods were developed for fast analysis of arsenic (As) and selenium (Se) fractions in fly ash (FA).

Accelerated screening of arsenic and selenium fractions and bioavailability in fly ash by microwave assistance.

Huge amounts of fly ash (FA) can be annually produced in power plants. Fly ash always contains high levels of arsenic (As) and selenium (Se) due to the preconcentration of these two elements during coal combustion process. It would be much concerned to screen their fractions and potential environmental behaviors in fly ash for beneficial use and treatment.

A comparative study on arsenic fractions in indoor/outdoor particulate matters: a case in Baoding, China.

The distribution and bioavailability of arsenic (As) in indoor/outdoor total suspended particulates (TSP), inhalable particulate matters (PM), and fine particulate matters (PM) in Baoding, China were investigated. The average I/O ratios for TSP, PM, and PM were 0.52, 0.

Speciation and bioaccessibility of heavy metals in PM in Baoding city, China.

The health risks and toxicity of heavy metals (HMs) in PM are not only associated with their total amounts, but also with their species and bioaccessibility. In this study, the speciation (fractions) and bioaccessibility of HMs (Pb, Cd, Cr, Cu and Zn) as well as their correlations in fine particulate matter (PM) samples from four seasons were studied. A sequential extraction procedure was applied to divide the studied HMs into four fractions: acid-soluble fraction (F1), reducible fraction (F2), oxidative fraction (F3) and residual fraction (F4).

Bioavailability/speciation of arsenic in atmospheric PM and their seasonal variation: A case study in Baoding city, China.

Arsenic (As) can be easily enriched in atmospheric particulate matters (PMs), especially in fine particulate matters (PM). In this study, thirty two PM samples were collected in four seasons in Baoding, China, where the haze pollution was very serious in recent years. The total contents, species and bioavailability of arsenic in PM samples were investigated.