Chemical Speciation Distribution and Thermal Stability of Heavy Metals along Flue Gas Cleaning Systems in a Hazardous Waste Incinerator

Hazardous heavy metals may release from incineration residues in the utilization concerning heat treatment or landfills, which would cause great harm on the environment. The evaluation of chemical speciation and thermal stability of heavy metals are of great significance for the control of heavy metal pollution during heat treatments. In this study, chemical speciation distribution and thermal stability of heavy metals (As, Cd, Cr, Cu, Pb, Se, Zn, and Hg) along flue gas cleaning systems were investigated in a hazardous waste incinerator located in Zhejiang, China. The chemical speciation and thermal stability of heavy metals, environmental risk evaluation, and morphological and mineralogical characteristics of incineration residues were assessed before and after heat treatments. Results indicated that the chemical speciation of heavy metals in the bottom slag, burn-out chamber ash, boiler ash, and bag filter ash varied significantly. The thermal stability of heavy metals in the incineration residues was significantly influenced by chemical speciation, and the thermal stability of the chemical speciation decreased basically in the order of residual form > reducible form > oxidizable form > acid soluble form. As, Cr, and Se showed high thermal stability due to the fact that they were involved in the crystallization reaction, and heat treatment would promote the transformation from mobile fractions into the residual fraction. Hg and Cd displayed the worst thermal stability, and high-temperature heat treatment would contribute to secondary volatilization from the incineration residues. More attention should be paid to the secondary volatilization of Hg and Cd during thermal disposal. Cu, Pb, and Zn had moderate thermal stability, and heat treatment would cause the volatilization of mobile fractions and the transformation from mobile fractions into the residual fraction. Pretreatments such as water-washing or adding a chemical stabilizer would be conducive to reducing the volatilization of heavy metals during thermal disposal

MOESM3 of BEST: a web server for brain expression Spatio-temporal pattern analysis

Additional file 3: Table S4. The addational Spatio-Temporal categories in reference dataset 1

MOESM4 of BEST: a web server for brain expression Spatio-temporal pattern analysis

Additional file 4: Table S5. The addational Spatio-Temporal categories in reference dataset 2

MOESM2 of BEST: a web server for brain expression Spatio-temporal pattern analysis

Additional file 2: Table S3. The Summary of Spatio-Temporal categories in reference datasets

MOESM1 of BEST: a web server for brain expression Spatio-temporal pattern analysis

Additional file 1: Table S1. The summary of reference expression data. Table S2. The age periods in BEST. Table S6. The statistics of co-expression clusters in different dataset

Flow diagram of study selection.

<p>Flow diagram of study selection.</p

In Situ Self-Assembled Formation of Nitrogen-Rich Ag@Ti₃C₂ Film for Sensitive Detection and Spatial Imaging of Pesticides with Laser Desorption/Ionization Mass Spectrometry (LDI-MS)

Pesticide residues are hazardous to human health; thus, developing a rapid and sensitive method for pesticide detection is an urgent need. Herein, novel nitrogen-rich Ag@Ti3C2 (Ag@N-Ti3C2) was synthesized via an ecofriendly, ultraviolet-assisted strategy, followed by in situ formation of a highly homogeneous film on target carriers via a facile water evaporation-induced self-assembly process. Ag@N-Ti3C2 shows greater surface area, electrical conductivity, and thermal conductivity than Ti3C2. This Ag@N-Ti3C2 film overcomes the limitations of conventional matrixes and allows laser desorption/ionization mass spectrometry (LDI-MS) to provide fast and high-throughput analysis of pesticides (e.g., carbendazim, thiamethoxam, propoxur, dimethoate, malathion, and cypermethrin) with ultrahigh sensitivity (detection limits of 0.5–200 ng/L), enhanced reproducibility, extremely low background, and good salt tolerance. Furthermore, the levels of pesticides were quantified with a linear range of 0–4 μg/L (R2 > 0.99). This Ag@N-Ti3C2 film was used for high-throughput analysis of pesticides spiked in traditional Chinese herbs and soft drink samples. Meanwhile, high-resolution Ag@N-Ti3C2 film-assisted LDI-MS imaging (LDI MSI) was used to successfully explore spatial distributions of xenobiotic pesticides and other endogenous small molecules (e.g., amino acids, saccharides, hormones, and saponin) in the roots of plants. This study presents the new Ag@N-Ti3C2 self-assembled film equably deposits on the ITO slides and provides a dual platform for pesticide monitoring and has the advantages of high conductivity, accuracy, simplicity, rapid analysis, minimal sample volume requirement, and an imaging function

Funnel plots of publication bias.

<p>(A) gender (male vs. female); (B) TNM stage (I & II vs. III & IV); (C) Dukes stage (A & B vs. C & D); (D) Location (Proximal vs. Distal); (E) tumor differentiation; (F) MSI status; (G) TP53 mutation status. MSI, microsatellite instability</p

Forest plots for the relationships between p14^ARF gene methylation and the clinicopathological features of CRC.

<p>(A) gender (male vs. female); (B) TNM stage (I & II vs. III & IV); (C) Dukes stage (A & B vs. C & D); (D) Location (Proximal vs. Distal); (E) tumor differentiation; (F) MSI status; (G) TP53 mutation status. OR, odds ratio; CI, confidence interval; CRC, colorectal cancer</p

Summary of pooled results in the meta-analysis.

<p>MSI, microsatellite instability.</p