As(V) adsorption by FeOOH@coal gangue composite from aqueous solution: performance and mechanisms.

Arsenic (As) pollution in water poses a significant threat to the ecological environment and human health. Meanwhile, the resource utilisation of coal gangue is of utmost importance in ecologically sustainable development. Thus, the FeOOH@coal gangue composite (FeOOH@CG) was synthesised for As(V) adsorption in this study. The results showed that α-FeOOH, ß-FeOOH and Schwertmannite loaded on the surface of FeOOH@CG. Moreover, the adsorption behaviour of As(V) by FeOOH@CG was investigated under different reaction conditions, such as pH, contact time, initial concentration and co-existing anions. The optimum adsorption conditions were as follows: initial As(V) concentration of 60 mg/L, pH of 3.0 and adsorption time of 180-240 h. The adsorption capacity of FeOOH@CG for As(V) was pH-dependent and the maximum adsorption capacity was 185.94 mg/g. The presence of anions (H2PO4-, HCO3- and Cl-) decreased the adsorption efficiency of FeOOH@CG for As(V). The adsorption process of FeOOH@CG for As(V) could be well-described by the pseudo-second-order model and Langmuir model, indicating that the adsorption process mainly depended on chemical adsorption. The thermodynamic analysis suggested that the adsorption was a spontaneous and endothermic process. In addition, according to the analyses of XRD, FTIR and XPS, the dominant mechanisms of As(V) adsorption by FeOOH@CG were electrostatic attraction, complexation and precipitation. In conclusion, FeOOH@CG has great potential as an efficient and environmentally friendly adsorbent for As(V) adsorption from aqueous solution.

Morphological Characteristics of Various Cells in Esophageal Squamous Dysplasia: Extremely Wide Morphological Spectrum.

The WHO classification of esophageal tumors divides esophageal squamous intraepithelial dysplasia into high and low grades, but does not specify its morphological spectrum. Here, the morphological characteristics of various cells were investigated in esophageal squamous (high-grade) dysplasia, and a morphological spectrum and terminology for this lesion were proposed to avoid misdiagnosis. The clinicopathological data of 540 patients with esophageal squamous dysplasia were analyzed retrospectively. According to the unique cytomorphological characteristics of the lesions and the predominant cell type, the esophageal squamous dysplasia was divided into the following morphological groups: classic type (34.6%, 187/540), basaloid subtype (10.7%, 58/540), spindle-cell subtype (4.6%, 25/540), differentiated subtype (48.9%, 264/540), and verrucous subtype (1.1%, 6/540). Gender, age, and lesions location did not differ among the subtypes (P > 0.05), while Paris classification and lesions diameter significantly differed among the subtypes (P < 0.01). Classic-type cells showed severe atypia. In the basaloid subtype, the cells were small, and resembled basal cells; most of these lesions were of the 0-IIb type with small lesion diameter. In the spindle-cell subtype, the cells and nuclei were spindle-shaped or long and spindle-shaped and arranged in parallel. Differentiated-subtype showed well-to-moderately differentiated cells, and epithelial basal cells were mature. Verrucous-subtype showed well-differentiated cells, and were characterized by verrucous or papillary structures. Esophageal squamous dysplasia has extremely wide morphological spectrum. Awareness of the spectrum of morphological presentations of this lesion, specifically the basaloid subtype, spindle-cell subtype, differentiated subtype, and verrucous subtype, is important for accurate diagnosis.

Study on the Effects of the Composite Addition of Al-5Ti-0.8C and La on the Microstructure and High-Temperature Mechanical Properties of ZL205A Alloy.

The effects of Al-5Ti-0.8C and the rare-earth element La on the microstructure and high-temperature mechanical properties of ZL205A alloy were investigated. We found that the grains of 0.1%La + 0.3%Al-5Ti-0.8C alloy were fine, the morphology of the as-cast Al2Cu phase was fragmented, and the precipitated phase was fine after T5 treatment. In particular, the high-temperature mechanical properties of 0.1%La + 0.3%Al-5Ti-0.8C alloy were significantly improved above 250 °C. The reason for the increase in high-temperature plasticity was attributed to the Al-La phase and the TiC particles, which refined the grains and reduced the tendency for intergranular fracture at high temperatures. More importantly, the high-temperature strengthening mechanism of the Al-5Ti-0.8C master alloy compounded with La was a result of the TiC introduced by the Al-5Ti-0.8C alloy, and the Al11La3 formed by the addition of La refined the grains in the matrix, promoted the precipitation of the needle-like θ'(Al2Cu) phase, reduced the size of the θ'(Al2Cu) phase, decreased the PFZ (Precipitation Free Zone), and increased the θ'(Al2Cu) phase number, hindering dislocation and grain boundary motion.

Enhanced Fluidity of ZL205A Alloy with the Combined Addition of Al-Ti-C and La.

The effects of Al-Ti-C and La on the fluidity of a ZL205A alloy after separate and combined addition were studied by conducting a fluidity test. The fluidity of the ZL205A alloy first increased and then decreased with the increasing addition of Al-Ti-C and La; it peaked at 0.3% and 0.1% for Al-Ti-C and La, respectively. The combined addition of Al-Ti-C and La led to better fluidity, which increased by 74% compared with the base alloy. The affecting mechanism was clarified through microstructure characterization and a DSC test. The heterogeneous nucleation aided by Al-Ti-C and La, the number of particles in the melt, and the evolution of the solidification range all played a role. Based on the evolution of the fluidity and grain size, the optimal levels of Al-Ti-C and La leading to both high fluidity and small grain size were identified.