Enhanced biosorption of bisphenol A from wastewater using hydroxyapatite elaborated from fish scales and camel bone meal: A RSM@BBD optimization approach (2023)

The engineering of a novel biocomposite based on Cerastoderma edule shells doped with copper and alginate (Ce–[emailprotected]) forming hydrogel beads was used for batch and dynamic adsorption thiabendazole (TBZ) pesticide from water. The prepared biosorbent was analyzed by various characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller analysis (BET), and energy dispersive spectroscopy (EDS), thermogravimetric and differential analysis (TGA-DTA). The results of the TBZ batch biosorption by Ce–[emailprotected] composite showed that the Langmuir model was the most adequate to describe the adsorption process, with a maximum adsorption capacity value of 21.98mg/g. Moreover, the adsorption kinetics were adjusted by the pseudo-second-order model. The optimal conditions determined by the RSM approach coupled with the CCD design were 100ppm of initial TBZ concentration, a Ce–[emailprotected] beads dose of 6g/L and a contact time of 180min for maximum removal of 83.42%. On the other hand, the TBZ sorption on a fixed bed of Ce–[emailprotected] beads was effective at high column height, low effluent flow and low solution concentration. The Thomas model was best fitted to the kinetic data. This study shows the possibility of using this new hybrid biocomposite in the industrial sector to treat large effluent volumes.

Water pollution is a serious environmental problem worldwide. This problem is augmented by the shortages in fresh water supplies in several parts of the world. Thus, the effective treatment and reuse of polluted water is an inevitable necessity. One of the highly toxic water pollutants with potentially mutagenic and carcinogenic effects is bisphenol A (BPA). Accordingly, the adsorptive removal of BPA from wastewater samples using novel graphene-based materials has been investigated in this study. The results showed the ineffectiveness of the unmodified graphene oxide (GO) in removing BPA from the wastewater samples. The functionalization of GO with short organic amines (i.e., hexamethylenetetramine (HTMA), diethylenetriamine (DETA), and diethylamine (DEA)) boosted the BPA removal by several folds relative to GO and hydrazine-reduced GO. Additionally, the amine structure affected the performance of the amine-modified GO adsorbents. The most effective adsorbent was found to be the one modified with DEA (GO-DEA) followed by GO-DETA. The maximum adsorption capacity ($q_{\max }$) of BPA on GO-DETA and GO-DEA were 258.6 and 334.4 mg/g respectively, relative to 16.2 and 87.0 mg/g in the case of the unmodified GO and the hydrazine-reduced GO (i.e., rGO), respectively. The results of the adsorption kinetics revealed that BPA adsorption on GO-DETA is much faster than its adsorption on GO-DEA. The adsorption kinetics for both adsorbents were best fitted using the Avrami model with adsorption rate constant of 0.0149 (GO-DETA) and 0.0033 min^−0.47 (GO-DEA). Although variations in BPA adsorption capacity were observed with changing the pH of the wastewater, the lowest BPA adsorption was encountered at pH 10 for all the graphene-based materials synthesized in this study. The characterization of the synthesized adsorbents revealed that BPA adsorption is not correlated with the surface area/porosity of the adsorbents. It is also not correlated with the degree of GO deoxygenation or nitrogen content alone. The most plausible adsorption mechanisms are π−π stacking interaction and hydrogen bonding. The findings reported in this study reveal the potential of GO functionalization with short organic amines in significantly boosting the adsorptive removal of phenolic pollutants from wastewater.

Ceramics International, Volume 48, Issue 11, 2022, pp. 15282-15292

The Mo-based glass-free spinel-type structure of the (Na_1-xK_x)₂MoO₄ (x=0.0, 0.1, and 0.2) ceramic series was prepared using the traditional solid-state method at the low sintering temperature (<650°C). The microwave dielectric properties of the (Na_1-xK_x)₂MoO₄ series were determined in terms of phase compositions, crystal structure (via XRD), and microstructure analysis (via FE-SEM and EDS). The results revealed that the double-phase (cubic and orthorhombic) formation plays a significant role in the entire (Na_1-xK_x)₂MoO₄ series. It exhibits excellent dielectric properties: dielectric constant ε_r=4 (1GHz)/3.77 (15GHz), tangent loss tanδ=8.3×10⁻² (1GHz)/7×10⁻³ (15GHz; Q×f=2143GHz), temperature coefficient of frequency (TCF) τ_f=−6.45ppm/°C, and room temperature thermal conductivity (κ)=1.76W/(m.K) for x=0.1at a sintering temperature of 575°C. These make the (Na_1-xK_x)₂MoO₄ ceramic series a potential candidate for low-temperature co-fired ceramic (LTCC) substrate applications (as used in antennas) for high-speed data communications.

Ceramics International, Volume 48, Issue 11, 2022, pp. 15780-15784

In dielectric capacitors, ferroelectric thin films with slim polarisation electric (P-E) hysteresis loops, which are mainly characterised by small residual polarisation (P_r) and large saturation polarisation (P_s) are expected to obtain high recoverable energy density (U_r) and efficiency (η). However, a lower breakdown in ferroelectric thin films usually impedes this result. Here, through the co-doping of La³⁺ and Pr³⁺ ions, a larger U_r of 54.27J/cm³ and high η of 85.6% were obtained in four-layered Aurivillius phase ferroelectric thin films capacitors due to the enhanced breakdown electric field. The doped films annealed at relatively low temperatures showed similar energy storage properties compared with those of the prototype and higher energy storage efficiency compared with that of higher annealing films. In addition, the obtained thin film shows excellent energy storage properties in a wide frequency range, fatigue durability and good thermal stability. These results indicated that four-layered Aurivillius films are promising candidate materials for dielectric energy storage capacitors. The co-doping of double ions was an effective way to improve energy storage performance.

Ceramics International, Volume 48, Issue 11, 2022, pp. 15862-15867

Sol-gel method was employed for the preparation of strontium-doped mesoporous bioactive glass nanoparticles (Sr-MBG NPs). These NPs have the size of 50±5nm, a pore size of 8.2nm, and a surface area of 379m²/g. Biocompatibility was confirmed by MTT and tissue histopathology in Balb/c mice. 5-Fluorouracil (5-Fu) was loaded to obtain Fu-Sr-MBG NPs which posed substantial inhibitory effects on the viability of the cancer cells (AGS). The amount of released drug was controlled by changing the pH of release medium. Formation of hydroxycarbonate apatite (HCA) was evaluated in simulated body fluid (SBF) and confirmed by XRD and FTIR. Thus a multipurpose nano-biomaterial was prepared and screened.

Ceramics International, Volume 48, Issue 11, 2022, pp. 15755-15761

In this work we detail the preparation of new luminescent Li⁺ and K⁺ doped Na₂Zn₃Si₂O₈: Er³⁺ up-conversion phosphors using the high-temperature solid-phase method. We investigate the phosphors phase structure, elemental distribution, up-conversion luminescence characteristics and temperature sensing properties. Our fabricated samples were found to be homogeneous and when excited using 980nm light, they emitted wavelengths in the green and red visible wavelength bands, which correspond to two major emission bands of Er³⁺. Doping with Li⁺ and K⁺ increased the luminescence intensity of the Na₂Zn₃Si₂O₈: Er³⁺ phosphor at 661nm by 36 and 21 times respectively. The highest relative temperature sensitivity (Sa) of the fabricated phosphor reached a value of 19.69% K⁻¹ and the highest absolute temperature sensitivity (Sr) reached 1.20% K⁻¹. These values are superior to other materials which utilize up-conversion by Er³⁺ ions as a tool for temperature sensing. We anticipate that these new phosphors will find significant application as components in optical temperature measurement systems.

Ceramics International, Volume 48, Issue 11, 2022, pp. 15613-15621

To explore the impact of the sintering rate on the microstructure and mechanical properties of cermets, the preparation of (Ti,W)C cermets by ultrafast sintering via spark plasma sintering (SPS) is reported. Compared with a slow heating rate, the electric field produced by an ultrafast heating rate enhances the liquid phase mass transfer of the metal binder phase, thus achieving rapid densification of (Ti,W)C cermets and effectively inhibiting abnormal grain growth. However, an excessive heating rate will lead to an “overflow” phenomenon, which reduces the grain growth difficulty and the bonding strength between grains. The results show that when the heating rate is 500°C/min, the liquid phase mass transfer is moderate, the densification degree is the highest and the mechanical properties are excellent. The flexural strength, Vickers hardness and fracture toughness are 1340.90±23.55MPa, 18.42±0.46GPa and 11.96±0.23MPa∙m^1/2, respectively.

Ceramics International, Volume 48, Issue 11, 2022, pp. 15832-15838

Development of novel materials with advanced properties is one of the main research directions of chemistry. New substances are not only crucial for many current technological applications but also should satisfy the needs of tomorrow. Industry often requires reliable, economically effective methods that can provide high quality reproducible results. Here we propose an inexpensive synthesis method that is suitable for synthesis of many types of particles. In this work we focused on Gd₂O₃:Tm³⁺, Er³⁺, Nd³⁺ particles with luminescence and magnetic properties. Based on the analysis of morphology, structural and optical properties of particles prepared by the standard Pechini methods and its variations, we found that the method with K₂CO₃ as additive yields particles with smaller sizes (down to tens of nm), higher crystallinity, and up to 1.7 times increased luminescence intensity. We also demonstrate that the unique combination of the particles’ characteristics, for example, the intensity ratio of the luminescent bands corresponding to different REI and the mass susceptibility, strongly depends on the composition, synthesis method, and structure. The variety of the combination of the properties makes these particles a promising candidate for safety markers applications.