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Microplastics (MPs) have aroused growing environmental concerns due to their biotoxicity and vital roles in accelerating the spread of toxic elements. Illuminating the interactions between MPs and heavy metals (HMs) is crucial for understanding the transport and fate of HM-loaded MPs in specific environmentally relevant scenarios. Herein, the adsorption of copper (Cu2+) and zinc (Zn2+) ions over polyethylene (PE) and polyethylene terephthalate (PET) particulates before and after heat persulfate oxidation (HPO) treatment was comprehensively evaluated in simulated and real swine wastewaters. The effects of intrinsic properties (i.e., degree of weathering, size, type) of MPs and environmental factors (i.e., pH, ionic strength, and co-occurring species) on adsorption were investigated thoroughly. It was observed that HPO treatment expedites the fragmentation of pristine MPs, and renders MPs with a variety of oxygen-rich functional groups, which are likely to act as new active sites for binding both HMs. The adsorption of both HMs is pH- and ionic strength-dependent at a pH of 4–6. Co-occurring species such as humic acid (HA) and tetracycline (TC) appear to enhance the affinity of both aged MPs for Cu2+ and Zn2+ ions via bridging complexation. However, co-occurring nutrient species (e.g., phosphate and ammonia) demonstrate different impacts on the adsorption, improving uptake of Cu2+ by precipitation while lowering affinity for Zn2+ owing to the formation of soluble zinc-ammonia complex. Spectroscopic analysis indicates that the dominant adsorption mechanism mainly involves electrostatic interactions and surface complexation. These findings provided fundamental insights into the interactions between aged MPs and HMs in swine wastewaters and might be extended to other nutrient-rich wastewaters. [Display omitted] • Heat persulfate oxidation treatment accelerates the fragmentation of pristine MPs. • HPO treatment endows pristine MPs with a variety of oxygen-containing groups. • Weathering time and size of MPs greatly affect their affinity toward Cu2+ and Zn2+. • Aged PE prefers to adsorb Zn2+ while aged PET prefers to capture Cu2+. • Humic acid and tetracycline enhance the adsorption of HMs by bridging complexation. [ABSTRACT FROM AUTHOR]

AGe 4 O 9 (A = Ba, Sr) ceramics with hexagonal structure were fabricated by solid-phase reaction. BaGe 4 O 9 sintered at 1060 °C had low ε r ∼9.8, high Q × f ∼78,400 GHz and τ f ∼ -44.2 ppm/°C, whilst SrGe 4 O 9 sintered at 1100 °C exhibited relatively high ε r ∼11.2, low Q × f ∼62,500 GHz and near-zero τ f ∼ -11.7 ppm/°C. The τ f of SrGe 4 O 9 was nearer to zero than that of BaGe 4 O 9 due to the smaller τ ε value and the smaller distortion of the [GeO 6 ] octahedrons. The 'rattling' cations at A-site contribute to comparatively high ε r , low Q × f and near-zero τ f values in Sr 1- x Ba x Ge 4 O 9 ceramics. This work presents a new idea of adjusting the microwave dielectric performance (MDP) of ceramics by changing the strength of the rattling effect at A-site. [ABSTRACT FROM AUTHOR]

To assess the feasibility of recovering P from water by combining batch adsorption enrichment with struvite crystallization, we prepared four ternary layered double hydroxides (LDHs) with P-preferring elements (i.e., zirconium (Zr) or lanthanum (La)) via a facile coprecipitation method, and evaluated their performance in recovering P from water, particularly in enriching P from a low-level P solution. We find that all ternary LDHs demonstrate remarkably high P adsorption capacities, e.g., 1029.3 mg PO 4 3− g−1 for ZnAlLa, outperforming other LDHs reported so far. Microstructural analyses show that the P uptake mechanisms are attributable to anion exchange, surface complexation and electrostatic attraction. Results of recycling tests indicate that all LDHs present good enrichment for P. Besides, more than 96% of phosphorus in the P-enriched eluates can be efficiently reclaimed via struvite crystallization in a fluidized bed reactor. These findings demonstrate the feasibility of combining adsorption enrichment with struvite crystallization for P recovery. [Display omitted] • Four ternary LDHs with P-preferring elements (Zr or La) were prepared. • These ternary LDHs show high stability against either acidic or basic solution. • These LDHs exhibit superior adsorption capacities of P compared to other LDHs. • P-enriched eluates can be obtained from consecutive adsorption-desorption cycles. • P in the eluates can be efficiently recovered via struvite crystallization in an FBR. [ABSTRACT FROM AUTHOR]

Artificial structural color materials from self-assembled colloidal spheres, which are similar to natural opals, are currently a subject of extensive investigation. However, the shortage of available colloidal spheres, especially polymer spheres for building artificial opals is still a major restriction for their practical application. Herein, a new kind of artificial opals with iridescent structural colors were prepared from the self-assembly of novel polythiourethane microspheres (PTUMS). The PTUMS with narrow size distribution were prepared through a simple phase separation process. Particle sizes can be easily adjusted from 175 nm to 304 nm, which is important for the construction of tunable structural colors. Sufficient surface charges were obtained from the reaction between the terminal isocyanate groups and water. Thus, PTUMS can arranged into periodic opal structures through self-assembly process and generate iridescent structural colors. The present study provided an effective and convenient approach to prepare artificial structural color materials from new kind of polymer microspheres. This was very important for the practical application of artificial opals in coating and paints. [ABSTRACT FROM AUTHOR]

In this study, a class F fly ash and palygorskite have been acid-modified and then evaluated for the adsorption of phosphate in aqueous solution via bench-scale batch experiments. XRD, XRF, SEM, and FTIR were employed to characterize the acid-modified fly ash (MFA) and palygorskite (MPal). Both MFA and MPal show enhanced phosphate adsorption after the modification treatment. The effects of pH, adsorbent dosage, and co-ions on phosphate adsorption, as well as adsorption thermodynamics and kinetics, and leaching features of spent (used) adsorbents were also investigated. The isotherms data fit well with the Langmuir model rather than the Freundlich model, giving maximum capacities (298 K) of 13.3 mg P g − 1 for MFA and 10.5 mg P g − 1 for MPal, respectively. Surface complexation modeling of P adsorption data with the nonelectrostatic generalized composite (GC) approach indicates that phosphate were directly bound to the metal centers by ligand exchange to form two monodentate complexes, ≡ SHPO 4 − and ≡ SPO 4 2 − . The GC model appears to be an easy and efficient tool to provide an insight into the mechanism of phosphate adsorption on complex adsorbents with limited model parameters. Leaching test results suggest that the spent adsorbents can be safely disposed or further reused. [ABSTRACT FROM AUTHOR]

Abstract: Iron-bearing minerals have been used as adsorbents for arsenic anions for many decades, but both the small surface area and the poorly defined pore structure limit their performance in removal of arsenic from aqueous systems. Herein, we report a sonochemical layer-by-layer (LBL) loading process for depositing of ferric species onto mesoporous silicas (i.e., MCM-41, SBA-15, and KIT-6). The surface area, pore size and volume, as well as the iron loading of these mesoporous silicas can be tailored and optimized with increasing in loading cycle via a LBL protocol. The surface functioned materials were characterized by X-ray diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrometry and zeta potential measurement. Their performance in As(V) adsorption was also tested. The results indicate that the iron-loaded mesoporous silicas retained their ordered pore structure as well as the large surface area, which enable them a good kinetic performance in uptake of As(V) anions. When iron loading is as much as 10wt.%, two representative iron-loaded silicas Fe10MCM-41 and Fe10KIT-6, exhibited the best performance in trapping the As(V) anions, with an Fe/As molar ratio of about 5.77 and 5.10, respectively. The Fe/As molar ratio implies they belong to the iron-containing adsorbents with the highest adsorption performance for As(V), and therefore could be used as alternative adsorbents for As(V) adsorption. [Copyright &y& Elsevier]

Abstract: Neuron-specific enolase (NSE) is the key molecular marker for diffuse neuroendocrine system (DNES) cells, its expression in the pregnant corpus luteum (CL) of dairy goats was studied by the immunofluorescence method and the ultra structural characteristics of luteal cells were detected by the electron microscopy to identify the existence of DNES cells in the pregnant CL of dairy goats. Besides, the coding sequence of dairy goats NSE gene was cloned and its biological information was analyzed. Results revealed that NSE immunopositive cells exhibited widespread cytoplasmic staining throughout the whole pregnant CL. In addition, these cells showed typical characteristics of DNES cells in the electron microscopy. These results suggested that many DNES cells exist in the pregnant CL of dairy goats. Meanwhile, we identified the coding sequence of dairy goats NSE (GenBank Accession No. JN887466). Its nucleotide sequence homology was found to be 97.9%, 89.3%, 90% and 92.6%, respectively, compared with that of Bos taurus, Rattus norvegicus, Mus musculus and Homo sapiens, while the amino acid sequence homology was 99.1%, 97%, 97.2% and 98.2% respectively. These results first showed that the functional amino acids coded by the NSE gene were highly conserved in Caprine, B. taurus, R. norvegicus, M. musculus and H. sapiens. It was implied that the gene NSE in dairy goats had close homology to that of NSE of other species. Our findings demonstrated the possible existence of DNES cells in pregnant CL, providing new clue for further understanding of interactions between the neuroendocrine and reproductive systems. Characterization of gene sequence of dairy goats NSE will enable us to synthesize interference RNA for further study on the role of NSE on the formation, function and apoptosis of pregnant CL in dairy goats. [Copyright &y& Elsevier]

Abstract: Mesostructured ferric oxyhydroxides (MFOs) were synthesized using both cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfonate (SDS) as templates in the present study. For CTAB-templating route, the effect of pH and fluoride ions on the resulting MFOs has been evaluated, and the active role of fluoride ions in promotion the mesostructural ordering was verified. Besides, the effect of solvents and hydrolysis ratio on the synthetic layered MFOs was examined via SDS-templating route. X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen physisorption were employed to characterize the MFOs before two typical MFOs with surface areas of 144.7 and 88.1m2 g−1, respectively, were evaluated as potential adsorbent for As(V) removal. Both MFOs presented adsorption isotherms well fitting the Freundlich equation. The two MFOs exhibited adsorption capacities of 75.19 and 10.68mgg−1, respectively, and could be adopted as adsorbent for As(V) removal. [Copyright &y& Elsevier]

Surface vaporization of metals is currently receiving significant attention as a wastewater treatment technique. This article examined the wettability transition of a treated titanium surface (so-called an evaporator) under varied storage conditions. Several aspects of the transition mechanism were evaluated, including contact angles, surface chemistry, and wetting dynamics. The titanium treated surface changed significantly in wettability when exposed to ambient air, going from highly water-attracting to ultra-hydrophobic after only 40 days of storage. The experiments conducted proved that the contaminants in the air absorbed on the Ti surface are responsible for this wettability shift. We found an increase in C/Ti ratios and C–C(H) (at. %) over time, which implied a nonpolar nature and showed a hydrophobic tendency. The samples kept in nitrogen and water, on the other hand, remained in their original state. In contrast, the sample stored in an open water environment increased its contact angles slowly over time, which could have been influenced by organic matter in the air. The results of this research are not only helpful in understanding the transition mechanism of nanosecond laser-treated titanium but also provide information that the wastewater industry can implement to store evaporators to avoid the rapid transition of wettability and produce super-hydrophilic surfaces with stability and durability. • Titanium plates were micro-structured using nanosecond laser. • The water and nitrogen environments are suitable storage conditions to maintain the hydrophilicity of the treated Ti surface. • The contaminants in the air, such as VOCs, are responsible for the wettability transition. [ABSTRACT FROM AUTHOR]

Hydrogen sensors are easily deactivated by hexamethyldisiloxane (HMDSO) poisoning. Moreover, the existing anti-poisoning strategies can also damage the overall sensing performance of these hydrogen sensors. Therefore, a new bilayer design with a Pd/In 2 O 3 sensitive layer and an In 2 O 3 /Al 2 O 3 catalytic filter layer is proposed to avoid the deactivation of hydrogen sensors. The In 2 O 3 /Al 2 O 3 layer helps in hindering HMDSO and its decomposition products from reaching the Pd/In 2 O 3 layer. The H 2 response of the sensors is enhanced due to the small size of In 2 O 3 and the electronic sensitization of Pd. As a result, the bilayer sensors exhibit high response (Ra/Rg = 53) and ultra-fast response time (1 s) towards 3000 ppm H 2 at 365 °C. The resistance and the H 2 response of the bilayer sensors are almost unchanged after 40 min of 10 ppm HDMSO poisoning. In this paper, the mechanism of resistance against silicone poisoning and the H 2 response of the bilayer sensors are discussed from the separation of sensing and catalytic filtration reactions to the behavior of adsorbed oxygen. [Display omitted] • Unique two-layer sensor design with catalytic filter layer and sensitive layer. • Bilayer sensors exhibit very short response/recovery times while resisting HMDSO. • After poisoning, the resistance and response of the sensor remain stable. • The sensing mechanism of the double-layer sensor is discussed. [ABSTRACT FROM AUTHOR]

Abstract: Blends of circulating fluidized bed combustion (CFBC) fly and bottom ashes of the same coal origin were investigated as raw materials for geopolymer synthesis. Reactivity of the low-reactive CFBC fly ash (CFA) was enhanced by an alkali-fusion pretreatment, which was optimized by an L16 (44) orthogonal array. It was found that, at a relatively low sodium hydroxide to CFA mass ratio of 0.5, effective alkali fusion could be achieved at 350°C for 0.5h. The fused CFA was blended with ground CFBC bottom ash (CBA) at mass ratios of 2.00, 1.00, 0.55, 0.29, and 0.12, and activated by two sodium silicate solutions (21.6wt% and 34.5wt%). Geopolymer pastes were cured at 40°C for 7days, reaching a highest compressive strength of 34.0MPa. Characterization of the raw materials and geopolymer products was also conducted by an alkaline dissolution test, thermogravimetric–differential thermal analysis (TG–DTA), X-ray diffractography (XRD), scanning electron microscopy (SEM), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study suggest that, by a moderate alkali-fusion pretreatment at temperatures slightly higher than the melting point for sodium hydroxide (318°C), low-reactive CFA can be recycled together with CBA for production of value-added geopolymer composites. [Copyright &y& Elsevier]

• Orthorhombic-structured CaIn 2 O 4 ceramics with a space group Pca2 1 were synthesized via a solid-state reaction method. • Excellent microwave dielectric properties (ε r ∼ 11.28, Qf = 74,200 GHz, τ f ∼ −4.6 ppm/°C) were obtained when the ceramics were sintered at 1375 °C for 6 h. • The dielectric properties were investigated on the basis of the Phillips–Van Vechten–Levine chemical bond theory and infrared reflectivity spectroscopy. • The dielectric properties of CaIn 2 O 4 ceramics were mainly determined by the In–O bonds, and these bonds contributed more (74.65%) to the dielectric constant than the Ca–O bonds (25.35%). Orthorhombic-structured CaIn 2 O 4 ceramics with a space group Pca2 1 were synthesized via a solid-state reaction method. A high relative density (95.6 %) and excellent microwave dielectric properties (ε r ∼11.28, Qf = 74,200 GHz, τ f ∼ −4.6 ppm/°C) were obtained when the ceramics were sintered at 1375 °C for 6 h. The dielectric properties were investigated on the basis of the Phillips–Van Vechten–Levine chemical bond theory. Results indicated that the dielectric properties were mainly determined by the In O bonds in the CaIn 2 O 4 ceramics. These bonds contributed more (74.65 %) to the dielectric constant than the Ca O bonds (25.35 %). Furthermore, the intrinsic dielectric properties of the CaIn 2 O 4 ceramics were investigated via infrared reflectivity spectroscopy. The extrapolated microwave dielectric properties were ε r ∼10.12 and Qf = 112,200 GHz. Results indicated that ion polarization is the main contributor to the dielectric constant in microwave frequency ranges. [ABSTRACT FROM AUTHOR]

The Ca 3 M 2 Si 3 O 12 (M = Yb, Y) ceramics with orthorhombic silico-carnotite structure were fabricated via high-energy ball milling and solid-state reaction route. Dense Ca 3 Yb 2 Si 3 O 12 and Ca 3 Y 2 Si 3 O 12 ceramics sintered at 1260 °C and 1240 °C revealed promising microwave dielectric properties with ε r = 9.2 and 8.7, Q×f = 56,400 GHz and 29,094 GHz, τ f = −77.5 ppm/°C and −76.8 ppm/°C, respectively. The connection between crystal structure and Q×f values of Ca 3 M 2 Si 3 O 12 (M = Yb, Y) ceramics was discussed with respect to the packing fraction, and their intrinsic microwave dielectric properties were examined using the infrared reflectivity spectra analysis. The thermal stability of Ca 3 Yb 2 Si 3 O 12 was improved successfully by forming 0.91Ca 3 Yb 2 Si 3 O 12 ‐0.09CaTiO 3 composite ceramics with τ f = +2.9 ppm/°C, ε r = 12.93 and Q×f = 26,729 GHz. [ABSTRACT FROM AUTHOR]

Two melilite ceramics Sr 2 AGe 2 O 7 (A = Mg, Zn) with low permittivity were prepared by a solid-state reaction method. The crystal structure and microstructure of the ceramics were characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and scanning electron microscopy. Both ceramics crystallized in a single melilite structure with a tetragonal space group P-42 m (113) and exhibited homogeneous microstructures. Optimum microwave dielectric properties with relative permittivity (ε r) of 8.56, quality factor (Q × f) of 28,800 GHz, and temperature coefficient of resonance frequency (τ f) of −70.5 ppm/°C were obtained in Sr 2 MgGe 2 O 7 sintered at 1330 °C. Sr 2 ZnGe 2 O 7 possessed ε r of 8.81, Q × f of 35,700 GHz, and τ f of −84.4 ppm/°C when sintered at 1290 °C. Thermal stability of resonance frequency was accessible when the negative τ f values of Sr 2 AGe 2 O 7 were adjusted after the formation of composite ceramics with CaTiO 3. [ABSTRACT FROM AUTHOR]

Global mining activities produce thousands of millions of toxic-bearing mine tailing (MT) wastes each year. Storage of the mine tailings not only encroaches upon large areas of cropland but also arouses additional ecological and environmental risks. Herein we demonstrate that geopolymerization of a mixture of the toxic-bearing mine tailings and the coal fly ash (FA) can effectively immobilize exogenous arsenic (As) species in addition to inherent As from the raw materials. The geopolymers also possess high compressive strengths (e.g., >25 MPa for specimens with 54 wt% FA and activated with 10 M sodium hydroxide (NaOH)), allowing them to be further used as low-carbon, cement-free building materials. The geopolymer strength was found to depend clearly upon the NaOH concentration, the FA content, and the curing time, with the maximum being 37.07 MPa for a specimen with 54 wt% FA, 0.03 wt% As, activated with 10 M NaOH and cured for 28 days. Leaching tests showed that all specimens achieved an immobilization efficiency as high as 95.4% toward As, and that both the short-term and long-term leachabilities of all toxic elements are far below the standard maximum contaminant levels. Microstructural analyses indicate that calcite, calcium silicate, and calcium silicate hydroxide are likely to play a crucial role in immobilizing As species and heavy metals of concern in the geopolymer matrixes. Given the superior mechanical strengths and long-term stabilities, the FA/MT-based geopolymers demonstrate a promising low-carbon material for both the remediation of As-bearing lands and the construction industry. [Display omitted] • A low-carbon fly ash/mine tailing-base geopolymer was developed. • The geopolymers have high mechanical strengths and long-term stabilities. • It can efficiently immobilize exogenous AsV in addition to the intrinsic AsV. • Calcite and calcium silicate hydroxide contribute mainly to immobilizing AsV. • The AsV-immobilized geopolymers can be further used as construction materials. [ABSTRACT FROM AUTHOR]

Abstract: The physical–chemical characteristics of mechanically-treated circulating fluidized bed combustion (CFBC) fly ash, such as 45μm sieve residue, granulometric distribution, water requirement, specific gravity, pH value, and mineralogical phases, were investigated. It was found that the grinding process can be divided into three stages. The increase in fineness of ground CFBC fly ash is very sharp in the first stage, then slows down in the second stage, and in the last stage it becomes almost invary. The water requirement decreases with prolonged grinding time, and slightly increases during the last stage of grinding. Ground CFBC fly ash shows a higher specific gravity due to the crushing of coarse particles and carbon particles. The pH of ground CFBC fly ash is greater than that of the original CFBC fly ash, indicating that ground samples react more rapidly with water. The mineralogical compositions remain unchanged with grinding, although the intensity of the crystalline phases decreases and the half peak width increases. [Copyright &y& Elsevier]

Abstract: Fly ash coming from a circulating fluidized bed combustion (CFBC) boiler co-firing coal and petroleum coke (CFBC fly ash) is very different from coal ash from traditional pulverized fuel firing due to many differences in their combustion processes, and thus they have different effects on the properties of Portland cement. The influences of CFBC fly ash on the strength, setting time, volume stability, water requirement for normal consistency, and hydration products of Portland cement were investigated. The results showed that CFBC fly ash had a little effect on the strength of the Portland cement when its content was below 20%, but the strength decreased significantly if the ash content was over 20%. The water requirement for normal consistency of cement increased from 1.8% to 3.2% (absolute increment value) with an addition of 10% CFBC fly ash; and the free lime (f-CaO) content of CFBC fly ash affected the value of increasing. The setting time decreased with an increase of CFBC fly ash content. The volume stability of the cement was qualified even when the content of SO3 and f-CaO reached 4.48% and 3.0% in cement, respectively. The main hydration productions of cement with CFBC fly ash were C–S–H (hydrated calcium silicate), AFt (ettringite), and portlandite. [Copyright &y& Elsevier]

Abstract: Self-cementitious properties of fly ash from circulating fluidized bed combustion boiler co-firing coal and high-sulphur petroleum coke (CPFA) were investigated. CPFA was self-cementitious which was affected by its fineness and chemical compositions, especially the contents of SO3 and free lime (f-CaO). Higher contents of SO3 and f-CaO were beneficial to self-cementitious strength; the self-cementitious strength increases with a decrease of its 45 μm sieve residue. The expansive ratio of CPFA hardened paste was high because of generation of ettringite (AFt), which was influenced by its water to binder ratio (W/A), curing style and grinding of the ash. The paste cured in water had the highest expansive ratio, and grinding of CPFA was beneficial to its volume stability. The hydration products of CPFA detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM) were portlandite, gypsum, AFt and hydrated calcium silicate (C–S–H). [Copyright &y& Elsevier]