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Herein, Factsage software and sintering experiment were conducted to predict and correlate thermodynamic calculations of Fe in a synthetic solid waste and the expansion behavior of ceramsite. With the increase of Fe 2 O 3 content, the liquid phase content and viscosity in the multi-component system gradually decreased and the melting temperature range became wider. This can match with the generation of the liquid phase with proper viscosity in the ceramsite and the full expansion properties. At 400–1000 °C, iron as a network former was tetrahedrally coordinated with oxygen to form Hercynite (Al 2 FeO 4) phase; at 1180–1200 °C, iron as a network modifier dissolved into the silicate mineral structure to form the eutectic composition of Diopside (Ca 4 Mg 3.62 Fe 0.78 Si 7.6 O 24) and Ferrosolite (Si 16 Mg 5.09 Fe 10.66 Ca 0.26 O 48). The formation of iron-bearing silicate facilitated the generation of the viscous layer, so that the outer layer of the ceramsite exhibited sealing performance. Finally, a preferable porous ceramsite with compressive strength of 10.7 MPa and an apparent density of 708 kg/m3 was obtained. This study analyzes the effect of Fe 2 O 3 on the expansion behavior of porous ceramsite and provides new insight into how to analyze different solid wastes to produce ceramsite in a predictable way. [ABSTRACT FROM AUTHOR]

Background: It is unknown whether the Dietary Approaches to Stop Hypertension (DASH) dietary pattern is associated with other blood pressure (BP) variables, beyond mean systolic blood pressure (SBP) and diastolic blood pressure (DBP).Objectives: The study aimed to study the associations between the DASH dietary pattern and daytime and nighttime mean BPs and BP variance independent of the mean (VIM).Methods: A sample of 324 Chinese adults aged ≥ 60 y who were not on BP-lowering medications were included in the analysis. The DASH score was calculated using data collected by a validated FFQ. The 24-h ambulatory BP was measured and the mean and VIM SBP and DBP were calculated for both the daytime (06:00-21:59) and nighttime periods (22:00-05:59). Multivariable linear models were constructed to assess associations between the DASH dietary pattern and daytime and nighttime BP outcomes, adjusting for sociodemographic factors, lifestyle, BMI, and hypertension (clinic SBP ≥ 140 mm Hg or DBP ≥ 90 mm Hg), and sleep parameters (only for nighttime BP outcomes). An interaction term between DASH score and hypertension status was added to explore the potential differential association in normotensive and hypertensive individuals.Results: Every 1-unit increase in the DASH score was associated with a 0.18-unit (95% CI: -0.34, -0.01 unit) and a 0.22-unit (95% CI: -0.36, -0.09 unit) decrease in nighttime VIM SBP and nighttime VIM DBP, respectively. DASH score was not associated with any daytime BP outcomes, nighttime mean SBP, or nighttime mean DBP. A significant interaction (DASH score × hypertension status) was detected for VIM SBP (P-interaction = 0.04), indicating a differential association between DASH score and nighttime VIM SBP by hypertension status.Conclusions: Independently of sleep parameters and other factors, the DASH dietary pattern is associated with lower nighttime BP variability in elderly adults. [ABSTRACT FROM AUTHOR]

• A novel C-C process was used to deep extract alumina from low-grade bauxite. • A near-neutral C-C residue with high Ca and low Al was obtained to prepare cement clinker. • The mineral transformation in alumina extraction and clinker preparation was studied. • The combined method realizes the efficient production of alumina and zero discharge. During the Bayer process for alumina production, the molecular formula of the bauxite residue is approximately equivalent to Na 2 O·Al 2 O 3 ·1.7SiO 2 · n H 2 O. This means that 1 kg of SiO 2 in bauxite will produce 1 kg of Al 2 O 3 and 0.608 kg of Na 2 O in bauxite residue. Thus, the extraction efficiency of alumina is low when processing low-grade bauxite. In addition, it is difficult to utilize bauxite tailings with solid alkali in the structure. In this study, low-grade bauxite was treated using a calcification–carbonization process. A new type of residue (C-C residue) with a different structure from that of traditional bauxite residue was obtained. A cement clinker was prepared with C-C residue as the main ingredient at a dosage of 50%. The experimental results show the alumina extraction efficiency reached 75.82% when processing low-grade bauxite of A/S 3.06 using the calcification–carbonization process. This is higher than the 61.44% of the Bayer process. The main phases of C-C residue [CaCO 3 , amorphous Ca (4−2x) Si x O 4 , and undecomposed Ca 3 Al 2 (SiO 4)(OH) 4 ] convert into Ca 2 SiO 4 , Ca 3 SiO 5 , and Ca 2 Fe x Al (2−x) O 5 after calcination. The calcification–carbonization process combined with cement production helped low-grade bauxite achieve highly efficient and clean alumina production, which is conducive to the sustainable development of alumina industry. [ABSTRACT FROM AUTHOR]

Coal slime is a solid waste generated during the coal washing process, and the high value-added clay minerals it contains are critical to reducing resource extraction and proactively adapting to changing policy requirements. In this work, sodium hexametaphosphate (SHMP) was selected to form thermodynamically stable complexes (i.e., Fe 7 P 6 O 24 , Fe 10 P 6 O 26 , Mg 3 P 2 O 8 , NaMgPO 4 , Na 12 Mg 4 P 10 O 35 , and Ca 5 HO 13 P 3) with exposed Fe3+, Mg2+ and Ca2+ ion sites on the surface of coal slime. The adsorption of SHMP effectively enhanced the zeta potential of the coal slime, and the energy potential increased from 5 × 10−18 J to 17 × 10−18 J, which overcame the van der Waals force at a short distance of 1–2 nm. It promoted the formation of the solvent hydration layer and achieved stable dispersion of the slurry. Meanwhile, through the magnetic difference between minerals, the kaolin in the system was purified by combined overflow filtration superconducting magnetic separation technology. Finally, under 3T/5T tandem magnetic separation conditions, the removal rates for Fe and Ti were approximately 94.96 % and 85.86 % respectively. The purified kaolin complies with Chinese kaolin categorization requirements and shares a similar composition to commercial kaolin. [ABSTRACT FROM AUTHOR]

Bauxite residue is an alkaline solid waste produced during the extraction of alumina from bauxite, which causes serious environmental problems and safety risks. In this study, alkali and alumina were recovered from Bayer bauxite residue using a novel calcification-carbonisation process. This produced a non-hazardous and near-neutral residue (C-C residue), the properties of which facilitated its subsequent reuse. After the calcification-carbonisation treatment, 46.5% of the alumina was extracted and the Na 2 O content in the final residue (C-C residue) dropped to less than 0.3%. In addition, the feasibility of using C-C residue in the production of cement and the preparation of soil was analysed. The results showed that the chemical composition of C-C residue is very close to that of Portland cement clinker, which allows the dosage of bauxite residue in cement production to be increased. A comparison of the C-C residue with a general soil showed that the former performed well for many soil parameters, such as alkalinity and salinity, and has great potential for application in soil preparation. Thus, the calcification-carbonisation method, combined with cement production or soil preparation, is a sustainable process for completely reusing Bayer bauxite residue and facilitating bauxite waste minimisation. [ABSTRACT FROM AUTHOR]

The calcification-carbonation process is a novel cleaner production method to recover alkali and alumina from bauxite residue and obtain harmless residue with low aluminum content and no alkali. At present, this method is only limited to laboratory research and has not been put into industrial application. The reason is that the existing research only focuses on the mineral transformation of the solid phase, but lacks consideration of the concentration and availability of the extract in the liquid phase. The calcification-carbonation process is a complex hydrometallurgical series process. Without a complete continuous production line, it is difficult to evaluate the reliable concentration distribution in the system. In order to obtain the concentration distribution of Na 2 O and Al 2 O 3 in the whole calcification-carbonation process, this paper adopts a combined research method of metallurgical process simulation and experimental research based on the existing solid phase transformation theory. This method turns out to be effective and inexpensive to develop new technology at present. On the basis of the previous experimental results of solid structure transformation and parameter optimization, this study employs the material balance analysis module of METSIM software to analyze the distribution and concentration of Na 2 O and Al 2 O 3 in the calcification-carbonation process. Combined with the concentration characteristics of input and output and the experimental verification of the key steps, a multi-material circulation optimization scheme of the calcification-carbonation process through the integration of liquid material flow resources is proposed to realize the effective recovery of low-concentration Al 2 O 3 and the circulation of alkali liquor in the system. It promotes the recycling of resources and cleaner production of alumina. Image 1 • A specific scheme is designed to recover alkali and alumina from bauxite residue. • The recovered resources are enriched based on multi-material balance and circulation. • Improve the availability of recovered low-concentration components. • Promote zero discharge of pollutants and cleaner production of alumina. [ABSTRACT FROM AUTHOR]

Two low cytotoxic fluorescence probes Rb1 and Rb2 detecting Fe 3+ were synthesized and evaluated. Rb1 and Rb2 exhibited an excellent selectivity to Fe 3+ , which was not disturbed by Ag + , Li + , K + , Na + , NH 4 + , Fe 2+ , Pb 2+ , Ba 2+ , Cd 2+ , Ni 2+ , Co 2+ , Mn 2+ , Zn 2+ , Mg 2+ , Hg 2+ , Ca 2+ , Cu 2+ , Ce 3+ , AcO − , Br − , Cl − , HPO 4 2− , HSO 3 − , I − , NO 3 − , S 2 O 3 2− , SO 3 2− and SO 4 2− ions. The detection limits were 1.87 × 10 −7 M for Rb1 and 5.60 × 10 −7 M for Rb2 , respectively. 1:1 stoichiometry and 1:2 stoichiometry were the most likely recognition mode of Rb1 or Rb2 towards Fe 3+ , and the corresponding OFF–ON fluorescence mechanisms of Rb1 and Rb2 were proposed. [ABSTRACT FROM AUTHOR]

Saline-alkali stress is a major abiotic stress limiting plant growth. The selection of saline-alkali-tolerant rootstock is an effective strategy to reduce salinization-alkalization influence in apple production. M. halliana is a highly saline-alkali-resistant apple rootstock in northwestern China. However, few metabolic response studies have been conducted on this species. In plants under saline-alkali stress, the uptake of K, Mg and Zn in M. halliana leaves were inhibited, whereas the absorption of Fe2+, Cu2+ or Mn2+ were increased. Metabolic analysis revealed 140 differentially expressed metabolites, which were mainly involved in alkaloid biosynthesis, phenylalanine biosynthesis, ATP-binding cassette (ABC) transporters, and mineral absorption. Especially, the expression of sucrose, amino acids, alkaloids, flavonoids and carotenoids were significantly upregulated under saline-alkali stress. qRT-PCR analysis demonstrated that NHX8 and ZTP1 involved in Na+ and Fe2+ transport were upregulated, while AKT1 , MRS2-4 and ZTP29 involved in K+, Mg2+ and Zn2+ transport were downregulated, respectively. ANT , ATP2A, CALM and SOS2 are involved in Ca2+ signal transduction, and ABCB1 , ABCC10 and NatA are key transporters that maintain ionic homeostasis. M. halliana regulates Na+/K+ homeostasis by mediating Ca2+ signalling and ABC transporters. The accumulation of metabolites contributes to improving the saline-alkali resistance of M. halliana because of the scavenging of ROS. An increase in pheophorbide a content in porphyrin and chlorophyll metabolism leads to leaf senescence in M. halliana leaves, which contributes to a reduction in stress-induced injury. These findings provide important insights into the saline-alkali tolerance mechanism in apple, which also provides an important starting point for future research. • M. halliana is a highly saline-alkali-resistant apple rootstock in northwestern China. • M. halliana regulates Na+/K+ homeostasis by mediating Ca2+ signalling and ABC transporters. • Sucrose, amino acids, alkaloids, flavonoids and carotenoids significantly accumulated under saline-alkali stress. • The accumulation of metabolites contributes to improving the saline-alkali resistance of M. halliana because of the scavenging of ROS. [ABSTRACT FROM AUTHOR]