Sustainable Utilization of Fe(â ¢) Isolated from Laterite Hydrochloric Acid Lixivium via Ultrasonic-Assisted Precipitation to Synthesize LiFePO4/C for Batteries.

Ultrasonic-assisted precipitation was employed to sustainably isolate Fe in the hydrochloric acid lixivium of low-grade laterite for the synthesis of battery-grade iron phosphate. The recovery efficiency of Ni and Co exceeded 99%, while the removal efficiency of the Fe impurity reached a maximum of 95%. Precipitation parameters for the selective isolation of Fe (MgO precipitant, pH 1, 70-80 °C) were optimized and used in ultrasonic precipitation experiments. The use of ultrasonic waves in the precipitation process enhanced micromixing by reducing the size of primary grains and mitigating particle agglomeration, thereby significantly improving the purity of the isolated compound and providing high-quality iron phosphate (FePO4·2H2O). The LiFePO4/C composite prepared from as-precipitated FePO4 exhibited excellent electrochemical performance, with a discharge capacity of 149.7 mAh/g at 0.1 C and 136.3 mAh/g at 0.5 C after 100 cycles, retaining almost 100% cycling efficiency. This novel and facile method for iron removal from laterite acid lixivium not only efficiently removes excess iron impurities leached due to the poor selectivity of hydrochloric acid, but also enables the high-value utilization of these iron impurities. It enhances economic benefits while simultaneously alleviating environmental pressure.

Combined associations of general obesity and central obesity with hypertension stages and phenotypes among children and adolescents in Zhejiang, China.

General and central obesity are suggested to be associated with elevated blood pressure (BP), whereas few studies have investigated their combined associations with hypertension in children. This study aimed to assess the associations of combinations of general obesity and central obesity with hypertension in Chinese children, including its stages and phenotypes. A total of 5430 children aged 7-17 years in Zhejiang Province were enrolled. General obesity was evaluated by body mass index (BMI), while central obesity was by waist circumference (WC). Then all children were sorted into three mutually exclusive groups: normal weight with or with no central obesity (NW), abnormal weight with no central obesity (AWNCO), and abnormal weight with central obesity (AWCO). Hypertension was defined as either a systolic or diastolic BP ≥ 95th percentile, and further classified into stage 1 hypertension, stage 2 hypertension, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic diastolic hypertension (SDH). Logistic regression was used. AWNCO and AWCO were associated with stage 1 hypertension (AWNCO, odds ratio [OR] = 1.94, 95% confidence interval [CI]: 1.59-2.37; AWCO, 2.67, 2.20-3.25), stage 2 hypertension (AWNCO, 2.35, 1.33-4.13; AWCO, 4.53, 2.79-7.37), ISH (AWNCO, 2.50, 1.96-3.18; AWCO, 3.95, 3.15-4.95), and SDH (AWNCO, 2.48, 1.75-3.52; AWCO, 2.78, 1.94-3.99). Children with AWCO were more likely to have stage 1 and stage 2 hypertension, as well as ISH and SDH. The combined measurement of general and central obesity is suggested as an appropriate screening tool for hypertension among children and adolescents.

Modeling of the Competition between Uranyl Nitrate and Nitric Acid upon Extraction with Tri-n-butyl Phosphate.

Uranium is a strategic element and plays an important role in energy resources. A H2O-HNO3-UO2(NO3)2-TBP (tri-n-butyl phosphate)-diluent system is commonly used for uranium separation and purification in liquid-liquid extraction. Uranyl nitrate is promoted by the existence of nitrate at low HNO3 concentrations but is inhibited at high HNO3 concentrations. Considering the competitive extraction between HNO3 and UO2(NO3)2, a generic extraction model is developed. The activities of components in the aqueous phase were estimated using Pitzer models. The thermodynamic equilibrium constants and Pitzer parameters were regressed by experimental data. The resulting model was able to successfully predict uranyl nitrate, nitric acid, and water extraction over a large range of conditions (U, 0-1.8 mol/L; HNO3, 0-10 mol/L; TBP, 5-100 vol %) within average absolute relative deviations of 11.2, 15.7, and 23.8%, respectively. The predicted results show that water and nitric acid were extracted as di-solvates HNO3·(TBP)2·H2O and (TBP)2·2H2O at low nitric acid concentrations, with the formation of mono-solvates HNO3·TBP and HNO3·TBP·H2O as the acid concentration increased. Uranyl nitrate was shown to be rejected from the organic phase as the formation of HNO3·TBP and HNO3·TBP·H2O in acid was extracted at high acid concentrations.

Application of a Sustainable Bioderived Solvent (Biodiesel) for Phenol Extraction.

Replacement of volatile organic compound solvents by greener or more environmentally sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns. In the present work, a bioderived solvent, soybean oil methyl ester, which is better known as biodiesel and is a nonvolatile organic compound, was used as a solvent to replace the fossil solvent (kerosene) for phenol extraction. First, biodiesel was selected as an optional solvent to replace kerosene based on Hansen solubility parameter calculation results. Second, the effects of solvent concentration, equilibrium pH of the aqueous phase, temperature, extraction time, etc. on phenol extraction were examined. The results show that biodiesel has strong extraction ability on phenol extraction than that of kerosene. An acidic environment decreases the phase disengagement time. Phenol extraction reached equilibrium in 30 s of contact time at room temperature. McCabe-Thiele diagram calculation results show that the phenol extraction efficiency can reach 98% in three theoretical stages at an A/O ratio of 10:1 (Cyanex923 + biodiesel). Finally, the extraction mechanism indicated that biodiesel could reduce the intermolecular hydrogen bond forces in the extractant so as to improve the extraction efficiency.

The P-Type ATPase PA1429 Regulates Quorum-Sensing Systems and Bacterial Virulence.

Pseudomonas aeruginosa is becoming an increasingly prevalent pathogen, capable of causing numerous life threatening infections in immunocompromised patients. The three hierarchically arranged quorum sensing (QS) systems, namely las, rhl, and pqs play key roles in coordinating virulence expression in P. aeruginosa. However, the regulatory mechanisms of the pqs system have not been fully elucidated. To identify new genes involved in synthesis of the Pseudomonas quinolone signal (PQS), a transposon mutagenesis library was constructed. PA1429 was found to inhibit PQS biosynthesis. The PA1429 deletion mutant also exhibited increased bacterial motility, biofilm formation, and virulence in a mouse model of acute lung infection. Interestingly, it also displayed reduced tolerance to oxidative stress. Mutated pqsH in the PA1429 deletion background restored bacterial susceptibility to H2O2. In addition, our data showed that PA1429 repressed the expression of las and rhl systems. Overall, these results provide new insights into the complex regulatory networks of quorum-sensing and virulence expression in P. aeruginosa.