Peracetic acid (PAA) is increasingly used as an alternative disinfectant and its advanced oxidation processes (AOPs) could be useful for pollutant degradation. Co(II) or Co(III) can activate PAA to produce acetyloxyl (CH3C(O)O•) and acetylperoxyl (CH3C(O)OO•) radicals with little •OH radical formation, and Co(II)/Co(III) is cycled. For the first time, this study determined the reaction rates of PAA with Co(II) (k PAA,Co(II) = 1.70 × 101 to 6.67 × 102 M–1·s–1) and Co(III) (k PAA,Co(III) = 3.91 × 100 to 4.57 × 102 M–1·s–1) ions over the initial pH 3.0–8.2 and evaluated 30 different aromatic organic compounds for degradation by Co/PAA. In-depth investigation confirmed that CH3C(O)OO• is the key reactive species under Co/PAA for compound degradation. Assessing the structure–activity relationship between compounds’ molecular descriptors and pseudo-first-order degradation rate constants (k′PAA• in s–1) by Co/PAA showed the number of ring atoms, E HOMO, softness, and ionization potential to be the most influential, strongly suggesting the electron transfer mechanism from aromatic compounds to the acetylperoxyl radical. The radical production and compound degradation in Co/PAA are most efficient in the intermediate pH range and can be influenced by water matrix constituents of bicarbonate, phosphate, and humic acids. These results significantly improve the knowledge regarding the acetylperoxyl radical from PAA and will be useful for further development and applications of PAA-based AOPs.
The calcium looping cycles method has been identified as an attractive method for CO2 capture during coal combustion and gasification processes. However, it is well-known that the capture capacity of CaO undergoes a rapid decrease after mutiple cycles. In order to improve the stability of CO2 capture capacity in CaO, this paper focuses on the development and performance of the synthetic CaO/La2O3 sorbents for calcium looping cycles.The sorbents were synthesized by three different methods: dry physical mixing, wet chemistry, and sol−gel combustion synthesis (SGCS). Their multicyclic CO2 capture capacity and the effect of the additive La2O3 were investigated in a fixed bed reactor system. The results indicate that the additive of La2O3 plays a positive role in the carbonation/calcination reactions, and the SGCS-made synthetic sorbent is composed of ultrafine well-dispersed hollow structured particles which are beneficial to the gas-phase diffusion on the surface area and can prevent small CaO particles from agglomeration effectively. As a result, the novel synthetic sorbent with the molar ratio of Ca to La of 10:1 made by the SGCS method provides the best performance of a carbonation conversion of 72% under mild calcination conditions and a carbonation conversion of 36% under severe calcination conditions (high temperature and high CO2 concentration) after 20 cycles.
Destruction of pharmaceuticals excreted in urine can be an efficient approach to eliminate these environmental pollutants. However, urine contains high concentrations of chloride, ammonium, and bicarbonate, which may hinder treatment processes. This study evaluated the application of ferrate(VI) (Fe VI O 4 2− , Fe(VI)) to oxidize pharmaceuticals (carbamazepine (CBZ), naproxen (NAP), trimethoprim (TMP), and sulfonamide antibiotics (SAs)) in synthetic hydrolyzed human urine and uncovered new effects from urine's major inorganic constituents. Chloride slightly decreased pharmaceuticals' removal rate by Fe(VI) due to the ionic strength effect. Ammonium (0.5 M) in undiluted hydrolyzed urine posed a strong scavenging effect, but lower concentrations (≤0.25 M) of ammonium enhanced the pharmaceuticals' degradation by 300 μM Fe(VI), likely due to the reactive ammonium complex form of Fe(V)/Fe(IV). For the first time, bicarbonate was found to significantly promote the oxidation of aniline-containing SAs by Fe(VI) and alter the reaction stoichiometry of Fe(VI) and SA from 4:1 to 3:1. In depth investigation indicated that bicarbonate not only changed the Fe(VI)/SA complexation ratio from 1:2 to 1:1 but provided a stabilizing effect for Fe(V) intermediate formed in situ, enabling its degradation of SAs. Overall, the results of this study suggested that Fe(VI) is a promising oxidant for the removal of pharmaceuticals in hydrolyzed urine.
This paper investigated the oxidation of recalcitrant micropollutants [i.e., atenolol (ATL), flumequine, aspartame, and diatrizoic acid] by combining ferrate(VI) (Fe VI O 4 2− , Fe VI ) with a series of metal ions [i.e., Fe(III), Ca(II), Al(III), Sc(III), Co(II), and Ni(II )]. An addition of Fe(III) to Fe VI enhanced the oxidation of micropollutants compared solely to Fe VI . The enhanced oxidation of studied micropollutants increased with increasing [Fe(III)]/[Fe VI ] to 2.0. The complete conversion of phenyl methyl sulfoxide (PMSO), as a probe agent, to phenyl methyl sulfone (PMSO 2 ) by the Fe VI −Fe(III) system suggested that the highly reactive intermediate Fe IV /Fe V species causes the increased oxidation of all four micropollutants. A kinetic modeling of the oxidation of ATL demonstrated that the major species causing the increase in ATL removal was Fe IV , which had an estimated rate constant as (6.3 ± 0.2) × 10 4 M −1 s −1 , much higher than that of Fe VI [(5.0 ± 0.4) × 10 −1 M −1 s −1 ]. Mechanisms of the formed oxidation products of ATL by Fe IV , which included aromatic and/or benzylic oxidation, are delineated. The presence of natural organic matter significantly inhibited the removal of four pollutants by the Fe VI −Fe(III) system. The enhanced effect of the Fe VI −Fe(III) system was also seen in the oxidation of the micropollutants in river water and lake water.
Objective To investigate the association between gestational diabetes mellitus and adverse outcomes of pregnancy after adjustment for at least minimal confounding factors. Design Systematic review and meta-analysis. Data sources Web of Science, PubMed, Medline, and Cochrane Database of Systematic Reviews, from 1 January 1990 to 1 November 2021. Review methods Cohort studies and control arms of trials reporting complications of pregnancy in women with gestational diabetes mellitus were eligible for inclusion. Based on the use of insulin, studies were divided into three subgroups: no insulin use (patients never used insulin during the course of the disease), insulin use (different proportions of patients were treated with insulin), and insulin use not reported. Subgroup analyses were performed based on the status of the country (developed or developing), quality of the study, diagnostic criteria, and screening method. Meta-regression models were applied based on the proportion of patients who had received insulin. Results 156 studies with 7 506 061 pregnancies were included, and 50 (32.1%) showed a low or medium risk of bias. In studies with no insulin use, when adjusted for confounders, women with gestational diabetes mellitus had increased odds of caesarean section (odds ratio 1.16, 95% confidence interval 1.03 to 1.32), preterm delivery (1.51, 1.26 to 1.80), low one minute Apgar score (1.43, 1.01 to 2.03), macrosomia (1.70, 1.23 to 2.36), and infant born large for gestational age (1.57, 1.25 to 1.97). In studies with insulin use, when adjusted for confounders, the odds of having an infant large for gestational age (odds ratio 1.61, 1.09 to 2.37), or with respiratory distress syndrome (1.57, 1.19 to 2.08) or neonatal jaundice (1.28, 1.02 to 1.62), or requiring admission to the neonatal intensive care unit (2.29, 1.59 to 3.31), were higher in women with gestational diabetes mellitus than in those without diabetes. No clear evidence was found for differences in the odds of instrumental delivery, shoulder dystocia, postpartum haemorrhage, stillbirth, neonatal death, low five minute Apgar score, low birth weight, and small for gestational age between women with and without gestational diabetes mellitus after adjusting for confounders. Country status, adjustment for body mass index, and screening methods significantly contributed to heterogeneity between studies for several adverse outcomes of pregnancy. Conclusions When adjusted for confounders, gestational diabetes mellitus was significantly associated with pregnancy complications. The findings contribute to a more comprehensive understanding of the adverse outcomes of pregnancy related to gestational diabetes mellitus. Future primary studies should routinely consider adjusting for a more complete set of prognostic factors. Review registration PROSPERO CRD42021265837.
Surgical treatment of displaced proximal humeral fractures with use of the locking proximal humeral plate that was evaluated in the present study can lead to a good functional outcome provided that the correct surgical technique is used. Because many of the complications were related to incorrect surgical technique, it behooves the treating surgeon to perform the operation correctly to avoid iatrogenic errors.
10 CaO-based sorbents were synthesized by a sol–gel process supported with various materials, and their cyclic behavior was investigated under the same reaction conditions.
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