High-valent metal-oxo species transformation and regulation by co-existing chloride: Reaction pathways and impacts on the generation of chlorinated by-products.

High-valent metal-oxo species (HMOS) have been extensively recognized in advanced oxidation processes (AOPs) owing to their high selectivity and high chemical utilization efficiency. However, the interactions between HMOS and halide ions in sewage wastewater are complicated, leading to ongoing debates on the intrinsic reactive species and impacts on remediation. Herein, we prepared three typical HMOS, including Fe(IV), Mn(V)-nitrilotriacetic acid complex (Mn(V)NTA) and Co(IV) through peroxymonosulfate (PMS) activation and comparatively studied their interactions with Cl- to reveal different reactive chlorine species (RCS) and the effects of HMOS types on RCS generation pathways. Our results show that the presence of Cl- alters the cleavage behavior of the peroxide OO bond in PMS and prohibits the generation of Fe(IV), spontaneously promoting SO4•- production and its subsequent transformation to secondary radicals like Cl• and Cl2•-. The generation and oxidation capacity of Mn(V)NTA was scarcely influenced by Cl-, while Cl- would substantially consume Co(IV) and promote HOCl generation through an oxygen-transfer reaction, evidenced by density functional theory (DFT) and deuterium oxide solvent exchange experiment. The two-electron-transfer standard redox potentials of Fe(IV), Mn(V)NTA and Co(IV) were calculated as 2.43, 2.55 and 2.85 V, respectively. Due to the different reactive species and pathways in the presence of Cl-, the amounts of chlorinated by-products followed the order of Co(II)/PMS > Fe(II)/PMS > Mn(II)NTA/PMS. Thus, this work renovates the knowledge of halide chemistry in HMOS-based systems and sheds light on the impact on the treatment of salinity-containing wastewater.

Peracetic acid activation via the synergic effect of Co and Fe in CoFe-LDH for efficient degradation of pharmaceuticals in hospital wastewater.

As an oxidant, peracetic acid (PAA) is gradually applied in advanced oxidation processes (AOPs) for pollutants degradation due to its high oxidation and low toxicity. In this study, the prepared Co2Fe1-LDH showed excellent PAA activation ability for efficient degradation of various pharmaceuticals with a removal efficiency ranging from 82.3% to 100%. Taking sulfamethoxazole (SMX) as a model pharmaceutical, it's found that organic radical (R-O•) with high concentration of 5.27 × 10-13 M is the dominant ROS responsible for contaminants degradation. Further analysis demonstrated that bimetallic synergistic effect between Co and Fe can improve electron transfer ability of Co2Fe1-LDH, resulting in the accelerated conversion of Co from +3 to +2 valence state with a high reaction rate (4.3 × 101-1.483 × 102 M-1 s-1) in this system. Density functional theory (DFT) reveals that C1, C3, C5 and N11 with higher ƒ0 and ƒ-values concentrated on aniline group of SMX are the main attack sites, which is consistent with the results of degradation products. Besides, Co2Fe1-LDH/PAA system can effectively reduce biological toxicity after reaction, due to lower biotoxicity of degradation products and the carbon sources provided by PAA. In application, Co2Fe1-LDH/PAA system was capable of resisting the influence of water matrix and effectively removing pollutants in actual hospital wastewater. Importantly, this study comprehensively evaluated the ability of Co2Fe1-LDH/PAA system to remove organics and improve the biodegradability of actual hospital wastewater, providing guidance for application of PAA activation system.

Decrease in Serum Levels of Adiponectin and Increase in 8-OHdG: a Culprit for Cognitive Impairment in the Elderly Patients with Type 2 Diabetes.

BACKGROUND: Adiponectin and 8-Hydroxy-2'-deoxyguanosine (8-OHdG) are identified as important biomarkers in the pathogenesis process of type 2 diabetes mellitus (T2DM). Whether adiponectin and 8-OHdG have a relation to cognitive decline in the elderly T2DM patients has been poorly understood. The aim of this study was to evaluate the effects of adiponectin and 8-OHdG in the elderly patients with T2DM and to determine the role of adiponectin and 8-OHdG in the cognitive impairment of the elderly patients with T2DM. METHODS: 57 individuals were recruited and analyzed , with 26 cases of T2DM without cognitive impairment and 31 cases of T2DM with cognitive impairment. All of them underwent an examination of diabetes scales and blood glucose at different times. A primary diagnosis of diabetes was in line with the diagnosis criteria set by the American Diabetes Association (ADA). Statistical significance was defined as a P-value of less than 0.05. RESULTS: The variables of sex, age, body mass index (BMI), hypertension, diabetes, metabolic syndrome, lacunar cerebral infarction, smoking and drinking in T2DM patients without cognitive impairment and with cognitive impairment showed no difference according to the univariate analysis exploring each variable separately (p>0.05). A significant difference was observed in the serum levels of adiponectin and 8-OHdG and the scales of MMSE and MoCA (p<0.05). Therefore, it was inferred that there is no correlation between glucose metabolic value and cognitive outcome of T2DM patients. Serum levels of adiponectin and 8-OHdG could act as biomarkers of cognitive impairment degree in the elderly T2DM patients. CONCLUSION: Serum levels of adiponectin and 8-OHdG could act as specific and sensitive biomarkers for the early diagnosis and treatment of cognitive impairment in elderly T2DM patients. Serum levels of adiponectin and 8-OHdG have a close relation to the neurological cognitive outcome of the elderly T2DM patients.