Solar-Assisted Photodegradation of Pesticides Over Pellet-Shaped TiO2-Kaolin Catalytic Macrocomposites at Semi-pilot-Plant Scale: Elucidation of Photo-Mechanisms and Water Matrix Effect

[Abstract] The behavior of novel pellet-shaped bulky titania-kaolin photocatalysts is herein evaluated for its application in the solar-assisted photocatalytic treatment of a bio-recalcitrant pesticide mix (imidacloprid, pyrimethanil and methomyl) in solar lab-scale and semi-pilot scale raceway pond photoreactors. The photocatalyst consists of 1 cm long titania-kaolin macro-composites that combine some advantages of both nanoparticulate and supported catalysts without being either. This opening the opportunity to extend the use of this photocatalyst to complex wastewater effluents. In addition, their stability and reusability potential was also evaluated, and reactive species leading to the solar-degradation of each pesticide were also identified using radical scavengers. Total removal of pesticides (2 mg L−1 each) with an optimal pellets dosage of 34.8 g L−1 was addressed, whether in ultrapure water (180–270 min of solar irradiation) or in two basic pH Municipal Wastewater Treatment Plant (MWWTP) effluents (≤300 min of solar irradiation) where methomyl was always the most recalcitrant pesticide. Lower Total Organic Carbon (TOC) removal (≈53–56%) was also found under the effect of these complex MWWTP effluents than in ultrapure water (>60%). Those results are very promising when comparing to the almost negligible TOC removal achieved with the Titania powder under basic MWWTP effluents due to the strong effect of particle aggregation. Very good photocatalyst stability and durability was shown along three consecutive cycles after applying a low-cost recovery protocol consisting of several washing and drying cycles without addressing a significant photoefficiency loss (TOC≈60-56%). The application of scavengers revealed that hydroxyl radical generated from photoinduced holes was the dominant species in the degradation of pyrimethanil and methomyl whereas reactive oxygen species formed from conduction band electrons were mainly involved in the photo-oxidation of imidacloprid.This research has been developed in the framework of Projects PID2020-114918RB-I00 (PHOTOPREBIO), funded by MCIN/AEI/10.13039/501100011033, Project PID2021-124021OB-I00 (URBRAINTREAT), funded by MCIN/AEI/10.13039/501100011033 and “ERDF: A way of making Europe”, and project TED2021-132667B–I00, funded by the EU NextGeneration EU/PRTR through project MCIN/AEI/10.13039/501100011033. M.C. and D.R.R. acknowledge financial support from “Xunta de Galicia” (Spain, Project GPC ED431B 2020/52), and D.R.R. acknowledges Universidade da Coruña for a Margarita Salas contractXunta de Galicia; GPC ED431B 2020/5

Colombian surgical outcomes study insights on perioperative mortality rate, a main indicator of the lancet commission on global surgery – a prospective cohort studyResearch in context

Summary: Background: Surgical care holds significant importance in healthcare, especially in low and middle-income countries, as at least 50% of the 4.2 million deaths within the initial 30 days following surgery take place in these countries. The Lancet Commission on Global Surgery proposed six indicators to enhance surgical care. In Colombia, studies have been made using secondary data. However, strategies to reduce perioperative mortality have not been implemented. This study aims to describe the fourth indicator, perioperative mortality rate (POMR), with primary data in Colombia. Methods: A multicentre prospective cohort study was conducted across 54 centres (hospitals) in Colombia. Each centre selected a 7-day recruitment period between 05/2022 and 01/2023. Inclusion criteria involved patients over 18 years of age undergoing surgical procedures in operating rooms. Data quality was ensured through a verification guideline and statistical analysis using mixed-effects multilevel modelling with a case mix analysis of mortality by procedure-related, patient-related, and hospital-related conditions. Findings: 3807 patients were included with a median age of 48 (IQR 32–64), 80.3% were classified as ASA I or II, and 27% of the procedures had a low-surgical complexity. Leading procedures were Orthopedics (19.2%) and Gynaecology/Obstetrics (17.7%). According to the Clavien–Dindo scale, postoperative complications were distributed in major complications (11.7%, 10.68–12.76) and any complication (31.6%, 30.09–33.07). POMR stood at 1.9% (1.48–2.37), with elective and emergency surgery mortalities at 0.7% (0.40–1.23) and 3% (2.3–3.89) respectively. Interpretation: The POMR was higher than the ratio reported in previous national studies, even when patients had a low–risk profile and low-complexity procedures. The present research represents significant public health progress with valuable insights for national decision-makers to improve the quality of surgical care. Funding: This work was supported by Universidad del Rosario and Fundación Cardioinfantil-Instituto de Cardiología grant number CTO-057-2021, project-ID IV-FGV017