ABSTRACT
This study aimed at emerging contaminant chloroquine (CQN) removal, widely used in the COVID-19 pandemic through adsorption and employing a low-cost activated biochar from açai fruit endocarp. Two different adsorbents from the same precursor were applied. The first (CAA) was activated at a high temperature using ZnCl2, and the second (CA) was obtained by physical activation. The adsorbents were characterized through BET, FTIR, DRX, TG/DTG, and SEM. The results showed that zinc chloride activation furnished a material with a high specific surface area (SBET) and pore volume of 762 m2 g−1 and 0.098 cm3 g−1, respectively. Adsorption kinetics and isotherm were best adjusted through the pseudo-second-order (PSO) and Freundlich for both biochars. The process was thermodynamically favorable, occurring spontaneously without energy request. Additionally, the maximum adsorption capacity for CQN was 15.56 and 40.31 mg g−1 for CA and CAA, respectively, in pH 6.84, at a temperature of 25 °C, 50 mL solution and with 0.05 and 0.02 g of adsorbent. Those results are congruent with the literature showing the versatility of the material and the efficiency of the applied adsorption process.
ABSTRACT
Background Although evidence has emerged indicating that patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia present a high risk of venous thromboembolism (VTE), its real incidence and best diagnosis course remain unclear. In this study, we aimed to determine the incidence of pulmonary embolism in these patients and the role of D-dimer serum level as a predictive factor of a new VTE event. Methodology This was a single-center retrospective observational cohort study conducted in a tertiary hospital. All patients admitted to the infectious diseases ward with SARS-CoV-2 pneumonia with clinical or laboratory criteria for suspected VTE events were eligible for inclusion in the study. The t-test or Mann-Whitney U test was used to analyze the differences between the with-VTE group and the without-VTE group. Results Overall, VTE incidence was registered to be 30%. Chest computed tomography angiography data revealed thrombus mainly in segmental (five patients, 71%) and subsegmental pulmonary artery branches (four patients, 57%). No thrombus on major branches was documented. D-dimer serum levels (collected at hospital admission, 48 hours before the suspected VTE event date and at suspected VTE event date) were analyzed, and, despite a consistent tendency of higher values in the with-VTE group, no statistical difference was observed. Moreover, no statistical difference was observed between the two groups in mortality rates. Conclusions A clear higher risk of VTE events in SARS-CoV-2 pneumonia patients was not documented, and a link between the impact of VTE occurrence and a worse prognosis was not demonstrated. Therefore, we suggest that the use of D-dimer serum level should not be used as a predictor of VTE in SARS-CoV-2 pneumonia patients.