Ultrasound‒induced facile synthesis of spinel CoFe2O4‒PAC magnetic nanocatalyst for remediation of hypersaline petrochemical wastewater: Degradation mechanism, biodegradability enhancement and phytotoxicity mitigation.

In this study, magnetic CoFe2O4-PAC nanocatalysts were synthesized through facile hydrothermal and co‒precipitation approaches with ultrasonic irradiation, which were used for the treatment of hypersaline petrochemical wastewater (HPCW). When an ultrasound‒induced synthesis process (US@CoFe2O4‒PAC) was used, a more efficient and stable magnetic spinel CoFe2O4‒PAC nanocatalyst was developed. The application of this nanocatalyst as a PMS activator, not only caused eradication of 90.4% of chemical oxygen demand (COD) of a HPCW after 90 min reaction time under the optimum conditions (pH 5-6, catalyst dose 1.0 g/L and 1.0 mM PMS), but also led to marginal leaching of iron (314 µg/L) and cobalt (95 µg/L) from the nanocatalyst. Recycling experiments over five consecutive runs showed a negligible decrease (7.2%) in COD removal efficiency which proved the stability and reusability of magnetic US@CoFe2O4-PAC. Two main mechanisms of adsorption and catalytic oxidation processes (homogeneous and heterogeneous PMS) are involved simultaneously in the PMS/US@CoFe2O4-PAC system, which are responsible for the destruction of refractory contaminants of HPCW through the generation of SO4•‒ and OH• radicals. COD of HPCW was mainly removed through SO4•- radical attack (73.6%) and the biodegradability of HPCW was enhanced dramatically after 90 min reaction time. The germination index (GI) of raw HPCW was increased 17.1 ± 4.2% and 24.3 ± 8.8% after 15 and 90 min reaction time, respectively, even PMS/US@CoFe2O4-PAC system showed less impact on phytotoxicity mitigation. Hence, it can be recommended to dilute the effluent before using for irrigational purpose. The findings of this study present practical significance of spinel US@CoFe2O4-PAC, which is an environment‒friendly catalyst, easy to handle and can sustain long‒term operation for the treatment of recalcitrant hypersaline wastewater and the other potential practical applications.

Prior COVID-19 infection among newly diagnosed tuberculosis patients in a tertiary care center in Tehran: A case-control study.

OBJECTIVE: To assess the risk of developing pulmonary tuberculosis (TB) in accordance with prior history of COVID-19 infection. BACKGROUND: Since the advent of the COVID-19 pandemic much discussion has been had on the possible role it might play on global efforts to combat TB; most, focusing on the pandemic's impact on health care systems' capabilities to manage TB cases. Mechanisms have also been proposed by which the COVID-19 infection may directly affect individuals' chance of developing TB infection. Cases have been reported with a history of COVID-19 infection preceding a diagnosis of TB, evidencing its possible role as a risk factor for the disease. METHODS: A case-control study was conducted enrolling patients diagnosed with pulmonary TB in the absence of major risk factors previous history of TB, (HIV) human immunodeficiency virus infection), end-stage renal disease, organ transplants, and use of immunosuppressive agents) for developing TB. Each patient was age and sex matched with one healthy control. Data regarding prior COVID-19 infection, diabetes, and smoking status as well as the use of corticosteroids and Tocilizumab for the treatment of COVID-19 infection was obtained. Bivariate analysis was conducted and variables with a likely association with TB status were entered in a multivariate model. RESULTS: Bivariate analysis demonstrated a significant relationship between prior COVID-19 infection and TB (95% confidence interval = 1.1-22.8, odds ratio [OR] = 5). Among other variables the severity of COVID-19 infection was found to have a likely association with TB status (p = .125). In a multivariate model, prior COVID-19 infection per se, was not found to be significantly associated with TB (p = .12, OR = 4.5). CONCLUSIONS: There seems to be an association between prior history of COVID-19 and a future diagnosis of TB partially linked to the severity of disease. The findings of the current study may serve as a basis for further studies to determine the need for and efficacy of measures to follow-up COVID-19 patients at an increased risk for developing TB.

Preparation, characterization, and application of modified magnetic biochar for the removal of benzotriazole: process optimization, isotherm and kinetic studies, and adsorbent regeneration.

The adsorption of benzotriazole (BTA) by chemically modified magnetic biochar (MMBC) as a cheap and abundant biosorbent was investigated and optimized using response surface methodology (RSM). Initially, the MMBC composite was synthesized and characterized by scanning electron microscopy (SEM) energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and Brunauer-Emmett-Teller (BET) techniques. The characterization results confirmed the existence of Fe3O4 in the composite structure, which had uniformly dispersed over biochar (BC) with porous texture. Moreover, the presence of Zn and Cl elements in EDX analysis indicated that the magnetic biochar (MBC) had been modified successfully. The effects of chemical modification methods on the adsorption capacity of magnetic biochar were investigated. Maximum BTA removal efficiency was demonstrated by MMBC, modifying using ZnCl2 (>99%). Optimization was carried out based on reaction time, BTA concentration and the concentration of adsorbent. Optimum experimental conditions for the removal of BTA from aqueous solutions were found to be 35 min of reaction time, 0.55 g/L of adsorbent, and 50 mg/L of initial BTA concentration. At these optimal conditions, the predicted BTA adsorption efficiency was 92.6%. The adsorption process followed the Avrami fractional-order reaction kinetic and the Langmuir adsorption isotherm with the maximum adsorption capacity of 563.1 mg/g. The values of thermodynamic parameters demonstrated that the adsorption of BTA on ZnCl2-MBC is endothermic and spontaneous. Under optimum usage of MMBC, the adsorptive removal efficiency of BTA non-significantly decreased from 99.2 to 93.9% after the 5th cycle. Thus, MMBC can be recommended as an environmentally friendly and cost-effective adsorbent to remove micropollutants from water.

Chronic obstructive pulmonary diseases related to outdoor PM10, O3, SO2, and NO2 in a heavily polluted megacity of Iran.

This study was conducted to quantify, by an approach proposed by the World Health Organization (WHO), the daily hospital admissions for chronic obstructive pulmonary disease (COPD) related to exposure to particulate matter (PM10) and oxidants such as ozone (O3), sulfur dioxide (SO2), and nitrogen dioxide (NO2) in a heavily polluted city in Iran. For the health impact assessment, in terms of COPD, the current published relative risk (RR) and baseline incidence (BI) values, suggested by the WHO, and the 1-h O3 concentrations and daily PM10, NO2, and SO2 concentrations were compiled. The results showed that 5.9, 4.1, 1.2, and 1.9% of the COPD daily hospitalizations in 2011 and 6.6, 1.9, 2.3, and 2.1% in 2012 were attributed to PM10, O3, SO2, and NO2 concentrations exceeding 10 µg/m3, respectively. This study indicates that air quality and the high air pollutant levels have an effect on COPD morbidity. Air pollution is associated with visits to emergency services and hospital admissions. A lower relative risk can be achieved if some stringent control strategies for reducing air pollutants or emission precursors are implemented.