Photodegradation of Amoxicillin in Aqueous Systems: A Review.

Amoxicillin (AMX) is utilized in the treatment of several infectious diseases, and its concentration in wastewater has increased quite significantly over the years, posing high health hazards for humans and other living organisms. Investigations are in progress globally to eliminate AMX and other related pollutants using several methods that include adsorption, photolysis, photocatalytic degradation, photoelectrocatalytic degradation, and electrochemical conversion. AMX can be eliminated efficiently from the environment using photodegradation, either by photolysis or a photocatalytic process. Several types of semiconductor NMs have been used to eliminate AMX and other related drugs present in wastewater. This review spans the photodegradation studies conducted during the years 2018-2024 to degrade and eliminate AMX in aquatic systems. Several studies have been reported to eliminate AMX from different water streams. These studies are categorized into TiO2-containing and non-TiO2-based catalysts for better comparison. A section on photolysis is also included, showing the use of UV alone or with H2O2 or PS without using any nanomaterial. A tabulated summary of both types of catalysts showing the catalysts, reaction conditions, and degradation efficiency is presented. Researchers have used a variety of reaction conditions that include radiation types (UV, solar, and visible), pH of the solution, concentration of AMX, number of nanomaterials, presence of other additives and activators such as H2O2 as oxidant, and the influence of different salts like NaCl and CaCl2 on the photodegradation efficiency. TiO2 was the best nanomaterial found that achieved the highest degradation of AMX in ultraviolet irradiation. TiO2 doped with other nanomaterials showed very good performance under visible light. WO3 was also used by several investigators and found quite effective for AMX degradation. Other metal oxides used for AMX elimination were derived from molybdenum, zinc, manganese, copper, cerium, silver, etc. Some researchers have used UV and/or visible irradiation or sunlight, without using solid catalysts, in the presence of oxidants such as H2O2. A summarized description of earlier published reviews is also presented.

Fe3O4-multiwalled carbon nanotubes-bentonite as adsorbent for removal of methylene blue from aqueous solutions.

The contamination of water due to present of dyes, poses serious health problems. Therefore, treatment of contaminated water is necessary to resolve this problem. A tailored co-precipitation technique has been successfully used to prepare Fe3O4-multiwalled Carbon Nanotubes (MWCNTs)-Bentonite nanocomposite. The methylene blue present in aqueous solutions was removed using synthesized nanocomposite as adsorbent. The synthesized novel nanocomposite was analyzed by various characterization techniques. The scanning electron microscope analysis shows that Bentonite and Fe3O4 nanoparticles are well decorated with the MWCNTs matrix. The nanocomposite exhibited a high BET surface area of 204.01 m2/g with a pore volume of 0.367 cm3/g. The BJH adsorption average pore diameter was analyzed to be 7.2 nm. Moreover, the adsorption model was in agreement with the Redlich-Peterson model with adsorption capacity of 48.2 mg/g with a high nonlinear regression coefficient (R2 = 0.985) and a low chi-square value (χ2 = 6.18). Kinetics data were described well by pseudo-first-order and pseudo second order, models with a high non-linear regression coefficient (R2 = 0.993). Adsorption of MB dye was determined to be a non-spontaneous and endothermic process since the values of ΔG, and ΔH were positive, and the entropy value was negative. Thus, the synthesized nanocomposite established itself as a promising candidate for the water treatment process.

Enhanced Organic Pollutant Removal Efficiency of Electrospun NiTiO3/TiO2-Decorated Carbon Nanofibers.

A nanocomposite comprised of nickel titanate/titania nanoparticles decorated with carbon nanofibers (NiTiO3/TiO2-decorated CNFs) is successfully synthesized via electrospinning and further utilized for methylene blue (MB) photodegradation. The morphology, phase, structural and chemical composition of the nanocomposite is investigated via scanning electron microscope, X-ray diffraction and transmission electron microscope equipped with energy dispersive X-ray. A mathematical model is developed to predict the photocatalytic activity of the produced nanocomposite by considering parameters such as initial dye concentration, light intensity, reaction temperature, and catalyst dosage. The reaction rate constant K1 decreased from 0.0153 to 0.0044 min-1 with an increase in the MB concentration from 5 to 15 mg L-1, while K2, K3, and K4 were found to increase with the increase in reaction temperature (0.0153 to 0.0222 min-1), light intensity (0.0153 to 0.0228 min-1) and catalyst dose concentration (0.0153 to 0.0324 min-1), respectively. The results obtained are found to be in good agreement with the modeling results and showed effective photodegradation activity. The performance of our catalyst is found to be better compared to other catalysts previously reported in the literature. The recyclability data of the synthesized NiTiO3/TiO2-decorated CNFs catalyst for four runs show that the catalyst is quite stable and recyclable. This nanocomposite photocatalyst offers a low-cost solution for wastewater pollution problems and opens new avenues to further explore the electrospinning method for the synthesis of nanocomposites.

Effectiveness of containment strategies and local cognition to control vehicular traffic volume in Dhaka, Bangladesh during COVID-19 pandemic: Use of Google Map based real-time traffic data.

BACKGROUND: To prevent the viral transmission from higher infected to lower infected area, controlling the vehicular traffic, consequently public movement on roads is crucial. Containment strategies and local cognition regarding pandemic might be helpful to control vehicular movement. This study aimed to ascertain the effectiveness of containment strategies and local cognition for controlling traffic volume during COVID-19 pandemic in Dhaka, Bangladesh. METHOD: Six containment strategies were considered to explore their influence on traffic condition, including declaration of general holiday, closure of educational institution, deployment of force, restriction on religious gathering, closure of commercial activities, and closure of garments factories. Newspaper coverage and public concern about COVID-19 were considered as local cognition in this research. The month of Ramadan as a potential event was also taken into account considering it might have an impact on the overall situation. Average daily journey speed (ADJS) was calculated from real-time traffic data of Google Map to understand the vehicular traffic scenario of Dhaka. A multiple linear regression method was developed to comprehend the findings. RESULTS: The results showed that among the containment strategies, declaration of general holiday and closure of educational institutions could increase the ADJS significantly, thereby referring to less traffic movement. Besides, local cognition could not significantly affect the traffic condition, although the month of Ramadan could increase the ADJS significantly. CONCLUSION: It is expected that these findings would provide new insights into decision-making and help to take appropriate strategies to tackle the future pandemic situation.

Coronavirus disease 2019 (COVID-19) manifestations during pregnancy in all three trimesters: A case series.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pandemic has raised concerns about the susceptibility amongst different groups of the population. Pregnant women are one such group. This study was conducted to investigate the effect of COVID-19 on pregnancy and maternal/neonatal outcomes. CASE PRESENTATION: This case series was conducted on 16 pregnant women with COVID-19 from March 21 to May 11, 2020. Clinical characteristics, pregnancy complications, medication used, maternal/neonatal outcomes, and fatality rate were investigated through this study. The mean age of the patients was 30.06 yrs. Patients from all three trimesters were included (1 in first, 5 in second, and 10 in the third trimesters). The most common clinical symptoms were shortness of breath (n = 10), dry cough (n = 10), myalgia (n = 8), and chills (n = 7). Also, three cases had papulosquamous skin lesions with fissuring. The most common laboratory results were leukocytosis (n = 8), increased liver enzymes (n = 6), elevated CRP (n = 5), and thrombocytopenia (n = 4). There was one case of maternal mortality, five of premature labor pain (PLP), two of preeclampsia, and two of placenta accreta. Twelve pregnancies were terminated (nine cesarean sections, three vaginal deliveries). Among neonates, we had 6 cases of preterm labor. All neonates had negative PCR results. CONCLUSION: Clinical manifestations and paraclinical results were similar to non-pregnant patients. There was no evidence of vertical transmission. PLP and premature rupture of membranes (PROM) were the most common complications in the second and third trimesters of pregnant COVID-19 women, which can lead to rupture of the uterus. Termination and delivery should be planned individually.