Cobalt doping of titanium oxide nanoparticles for atenolol photodegradation in water.

Cobalt-doped TiO2 nanoparticles were prepared and characterized by FT-IR, TEM, SEM, and XRD. The surface morphology was sphere-shaped with ~ 26.46 nm of the size of the nanoparticles. Ninety percent atenolol photodegradation was obtained with 15 mg/L concentration, 40 min stirring time, 2 pH, 2.0 g/L dosage of nanoparticles, 200.0 nm irradiation UV wavelength, and hydrogen peroxide amount 2.0 mL/L at 30 °C temp. Atenolol photodegradation conformed the first-order kinetics with a mechanism comprising atenolol sorption on the doped TiO2 nanoparticles and its degradation in UV irradiation. Hole (h+) and electron (e-) pairs are produced by doped TiO2 nanoparticles, creating hydroxyl free radicals and superoxide oxygen anions. These species break down atenolol.

Copper carboxymethyl cellulose nanoparticles for efficient removal of tetracycline antibiotics in water.

Copper carboxymethyl cellulose nanoparticles were prepared and characterized by FT-IR, XRD, SEM, TEM, and EDX techniques. Removal of tetracycline was obtained at 90% with optimized parameters of 500 µg/L concentration, 40 min contact time, 7.5 pH, 1.5 g/L dose, and 298 K temp. The adsorption followed Freundlich model very well in comparison to Langmuir. Tempkin model described good interactions between tetracycline and nanoparticles. Dubinin-Radushkevich isotherm confirmed the chemical nature of adsorption. The adsorption was pseudo-second order with a liquid film diffusion kinetics mechanism. The adsorption was endothermic and spontaneous as suggested by thermodynamics results. The supramolecular mechanism was developed for the process. Interestingly, the process was suitable at 7.5 pH with low contact time. These features of the adsorption made this process applicable at natural water conditions, making the process eco-friendly and feasible. Therefore, it may be an excellent method for the removal of tetracycline in any water system.

Synthesis of chitosan composite iron nanoparticles for removal of diclofenac sodium drug residue in water.

Iron composite nanoparticles were prepared (90% yield) using macromolecule chitosan and characterized by spectroscopic techniques (FT-IR, XRD, SEM, TEM & EDX). These were utilized to remove diclofenac sodium in water. The adjusted parameters were 400 µg/ L, 50.0 min., 5.0, 2.0 g/ L and 25.0 °C as concentration, contact time, pH, adsorbent amount and temperature for the elimination of diclofenac sodium in water with maximum 85% elimination. The sorption was spontaneous with exothermic. Data followed Langmuir, Temkin and Dubinin-Radushkevich models. Thermodynamic parameter ΔG° values were -12.19, -13.74 and -15.67 kJ/mol at 20, 25 and 30 °C temperatures. The values of ΔH° and ΔS° were 8.58 and 20.84 kJ/mol. Pseudo-first-order and liquid film diffusion mechanisms were proposed for the adsorption. This adsorption method is fast, effective eco-friendly and low-cost as it may be used in natural circumstances of water resources. The sorption method may be applied for the elimination of diclofenac sodium in any water body at a huge and financial scale.

COVID-19: Disease, management, treatment, and social impact.

COVID-19 was originated from Wuhan city of Hubei Province in China in December 2019. Since then it has spread in more than 210 countries and territories. It is a viral disease due to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus. The patients show flu-like symptoms with a dry cough, sore throat, high fever, and breathing problems. The disease due to SARS-CoV-2 was named as COVID-19. About 2.2 million people have been infected with more than 0.15 million deaths globally. The United States of America is the most affected country with the highest patients of about 0.7 million. Despite great efforts, there is no treatment of this disease. However, prevention and management are the best options. This article describes SARS-CoV-2, disease, prevention and management, treatment and social impact on society. It was analyzed that a combination of antiviral drugs with hydroxyl-chloroquine and azithromycin (with the consultation of a medical practitioner) may be the best option to treat the patients, depending on the patient's conditions and symptoms. However, Unani therapy may be useful along with allopathic treatment. It is urgently advised and requested that all the persons should follow the preventive measures, managements and quarantine strictly without any religious discrepancy otherwise the situation may be the worst. Also, there is an urgent requirement to educate our new generation for science and technology to fight against any such disaster in future; if any. There is no need to be panic and proper prevention and management are essential to combat this disease. This article may be useful to create awareness among the public, to prevent, manage and treat COVID-19.

Preparation of a carboxymethylcellulose-iron composite for uptake of atorvastatin in water.

Many water bodies are being contaminated by atorvastatin, which has certain side effects and problems on healthy individuals through contaminated water. For this purpose, effective and selective carboxymethylcellulose macromolecule iron composite nanoparticles were synthesized by green methods, characterized and used for uptake of atorvastatin drug residue from water. Atorvastatin in water was analyzed by HPLC using Aqua C28 (250 mm × 46 mm id) column and buffer-ACN (35:65, v/v) as eluent. The maximum elimination of atorvastatin was 80% with 40 µg L-1 concentration; 40 min agitated time, 5.0 pH, 1.0 g L-1 dose and 298 K temp. The removal data obeyed Freundlich, Langmuir, Dubinin-Radushkevich and Temkin models. The values of free energy were -8.79, -8.73 and -8.65 kJ mol-1 at 20.0, 25.0 and 30.0 °C temperatures. Enthalpy value was -14.16 kJ mol-1; showing exothermic removal. Entropy was -18.74 × 10-3 kJ mol-1 K; presenting decrease in entropy in the process. The kinetics modeling showed pseudo-first-order and liquid film diffusion mechanisms of removal. The removal technology was quick, conservation pleasant and lucrative. It is because of it capability with little dose and interaction time. Hence, the reported technology is practical for the exclusion of atorvastatin in water resource.

Modeling of fenuron pesticide adsorption on CNTs for mechanistic insight and removal in water.

Inexpensive multi-walled carbon nanotubes (MCNTs) were prepared with 10-40 nm particle sizes and 9.0 m2g-1 surface area. Fenuron pesticide was removed in water using these CNTs with 100.0 µgL-1 concentration, 60 min contact time, 2.0 g L-1 dose, 7.0 pH, and 25 °C. 90% removal of fenuron pesticide was achieved. Adsorption data obeyed Tempkin, Freundlich, Langmuir and Dubinin-Radushkevich models. The standard free energies values of fenuron pesticide adsorption were -11.89, -11.59, -11.55 kJ mol-1. The values of enthalpy and entropy were -9.12 kJmol-1 and -26.61 × 10-3 kJ mol-1 K. The negative values of free energy showed speedy adsorption of fenuron pesticide on CNTs. The supramolecular mechanism of fenuron adsorption onto CNTs was fixed by simulation studies and the binding energy and binding affinity of fenuron with CNTs were - 6.5 kcal mol-1 and 5.85 × 104 M-1, respectively. There were one π-σ, seven π-π stacked, one π-π T-shaped, and three π-alkyl type of hydrophobic interactions between fenuron and carbon nanotube. These results clearly indicated the physical nature of the adsorption. The method is speedy, cost-effective, efficient and repeatable. Therefore, the established adsorption method is appropriate for adsorption of fenuron pesticide in waters.

Facile and eco-friendly synthesis of functionalized iron nanoparticles for cyanazine removal in water.

Second generation herbicide is applied for broad leaf weeds and yearly grasses in the growing fields of bananas, pineapple, sugarcane - polluting water sources. Cyanazine removal is described on functionalized iron nano particles (nano-adsorbent). The nano-adsorbent was developed via eco-friendly method, functionalized with 1-butyl-3-methylimidazolidium bromide followed by SEM, XRD and FT-IR characterization. Remaining cyanazine in water was examined by C18-HPLC method. The batch experimentation limits were 30.0 µg/L (concen.), 30.0 min. (time) 7.0 (pH), 2.5 g/L (dose) and 25.0 °C temperature. The experimentation data followed Freundlich, Temkin Dubinin-Radushkevich and Langmuir isotherms. The values of ΔG°, ΔH° and ΔS° were -7.41, -6.47 and -6.27 kJ/mol at 20, 25 and 30 °C temps.; -8.27 kJ/mol and -7.93 × 10-3 kJ/mol K. These observations shown removal process fast and exothermic. The removal obeyed pseudo-first-order and liquid film diffusion mechanism. The removal method was quick, eco-friendly, and cheap owing to be appropriate under usual situations of water assets. The removal method can be applied for cyanazine removal in different waters.

Kinetics, Thermodynamics, and Modeling of Amido Black Dye Photodegradation in Water Using Co/TiO2 Nanoparticles.

Titanium oxide nanoparticles were doped with copper and characterized by XRD, FT-IR, TEM, and SEM. The surface morphology was spherical with 15-26 nm as particle size. The doped titanium oxide (Co/TiO2 ) nanomaterial was used for photodegradation of amido black dye in water. The maximum photodegradation of amido black obtained was 90%. The values of free energy and enthalpy were negative, indicating spontaneous photodegradation of amido black dye. The photodegradation of amido black dye obeyed first-order kinetic model. The photodegradation mechanism of amido black involved adsorption of the dye on the surface of cobalt doped titanium oxide and its degradation under UV radiation. The electron (e- ) and hole (h+ ) pairs were generated by Co/TiO2 , which consequently generated superoxide oxygen anion and hydroxyl free radical. These species degraded amido black dye. The reported method was fast, effective, and economic, which may be utilized to remove amido black in water. The doped TiO2 catalyst was quite stable and can be used up to 5 cycles.

Water treatment by new-generation graphene materials: hope for bright future.

Water is the most important and essential component of earth's ecosystem playing a vital role in the proper functioning of flora and fauna. But, our water resources are contaminating continuously. The whole world may be in great water scarcity after few decades. Graphene, a single-atom thick carbon nanosheet, and graphene nanomaterials have bright future in water treatment technologies due to their extraordinary properties. Only few papers describe the use of these materials in water treatment by adsorption, filtration, and photodegradation methods. This article presents a critical evaluation of the contribution of graphene nanomaterials in water treatment. Attempts have been made to discuss the future perspectives of these materials in water treatment. Besides, the efforts are made to discuss the nanotoxicity and hazards of graphene-based materials. The suggestions are given to explore the full potential of these materials along with precautions of nanotoxicity and its hazards. It was concluded that the future of graphene-based materials is quite bright.

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system.

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system is described. Both uptake and degradation processes of (-)-o,p-DDT were slightly higher than (+)-o,p-DDT enantiomer. The optimized parameters for uptake were 7.0µgL-1 concentration of o,p-DDT, 60min contact time, 5.0pH, 6.0gL-1 amount of reverine sediment and 25°C temperature. The maximum degradation of both (-)- and (+)-o,p-DDT was obtained with 16 days, 0.4µgL-1 concentration of o,p-DDT, pH 7 and 35°C temperature. Both uptake and degraded process followed first order rate reaction. Thermodynamic parameters indicated exothermic nature of uptake and degradation processes. Both uptake and degradation were slightly higher for (-)-enantiomer in comparison to (+)-enantiomer of o,p-DDT. It was concluded that both uptake and degradation processes are responsible for the removal of o,p-DDT from nature but uptake plays a crucial role. The percentage degradations of (-)- and (+)-o,p-DDT were 30.1 and 29.5, respectively. This study may be useful to manage o,p-DDT contamination of our earth's ecosystem.

Nano-capillary electrophoresis for environmental analysis.

Many analytical techniques have been used to monitor environmental pollutants. But most techniques are not capable to detect pollutants at nanogram levels. Hence, under such conditions, absence of pollutants is often assumed, whereas pollutants are in fact present at low but undetectable concentrations. Detection at low levels may be done by nano-capillary electrophoresis, also named microchip electrophoresis. Here, we review the analysis of pollutants by nano-capillary electrophoresis. We present instrumentations, applications, optimizations and separation mechanisms. We discuss the analysis of metal ions, pesticides, polycyclic aromatic hydrocarbons, explosives, viruses, bacteria and other contaminants. Detectors include ultraviolet-visible, fluorescent, conductivity, atomic absorption spectroscopy, refractive index, atomic fluorescence spectrometry, atomic emission spectroscopy, inductively coupled plasma, inductively coupled plasma-mass spectrometry, mass spectrometry, time-of-flight mass spectrometry and nuclear magnetic resonance. Detection limits ranged from nanogram to picogram levels.