Response surface modeling of ceftriaxone removal from hospital wastewater.

In recent decades, an emerging concern of widespread antimicrobial resistance has been raised due to the existence of pharmaceutical samples such as antibiotics in an aqueous medium. Herein, antibiotic ceftriaxone (CTX) removal from hospital wastewater employing a hybrid process of electrocoagulation (EC) and adsorption (AD) was investigated. The response surface methodology (RSM) was employed to study the influences of main operating variables, including initial CTX concentration, pH, current density, reaction time, and chitosan dosage, on the removal efficiency of the treatment process. Under the optimum condition of the employed EC/AD hybrid treatment process, where initial CTX concentration, pH solution, the current density, adsorbent dosage, and reaction time were set at 20.0 mg L-1, 7.5, 6.0 mA cm-2, 0.75 g L-1, and 12.5 min, respectively, the removal efficiency of 100% was achieved. Analysis of variance (ANOVA) confirmed that the developed quadratic treatment model is highly significant. The applied EC/AD hybrid treatment process revealed the electrical energy consumption of 0.84 kWh m-3 and 0.2168 kWh (g Al)-1 per cubic meter of hospital wastewater and gram of consumed aluminum electrode, respectively. The second-order kinetic model with R2 of 0.9514 and the Langmuir isotherm model with R2 of 0.973 best fit the developed EC/AD hybrid treatment process, and qm was found to be 111.1 mg g-1. The obtained experimental results confirmed that the CTX concentration of the hospital wastewater was reduced to zero after applying the EC/AD hybrid process.

Green synthesis of strontium nanoparticles self-assembled in the presence of carboxymethyl cellulose: an in vivo imaging study.

Carboxymethyl cellulose (CMC) is one of the main derivatives of cellulose and is used as a drug carrier for hydrophobic and hydrophilic drugs, imaging in vivo, and biological applications. Encapsulation is a technology in which target compounds are coated with wall compounds to form microcapsules. This study reports a new chemical processing wet method for precipitation and encapsulation of strontium nanoparticles (Sr NPs) within CMC structures using a sonochemical method. Preparation parameters such as microwave power and irradiation time as well as morphology and particle size of Sr NPs were also investigated. Products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and atomic force microscopy. In this study, CMC was used as a biological stabilizer in a retentive phase to encapsulate Sr NPs. For the first time, Sr NPs were synthesized using CMC in a cost-effective, simple, fast, micellation-assisted, ultrasound method. Sr NPs were encapsulated in green capping agent structures of either 1%, 2% or 3% weight to provide an efficient optical nanostructure with a high yield at wavelengths 200-700 nm for use in in vivo imaging studies.