Outstanding Performance of a New Exfoliated Clay Impregnated with Rutile TiO2 Nanoparticles Composite for Dyes Adsorption: Experimental and Theoretical Studies

Photodegradation of ibuprofen laden-wastewater using sea-mud catalyst/H2O2 system: evaluation of sonication modes and energy consumption

The main goal of the current investigation was to decontaminate ibuprofen (IBP) from hospital wastewater using sea mud as an H2O2 activator. Sea sludge was converted into catalysts at different temperatures and residence times in furnaces, and then tested in the removal of IBP, and the most efficient ones were reported for the production of catalysts. The catalyst was optimized at 400 °C and 3 h. SEM-mapping, FTIR, EDX, BET, and BJH experiments were used to characterize the catalyst. Experiments were done at two pulsed and continuous ultrasonication modes in a photoreactor, and their efficiencies were statistically compared. The designed variables included IBP concentration (10-100 mg/L), the catalyst concentration (0-3 g/L), pH (4-9), and time (10-90 min). The oxidation process had the maximum efficiency at pH 4, treatment time of 60 min, catalyst quantity of 5 g/L, and IBP content of 50 mg/L. The catalyst was recycled, and in the fifth stage, the removal efficiency of IBP was reduced to 50%. The amount of energy consumed for treating IBP laden-wastewater using the evaluated catalyst in two modes of continuous and pulsed ultrasonic was calculated as 102 kW h/m3 and 10 kW h/m3, respectively. IBP oxidation process was fitted with the first-order kinetic model. The system can be proposed for purifying hospital and pharmaceutical wastewaters.

Graphene Oxide@Heavy Metal Ions (GO@M) Complex Simulated Waste as an Efficient Adsorbent for Removal of Cationic Methylene Blue Dye from Contaminated Water

Graphene oxide (GO) was heavily used in the adsorption process of various heavy metal ions (such as copper (Cu) and iron (Fe) ions), resulting in a huge waste quantity of graphene oxide@metal ions complex. In this research, the authors try to solve this issue. Herein, the GO surface was loaded with divalent (Cu2+) and trivalent (Fe3+) heavy metal ions as a simulated waste of the heavy metal in various removal processes to form GO@Cu and (GO@Fe) composites, respectively. After that, the previous nanocomposites were used to remove cationic methylene blue (MB) dye. The prepared composites were characterized with a scanning electron microscope (SEM), transition electron microscope (TEM), Fourier transmission infrared (FTIR), Raman, and energy-dispersive X-ray (EDS) before and after the adsorption process. Various adsorption factors of the two composites towards MB-dye were investigated. Based on the adsorption isotherm information, the adsorption process of MB-dye is highly fitted with the Langmuir model with maximum capacities (mg g-1) (384.62, GO@Cu) and (217.39, GO@Fe). According to the thermodynamic analysis, the adsorption reaction of MB-species over the GO@Cu is exothermic and, in the case of GO@Fe, is endothermic. Moreover, the two composites presented excellent selectivity of adsorption of the MB-dye from the MB/MO mixture.