Stabilization and dewatering of wastewater treatment plant sludge using combined bio/Fenton-like oxidation process

Wastewater sludge usually contains large amounts of water and organic materials; therefore, its stabilization and dewatering are of particular importance. The present study aimed to investigate the possibility of sludge stabilization and dewatering from wastewater sludge by bioleaching (Thiobacillus ferrooxidans), Fenton/bioleaching, and bioleaching/Fenton-like processes. To evaluate sludge stabilization and dewatering, specific resistance to filtration (SRF), volatile suspended solids (VSS), total suspended solids (TSS), and soluble chemical oxygen demand (SCOD) were measured. In biological treatment with T. ferrooxidans with Fe²⁺ (2?g?L^?1), 99.75, 33, 37, and 72% reduction were observed in SRF, VSS, TSS, SCOD, respectively, after 2 days. In the combined treatment of Fenton before bioleaching (including Fe²⁺ 2?g?L^?1 and H₂O₂ 1?g?L^?1 with Fenton oxidation for 30?min followed by biological treatment with T. ferrooxidans for 2 days), the reduction rates in TSS, VSS, SCOD, and SRF were 40.18, 40.88, 60.95, and 75.43%, respectively. In treatment with the combined method of bioleaching before Fenton-like oxidation, the removal rates of the aforementioned parameters were 52.5, 54.4, 88, and 99.82%, respectively. In comparison to Fenton oxidation and bioleaching alone, combined biological method of bioleaching/Fenton-like oxidation using a lower dose of H₂O₂ and Fe²⁺ significantly improved sludge dewatering and stabilization.     

Synthesis of sulfides via reaction of aryl/alkyl halides with S8 as a sulfur-transfer reagent catalyzed by Fe3O4-magnetic-nanoparticles-supported L-Histidine-Ni(II)

One-pot synthesis of symmetrical diaryl/alkyl sulfides in high yields from the reaction between aryl/alkyl halides and S₈ can be carried out in a short period, using Fe₃O₄@SiO₂@His@Ni(II) as a reusable catalyst. The present approach offers the advantages of a clean reaction, simple methodology and high efficiency, and avoids the use of a toxic catalyst.     

Synthesis of new electromagnetic nanocomposite based on modified Fe3O4 nanoparticles with enhanced magnetic,conductive, and catalytic properties

A new method for the fabrication of an electromagnetic nanocomposite based on Fe₃O₄ and polyaniline (PANI) is offered. The authors focused on improvement of the physical and electromagnetic properties of the nanocomposite using a new synthetic method. Supermagnetic Fe₃O₄ nanoparticles were synthesized through coprecipitation method. As a chemical modification, the third generation of poly (amidoamine) dendrimer was grafted on the surface of the nanoparticles. PANI was grafted from –NH₂ functional groups of dendrimer via in situ polymerization of aniline. Finally, Au nanoparticles were loaded on the nanocomposite and its catalytic activity for reduction reactions was studied.     

Probiotic yoghurt functionalised with microalgae and Zedo gum: chemical,microbiological, rheological and sensory characteristics

In this study, using a central composite design, the effects of addition of Spirulina platensis and Zedo gum to plain and probiotic yoghurt samples were investigated during storage. Lactobacillus paracasei proliferation was directly dependent on the addition of microalgae and was inversely affected by storage time. Probiotic samples containing S. platensis showed the highest antioxidative activity. Maximum stability was obtained at higher amounts of Zedo gum, while organoleptic and rheological attributes improved at 0.25% Zedo gum. Given the importance of probiotic viability, supplementation of probiotic yoghurt with Zedo gum/S. platensis may be consideredas a novel nutraceutical formulation.     

Catalytic performance of Samaria-promoted Ni and Co/SBA-15 catalysts for dry reforming of methane

Methane reforming with CO₂ over Samaria-promoted Ni and Co/SBA-15 was comparatively investigated. The Co, Ni (10%wt) and Sm (0.5, 1 and 1.5%wt) ions were introduced by two-solvent impregnation method. The Ni and Co catalysts with/without promoter, were examined by N2 adsorption-desorption, x-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), temperature programmed reduction (TPR) and thermogravimetric analysis (TGA) methods, and then evaluated in CO₂ reforming of methane. The XRD and TEM results indicated that Ni and Co/SBA-15 promoted by 1%wt of Samaria, had the smallest NiO and Co₃O₄ particles size and the highest dispersion; as a result, they would rather studying dry reforming of methane test. Catalytic results indicated that Samaria promoted Ni/SBA-15 had the highest conversion (CH₄ conversion～58% at 700 °C), while a remarkable decrease of catalytic activity was observed over Samaria-promoted Co/SBA-15 (CH₄ conversion～25% at 700 °C). The positive effect of Samaria on Ni/SBA-15 catalyst activity is probably due to smaller NiO particles, higher NiO dispersion and lower trend to carbon deposition. On the contrary, the negative effect of Samaria on Co/SBA-15 catalyst activity is maybe due to Co oxidation to inactive phase and sintering of Co particles in high temperatures.     

Tuning the crystal structure and optical properties of selective area grown InGaAs nanowires

Catalyst-free InGaAs nanowires grown by selective area epitaxy are promising building blocks for future optoelectronic devices in the infrared spectral region.D...     

Performance of ANFIS Coupled with PSO in Manufacturing Superior Wear Resistant Aluminum Matrix Nano Composites

In this study, ANFIS was combined with PSO in order to optimize the parameters in pressure assisted semi solid processing of A360 aluminum matrix nano composites. ANFIS was utilized to calculate the objective function, which was later minimized using PSO. Combination of EMS semi solid processing and pressure assistance during solidification resulted in improvement of microstructural features and tribological properties. Globular grain structure was formed in the pressure assisted EMS parts. Tribological properties were investigated using pin on disk. It was noted that wear properties of EMS parts were benefited from the refinement of the primary α-Al phase and uniform distribution of the particles. EMS composites showed higher hardness than conventional cast parts, consequently there was a lower real area of contact and therefore lower wear rate. Moreover, hard dispersoid made the virgin alloy plastically constrained and improved their wear resistance.     

Comparison of pH-dependent sonodisruption of re-assembled casein micelles by 35 and 130 kHz ultrasounds

Sonodisruption behavior of re-assembled casein micelles was compared at two ultrasound frequencies (35 and 130 kHz) by turbidity measurement and laser-diffraction based particle size analysis. Sonochemical ultrasound (130 kHz) was more effective than power ultrasound (35 kHz) in micelle disruption. This was attributed to the higher strain rates generated upon implosion of cavities, as well as the liberation of more free radicals to the surrounding medium. The higher the pH of solution, the more effective was the ultrasonic disruption due to a looser expanded assembly of particles at higher pH values. Sonochemical ultrasound decreased the consistency coefficient of casein solutions and increased their flow index except at a pH value of 6.35, while power ultrasound did not affect the flow behavior of solutions across the whole pH range.