1,721,260 research outputs found
Potential utilization as fertilizer of waste liquid from bio-trickling reactor for greenhouse gases treatment
No full textThis research mainly focused on the exploration of the possibility to utilize the liquid by-products (the circulating alkaline fluid of a bio-trickling reactor, containing NO3-, 7.0 ≤ pH ≤7.5) as a fertilizer, with reduced environmental impact and economic benefits. The composition of the exhausted bio-trickling liquid (TL) was analysed in accordance with Dlgs. 75, 2010 of Italian Republic, which recognizes the CE Rules n. 2003/2003 and n.834/2007. In particular, the TL discharged from a bio-trickling filter can be recognized into the category of nitrogen mineral organo-fluid fertilizers
Waste cooking oil for wax esters synthesis using Candida rugosa lipase immobilized on Fe3O4@OA nanoparticles
No full textWax ester is an important skin conditioning agent derived from the esterification of fatty acids with alcohols. It is widely used in cosmetic as it has a composition similar to that of natural skin lipids. This study presents the synthesis of wax esters from hydrolyzed WCO in presence of cetyl alcohol and Candida rugosa lipase immobilized on Fe3O4@OA. The effects of the reaction time and cycles of reuse were investigated. The wax ester conversion has been monitored for 24 h. High conversion of ∼ 89.3 % was observed already at 12 hours of synthesis. No significant reduction, during four cycles of use, of the lipase activity occurs
Single-Atom Catalysts for the Electro-Reduction of CO2 to Syngas with a Tunable CO/H2 Ratio: A Review
No full textNowadays, transition towards green chemistry is becoming imperative. In this scenario, an attractive perspective consists in the generation of CO through the electrochemical reduction of CO2 under ambient conditions. This approach allows storage of the electrical energy from intermittent renewable sources in the form of chemical bonds, and simultaneously reduces greenhouse gas emissions, giving carbon a second chance of life. However, most catalysts adopted for this process, i.e., noble metal-based nanoparticles, still have several issues (high costs, low current densities, high overpotentials), and in the view of generating syngas through co-electrolysis of H2O and CO2, do not enable a widely tunable CO/H-2 ratio. Single-atom catalysts with N-doped carbon supports have been recently introduced to face these challenges. The following review aims to answer the demand for an extended and exhaustive analysis of the metal single-atom catalysts thus far explored for the electro-reduction of CO2 in aqueous electrolyte solution. Moreover, focus will be placed on the objective of generating a syngas with a tunable CO/H-2 ratio. Eventually, the advantages of single-atom catalysts over their noble metal-based nano-sized counterparts will be identified along with future perspectives, also in the view of a rapid and feasible scaling-up
Investigation on the removal of 2,4-chlorophenol using horseradish peroxidase immobilized on nanohybrid
No full textHerein, in this report, was developed a nano-hybrid of Fe3O4/Ag/GO nanoparticles (NPs), constituted of graphene oxide (GO) supporting flower-like Fe3O4/Ag NPs in the presence of citric acid surfactant. The citric acid-functionalized Fe3O4/Ag/GO nanoparticles were used for Horseradish peroxidase (HRP) immobilization. The immobilized HRP can be tested to remove 2, 4-dichlorophenols in the presence of H2O2, the degradation of 2, 4-DCP at pH 6 at 25°C and in the presence of H2O2 (0.8 mM) was for free and immobilized HRP of 40 % and 77 %, respectively. Moreover, immobilized HRP showed a high removal efficiency of ∼94% in the presence of 0.6 mM of H2O2,
Immobilization of horseradish peroxidase on Fe3O4/Au_Go nanoparticles to remove 4-chlorophenols from waste water
No full textMetal–metal oxide nanostructure supported on graphene oxide as a multifunctional electro-catalyst for simultaneous detection of hydrazine and hydroxylamine
No full textSynthesis of ethyl levulinate by a new bio-nanocatalyst
No full textLipase from Thermomyces lanuginosus was physically anchored to AgAu-Fe3O4@tartaric acid nanoparticles (NPs) to be used for the conversion of levulinic acid into ethyl-levulinate, in the presence of ethanol. The proposed strategy explored the direct immobilization of the enzyme on the as-prepared tartaric acid modified NPs. A very remarkable conversion of 90 % was achieved at 4:1 ETOH/acid molar ratio, after 12 h and at 45°C reaction temperature, higher than that shown by free lipase
Fe3O4/graphene electrode for the electrochemical detection of 4-ntrophenol
No full textHere the performance in 4-Nitrophenol (4-NP) detection of magnetite-few layer graphene-based electrode was reported. The prepared nanocomposite, synthesized according to a "wet chemistry" approach, was broadly characterized: SEM and TEM images and XRD spectra indicate the formation of nanoparticles with a few nanometers size dispersed on graphene layers. The sample was tested as an electrochemical sensor for the detection of small traces of 4-NP in aqueous solutions with a limit of detection (LOD) of 4 μM. The sensor was tested also for 1 month, showing proper operation and excellent stability
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