Removal of aniline from water by an Fe(II)-nano-Fe3O4@PAC heterogeneous catalyst in a Fenton-like process.

Aniline is a toxic chemical, and in many industries it is degraded by Fenton processes. In this study, an Fe(II)-nano-Fe3O4@PAC heterogeneous Fenton catalyst (MFC) was prepared with a coprecipitation and impregnation method, which is simple, efficient and cost effective. The results of the magnetic performance tests showed that the MFC has typical ferromagnetism properties. Nano-Fe3O4 was found both on the surface and inside the pores of the powdered activated carbon (PAC). MFC was found to be an efficient catalyst in the Fenton-like process for aniline degradation. The optimal conditions were obtained by the orthogonal experimental method. The results showed that under the optimal conditions (pH = 3.00, temperature = 20°C, concentration of MFC = 1.0 g/L, concentration of H2O2 = 0.27 g/L), the 5 mg/L aniline solution degradation ratio reached 91.2% and the mineralization ratio reached 75.77% in 30 min. In addition, kinetics studies indicated that the aniline degradation process follows a pseudo-first-order kinetics model. No refractory intermediate such as azobenzene, was found during the reaction. The pH value is an important factor in aniline solution degradation. This result indicates that in addition to the surface catalytic reaction, the Fenton reaction also occurs in solution. Fe2+/Fe3+ on the MFC surface and Fe2+/Fe3+ in solution both affect aniline degradation. This catalyst has the advantage of being easily magnetically separated from the aqueous phase. It has useful application prospects in solving organic industrial wastewater pollutions in developing countries because of its cost-effectiveness.

Ex vivo fat graft preservation: effects and implications of cryopreservation.

There are a variety of recommended methods for harvesting, treating, and utilizing autologous fat grafts. Previous work with the MTT assay illustrated that various preimplantation handling techniques had minimal effect on the viability of fat samples. This assay was used to test the viability of harvested fat samples after being stored for up to 8 days in a variety of conditions. Surprisingly, freezing the fat before assaying also had no measurable detrimental effect, which led us to study this phenomenon in greater detail. The results demonstrated that fat stored at subzero temperatures showed remarkable maintenance of their mitochondrial metabolic activity as compared with fat stored in a 32 degrees C incubator. These data suggest exciting possibilities for storage and banking of human adipose tissue, which would reduce patient cost, discomfort, and time associated with multiple grafting procedures.

Human adipocyte viability testing: a new assay.

BACKGROUND: Surgical experience and anecdotal data on the most effective method of harvesting, preparing, and injecting autologous fat grafts are inconsistent and conflicting. Because the limitation of fat grafting is its resorption, understanding how various handling techniques affect adipocyte survival is crucial to optimizing its long-term survival. OBJECTIVE: We sought to develop a method for assaying fat viability in its clinically used form and then to test several common techniques used in fat grafting for their effects on the viability of the fat. METHODS: We performed the well-established MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide] cell survival and proliferation assay on fat, but the colored enzyme-breakdown product could not be released into the supernatant for spectrophotometric analysis. An entirely new protocol was developed that allowed the MTT assay to quantitate the viability of free fat grafts. The assay was able to distinguish between different quantities of live fat and to quantify the decrease in viability when the fat is stored. We subjected the fat to various treatments, including insulin and Triton-X 100 detergent, (Sigma Aldrich, St. Louis, MO) centrifugation, extrusion through different types and sizes of needles, and freezing. RESULTS: With the exception of detergent, which decreased viability, all other treatments had no statistically significant effect on adipocyte survival. Freezing did not result in decreased cell viability. CONCLUSIONS: It is unlikely that variations in the clinical results of free fat grafting are the result of the handling techniques examined in this study.