ZSM-5 Zeolite As Host Material for Semiconductor Nanoparticles

Abstract: This work describes the optical and structure properties of nickel sulfide and cobalt sulfide nanoparticles i

Biological decolorization of xanthene dyes by anaerobic granular biomass

Biodegradation of a xanthene dyes was investigated for the first time using anaerobic granular sludge. On a first screening, biomass was able to decolorize, at different extents, six azo dye solutions: acid orange 7, direct black 19, direct blue 71, mordant yellow 10, reactive red 2 and reactive red 120 and two xanthene dyes—Erythrosine B and Eosin Y. Biomass concentration, type of electron donor, induction of biomass with dye and mediation with activated carbon (AC) were variables studied for Erythrosine B (Ery) as model dye. Maximum color removal efficiency was achieved with 4.71 g VSS L−1, while the process rates were independent of the biomass concentration above 1.89 g VSS L−1. No considerable effects were observed when different substrates were used as electron donors (VFA, glucose or lactose). Addition of Ery in the incubation period of biomass led to a fivefold increase of the decolorization rate. The rate of Ery decolorization almost duplicated in the presence of commercial AC (0.1 g L−1 AC0). Using different modified AC samples (from the treatment of AC0), a threefold higher rate was obtained with the most basic one, \textAC\textH2ACH2, as compared with non-mediated reaction. Higher rates were obtained at pH 6.0. Chemical reduction using Na2S confirmed the recalcitrant nature of this dye. The results attest that decolorization of Ery is essentially due to enzymatic and adsorption phenomena.This work was supported by the PTDC/AMB/69335/2006 project grants (Fundacao para a Ciencia e Technologia, FCT, Portugal), BRAIN project (ID 6681, European Social Found and Romanian Government and the grant of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-II-ID-PCE-2011-3-0559, Contract 265/2011

Corrosion protection and mechanical properties of the electroless Ni-P-MOF nanocomposite coating on AM60B magnesium alloy

Al-based MIL-53 MOF nanostructure was synthesized hydrothermally and then co-deposited in the electroless nickel coating on AM60B magnesium alloy using Zr pretreatment as an eco-friendly underlayer. The MIL-53(Al) nanostructure was synthesized in the form of layered semi-cube crystals with the surface area and mean pore diameter of 985.72 m2g−1 and 2.00 nm, respectively. The SEM images captured with two various zooming scales from the surface of the plain and MOF containing electroless layers showed cauliflower-like morphology with even distribution of nodule size. Also, the sub-grains of the plain coating disappeared after incorporation of the MOF. Although, both the normal and nanostructure-containing electroless layers have crystalline-amorphous structure, but the nanocomposite coating showed less crystallinity. The average surface roughness of the plain electroless coating was about 309 nm, which decreased to about 222 nm after incorporation of the MOF. The XRD patterns showed that the characteristic peak of Ni broadened after incorporation of the MOF, probably due to the decreasing of the crystallinity. For the heat-treated normal and MOF containing coatings at 200 °C no phase transition takes place, but new peaks appeared for heat-treated coatings at 400 °C due to the crystallization and second-phase precipitation. The results of the EIS tests showed an increase in the amount of the charge transfer resistance (from 19 to 29 kΩ cm2) after addition of the MOF, which means an improvement in the corrosion resistance. Also, low Jcorr of the composite coating represents its higher corrosion resistance with respect to the plain coating. The micro-hardness values of the composite coating before and after the heat treatment were higher than the plain coating. Also, the Ni-P-MOF coating has a lower wear rate both before and after the heat treatment due to an improvement in its micro-hardness