Ultra-Selective CMSMs Derived from Resorcinol-Formaldehyde Resin for CO Separation.

A resorcinol-formaldehyde precursor was synthesized to fabricate the CO selective Carbon Molecular Sieve Membranes (CMSMs) developed in this study. The degree of polymerization (DP) was analyzed via Gel Permeation Chromatography (GPC) and its effect on the CO/N perm-selectivity and CO permeance was investigated. The membrane that was polymerized at 80 °C (named R80) was selected as the best performing CMSM after a preliminary test.

Intensification of Red-G dye degradation used in the dyeing of alpaca wool by advanced oxidation processes assisted by hydrodynamic cavitation.

Red-G dye is one of the main dyes used in the textile industry to dye alpaca wool. Therefore, considering the large volume of processed wool in Perú, the development of efficient technologies for its removal is a present scientific issue. In this study, an integrated system based on hydrodynamic cavitation (HC) and photo-Fenton process was evaluated to remove the Red-G dye.

Alternative methods for cleaning membranes in water and wastewater treatment.

Membrane fouling is caused by foulant deposition or adsorption through physical or chemical interactions on the membrane surface, causing the reduction of flux through the membrane. The main drawbacks of chemical agents used for cleaning are cost, damage caused on the membrane, and waste stream making the process unattractive. Alternative, methods such as ultrasound, enzymatic process, and osmotic backwashing were explored for membrane cleaning.

Emerging contaminants, SARS-COV-2 and wastewater treatment plants, new challenges to confront: A short review.

The current pandemic caused by SARS-CoV-2 has put public health at risk, being wastewater-based epidemiology (WBE) a potential tool in the detection, prevention, and treatment of present and possible future outbreaks, since this virus enters wastewater through various sources such as feces, vomit, and sputum. Thus, advanced technologies such as advanced oxidation processes (AOP), membrane technology (MT) are identified through a systematic literature review as an alternative option for the destruction and removal of emerging contaminants (drugs and personal care products) released mainly by infected patients. The objectives of this review are to know the implications that the new COVID-19 outbreak is generating and will generate in water compartments, as well as the new challenges faced by wastewater treatment plants due to the change in a load of contaminants and the solutions proposed based on the aforementioned technologies to be applied to preserve public health and the environment.

Acid precipitation followed by microalgae (Chlorella vulgaris) cultivation as a new approach for poultry slaughterhouse wastewater treatment.

Poultry slaughterhouse wastewater (PSW) contains high organic matter and nutrients requiring thus a special treatment before its final disposal. In this work, acid precipitation (HSO) followed by microalgae "Chlorella vulgaris" cultivation both in batch and continuous processes was studied as an alternative method for PSW treatment. By reducing the pH value of PSW from 6 to 7 to 4, about 80% of the total chemical oxygen demand (COD) was removed as sludge.

Preparation of Porous Stainless Steel Hollow-Fibers through Multi-Modal Particle Size Sintering towards Pore Engineering.

The sintering of metal powders is an efficient and versatile technique to fabricate porous metal elements such as filters, diffusers, and membranes. Neck formation between particles is, however, critical to tune the porosity and optimize mass transfer in order to minimize the densification process. In this work, macro-porous stainless steel (SS) hollow-fibers (HFs) were fabricated by the extrusion and sintering of a dope comprised, for the first time, of a bimodal mixture of SS powders.

Recent Advances in Pd-Based Membranes for Membrane Reactors.

Palladium-based membranes for hydrogen separation have been studied by several research groups during the last 40 years. Much effort has been dedicated to improving the hydrogen flux of these membranes employing different alloys, supports, deposition/production techniques, etc. High flux and cheap membranes, yet stable at different operating conditions are required for their exploitation at industrial scale.

Fluidized Bed Membrane Reactors for Ultra Pure H₂ Production--A Step forward towards Commercialization.

In this research the performance of a fluidized bed membrane reactor for high temperature water gas shift and its long term stability was investigated to provide a proof-of-concept of the new system at lab scale. A demonstration unit with a capacity of 1 Nm³/h of ultra-pure H₂ was designed, built and operated over 900 h of continuous work. Firstly, the performance of the membranes were investigated at different inlet gas compositions and at different temperatures and H₂ partial pressure differences.

Morphology and N₂ Permeance of Sputtered Pd-Ag Ultra-Thin Film Membranes.

The influence of the temperature during the growth of Pd-Ag films by PVD magnetron sputtering onto polished silicon wafers was studied in order to avoid the effect of the support roughness on the layer growth. The surfaces of the Pd-Ag membrane films were analyzed by atomic force microscopy (AFM), and the results indicate an increase of the grain size from 120 to 250-270 nm and film surface roughness from 4-5 to 10-12 nm when increasing the temperature from around 360-510 K. After selecting the conditions for obtaining the smallest grain size onto silicon wafer, thin Pd-Ag (0.

Importance of the support material in thin palladium composite membranes for steady hydrogen permeation at elevated temperatures.

Hydrogen permeation performance of palladium membranes supported on porous alpha-alumina and yttria-stabilized zirconia (YSZ) was studied at 300-850 degrees C. The hydrogen permeation flux across the palladium-alpha-alumina membrane decreased markedly during permeation tests conducted at >600 degrees C. The SEM and XPS studies of the post-test membrane revealed the presence of aluminium in the palladium layer.

Simple detection of trace Pb2+ by enrichment on cerium phosphate membrane filter coupled with color signaling.

A Pb(2+) selective membrane filter was fabricated from the fibrous CeO(H(2)PO(4))(2).2H(2)O (CeP) crystals by blending with cellulose fiber. Enrichment of ppb level of Pb(2+) was achieved simply by filtration of aqueous sample solution through the membrane filter.

Switching of PET fluorescence signals induced by ligand exchange reactions of N-(9-anthrylmethyl)amine on Cu(II) complexes and its application to postcolumn detection of glyphosate.

N-(9-Anthrylmethyl)amines which combine a fluorescent subunit and a chelate forming fragment have revealed a signal switching property in an aqueous solution upon complexation (off) with Cu(II) and liberation (on) of the probe molecule by substitution with an other ligand. The ligand exchange reaction between N-(phosphonomethyl)glycine (glyphosate), a typical herbicide, with N-(9-anthrylmethyl)amines on Cu(II) ion leads the fluorescence signal intensity to revive, providing an indirect detection system of glyphosate available in water of neutral pH region. The present system has been applied to the post column detection in the ion chromatographic separation of glyphosate and its metabolite aminomethylphosphonic acid (AMPA).

A density functional study to choose the best fluorophore for photon-induced electron-transfer (PET) sensors.

Anthracenes bearing aliphatic or aromatic amino substituents, which behave as molecular sensors, have shown their potential to act as photon-induced electron-transfer (PET) systems. In this PET, the fluorophore moieties are responsible for electron release during protonation and deprotonation. The principle of hard and soft acids and bases (HSAB) deals with both intra- and intermolecular electron migration.