Study of the influence of the aluminum source (acetate or sulfate) on the synthesis of the ceramic membrane and applications of emulsion oil water: use and reuse

The objective of this work was to prepare ceramic membranes and to evaluate the effect of the raw material on the ceramic membrane and on the efficiency of the emulsion separation oil/water. The ceramic membranes were manufactured using the uniaxial dry compaction method, from the thermal decomposition of aluminum sulfate or aluminum acetate, to evaluate the effect of the raw material (aluminum acetate or aluminum sulfate) on the efficiency in the emulsion oil/water separation. Ceramic membranes were characterized by measurements of X-ray diffraction patterns, scanning electron microscopy, mechanical strength, bubble point and water flow. In this study, membranes were produced with different characteristics. The values found for the permeate for the A1 membrane were 9.20 mg / L due to characteristics such as porosity and mechanical strength (44.63 % and 1.3 MPa), while the values A2 membrane was 6.52 mg / L, 18.86 % and 6.7 MPa. In conclusion, the membranes prepared are effective in removing the oil from the oily waste water. According to the results, the treatment of oil-water emulsions by microfiltration facilitates a significant reduction in the concentration of permeate oil.

Measurement of Aluminum and Chemical Oxygen Demand in the Effluent of Mordanted Cotton Against Environmental Regulations

Despite toxicity concerns of chemical mordants used in natural dyeing, there is limited research on the measurement, quality, and safe disposal of the chemical mordant effluent. This study measured the aluminum ions across the premordanting process of cotton print cloth using inductively coupled plasma mass spectrometry and calculated the oxidizable organic matter in the effluent through chemical oxygen demand (COD). The amount of aluminum absorbed by the cotton print cloth was low (2.31%–5.16%). The effluent COD was 23.91g COD/kg. Upon neutralization of the acidic condition, the aluminum in the effluent met discharge to freshwater regulations, and the COD met discharge to U.S. municipal sewage systems. However, the Global Harmonized System restricts aluminum acetate dibasic from organic certification due to its boric acid content. The high mordant concentration in the effluent supports the reuse of mordant baths but not direct disposal to the land or standing waters.

Silane coupling and mordanting as attachment techniques for pyridylazo and thiazolylazo ligands in the synthesis of adsorbents for uranium in seawater

Activated carbon adsorbents modified with azo compounds (4-(2-pyridylazo)resorcinol, 1-(2-pyridylazo)-2-naphthol, 4-(2-thiazolylazo)resorcinol), or with allyl and vinylbenzyl derivatives of 4-(2-thiazolylazo)resorcinol, were observed to be highly effective in removing uranium from seawater and providing high loadings. Adsorbents consisting of azo compounds attached to fiber fabrics were prepared using silane coupling to attach azo reagents to silica fibers or mordanting agents such as tannic acid or aluminum acetate to attach them to cellulose fibers. Loadings of 15–45 mg U g−1 adsorbent were obtained. Scanning electron microscopy/energy dispersive X-ray spectroscopy measurements confirmed the presence of high concentrations of uranium on the surface of the silica-based and cellulose-based fibers.

Synthesis of Alumina Using Aluminum Acetate

Alumina is a material used in a wide range of applications, including refractories, structural materials, sensors, catalysts, etc. Several synthesis methods are available for the production of submicrometric and nanometric alpha alumina. However, there is few studies on the use of acetate for the synthesis of alumina. Thus, the present work has as aim the synthesis of alumina powders using aluminum acetate. The precursors were obtained from the decomposition of aluminum acetate under temperatures of 650oC and 850oC, resulting in an amorphous precursors and gamma-alumina. These materials were submitted to dissolution and calcination. Based on the results, it is observed a reduced in the temperature formation of alpha phase, at around 900oC, when using the adopted methodology of synthesis. Amorphous precursor was more susceptible to the synthesis procedure used and generated alpha alumina in lower temperatures.

Al-Doped ZnO Nanoparticles Synthesized by Sonochemical-Assisted Method

Al-doped ZnO nanoparticles were synthesized by sonochemical method from zinc acetate dehydrate and aluminum acetate as starting precursors. The deionized (DI) water was selected as the solvent. Sonication of the precursor was performed by a Sonics Model VCX 750 for 30 minutes until precipitated product was finally obtained. The as-precipitated powders were calcined at different temperature range of 550-1100 °C for 2 hr. For all samples, their crystal structures were investigated by X-ray diffraction (XRD) and surface morphologies were observed by scanning electron microscope (SEM). The XRD results revealed that, the purity of as-synthesized powders increases when the calcination temperature increases. Moreover, it is noticed that the AlZnO partial peaks will appear when the as-synthesized powders were calcined at 800 – 1000 °C. In addition, SEM micrographs show the increase of agglomeration and the particles when the calcination temperature increases.