Kinetics of wet oxidation of black liquor over a Pt–Pd–Ce/alumina catalyst

The catalytic oxidation of industrial wastewater from paper and pulp mills has been investigated in a slurry reactor at a temperature range 433–463 K and at pressures from 1.5 to 2.2 MPa. Adding Ce on alumina support promotes the catalytic activity for oxidation of black liquor. Pt–Pd–Ce/alumina catalyst shows a promising activity for wet catalytic oxidation of black liquor. The oxidation reaction over a Pt–Pd–Ce catalyst is characterized by an initial fast reaction step followed by a slow reaction step. The rate of total organic carbon (TOC) reduction was described by first-order kinetics with respect to TOC concentration in black liquor for both initial and later reaction steps. The activation energies were determined to be 54.53 and 50.13 kJ/mol for the initial and later oxidation steps, respectively. Comparison of the data with the generalized kinetic model was also presented.     

Reduced laying depths for supply mains

Laying of supply piping below ground involves heavy costs. This paper from the GDR Bauakademie, Institute of Construction and Civil Engineering, Leipzig, describes how the costs have been reduced by up to 30 percent as a result of reducing the minimum depths required, by reassessing piping statics (interaction of the load ‐ soil ‐pipe system), and the precautions for irregular frost heave, which can be of decisive importance.     

THE BULK AND SURFACE STRUCTURE OF γ-ALUMINA

Despite its widespread use, the composition and structure of γ-alumina have been the subject of controversy for decades. In this article we review the historical attempts to resolve two principal questions that have each been extensively debated, but in independent communities: (1) What is the distribution of vacancies over the two cation sublattices in the nominal spinel structure, and (2) what is the hydrogen content of γ-alumina, if any? We then review how recent investigations have shown that these two questions are, in fact, related, and have a single resolution. The experimental study of γ-alumina surfaces has long been dominated by IR spectroscopy of the hydroxylated surfaces, and ²⁷AI NMR. Both techniques have produced perplexing results. Here we review the development of these surface studies and parallel computational studies. Finally, we review recent computational results that explain the puzzling experimental findings.     

Home visits by neighborhood Mentor Mothers provide timely recovery from childhood malnutrition in South Africa: results from a randomized controlled trial

Background  

Child and infant malnourishment is a significant and growing problem in the developing world. Malnourished children are at high risk for negative health outcomes over their lifespans. Philani, a paraprofessional home visiting program, was developed to improve childhood nourishment. The objective of this study is to evaluate whether the Philani program can rehabilitate malnourished children in a timely manner.     

Application of cross-flow microfiltration to semi-hard cheese production from milk retentates

In the cheese industry, the concentration of milk using ultrafiltration for continuous soft and fresh cheese production is standard technology. The object of the work presented here was to produce a semi-hard cheese of quality and composition comparable to that of traditionally made cheese from highly concentrated microfiltered milk retentate. Two different membrane systems were tested for the production of high viscous milk retentate with high dry matter content. For milk containing 3.2% fat and skim milk, a concentration factor of 6.6 and 9.1 respectively was obtained using the MF/UF/UF pilot plant fitted with cassette modules. Milk containing 3.2% fat was concentrated in batches by a factor of 5.7 in the pilot plant using a ceramic membrane. Using minimal curd separation, a semi-hard one day old cheese with a dry matter of 533 g/kg, moisture on a fat-free basis (MFFB) of 626 g/kg and fat on a dry basis (FDB) value of 478 g/kg was made from the milk retentate produced with the ceramic module. The ripened cheese fulfilled the legal requirements of a traditionally produced semi-hard cheese with superb sensory qualities. Using the MF/UF/UF plant, a dry matter of 495 g/kg (MFFB 669 g/kg, FDB 493 g/kg) was achieved in a semi-hard cheese made from skim milk retentate. Our results suggest that by using a larger spacer distance in the last loop of the MF/UF/UF plant, combined with new hybrid technologies, semi-hard cheese production from full concentrate milk will soon become possible.     

Beitrag zur Kenntnis des Hagebuttenmarks

Ohne ZusammenfassungMitteilung aus dem Chemischen Laboratorium der Stadt Stuttgart. (Direktor: Dr. Bujard.)     

Green manufacturing practices among wooden furniture manufacturers in Malaysia

The adoption of green manufacturing practices by the Malaysian wooden furniture industry is limited as is shown by a questionnaire-based survey of wooden furniture manufacturers. The lack of price premium for green furniture products and the high cost involved in adopting such practices have been identified as the major restraints. Currently most green manufacturing practices are related to the use of environmental-friendly materials.