In Situ ATR-FTIR Investigation of Photodegradation of 3,4-Dihydroxybenzoic Acid on TiO2

The catalytic photo-oxidation of 3,4-dihydroxybenzoic acid on TiO2 has been studied by in situ ATR-FTIR in flowing water and in flowing wet air/nitrogen gas. In flowing water it was difficult to observe photodegradation intermediates despite photocatalytic action during UV illumination. In the flowing wet air/nitrogen system carboxylic acids and carbonates were observed. It was shown that water plays an important role in the formation of oxidation active species. Oxygen shows a prominent role for carboxylic acid degradation, but the photogenerated hole plays the important role for the 3,4-dihydroxybenzoic acid ring cleavage

Photocatalytic degradation of chlorobenzene using solar and artificial UV radiation

In this work photocatalytic degrdn. of chlorobenzene has been studied using solar and artificial UV radiations. The effect of pH and the presence of different anions on the degrdn. of chlorobenzene has been studied for both cases. Chlorobenzene has been found to be a strongly adsorbing and hence rapidly degrading species when subjected to photocatalysis. The effect of pH in the range of 3-10 and the presence of different anions at a concn. of 0.1 mol dm-3 on the adsorption was studied. Both pH and the presence of anions affect adsorption and the degrdn. but the overall effect is negligible

Proposing a Tool for Supply Chain Configuration: An Application to Customised Production

This work aims to develop methodologies and tools to support the design and management of sustainable processes for the production of biodegradable polyhydroxyalcanoates (PHAs) biopolymers. PHAs are linear polyesters produced in nature by bacteria through aerobic fermentation of many carbon sources, completely biodegradable and biocompatible. We carried out a study inherent to the advancement of an innovative, cost-effective and environmentally sustainable technology for isolating PHAs from bacteria mixed cultures by combining: (a) innovative cells' pre-treatments and polymer purification's strategy by means of TiO2/UV or Ag0 nanostructured materials; (b) polymer extraction through a green and safe system directly applicable to bacterial cultures, which combines the advantages of solvent extraction and these of dissolution of the non-PHAs cellular matrix through surfactants; (c) monitoring and control tools for process energy and efficiency management. The outcomes put the basis for the design and subsequent building of a working pilot system for the production of completely biodegradable and biocompatible PHAs. The efficiency can be improved and the investments and operating costs can be decreased thanks to the optimization of the production process with the introduction of safe and cheap PHAs extraction route without use of toxic and harmful chemicals and the integration of monitoring and automation tools. The engineering and integration of nano-TiO2 phase within textile fibres and their use as photocatalytic active media for bacteria pre- and post-treatment of waste water added a new opportunity for improving process efficiency and sustainability