Characterisation of enzymatically oxidised lignosulfonates and their application on lignocellulosic fabrics

BACKGROUND: The ‘double function’ of laccase, from the ascomycete Myceliophthora, to depolymerise/polymerise lignin was studied in this work. A lignosulfonate (LS) compound was oxidised by enzymatic action and several techniques were applied to measure the polymeric changes obtained. This study was focused on the attachment level of the oxidised LS at the flax surface. RESULTS: Modified solutions were studied in terms of surface charge. Zeta potential values obtained showed an increase of polymerisation after several days of incubation. The change in molecular weight after LS polymerisation was detected using gel permeation chromatography. An increase of 1700 Da was achieved. Fourier transform infrared and UV‐visible spectroscopy techniques were applied and the results showed an increase of the degree of polymerisation. The colour strength of flax fabrics incubated with oxidised LS solutions was also measured and an increase of K/S (K, absorption coefficient; S, scattering coefficient) after enzymatic oxidation was observed. CONCLUSION: The oxidised lignin products obtained show good potential for use in natural surface modification of textile materials containing flavonoids. These findings have important practical implications for lignocellulosic fibre coloration, where new polymers can replace harsh chemicals in the textile industry. Copyright © 2009 Society of Chemical Industry     

New type of two-axis magnetometer

A new simple two-axis magnetometer has been developed. based on the superposition of an amorphous ferromagnetic disc over a disc-shaped piezoelectric support. At low frequencies, this device exhibits a sensitivity of ~1.7 μV/μT when the external magnetic field is orthogonal to one of the pick-up coils     

Tannery wastewater treatment by sequencing batch biofilm reactor

The paper reports the results of an investigation aimed to evaluate the performances of an innovative process for treating tannery wastewater. In such a process biological degradation, carried out in a sequencing batch biofilm reactor (SBBR), is combined with chemical oxidation by ozone. The treatment was carried out at laboratory scale on a real primary effluent coming from a centralized plant treating the wastewater of a large tannery district in Northern Italy. SBBR performances without and with ozonation were compared with very satisfactory results particularly in the latter instance when the recorded COD, TKN, and TSS average removals, (96%), (92%), and (98%), respectively, permitted to achieve the fixed limits enforced by Italian regulation without needing any additional polishing step. With or without ozonation, the process that resulted was characterized by a specific sludge production (0.1 kgVSS/kg CODremoved) significantly lower than the values featuring conventional biological systems (i.e., 0.3-0.5 VSS/kg CODremoved). Moreover, as in the reactor the biomass density results were very high, i.e., 98 gVSS/Lsludge, it was possible to achieve and maintain biomass concentration as high as 20 gVSS/L.     

Guidance on individual monitoring programmes for radioisotopic techniques in molecular and cellular biology

The radioisotope techniques used in molecular and cellular biology involve external and internal irradiation risk. The personal dosemeter may be a reasonable indicator for external irradiation. However, it is necessary to control the possible internal contamination associated with the development of these techniques. The aim of this project is to analyse the most usual techniques and to establish programmes of internal monitoring for specific radionuclides (32P, 35S, 14C, 3H, 125I and 131I). To elaborate these programmes it was necessary to analyse the radioisotope techniques. Two models have been applied (NRPB and IAEA) to the more significant techniques, according to the physical and chemical nature of the radionuclides, their potential importance in occupational exposure and the possible injury to the genetic material of the cell. The results allowed the identification of the techniques with possible risk of internal contamination. It was necessary to identify groups of workers that require individual monitoring. The risk groups have been established among the professionals exposed, according to different parameters: the general characteristics of receptor, the radionuclides used (the same user can work with one, two or three radionuclides at the same time) and the results of the models applied. Also a control group was established. The study of possible intakes in these groups has been made by urinalysis and whole-body counter. The theoretical results are coherent with the experimental results. They have allowed guidance to individual monitoring to be proposed. Basically, the document shows: (1) the analysis of the radiosotopic techniques, taking into account the special containment equipment; (2) the establishment of the need of individual monitoring; and (3) the required frequency of measurements in a routine programme.     

By-products formation during degradation of isoproturon in aqueous solution. II: Chlorination

After a previous study in which the considered oxidant was ozone (Part I), a laboratory investigation has been carried out to study the degradation of the herbicide isoproturon during its reaction with another oxidant, i.e. chlorine, in aqueous solution (Part II; this paper). The specific aim was to identify the by-products formed. The effects of pH and the presence of bromide ions were studied. Reactions have been carried out at room temperature, in phosphate buffered aqueous solutions, at four pHs (6, 7, 8 and 9). By-products identification was first performed using relatively high initial reagent concentrations which were analytically convenient ([isoproturon] = 40 mg/l, [HClO + ClO-] = 160 mg Cl/l, [Br-] = 80 mg/l). In follow-up studies, the by-products identified during this preliminary step were searched for when using concentration values closer to those actually encountered at real water treatment plants ([isoproturon] = 0.4 and 0.004 mg/l, [HClO + ClO-] = 1.6 mg Cl/l, [Br-] = 0.8 and 0.008 mg/l). Under all of the studied conditions, the results showed that isoproturon is completely degraded and that it decays much faster in the presence of bromide. The pH has a negligible influence when bromide ions are absent. On the contrary, if bromide ions are present, the isoproturon decay is slower at higher pH values. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analyses have led to the identification of several by-products as a result of simultaneous oxidation and substitution reactions, both occurring on the aromatic ring of the herbicide. However, the more abundant by-products are those resulting from the oxidation of the isoproturon aromatic ring. As far as halogenated by-products are concerned, the higher the bromide ion concentration the higher the ratio of brominated to chlorinated by-products. On the basis of the analytical results, a pathway for isoproturon degradation under the studied conditions is proposed.     

EURADOS Annual Meeting 2007, Scientific Symposium on Characterisation of Workplaces for the Assessment of the Doses to Individuals and Winter School on Practical Examples to Determine Uncertainties in Radiation Dosimetry

The European Radiation Dosimetry Group, EURADOS, stimulatescollaboration in the dosimetry of ionising radiation particularlyby setting up working groups (WGs) of experts to address specificproblem areas. It presently comprises 54 member institutionsthroughout Europe. One of the means by which EURADOS coordinates its work and disseminatesresults is via annual meetings, usually held at the start ofthe year. Since 2004, this annual meeting has been increasedby a day set aside as a Scientific Symposium to address issuesin a particular topic area. Thus, during the annual meeting2004 in Braunschweig, a symposium