WASTE MANAGEMENT IN THE LABORATORIES OF THE UNIVERSITY OF ÉVORA (2007-2021). Waste generated in university laboratories is an important component of university waste management, especially regarding their hazardousness and, also, the cost involved in their forwarding. To make a good management of this waste, it is essential to know the amount generated and the composition. However, this type of information remains scarce. In this work, waste from the laboratories of the University of Évora (Portugal) was surveyed from 2007 to 2021, using existing records. In the 15 years under analysis, the laboratories of the University of Évora generated about 61 tonnes of waste, 88% of which were hazardous and 66% were in the liquid state. In addition, only 3% of this waste was subjected to recovery operations. Moreover, the COVID-19 pandemic contributed to a double increase in hospital waste generated and to a substantially decreased of hazardous liquid waste from the laboratory activity, especially in the first year of the pandemic. In 2021, the second year of the pandemic, there was a “return to normality”, reaching the highest value of waste generated in the laboratories, of 8.6 tonnes. Finally, possible solutions for improving laboratory waste management were also discussed.

A flux cell with vitreous carbon tubular electrodes, as auxiliary and working electrodes, was tested. The following procedure was used: (1) study and optimization of the mercury deposition conditions at the working electrode, (2) study the electrodes position and distance in order to minimize dispersion of the sample, (3) study of the linearity and reproducibility using different concentrations of manganese (2.10-7 to 6.10-7 M), with differential pulse anodic stripping voltammetry (DPASV) and square wave stripping voltammetry (SWSV). Good linear correlation was obtained for concentration of manganese used.

The complexation of nitriloacetic acid (NTA) with copper and lead was studied by square wave stripping voltammetry (SWSV) using a mercury iridium microelectrode as the working electrode. The results show that NTA interfere with the measurements, but if the mercury iridium microelectrode is coated with different concentrations of agarose (0.75%, 1.5% and 15% w/v) this interference is greatly minimized. The best results were obtained with 1.5% agarose.