Due to the lack of knowledge regarding annual bioaccumulation rates in estuarine and marine fauna, the main aim of this work was to study the annual mercury bioaccumulation in the well-documented bivalve species Scrobicularia plana along a human induced mercury gradient in the Ria de Aveiro coastal lagoon (Portugal) and in a nearby, non-polluted system (Mondego estuary), parallel to the risks associated with its consumption by humans.Minimum total mercury concentration was as low as 0.019 mg kg À1 (wwt) in 4þ year old organisms in the reference site, where a significant negative correlation ( p < 0.05) was found between total mercury concentrations and size, resulting in negative bioaccumulation rates (detoxification). On the other hand, values reached 1.8 mg kg À1 (wwt) in 3þ year old bivalves from the most contaminated area, where a strong positive correlation with size was found ( p < 0.01) and annual bioaccumulation rates were as high as 0.25 mg kg À1 yr À1 . Annual bioaccumulation rates were highly correlated with suspended particulate matter mercury concentrations. Even though the levels of organic mercury contents increased parallel to the contamination gradient, at each sampling station, no increment was found with age, which corresponded to a decrease in organic mercury percentage with age.In terms of ecological management and public health, the ratio of 0.01 consistently found between Scrobicularia plana annual mercury accumulation rates and SPM mercury levels for most sites may permit to roughly estimate S. plana contamination of commercial sized individuals (>2.5 cm) and, if verified and confirmed in other systems, be used as a simple management tool.

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Purpose The purpose of this paper is to describe the case of the Valorbio research project, in which students of different high-level programs were involved in the experimental work and in the dissemination of results in collaboration with the research team. Design/methodology/approach The inclusion in higher education curricula of content related to the sustainable development should be a preferred mechanism for the dissemination of good practices of sustainability. Another equally important way to achieve this is to involve students in research projects that seek solutions to the societal challenges related to sustainable growth. The Valorbio project aims to meet the needs for treating and reusing wastewater and solid waste. Its main goal was the development of modular systems for wastewater treatment based on constructed wetlands, exploring the possibility of the treatment systems being composed of solid waste and by-products from significant industrial sectors. Findings The students’ contribution to the research work was relevant and simultaneously allowed them to acquire skills on sustainable development. Additionally, the students contributed to the dissemination of the results. The Valorbio project can thus be considered a successful application of the concept of project-based learning (PBL), as a way to include sustainability issues content in the higher education curricula. Originality/value The applied experimental work had an original approach regarding the equipment design, the waste materials valuation, as well as the integration of waste treatment processes in the circular economy paradigm. This paper is the first reported PBL experience involving students of short-cycle technical–professional programs in partnership with first and second-level students and a research team.

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-The aim of this work is to compare several of the commercial dynamic models for batch distillation available worldwide. In this context, BATCHFRAC™, CHEMCAD™ BATCH, and HYSYS.Plant ® software performances are compared to experimental data. The software can be used as soft sensors, playing the roll of ad-hoc observers or estimators for control objectives. Rigorous models were used as an alternative to predict the concentration profile and to specify the optimal switching time from products to slop cuts. The performance of a nonlinear model obtained using a novel identification algorithm was also studied. In addition, the strategy for continuous separation was revised with residue curve map analysis using Aspen SPLIT™.