Simple gold recovery from e-waste leachate by selective precipitation using a quaternary ammonium salt

Precipitation processes, if selective, present a simple and economical alternative for the recovery of critical metals from primary and secondary ores including electronic wastes. In this work, the recovery of gold by precipitation from both mono-elemental solutions and real CPU leach solution was demonstrated using hydrophilic quaternary ammonium salts. The gold precipitation yield is shown to be dependent on the apolar volume of the precipitant, with the addition of tetrabutylammonium-based salts resulting in the recovery of over 90 % of gold from synthetic solutions. The origin of gold precipitation selectivity relative to common metal ions upon addition of tetrabutylammonium nitrate ([N4444][NO3]) was assigned by X-ray crystal structure to the formation of size selective apolar cavity between neighbouring [N4444]+ cation and the [AuCl4]- anion. Following optimisation as a function of the gold to precipitant molar ratio, aqua regia concentration and time, approximately 70 % of gold could be recovered from waste CPU leach solution with a final purity of 91.4 % (mol/mol). [N4444][NO3] proved to be a versatile gold extractant and could be further applied as part of an acidic aqueous biphasic system at higher aqua regia concentrations were precipitation yields decreased, ensuring a selective gold recovery across a range of leachate conditions. The disclosed results improve the circularity of gold by providing a new avenue for its simple recycling.publishe

Smart monitoring of constructed wetlands to improve efficiency and water quality

The Smart monitoring of constructed wetlands to improve efficiency and water quality (SmarterCW) project aims to monitor biological wastewater treatment processes by gathering continuous data from remote water and environmental sensors. The acquired data can be processed and analysed through data science tools to better understand the complex and coupled phenomena underneath wastewater treatment, as well as, to monitor and optimize the system performance. The results will improve the efficiency and control of nature-based wastewater treatment technologies. The methodology comprises the following tasks and activities: Implementation of a set of electrochemical sensors in the input and output flow streams of pilot-scale constructed wetlands; Acquisition of water quality parameters such as pH, electrical conductivity, temperature, and ionic compounds; Acquisition of environmental parameters, such as temperature and humidity; Application of data analysis tools to design and optimize conceptual models to correlate pollutants removal with operative parameters in green technologies for wastewater treatment. This methodology was applied to a patent-protected pilot-scale modular constructed wetland in which filling media consists of a mixture of solid waste. The system is complemented by a high-level IoT communication layer structure to support remote real-time water and environmental monitoring, system performance, and data dissemination. The project contributes to: Water and Environment through the efficient management and use of water resources and waste reduction, management, treatment, and valorisation; Materials and raw-materials through efficient, secure, and sustainable use of resources; and Environmental Education promoting environmental awareness and best environmental practices through the dissemination of scientific data and results using Information and Communication Technologies (ICT) tools and IoT platforms. The project also contributes to giving response to Societal Challenges, such as Environment protection, sustainable management of natural resources, water, biodiversity, and ecosystems; Enabling the transition to a green society and economy through eco-innovation.info:eu-repo/semantics/submittedVersio

Body yield and quality of fresh and post-freezing filet of Nile tilapia (Oreochromis niloticus) genetic groups

Abstract The aim of this study was to evaluate the body yield and quality of fresh and post-freezing filet of male and female fish of inbred and non-inbred AquaAmérica genetic group and the hybrid between the AquaAmérica and Tilamax varieties. Forty fish (20 males and 20 females) of each genetic group were housed in four 48-m3 hapa net cages, getting 120 fish per cage. The fish were housed at 51 days of age and farmed for 269 days. Pre-slaughter weight was higher (P<0.05) in the AquaAmérica × Tilamax males (0.805±0.204 kg) than in the inbred AquaAmérica male (0.643±0.115 kg). Filet yield percentage was higher (P<0.05) in the AquaAmérica × Tilamax males (32.14±4.72%) than in the inbred AquaAmérica (28.15±2.67%) and non-inbred AquaAmérica (29.06±2.80%) males. Head and viscera yield percentages, pH, color values (L*, a* and b*), shear force, drip loss and cooking loss did not differ significantly between the genetic groups and sexes. Alterations in meat quality were observed after freezing. In conclusion, inbreeding in the AquaAmérica variety resulted in reduced slaughter weight for males; AquaAmérica × Tilamax males have a higher filet yield; and filet quality is not influenced by crossing, inbreeding, or sex, but is changed after freezing

Precautionary allergen labeling: Current communication problems and potential for future improvements

While there are EU laws for priority allergenic ingredients information on food product packaging, there is no legislation about Precautionary Allergen Labelling (PAL) for unintended allergen presence (UAP). As a result, PAL is used in different ways by different manufacturers and retailers, which hampers consumers’ interpretation of the information in the PAL. Previous research has focused on the forms of PAL that are used and on the way they are interpreted and used by consumers. This study adds the perspective of producers, retailers and branch organizations. Thirteen interviews with QA- and QC-professionals were conducted to find out more about the reasoning behind their PAL-use and to find out how PAL could be optimized. Results show that harmonization is needed, on different levels: in the way information on UAP is shared between parties involved in the food chain; in the way PAL is presented and phrased; and in the rules and regulations on PAL. More research is needed on possible ways to share (updates on) information on UAP with consumers

Precautionary allergen labeling: Current communication problems and potential for future improvements

While there are EU laws for priority allergenic ingredients information on food product packaging, there is no legislation about Precautionary Allergen Labelling (PAL) for unintended allergen presence (UAP). As a result, PAL is used in different ways by different manufacturers and retailers, which hampers consumers’ interpretation of the information in the PAL. Previous research has focused on the forms of PAL that are used and on the way they are interpreted and used by consumers. This study adds the perspective of producers, retailers and branch organizations. Thirteen interviews with QA- and QC-professionals were conducted to find out more about the reasoning behind their PAL-use and to find out how PAL could be optimized. Results show that harmonization is needed, on different levels: in the way information on UAP is shared between parties involved in the food chain; in the way PAL is presented and phrased; and in the rules and regulations on PAL. More research is needed on possible ways to share (updates on) information on UAP with consumers

Biological Sensors for Solar Ultraviolet Radiation

Solar ultraviolet (UV) radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products