Monitoring the photochemical degradation of triclosan in wastewater by UV light and sunlight using solid-phase microextraction

Photo solid-phase microextraction (photo-SPME) is applied for the first time to study the photochemical behavior of an emerging pollutant, triclosan, in real contaminated wastewater samples using a solar simulator. In this study, water samples are extracted by SPME and then, the fiber coating is irradiated for a selected time. This on-fiber procedure, so-called photo-SPME, followed by gas chromatography-mass spectrometry makes it possible to study photodegradation kinetics and the generation of byproducts. Several photoproducts were identified in the real samples including the 2,8-dichlorodibenzo-p-dioxin, dichlorophenols and a compound tentatively identified as other DCDD congener or a dichlorohydroxydibenzofuran. Accordingly, it was possible to postulate main photodegradation mechanisms. Photo-SPME demonstrated slower kinetics in wastewater than in spiked ultrapure water probably due to the presence of dissolved organic matter. This technique was extensively compared with conventional aqueous photodegradation showing high similarity. The influence of pH on the triclosan photolysis and on the triclosan-dioxin conversion was also investigated in wastewater. Photodegradation of triclosan and formation of 2,8-DCDD occurred independently of sample pH. This study represents an advance in the use of photo-SPME to understand the photochemical fate of environmental organic pollutants and demonstrates its clear advantages with real samples.     

Analysis of heavy metals in ecstasy tablets by electrochemical methods

Trace amounts of heavy metals have been analysed by electrochemical techniques in ecstasy tablets obtained from different police seizures in Spain. Lead, cadmium, copper and zinc were determined by differential-pulse anodic stripping voltammetry at a hanging mercury drop electrode, whereas nickel and cobalt were determined by adsorptive differential-pulse cathodic stripping voltammetry from their dimethylglyoxime complexes, M(DMG)₂. The performance of the procedure was compared with electrothermal atomic absorption spectrometry. The procedure was applied to the determination of these elements in nine ecstasy samples, finding that Zn is the element present in the highest concentration, ranging from 0.3 to 200?mg?kg^?1, Ni, Cu appear below 15?mg?kg^?1 and Pb below 8?mg?kg^?1, while Cd and Co levels were always lower than 0.51?mg?kg^?1.     

Acute toxicity of sugarcane vinasse to aquatic organisms before and after pH adjustment

The purpose of this study was to investigate the toxicity of vinasse to cladocerans and fish before and after pH adjustment using an acute toxicity test. Linear and quadratic regression models were adjusted to demonstrate the concentration–response relationship between vinasse and the endpoints evaluated. The median lethal concentrations (LC_50–48h) of vinasse before pH adjustment for Ceriodaphnia dubia and Daphnia magna were 0.67% and 0.80% respectively, and the median lethal concentrations (LC_50–96h) for Danio rerio was 2.62%. After pH adjustment, the values increased for all organisms, demonstrating a decrease in toxicity. This study reported marked toxicity for vinasse to aquatic organisms with toxicity reduction after pH adjustment.     

Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk

Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers—a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators.     

Primary prevention for worker health and safety: cleaner production and toxics use reduction in Massachusetts

Worker health and safety and environmental protection are not always considered simultaneously when attempting to reduce or eliminate hazardous materials from our environment. Cleaner Production-Pollution Prevention (CPPP), as primary prevention, has the ability to shift worker health and safety strategies from control to prevention, where exposure prevention precedes exposure control. This paper evaluates the effect of Cleaner Production-Pollution Prevention in the form of toxics use reduction (TUR) on worker health and safety at three printed wire board facilities covered under the Massachusetts Toxics Use Reduction Act. In-depth case study analysis, including an assessment of each facility’s health and safety status, explores the root causes of the worker health and safety changes attributable to the TUR interventions. By exploring the relationship between worker health and safety and environmental protection within the corporate structure; we can identify the factors driving companies to reduce toxics both inside and outside of their plants, as a single concern.While traditionally there have been divergent paths of practice for worker health and safety and environmental protection, the two are closely connected. It is important, however, to consider the implications of risk transfer/shifting between the general and work environment. In order to avoid this risk shifting, worker health and safety perspectives and goals must be more clearly incorporated into the Cleaner Production-Pollution Prevention/TUR management system. This study opens a dialog around the effects of environmental intervention programs on worker health and safety. We realize now that while CPPP/TUR reduces exposure to toxic substances in the general environment, it also offers unique opportunities to reaffirm primary prevention principles in the work environment.     

Dynamic real-time risk analytics of uncontrollable states in complex internet of things systems: cyber risk at the edge

The Internet of Things (IoT) triggers new types of cyber risks. Therefore, the integration of new IoT devices and services requires a self-assessment of IoT cyber security posture. By security posture this article refers to the cybersecurity strength of an organisation to predict, prevent and respond to cyberthreats. At present, there is a gap in the state of the art, because there are no self-assessment methods for quantifying IoT cyber risk posture. To address this gap, an empirical analysis is performed of 12 cyber risk assessment approaches. The results and the main findings from the analysis is presented as the current and a target risk state for IoT systems, followed by conclusions and recommendations on a transformation roadmap, describing how IoT systems can achieve the target state with a new goal-oriented dependency model. By target state, we refer to the cyber security target that matches the generic security requirements of an organisation. The research paper studies and adapts four alternatives for IoT risk assessment and identifies the goal-oriented dependency modelling as a dominant approach among the risk assessment models studied. The new goal-oriented dependency model in this article enables the assessment of uncontrollable risk states in complex IoT systems and can be used for a quantitative self-assessment of IoT cyber risk posture.

     

Investigation on the role of graphene-based composites for in photocatalytic degradation of phenol-based compounds in wastewater: a review

Environmental Science and Pollution Research - The ineptitude of conventional water management systems to eradicate noxious compounds leads to the development of advanced treatment systems. The...     

Application of polysaccharide-based biopolymers as supports in photocatalytic treatment of water and wastewater: a review

Environmental Chemistry Letters - Rising health issues of Worldwide pollution by fossil fuel products are Fostering the development of safer materials such as biopolymers in many sectors such as...     

Biocapacity convergence clubs in Latin America: an analysis of their determining factors using quantile regressions

Latin America experiences an increasing urban primacy index and a rapid expansion of the financial system, putting direct pressure on the demand for resources to satisfy the consumption of large cities. We investigate the convergence of per capita biocapacity in 16 Latin America countries and evaluate the factors that influence its evolution over time. Specifically, we analyze the impact of the urban primacy index, economic progress, and the financial globalization index on the convergence of per capita biocapacity. We use the methodological framework developed by Phillips and Sul Econometrica 75:1771-1855, (2007) to analyze the convergence and the formation of convergence clubs of biocapacity during 1970–2017. The findings indicate that the countries of the region do not share a common trend of biocapacity, although they are grouped into five converging clubs. Biocapacity transition analysis reveals that countries have heterogeneous transition pathways between them. Using marginal effects, we find that the urban primacy index and economic progress reduce the biocapacity. The effect of the financial globalization index on biocapacity is not conclusive. The quantile regressions reveal that quantiles’ impact of the urban primacy index and financial globalization on per capita biocapacity is heterogeneous. However, the effect of economic progress on biocapacity that predominates among quantiles is positive. The adoption of common policies among the countries that form the converging clubs could improve the effectiveness of pro-environmental policies and promote the achievement of the Sustainable Development Goals related to environmental quality.

     

Retesting the EKC hypothesis through transmission of the ARMEY curve model: an alternative composite model approach with theory and policy implications for NAFTA countries

Environmental Science and Pollution Research - We investigate the validity of the environmental Kuznets curve (EKC) hypothesis for the NAFTA countries. In this investigation, we approach this...