There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Impatti, adattamento e vulnerabilita Le cause e le responsabilita dei cambiamenti climatici sono state trattate sul numero di ottobre della rivista Cda. Approfondiamo l’argomento presentando il documento: “Cambiamenti climatici 2007: impatti, adattamento e vulnerabilita” votato ad aprile 2007 dal secondo gruppo di lavoro del Comitato Intergovernativo sui Cambiamenti Climatici (Intergovernmental Panel on Climate Change). Si tratta del secondo di tre documenti che compongono il quarto rapporto sui cambiamenti climatici.

/pdf/climate-change-2007-impacts-adaptation-and-vulnerability-31xc1cf4d3.pdf

Climate Change 2007: Impacts, Adaptation and Vulnerability.

An overview of brominated flame retardants in the environment.

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in many types of consumer products. Perhaps as a result of their widespread use and their lipophilicity, these compounds have become ubiquitous in the environment and in people. This review summarizes PBDE concentrations measured in several environmental media and analyzes these data in terms of relative concentrations, concentration trends, and congener profiles. In human blood, milk, and tissues, total PBDE levels have increased exponentially by a factor of ∼100 during the last 30 yr; this is a doubling time of ∼5 yr. The current PBDE concentrations in people from Europe are ∼2 ng/g lipid, but the concentrations in people from the United States are much higher at ∼35 ng/g lipid. Current PBDE concentrations in marine mammals from the Canadian Arctic are very low at ∼5 ng/g lipid, but they have increased exponentially with a doubling time of ∼7 yr. Marine mammals from the rest of the world have current PBDE levels of ∼1000 ng/g lipid, and...

https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.files/fileID/13105

Polybrominated Diphenyl Ethers in the Environment and in People: A Meta-Analysis of Concentrations

The state of desalination and brine production: A global outlook.

Environmental assessment of urban wastewater reuse: Treatment alternatives and applications

Life cycle assessment (LCA) methodology is used to evaluate the environmental profile of a product or process from its origin to its final destination. In this paper we used LCA to evaluate the current situation of a wastewater treatment plant and identify improvement alternatives. Currently, the highest environmental impacts are caused by the stages of the plant with the highest energy consumption, the use of biogas from anaerobic digestion (95% burned in torch) and the final destination of the sludge (98.6% for agricultural use and 1.4% for compost). We propose four alternatives for biogas applications and five alternatives for sludge applications and compare them to the current situation. The alternatives were incorporated in a decision support system to identify and prioritize the most positive environmental option. Using biogas to produce electricity or a combination of electricity and heat provided the best environmental options since the energy produced would be enough to supply all the stages of t...

LCA as a decision support tool for the environmental improvement of the operation of a municipal wastewater treatment plant.

Environmental assessment of urban water cycle on Mediterranean conditions by LCA approach

The carbon footprint and energy consumption of beverage packaging selection and disposal

Summary

Continuous population growth is causing increased water contamination. Uneven distribution of water resources and periodic droughts have forced governments to seek new water sources: reclaimed and desalinated water. Wastewater recovery is a tool for better management of the water resources that are diverted from the natural water cycle to the anthropic one.



The main objective of this work is to assess the stages of operation of a Spanish Mediterranean wastewater treatment plant to identify the stages with the highest environmental impact, to establish the environmental loads associated with wastewater reuse, and to evaluate alternative final destinations for wastewater. Tertiary treatment does not represent a significant increment in the impact of the total treatment at the plant. The impact of reclaiming 1 cubic meter (m3) of wastewater represents 0.16 kilograms of carbon dioxide per cubic meter (kg CO2/m3), compared to 0.83 kg CO2/m3 associated with basic wastewater treatment (primary, secondary, and sludge treatment). From a comparison of the alternatives for wastewater final destination, we observe that replacing potable water means a freshwater savings of 1.1 m3, whereas replacing desalinated water means important energy savings, reflected in all of the indicators. To ensure the availability of potable water to all of the population—especially in areas where water is scarce—governments should promote reusing wastewater under safe conditions as much as possible.

https://papers.ssrn.com/sol3/Delivery.cfm?abstractid=1783366

Montse Meneses

Papers

Environmental assessment of urban wastewater reuse: Treatment alternatives and applications

LCA as a decision support tool for the environmental improvement of the operation of a municipal wastewater treatment plant.

Environmental assessment of urban water cycle on Mediterranean conditions by LCA approach

The carbon footprint and energy consumption of beverage packaging selection and disposal

Life Cycle Assessment of Urban Wastewater Reclamation and Reuse Alternatives