Visible light photocatalytic degradation of microplastic residues with zinc oxide nanorods

Microplastics have recently become a major environmental issue due to their ubiquitous distribution, uncontrolled environmental occurrences, small sizes and long lifetimes. Actual remediation methods include filtration, incineration and advanced oxidation processes such as ozonation, but those methods require high energy or generate unwanted by-products. Here we tested the degradation of fragmented, low-density polyethylene (LDPE) microplastic residues, by visible light-induced heterogeneous photocatalysis activated by zinc oxide nanorods. The reaction was monitored using Fourier-transform infrared spectroscopy, dynamic mechanical analyser and optical imaging. Results show a 30% increase of the carbonyl index of residues, and an increase of brittleness accompanied by a large number of wrinkles, cracks and cavities on the surface. The degree of oxidation was directly proportional to the catalyst surface area. A mechanism for polyethylene degradation is proposed.

     

The choice of system boundaries for effective long-term management of phosphorus

Journal of Material Cycles and Waste Management - Material flow analysis (MFA) is a well-established tool for supporting decisions on nutrient management. This paper shows the importance of the...     

Developing Effective Decision Support for the Application of “Gentle” Remediation Options: The GREENLAND Project

Gentle remediation options (GRO) are risk management strategies/technologies that result in a net gain (or at least no gross reduction) in soil function as well as risk management. They encompass a number of technologies, including the use of plant (phyto‐), fungi (myco‐), and/or bacteria‐based methods, with or without chemical soil additives or amendments, for reducing contaminant transfer to local receptors by in situ stabilization, or extraction, transformation, or degradation of contaminants. Despite offering strong benefits in terms of risk management, deployment costs, and sustainability for a range of site problems, the application of GRO as practical on‐site remedial solutions is still in its relative infancy, particularly for metal(loid)‐contaminated sites. A key barrier to wider adoption of GRO relates to general uncertainties and lack of stakeholder confidence in (and indeed knowledge of) the feasibility or reliability of GRO as practical risk management solutions. The GREENLAND project has therefore developed a simple and transparent decision support framework for promoting the appropriate use of gentle remediation options and encouraging participation of stakeholders, supplemented by a set of specific design aids for use when GRO appear to be a viable option. The framework is presented as a three phased model or Decision Support Tool (DST), in the form of a Microsoft Excel‐based workbook, designed to inform decision‐making and options appraisal during the selection of remedial approaches for contaminated sites. The DST acts as a simple decision support and stakeholder engagement tool for the application of GRO, providing a context for GRO application (particularly where soft end‐use of remediated land is envisaged), quick reference tables (including an economic cost calculator), and supporting information and technical guidance drawing on practical examples of effective GRO application at trace metal(loid) contaminated sites across Europe. This article introduces the decision support framework. ©2015 Wiley Periodicals, Inc.     

Economies of scale in global iron-making

In this paper, we investigate the presence of economies of scale in the global iron-making industry for integrated steel plants, iron making being the first stage in the steel-making process. Iron making depends on basic commodities, such as iron ore, coke and various forms of energy, required in the operation of the blast furnace, which can be classified as essential inputs and used in fixed proportions to produce iron. A generalized Leontief cost function is estimated using panel data for 69 integrated plants, such a specification being appropriate for technologies with essential inputs that are used in fixed proportions in production. A significant scale effect is observed due to the existence of fixed costs and a linear dependence of the cost function on production. Under a simple linear cost function, a rough estimate of the breakeven scale of plant, where costs equal revenue, is 4.5 Mt per year. Competitiveness, as measured by the ratio of plant average cost per tonne to best practice cost per tonne, can be shown to be positively related to the scale of production as well as the cost of essential inputs. Therefore, low-cost producers are also often producers with low raw material costs and production levels below the estimated breakeven scale of operation. Labor costs, although significant, are comparatively less important as a driver towards low costs.     

Funipuncture for fetocide in late termination of pregnancy

The most widely used method for fetocide in late termination of pregnancy for fetal abnormalities (TOPFA) consists of injecting of potassium chloride (KCl) into the fetal heart and is likely to be painful after 22 weeks of gestation. We studied ten consecutive women undergoing TOPFA between 22 and 38 weeks. This technique for fetocide consisted of a single umbilical vein puncture under ultrasound guidance with injections of sufentanil 5 µg followed by KCl 2 g. No electrocardiographic modifications could be observed and maternal plasma potassium levels did not show any significant variation throughout the procedure. Fetal umbilical phlebotomy for fetal analgesia followed by fetocide therefore appears to be a safe procedure for the mother and allows the fetus to die without pain when late termination of pregnancy (TOP) is indicated. Copyright © 2002 John Wiley & Sons, Ltd.     

Multi-function Landscape Plans: a missing link in sustainability planning?

This paper argues that important issues of sustainable development have been addressed through single-issue landscape plans, and that these plans have carried little weight within the land use decision-making process. A more consolidated approach, based on multi-function landscape plans, is proposed. After reviewing the range of plans which, in the UK, cover woodland, farmscapes, visual amenity, coasts, catchments and biodiversity, the case is made for an integrative plan capable of addressing natural resource issues at the landscape scale. The preliminary character of an integrative plan is outlined. Whilst landscape plans have a relatively weak basis for implementation, it is concluded that a sufficient range of powers is available to ensure some progress.