RESUMEN

Water pollution emissions permit systems (WPEPS) and constructed wetland systems (CWS) are widely but independently used to balance regional economic development and ecosystem health. In this paper, a watershed scale framework that incorporates a CWS into a WPEPS is proposed for regional economic and ecosystem health sustainability. A strategy that integrates three allocation principles: per capita emissions, economic utility, and water quality contributions, is established for the initial CWS-incorporated WPEPS emissions permit allocations. To quantitatively verify the effectiveness of the CWS-incorporated WPEPS, a bi-level optimization model is formulated, in which fuzzy random variables are employed to describe the system uncertainties. The model is then applied to a practical case in the Chaohu watershed, China, to assess the effects of changing watershed management targets, from which practical insights are obtained on the initial emissions permit allocation strategies and the CWS coordination effects. It has proved that the integrated watershed management of the CWS-incorporated WPEPS is more able to rationally allocate the limited water pollution emissions permits and better balance the Chaohu watershed economic development to ensure ecological health sustainability. The CWS-incorporated WPEPS model under uncertainty can be used to guide local governments when formulating their sustainable watershed management strategies.

Asunto(s)

RESUMEN

The simultaneous use of nitrite and sorbate as preservatives in meat products may produce mutagenic compounds such as the ethylnitrolic acid and 2-methyl-1,4-dinitro-pyrrole. We developed a sensitive analytical method with high metrological reliability. After assessing several extraction approaches and chromatographic separation modes, a modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) approach was chosen for sample preparation, which were analyzed by reversed-phase liquid chromatography (with C18 as stationary phase) coupled to tandem mass spectrometry. After validation, we confirmed that this method is fit-for-purpose, since it was applied to the analysis of several meat products. Limits of detection were set from 5 to 20 µg kg-1. Satisfactory results were obtained for both compounds, such as precision (CV > 20%) and recoveries (77-92%). This method determine these carcinogenic compounds in processed meats, contributing to the preservation of public health and the improvement of food regulation and control.

Asunto(s)

RESUMEN

Ozone (O3) fluxes above a temperate mountain grassland were measured by means of the eddy covariance (EC) method using a slow-response O3 analyser. The resultant flux loss was corrected for by a series of transfer functions which model the various sources of high- and, in particular, low-pass filtering. The resulting correction factors varied on average between 1.7 and 3.5 during night and day time, respectively. A cospectral analysis confirmed the accuracy of this approach. O3 fluxes were characterised by a comparatively large random uncertainty, which during daytime typically amounted to 60 %. EC O3 fluxes were compared against O3 flux measurements made concurrently with the flux-gradient (FG) method. The two methods generally agreed well, except for a period between sun rise and early afternoon, when the FG method was suspected of being affected by the presence of photochemical sources/sinks. O3 flux magnitudes and deposition velocities determined with the EC method compared nicely with the available literature from grassland studies. We conclude that our understanding of the causes and consequences of various sources of flux loss (associated with any EC system) has sufficiently matured so that also less-than-ideal instrumentation may be used in EC flux applications, albeit at the cost of relatively large empirical corrections.