Validation and global uncertainty of a gas chromatographic with mass spectrometry method for fenamidone analysis in grapes and wines

Fenamidone is an imidazolinone fungicide recently introduced in viticulture practices. This work reports the validation and assessment of global uncertainty of a gas chromatographic with mass spectrometry method to analyze fenamidone in grapes and wines. This method consists in a simple and fast liquid-liquid extraction step followed by chromatographic determination. Limits of detection for fenamidone in grapes and wines were, respectively, 0.05 mg/kg and 0.06 mg/L, precision was below 9.4% and average recovery was 89 ± 5%. In the concentration range from 0.05 to 1.00 mg/kg (or mg/L) of fenamidone, global uncertainty calculated following the EURACHEM/CITAC rules, and also by the Horwitz function, was below 25%. The EURACHEM/CITAC global uncertainty budget used gave lower estimates than those obtained from the Horwitz function.     

Production of irrigation water from bioremediation of acid mine drainage: comparing the performance of two representative systems

The ability of two active bioremediation systems, based on the activity of sulphate-reducing bacteria, for the production of irrigation water from acid mine drainage (AMD), was compared. System I consisted of a packed bed reactor containing calcite tailing followed by an anaerobic packed bed bioreactor. System II consisted of a settler, fed with AMD and treated water recycle, and a sulphidogenic anaerobic packed bed bioreactor, fed with clarified settler effluent. Although efficient in terms of pH neutralisation and metals removal, system I did not allow continuous production of suitable irrigation water, since the concentration of sulphate in the effluent frequently exceeds the maximum recommended value by local legislation. On the other hand, in system II very high sulphate reduction (>99.0%) was achieved during the whole experiment, being the values in the effluent much lower than legislated limits for irrigation water. System II, not requiring the addition of any neutralising agent, can also be advantageous from an economical perspective.     

Sorption and desorption of the herbicide alachlor on humic acid fractions from two vermicomposts.

The present study focuses on the analysis of two vermicomposts, that have been used as alternative sources of restitution of soil organic matter, as well as sources of nutrient replacements. For this purpose, two samples of vermicomposts from different Brazilian regions (S?o Carlos-SP and Londrina-PR) were characterized according to their humic acid content. Both samples had a pH value near 7.0, and the humic acids present showed high cationic exchange capacities and low values for the C/N ratios. The infrared spectra showed bands that suggested the presence of aliphatic and aromatic components bound to phenolic, carboxylic and amide groups. The effect of vermicompost added to soil on the application of alachlor was evaluated. Alachlor sorption, Freundlich isotherms and alachlor desorption curves in the soil matrix and the vermicompost/soil mixture matrix were determined.     

Artificial lakes as a climate change adaptation strategy in drylands: evaluating the trade-off on non-target ecosystem services

Drylands are very susceptible to the effects of climate change due to water stress. One possible climate change adaptation measure is the construction of lakes to increase water availability for drinking and irrigation (food production) and decrease fire risk. These lakes can also increase local biodiversity and human well-being. However, other non-target services such as carbon (C) storage, water purification, and sediment retention might also change. Our main aim was to evaluate the trade-offs on non-targeted ecosystem services due to lakes construction in drylands. This was done using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) modeling tools, comparing a Mediterranean area located in southwest (SW) Europe, with and without artificial lakes. Results showed that the construction of artificial lakes caused an increase of 9.4% in C storage. However, the consequent increase in agricultural area decreased water purification and sediment retention services. This could diminish the life span of the lakes changing the initial beneficial cost-benefit analysis on lakes as adaptation measures to climate change. As a global measure for mitigation and adaptation to climate change strategy, we consider lake construction in drylands to be positive since it can store C in sediments and reduces the vulnerability to water scarcity. However, as a general recommendation and when built to support or increase agriculture in semi-arid landscapes, we consider that lakes should be complemented with additional measures to reduce soil erosion and nutrient leaching such as (i) locate agricultural areas outside the lakes water basin, (ii) afforestation surrounding the lakes, and (iii) adopt the best local agriculture practices to prevent and control soil erosion and nutrient leaching.