Global variability of food waste chemical composition and its consequences on the production of biofuels and chemical compounds

Journal of Material Cycles and Waste Management - The use of food waste (FW) for the production of biofuels and value-added compounds is growing worldwide. However, the significant chemical...     

Rapid and Low-Cost Method for Evaluation of Nutrient Release from Controlled-Release Fertilizers Using Electrical Conductivity

Methods to determine nutrient release rates of coated fertilizers usually rely on chemical analyses, which often are time-consuming and/or expensive. Our goal was to develop an innovative and rapid low-cost method to evaluate nutrient release from polymer coated MAP or urea using conductometry. The release in water is determined by measuring the electric conductivity (EC) over time, with intervals dependent on release rates. In the case of soluble salt fertilizers, EC can be immediately determined and converted to a concentration using a calibration curve. In the case of urea, an additional step is needed to convert the neutral urea into ammonium. The release rates in water were assessed for a range of commercial and laboratory-coated fertilizers. A validation test demonstrated strong agreement with the release determined using analytical techniques. The EC method hence offers an easy way to quickly evaluate the time course of release of nutrients from controlled-release fertilizers.     

Determination of pesticides of different chemical classes in drinking water of the state of Santa Catarina (Brazil) using solid-phase microextraction coupled to chromatographic determinations

The evaluation of the concentration of pesticides in drinking water presents a real concern. In this study, a simple and rapid method based on solid-phase microextraction (SPME) followed by gas chromatography–mass spectrometry and electron capture detectors was developed aiming at multiclass determination of 23 pesticides regulated by the Brazilian legislation. The extraction was carried out by direct immersion mode (DI-SPME) using DVB/Car/PDMS fiber coating. In order to improve the extraction efficiency, parameters such as temperature, salting-out effect, and extraction time were optimized. The method was evaluated using drinking water samples spiked with the analytes at different concentrations, and it showed good linearity in the range studied. The values obtained for limits of quantification (LOQ) were below the limits established by Brazilian regulations. Accuracy and precision of the method exhibited satisfactory results, providing relative recoveries from 70 to 123.34% at three spiked levels, and the relative standard deviations ranged from 0.53 to 24.8%. The method was applied in 20 drinking water samples from 13 cities in the State of Santa Catarina, Brazil.

     

Spatial and temporal drivers of zoonotic pathogen contamination of an agricultural watershed

In regions where animal agriculture is prominent, such as southern Alberta, higher rates of gastrointestinal illness have been reported when compared with nonagricultural regions. This difference in the rate of illness is thought to be a result of increased zoonotic pathogen exposure through environmental sources such as water. In this study, temporal and spatial factors associated with bacterial pathogen contamination of the Oldman River, which transverses this region, were analyzed using classification and regression tree analysis. Significantly higher levels of fecal indicators; more frequent isolations of Campylobacter spp., Escherichia coli O157:H7, and Salmonella enterica spp.; and higher rates of detection of pig-specific Bacteroides markers occurred at downstream sites than at upstream sites, suggesting additive stream inputs. Fecal indicator densities were also significantly higher when any one of these three bacterial pathogens was present and where there were higher total animal manure units; however, occasionally pathogens were present when fecal indicator levels were low or undetectable. Overall, Salmonella spp., Campylobacter spp., and E. coli O157:H7 presence was associated with season, animal manure units, and total rainfall on the day of sampling and 3 d in advance of sampling. Several of the environmental variables analyzed in this study appear to influence pathogen prevalence and therefore may be useful in predicting water quality and safety and in the improvement of watershed management practices in this and other agricultural regions.     

Five years of formaldehyde and acetaldehyde monitoring in the Rio de Janeiro downtown area – Brazil

The fuel matrix used in Brazil is unique around the world. The intensive use of hydrated ethanol, gasohol (gasoline with 25% v/v of ethanol), compressed natural gas (CNG), and biodiesel leads to a peculiar composition of the urban atmosphere. From 1998 to 2002 an increase in formaldehyde levels was observed and since then, a reduction. This work presents a monitoring campaign that was executed from March 2004 to February 2009 by sampling at early morning on every sunny Wednesday for a total of 183 samples. The results indicate a strong reduction in formaldehyde levels from 2004 (average of 135.8 μg m^?3 with SD 28.4 μg m^?3) to 2009 (average of 49.3 μg m^?3 with SD 27.4 μg m^?3). The levels of acetaldehyde showed a slight reduction from 2004 (average of 34.9 μg m^?3 with SD 8.0 μg m^?3) to 2009 (average of 26.8 μg m^?3 with SD 11.5 μg m^?3). Comparing the results with the concurrent evolution of the fleet and of fuel composition indicates that the observed formaldehyde levels could be associated with the increase in ethanol use and in CNG use by engines with improved technology over the first converted CNG engines. Modelling studies using the OZIPR trajectory model and the SAPRC chemical mechanism indicate that formaldehyde is the main ozone precursor in Rio de Janeiro and acetaldehyde is the forth one.     

Monitoring of firefighters exposure to smoke during fire experiments in Portugal

Forest fires represent a serious threat to public security in Europe due to the large burned area. Moreover, smoke pollution due to forest fire events is an important public health issue for the communities directly affected, and particularly for the personnel involved in firefighting operations. Aiming to contribute to the scientific knowledge concerning firefighters exposure to forest fires smoke, data of individual exposure to carbon monoxide, nitrogen dioxide, volatile organic compounds, and particulate matter were obtained during experimental field fires for a group of 10 firefighters equipped with portable “in continuum” measuring devices. Measured values are very high exceeding the Occupational Exposure Standard limits, in particular for peak limit thresholds. These are the first measurements and analysis of firefighter's individual exposure to toxic gases and particles in fire smoke experiments in Europe. However, they already indicate that urgent measures to avoid these levels of exposure are needed.     

Ensemble Modeling of the Baltic Sea Ecosystem to Provide Scenarios for Management

We present a multi-model ensemble study for the Baltic Sea, and investigate the combined impact of changing climate, external nutrient supply, and fisheries on the marine ecosystem. The applied regional climate system model contains state-of-the-art component models for the atmosphere, sea ice, ocean, land surface, terrestrial and marine biogeochemistry, and marine food-web. Time-dependent scenario simulations for the period 1960–2100 are performed and uncertainties of future projections are estimated. In addition, reconstructions since 1850 are carried out to evaluate the models sensitivity to external stressors on long time scales. Information from scenario simulations are used to support decision-makers and stakeholders and to raise awareness of climate change, environmental problems, and possible abatement strategies among the general public using geovisualization. It is concluded that the study results are relevant for the Baltic Sea Action Plan of the Helsinki Commission.     

Leaf morphoanatomy of species tolerant to excess iron and evaluation of their phytoextraction potential

Setaria parviflora (Poir.) Kerguélen and Paspalum urvillei Steudel are grasses that grow naturally in a soil with high iron contents. This study aimed to characterize morphoanatomically and histochemically the iron phytotoxicity on leaves and evaluate the phytoextraction potential of these grasses. Saplings were cultivated in hydroponic solution with and without excess Fe-EDTA. Regarding measurements taken on leaves, reduction was observed among treatments of Fe-EDTA on height values of abaxial epidermis and bundle sheath in both species. As for iron histolocalization, stronger reaction was observed in leaves of S. parviflora, in comparison with P. urvillei. Anatomical damage, such as protoplast retraction, irregular xylem, changes in cell volume, and cell collapse, and visual symptoms, like leaf bronzing, chlorosis, and necrosis, were similar in both species when exposed to excess iron; however, P. urvillei showed more severe damage. This species accumulated more iron in shoots than S. parviflora and therefore is more favorable for use in phytoextraction. The root system of both species accumulated higher iron concentrations in relation to shoots.     

How changes in diet and trade patterns have shaped the N cycle at the national scale: Spain (1961–2009)

During the last five decades (1961–2009), Spain has experienced a considerable expansion in the nutrient cycle of its agricultural sector and, in particular, a threefold increase in anthropogenic reactive nitrogen inputs, from 536 Gg N year^?1 in 1961–1965 to 1673 Gg N year^?1 in 2005–2009. Import of feed (soybean, cereals, and cakes) from America and Europe to supply a growing livestock population constitutes the largest share of this increase, along with intensification of synthetic fertilizer use. While in the early 1960s, Spain was nearly self-sufficient in terms of food and feed supply, the net import of agricultural products presently equals domestic crop production, when expressed in terms of nitrogen content (ca. 650 Gg N year^?1). The most important driver of this shift appears to be the rapid change in domestic consumption patterns, which evolved from a typical Mediterranean diet to an animal-protein-rich diet similar to the North European and American diets. Besides livestock production mostly for national consumption, the Spanish agricultural system has specialized in vegetal products with low N content such as olive oil, wine, vegetables, and citrus fruit, which are for the most part exported. The nitrogen load exported outside the Spanish borders by rivers is very low (6.5 % of the total net N input). As a result of the high import and low export of reactive nitrogen, the Spanish mainland is suffering from considerable pollution by local emissions of reactive nitrogen forms to air and water.     

Biochemical and standard toxic effects of acetaminophen on the macrophyte species Lemna minor and Lemna gibba

Acetaminophen is globally one of the most prescribed drugs due to its antipyretic and analgesic properties. However, it is highly toxic when the dosage surpasses the detoxification capability of an exposed organism, with involvement of an already described oxidative stress pathway. To address the issue of the ecotoxicity of acetaminophen, we performed acute exposures of two aquatic plant species, Lemna gibba and Lemna minor, to this compound. The selected biomarkers were number of fronds, biomass, chlorophyll content, lipid peroxidation (TBARS assay), and proline content. Our results showed marked differences between the two species. Acetaminophen caused a significant decrease in the number of fronds (EC₅₀?=?446.6 mg/L), and the establishment of a dose-dependent peroxidative damage in L. minor, but not in L. gibba. No effects were reported in both species for the indicative parameters chlorophyll content and total biomass. However, the proline content in L. gibba was substantially reduced. The overall conclusions point to the occurrence of an oxidative stress scenario more prominent for L. minor. However, the mechanisms that allowed L. gibba to cope with acetaminophen exposure were distinct from those reported for L. minor, with the likely involvement of proline as antioxidant.