Utilization of Waste Lignin and Hydrolysate From Chromium Tanned Waste in Blends of Hot-Melt Extruded PVA-Starch

The demand for biodegradable plastic material is increasing worldwide. However, the cost remains high in comparison with common forms of plastic. Requirements comprise low cost, good UV-stability and mechanical properties, as well as solubility and water uptake lead to the preparation of multi-component polymer blends based on polyvinyl alcohol and starch in combination with waste products that are hard to utilize—waste lignin and hydrolysate extracted from chromium tanned waste. Surprisingly the addition of such waste products into PVA gives rise to blends with better biodegradability than commercial PVA in an aquatic aerobic environment with non-adapted activated sludge. These blends also exhibited greater solubility in the water and UV stability than commercial PVA. Tests on the processing properties of the blends (melt flow index, tensile strength and elongation at break of the films) as well as their mechanical properties showed that materials based on these blends might be applied in agriculture (for example as the systems for controlled-release pesticide or fertilizer) and, somewhat, in the packaging sector.     

Changing ideas in forestry: A comparison of concepts in Swedish and American forestry journals during the early twentieth and twenty-first centuries

By combining digital humanities text-mining tools and a qualitative approach, we examine changing concepts in forestry journals in Sweden and the United States (US) in the early twentieth and early twenty-first centuries. Our first hypothesis is that foresters at the beginning of the twentieth century were more concerned with production and less concerned with ecology than foresters at the beginning of the twenty-first century. Our second hypothesis is that US foresters in the early twentieth century were less concerned with local site conditions than Swedish foresters. We find that early foresters in both countries had broader—and often ecologically focused—concerns than hypothesized. Ecological concerns in the forestry literature have increased, but in the Nordic countries, production concerns have increased as well. In both regions and both time periods, timber management is closely connected to concerns about governance and state power, but the forms that governance takes have changed.     

Use of modeling to protect,plan, and manage water resources in catchment areas

The degradation of water resources by diffuse pollution, mainly due to nitrate and pesticides, is an important matter for public health. Restoration of the quality of natural water catchments by focusing on their catchment areas is therefore a national priority in France. To consider catchment areas as homogeneous and to expend an equal effort on the entire area inevitably leads to a waste of time and money, and restorative actions may not be as efficient as intended. The variability of the pedological and geological properties of the area is actually an opportunity to invest effort on smaller areas, simply because every action is not equally efficient on every kind of pedological or geological surface. Using this approach, it is possible to invest in a few selected zones that will be efficient in terms of environmental results. The contributive hydraulic areas (CHA) concept is different from that of the catchment area. Because the transport of most of the mobile and persistent pollutants is primarily driven by water circulation, the concept of the CHA is based on the water pathway from the surface of the soil in the catchment area to the well. The method uses a three-dimensional hydrogeological model of surface and groundwater integrated with a geographic information system called Watermodel. The model calculates the contribution (m³/h or %) of each point of the soil to the total flow pumped in a well. Application of this model, partially funded by the Seine Normandy Basin Agency, to the catchment of the Dormelles Well in the Cretaceous chalk aquifer in the Orvanne valley, France (catchment area of 23,000 ha at Dormelles, county 77), shows that 95 % of the water pumped at the Dormelles Well comes from only 26 % of the total surface area of the catchment. Consequently, an action plan to protect the water resource will be targeted at the 93 farmers operating in this source area rather than the total number of farmers (250) across the entire 23,000 ha. Another model, developed from Epiclès© software, permits the calculation of the under-root nitrate concentrations for each field based on soil type, climate, and farming practices. When the Watermodel and Epiclès© are coupled, nitrate transfers from the soil to the catchment and the river can be modeled. In this study, the initial pollution due to the actual farming practices was simulated and we were also able to estimate the efficiency of the agronomic action plan by testing several scenarios and calculating the time needed to reach the target nitrate concentration in the well.     

Integrated spatial health assessment of yellow perch (Perca flavescens) populations from the St. Lawrence River (QC,Canada), part B: cellular and transcriptomic effects

Environmental Science and Pollution Research - Multi-biological level assessments have become great tools to evaluate the health of aquatic ecosystems. Using this approach, a complementary study...     

Metal contents of marine turtle eggs (Chelonia mydas; Lepidochelys olivacea) from the tropical eastern pacific and the implications for human health

Concentrations of eight elements were measured in Chelonia mydas and Lepidochelys olivacea eggs collected along the Pacific coast of Panama. Manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), and mercury (Hg) concentrations were similar to previous reports of these species from around the world, while lead (Pb) was lower than previous reports. Cd posed the highest health risk to people who regularly eat the eggs, with average consumption rates leading to target hazard quotients (THQ) of up to 0.35 ± 0.15. Our conclusions indicate that current turtle egg consumption in isolated, coastal Pacific communities may pose a health concern for young children, and that youth and young adults should limit their consumption of turtle eggs to reduce their total intake of nonessential metals.     

Occurrence of PPCPs in the marine environment: a review

Little research has been conducted on the occurrence of pharmaceuticals and personal care products (PPCPs) in the marine environment despite being increasingly impacted by these contaminants. This article reviews data on the occurrence of PPCPs in seawater, sediment, and organisms in the marine environment. Data pertaining to 196 pharmaceuticals and 37 personal care products reported from more than 50 marine sites are analyzed while taking sampling strategies and analytical methods into account. Particular attention is focused on the most frequently detected substances at highest concentrations. A snapshot of the most impacted marine sites is provided by comparing the highest concentrations reported for quantified substances. The present review reveals that: (i) PPCPs are widespread in seawater, particularly at sites impacted by anthropogenic activities, and (ii) the most frequently investigated and detected molecules in seawater and sediments are antibiotics, such as erythromycin. Moreover, this review points out other PPCPs of concern, such as ultraviolet filters, and underlines the scarcity of data on those substances despite recent evidence on their occurrence in marine organisms. The exposure of marine organisms in regard to these insufficient data is discussed.     

Heavy metal contamination in sediments of an artificial reservoir impacted by long-term mining activity in the Almadén mercury district (Spain)

Sediments from the Castilseras reservoir, located downstream on the Valdeazogues River in the Almadén mercury district, were collected to assess the potential contamination status related to metals(oids) associated with river sediment inputs from several decommissioned mines. Metals(oids) concentrations in the reservoir sediments were investigated using different physical and chemical techniques. The results were analyzed by principal component analysis (PCA) to explain the correlations between the sets of variables. The degree of contamination was evaluated using the enrichment factor (EF) and the geoaccumulation index (Igeo). PCA revealed that the silty fraction is the main metals(oids) carrier in the sediments. Among the potentially harmful elements, there is a group (Al, Cr, Cu, Fe, Mn, Ni, and Zn) that cannot be strictly correlated to the mining activity since their concentrations depend on the lithological and edaphological characteristics of the materials. In contrast, As, Co, Hg, Pb, and S showed significant enrichment and contamination, thus suggesting relevant contributions from the decommissioned mines through fluvial sediment inputs. As far as Hg and S are concerned, the high enrichment levels pose a question concerning the potential environmental risk of transfer of the organic forms of Hg (mainly methylmercury) from the bottom sediments to the aquatic food chain.     

Integrated spatial health assessment of yellow perch (<Emphasis Type="Italic">Perca flavescens</Emphasis>) populations from the St. Lawrence River,Quebec, Canada) part A: physiological parameters and pathogen assessment

A multi-disciplinary approach was used to evaluate the health of yellow perch (Perca flavescens) in the St. Lawrence River (Quebec, Canada), which is experiencing a severe population decline in the downstream portion of the river. Physiological parameters, liver alterations, trace metal concentrations, parasite prevalence and abundance, stable isotope composition, and the presence/absence of the viral hemorragic septicemia virus (VHSV) were evaluated in perch collected at six sites along the river: Lake St. François, Lake St. Louis (north and south), Beauregard Island, and Lake St. Pierre (north and south). Trace metal concentrations in surface water were higher in Lake St. Louis and downstream of a major urban wastewater treatment plant discharge, indicating that this effluent was a significant source of Cu, As, Ag, Zn, and Cd. Levels of Pb in surface water exceeded thresholds for the protection of aquatic life in Lake St. Louis and were negatively correlated with body condition index in this lake. In Lake St. Pierre, Cu, Ag, and Cd bioaccumulated significantly in perch liver and lower body condition index and greater liver damage were observed compared to upstream sites. Parasite analyses indicated a higher abundance of metacercariae of the trematodes Apophallus brevis and Diplostomum spp. in Lake St. Louis, and VHSV was not detected in the liver of yellow perch for all studied sites. Overall, results suggested that the global health of yellow perch from Lake St. Pierre is lower compared to upstream studied sites, which could contribute to the documented population collapse at this site.     

Glyphosate input modifies microbial community structure in clear and turbid freshwater systems

Since it was commercially introduced in 1974, glyphosate has been one of the most commonly used herbicides in agriculture worldwide, and there is growing concern about its adverse effects on the environment. Assuming that glyphosate may increase the organic turbidity of water bodies, we evaluated the effect of a single application of 2.4?±?0.1 mg l^?1 of glyphosate (technical grade) on freshwater bacterioplankton and phytoplankton (pico, micro, and nanophytoplankton) and on the physical and chemical properties of the water. We used outdoor experimental mesocosms under clear and oligotrophic (phytoplanktonic chlorophyll a?=?2.04 μg l^?1; turbidity?=?2.0 NTU) and organic turbid and eutrophic (phytoplanktonic chlorophyll a?=?50.3 μg l^?1; turbidity?=?16.0 NTU) scenarios. Samplings were conducted at the beginning of the experiment and at 1, 8, 19, and 33 days after glyphosate addition. For both typologies, the herbicide affected the abiotic water properties (with a marked increase in total phosphorus), but it did not affect the structure of micro and nanophytoplankton. In clear waters, glyphosate treatment induced a trend toward higher bacteria and picoeukaryotes abundances, while there was a 2 to 2.5-fold increase in picocyanobacteria number. In turbid waters, without picoeukaryotes at the beginning of the experiment, glyphosate decreased bacteria abundance but increased the number of picocyanobacteria, suggesting a direct favorable effect. Moreover, our results show that the impact of the herbicide was observed in microorganisms from both oligo and eutrophic conditions, indicating that the impact would be independent of the trophic status of the water body.