scholarly journals Perfluoroalkylated Substances (PFAS) Associated with Microplastics in a Lake Environment

Toxics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 106
Author(s):  
John W. Scott ◽  
Kathryn G. Gunderson ◽  
Lee A. Green ◽  
Richard R. Rediske ◽  
Alan D. Steinman
Keyword(s):  
Organic Matter ◽  
Environmental Exposure ◽  
Field Experiments ◽  
Adsorption Properties ◽  
Ecological Impacts ◽  
Controlled Experiment ◽  
Controlled Environment ◽  
Aquatic Biota ◽  
Polyfluoroalkyl Substances ◽  
Perfluoroalkylated Substances

The presence of both microplastics and per- and polyfluoroalkyl substances (PFAS) is ubiquitous in the environment. The ecological impacts associated with their presence are still poorly understood, however, these contaminants are extremely persistent. Although plastic in the environment can concentrate pollutants, factors such as the type of plastic and duration of environmental exposure as it relates to the degree of adsorption have received far less attention. To address these knowledge gaps, experiments were carried out that examined the interactions of PFAS and microplastics in the field and in a controlled environment. For field experiments, we measured the abundance of PFAS on different polymer types of microplastics that were deployed in a lake for 1 month and 3 months. Based on these results, a controlled experiment was conducted to assess the adsorption properties of microplastics in the absence of associated inorganic and organic matter. The adsorption of PFAS was much greater on the field-incubated plastic than what was observed in the laboratory with plastic and water alone, 24 to 259 times versus one-seventh to one-fourth times background levels. These results suggest that adsorption of PFAS by microplastics is greatly enhanced by the presence of inorganic and/or organic matter associated with these materials in the environment, and could present an environmental hazard for aquatic biota.

Soil stripping and replacement for the rehabilitation of bauxite-mined land at Weipa. I. Initial changes to soil organic matter and related parameters

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 345 ◽  
Author(s):  
G. D. Schwenke ◽  
D. R. Mulligan ◽  
L. C. Bell
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Field Experiments ◽  
Surface Soil ◽  
Soil Disturbance ◽  
Microbial Biomass C ◽  
Low Grade ◽  
Double Pass ◽  
Organic C ◽  
The Difference

At Weipa, in Queensland, Australia, sown tree and shrub species sometimes fail to establish on bauxite-mined land, possibly because surface-soil organic matter declines during soil stripping and replacement. We devised 2 field experiments to investigate the links between soil rehabilitation operations, organic matter decline, and revegetation failure. Experiment 1 compared two routinely practiced operations, dual-strip (DS) and stockpile soil, with double-pass (DP), an alternative method, and subsoil only, an occasional result of the DS operation. Other treatments included variations in stripping-time, ripping-time, fertiliser rate, and cultivation. Dilution of topsoil with subsoil, low-grade bauxite, and ironstone accounted for the 46% decline of surface-soil (0–10 cm) organic C in DS compared with pre-strip soil. In contrast, organic C in the surface-soil (0–10 cm) of DP plots (25.0 t/ha) closely resembled the pre-strip area (28.6 t/ha). However, profile (0–60 cm) organic C did not differ between DS (91.5 t/ha), DP (107 t/ha), and pre-strip soil (89.9 t/ha). Eighteen months after plots were sown with native vegetation, surface-soil (0–10 cm) organic C had declined by an average of 9% across all plots. In Experiment 2, we measured the potential for post-rehabilitation decline of organic matter in hand-stripped and replaced soil columns that simulated the DS operation. Soils were incubated in situ without organic inputs. After 1 year’s incubation, organic C had declined by up to 26% and microbial biomass C by up to 61%. The difference in organic C decline between vegetated replaced soils (Expt 1) and bare replaced soils (Expt 2) showed that organic inputs affect levels of organic matter more than soil disturbance. Where topsoil was replaced at the top of the profile (DP) and not ploughed, inputs from volunteer native grasses balanced oxidation losses and organic C levels did not decline.

scholarly journals Environmental exposure to per- and polyfluoroalkyl substances mixture and male reproductive hormones

2021 ◽  
Vol 152 ◽  
pp. 106496
Author(s):  
Kai Luo ◽  
Xiaotu Liu ◽  
Min Nian ◽  
Yuqing Wang ◽  
Jin Qiu ◽  
...  
Keyword(s):  
Environmental Exposure ◽  
Reproductive Hormones ◽  
Polyfluoroalkyl Substances

scholarly journals Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter

2017 ◽  
Vol 8 ◽  
Author(s):  
Juliane Hirte ◽  
Jens Leifeld ◽  
Samuel Abiven ◽  
Hans-Rudolf Oberholzer ◽  
Andreas Hammelehle ◽  
...  
Keyword(s):  
Organic Matter ◽  
Root Biomass ◽  
Field Experiments ◽  
Crop Root

Progress towards small-scale field trials of coastal enhanced weathering of olivine

2021 ◽  
Author(s):  
Stephen Romaniello ◽  
Shanee Stopnitzky ◽  
Tom Green ◽  
Francesc Montserrat ◽  
Eric Matzner ◽  
...  
Keyword(s):  
Real World ◽  
Field Experiments ◽  
Ecological Impact ◽  
Field Trials ◽  
Research Strategy ◽  
Unintended Consequences ◽  
Ecological Impacts ◽  
Small Scale ◽  
Climate Mitigation ◽  
Stage Of Development

<p>Slow progress towards achieving global greenhouse gas emissions targets significantly increases the likelihood that future climate efforts may require not only emissions cuts but also direct climate mitigation via negative emissions technologies (IPCC AR5). Currently, such technologies exist at only a nascent stage of development, with significant uncertainties regarding their feasibility, cost, and potential unintended consequences and/or co-benefits.</p><p>Coastal enhanced weathering of olivine (CEWO) has been suggested as one potential pathway for achieving net negative CO<sub>2</sub> emissions at scale. CEWO involves the mining of olivine-rich ultramafic rocks (such as dunite) for incorporation during beach augmentation and restoration work. While grinding this rock into increasingly fine particle sizes is essential for increasing its surface area and reactivity, this step is also costly and energetically expensive. CEWO attempts to minimize this cost and energy penalty by relying on wave and tidal action to provide ongoing physical weathering of olivine grains once distributed on beaches. Laboratory experiments and carbon emissions assessments of CEWO suggest that these approaches may be technically feasible and carbon negative, but significant uncertainties remain regarding the real-world kinetics of coastal olivine dissolution. Furthermore, concerns about the fate and ecological impact of nickel (Ni) and chromium (Cr)—potentially toxic trace metals found in olivine—require careful evaluation.</p><p>In 2019, Project Vesta was established as a nonprofit, philanthropically funded effort to evaluate the technical feasibility and ecological impacts of CEWO through a dedicated research program ultimately culminating in small-scale, real-world field trials of CEWO. This presentation will provide an overview and discussion of our overall research strategy, share insights from interim modeling and mesocosm experiments designed to ensure the practicality and safety of future field experiments, and explain our approach for ensuring transparent, responsible, and ethical research oversight and governance.</p>

Propanil Plus Methyl Parathion on Rice (Oryza sativa)

Weed Science ◽  
1988 ◽  
Vol 36 (3) ◽  
pp. 335-339 ◽  
Author(s):  
Gene D. Wills ◽  
Joe E. Street
Keyword(s):  
Oryza Sativa ◽  
Soil Moisture ◽  
Environmental Conditions ◽  
Methyl Parathion ◽  
Field Experiments ◽  
Controlled Environment ◽  
Planting Dates ◽  
Effects Of Temperature ◽  
Effect On Yield ◽  
Wilting Point

Effects of propanil [N-(3,4-dichlorophenyl)propanamide] applied to three- to four-leaf rice (Oryza sativaL.) 1 or 7 days before, after, or tank mixed with methyl parathion (O,O-dimethyl-O-4-nitrophenyl phosphorothioate) were determined under different environmental conditions. Field experiments determined the effect on yield of drill-seeded rice, ‘Labelle’ for two planting dates in 1982 and ‘Lemont’ for one planting date in 1986. Treatments were applied at sunrise and at noon. Growth chamber and greenhouse experiments determined the effects of temperature, relative humidity (RH), and soil moisture on response of Labelle rice. In all experiments, propanil, both alone and with methyl parathion, resulted in 20 to 30% leaf burn during the first week after treatment with rapid recovery to less than 10% injury after 3 to 4 weeks. In field experiments, yields were not reduced in the treated rice below that in the untreated controls. In controlled-environment experiments, rice was not injured by propanil plus methyl parathion more than by propanil alone after 2 to 4 weeks. Both treated and untreated rice were injured more by the environmental conditions of high (40 C) temperature, low (40%) RH, and low (near the wilting point) soil moisture than by low (30 C) temperature, high (100%) RH, and flooded soil.

Control of Annual Bluegrass (Poa annua) in Kentucky Bluegrass (Poa pratensis) Turf with Linuron

1992 ◽  
Vol 6 (4) ◽  
pp. 852-857 ◽  
Author(s):  
J. Christopher Hall ◽  
C. Ken Carey
Keyword(s):  
Field Experiments ◽  
Poa Pratensis ◽  
Stand Density ◽  
Normal Growth ◽  
Dry Weight ◽  
Kentucky Bluegrass ◽  
Controlled Environment ◽  
Annual Bluegrass ◽  
Turf Quality ◽  
Severe Reduction

Effects of linuron on annual bluegrass control and Kentucky bluegrass cultivar tolerance were studied in field and growth chamber experiments. In controlled environment experiments, linuron at 0.06, 0.12, 0.25, 0.50, and 0.75 kg ai ha-1 was applied to pure stands of annual bluegrass and eight Kentucky bluegrass cultivars. Linuron at the two highest rates controlled annual bluegrass, reducing the clipping dry weight by more than 85% 4 wk after treatment, and by 65 to 92% 6 wk after treatment. Growth of Kentucky bluegrass was reduced with the most severe reduction occurring 2 wk after linuron application. All cultivars exhibited normal growth 8 wk after treatment. In field experiments, linuron at rates from 1.5 to 2.0 kg ai ha-1 controlled annual bluegrass in old (> 5 yr) Kentucky bluegrass stands, and in 16 cultivars of 1-yr and 2-yr-old Kentucky bluegrass stands, with little or no damage. At rates of 1.5, 2.0, and 2.5 kg ai ha-1 linuron, damage to newly seeded cultivars was moderate to severe. However, 6 to 7 wk after linuron application to newly seeded cultivars, stand density and turf quality were equivalent to untreated checks.

scholarly journals Peat decomposability in managed organic soils in relation to land use, organic matter composition and temperature

2018 ◽  
Vol 15 (3) ◽  
pp. 703-719 ◽  
Author(s):  
Cédric Bader ◽  
Moritz Müller ◽  
Rainer Schulin ◽  
Jens Leifeld
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Co2 Emissions ◽  
Field Experiments ◽  
Crop Residues ◽  
Organic Soils ◽  
Emission Rates ◽  
Data Set ◽  
Plant Materials ◽  
C Cycle

Abstract. Organic soils comprise a large yet fragile carbon (C) store in the global C cycle. Drainage, necessary for agriculture and forestry, triggers rapid decomposition of soil organic matter (SOM), typically increasing in the order forest < grassland < cropland. However, there is also large variation in decomposition due to differences in hydrological conditions, climate and specific management. Here we studied the role of SOM composition on peat decomposability in a variety of differently managed drained organic soils. We collected a total of 560 samples from 21 organic cropland, grassland and forest soils in Switzerland, monitored their CO2 emission rates in lab incubation experiments over 6 months at two temperatures (10 and 20 °C) and related them to various soil characteristics, including bulk density, pH, soil organic carbon (SOC) content and elemental ratios (C / N, H / C and O / C). CO2 release ranged from 6 to 195 mg CO2-C g−1 SOC at 10 °C and from 12 to 423 mg g−1 at 20 °C. This variation occurring under controlled conditions suggests that besides soil water regime, weather and management, SOM composition may be an underestimated factor that determines CO2 fluxes measured in field experiments. However, correlations between the investigated chemical SOM characteristics and CO2 emissions were weak. The latter also did not show a dependence on land-use type, although peat under forest was decomposed the least. High CO2 emissions in some topsoils were probably related to the accrual of labile crop residues. A comparison with published CO2 rates from incubated mineral soils indicated no difference in SOM decomposability between these soil classes, suggesting that accumulation of recent, labile plant materials that presumably account for most of the evolved CO2 is not systematically different between mineral and organic soils. In our data set, temperature sensitivity of decomposition (Q10 on average 2.57 ± 0.05) was the same for all land uses but lowest below 60 cm in croplands and grasslands. This, in turn, indicates a relative accumulation of recalcitrant peat in topsoils.

The tillering pattern in barley varieties: II. The effect of temperature, light intensity and daylength on the frequency of occurrence of the coleoptile node and second tillers in barley

1969 ◽  
Vol 72 (3) ◽  
pp. 423-435 ◽  
Author(s):  
R. Q. Cannell
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Light Intensity ◽  
Field Experiments ◽  
Tiller Number ◽  
Effect Of Temperature ◽  
Controlled Environment ◽  
Frequency Of Occurrence ◽  
Low Light ◽  
Late Sowing

SUMMARYControlled-environment experiments showed that development of the coleoptile node tiller (T1) was suppressed much more than that of the tiller appearing in the axil of the first true leaf (T2) by high temperature (24/15 °C; 19/10 °C; 10/6 °C), by reduced photoperiod (16 h; 12·5 h) or by low light intensity (1100 ft-c; 1000 ft-c), but minimally in the newest variety, Deba Abed. Unlike previous field experiments, the T1 tiller appeared on more Spratt Archer than Maris Badger plants. Maris Badger plants produced more T1 tillers in a high-low temperature regime (19/10 °C; 10/6 °C) than in continuous low temperature (10/6 °C). In a field experiment T1 tiller number (and yield), but not the number of other major shoots, were severely reduced by late sowing of Spratt Archer, progressively reduced in Maris Badger, but minimally in Deba Abed. This seemed to be associated with higher temperatures at later sowings.

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