scholarly journals Accelerated Weathering Increases the Release of Toxic Leachates from Microplastic Particles as Demonstrated through Altered Toxicity to the Green Algae Raphidocelis subcapitata

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 185
Author(s):  
Márta Simon ◽  
Nanna B. Hartmann ◽  
Jes Vollertsen
Keyword(s):  
Green Algae ◽  
Model Organism ◽  
Accelerated Weathering ◽  
Antifouling Paints ◽  
Raphidocelis Subcapitata ◽  
Effect Concentration ◽  
Algae Growth ◽  
Physical And Chemical ◽  
The Impact ◽  
Uv C

Studies that evaluate the impact of microplastic particles (MPs) often apply particles of pristine material. However, MPs are affected by various abiotic and biotic processes in the environment that possibly modify their physical and chemical characteristics, which might then result in their altered toxic effect. This study evaluated the consequence of weathering on the release of toxic leachates from microplastics. MPs derived from six marine antifouling paints, end-of-life tires, and unplasticised PVC were exposed to UV-C radiation to simulate weathering. Non-weathered and weathered MPs were leached in algae growth medium for 72 h to demonstrate additive release under freshwater conditions. The model organism, green algae Raphidocelis subcapitata, was exposed to the resulting leachates of both non-weathered and weathered MPs. The results of the growth inhibition tests showed that the leachates of weathered microparticles were more toxic than of the non-weathered material, which was reflected in their lower median effect concentration (EC50) values. Chemical analysis of the leachates revealed that the concentration of heavy metals was several times higher in the leachates of the weathered MPs compared to the non-weathered ones, which likely contributed to the increased toxicity. Our findings suggest including weathered microplastic particles in exposure studies due to their probably differing impact on biota from MPs of pristine materials.

THE IMPACT OF PHYSICAL AND CHEMICAL WEATHERING ON IRON SLAG FROM STANDISH, NY

2019 ◽  
Author(s):  
Maria L. Leonard ◽  
◽  
Rachel M. Kelk ◽  
Dori J. Farthing
Keyword(s):  
Chemical Weathering ◽  
Iron Slag ◽  
Physical And Chemical ◽  
The Impact

scholarly journals Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

2015 ◽  
Vol 63 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Karsten Schacht ◽  
Bernd Marschner
Keyword(s):  
Hydraulic Conductivity ◽  
Chemical Properties ◽  
Aggregate Stability ◽  
Treated Wastewater ◽  
Soil Aggregate Stability ◽  
Irrigation Effects ◽  
Physical And Chemical ◽  
The Impact

Abstract The use of treated wastewater (TWW) for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW) resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC) and soil aggregate stability (SAS). To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm) were collected for analyzing SAS and determination of selected soil chemical and physical characteristics. The mean HC values decreased at all TWW sites by 42.9% up to 50.8% compared to FW sites. The SAS was 11.3% to 32.4% lower at all TWW sites. Soil electrical conductivity (EC) and exchangeable sodium percentage (ESP) were generally higher at TWW sites. These results indicate the use of TWW for irrigation is a viable, but potentially deleterious option, as it influences soil physical and chemical properties.

scholarly journals Templated quasicrystalline ordering of single elements and molecules

2014 ◽  
Vol 70 (a1) ◽  
pp. C81-C81
Author(s):  
H. R. Sharma ◽  
J. A. Smerdon ◽  
K. Nozawa ◽  
K. M. Young ◽  
T. P. Yadav ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Chemical Properties ◽  
Scanning Tunneling ◽  
Three Dimension ◽  
Tunneling Microscopy ◽  
Quantum Size ◽  
Adsorption Energies ◽  
Molecular Layers ◽  
Physical And Chemical ◽  
The Impact

We have used quasicrystals as templates for the exploration of new epitaxial phenomena. Several interesting results have been observed in the growth on surfaces of the common Al-based quasicrystals [1]. These include pseudomorphic monolayers, quasiperiodically modulated multilayer structures, and fivefold-twinned islands with magic heights influenced by quantum size effects [1]. Here we present our recent works on the growth of various elements and molecules on a new substrate, icosahedral (i) Ag-In-Yb quasicrystal, which have resulted in various epitaxial phenomena not observed previously. The growth of Pb on the five-fold surface of i-Ag-In-Yb yields a film which possesses quasicrystalline ordering in three-dimension [2]. Using scanning tunneling microscopy (STM) and DFT calculations of adsorption energies, we find that lead atoms occupy the positions of atoms in the rhombic triacontahedral (RTH) cluster, the building block of the substrate, and thus grow in layers with different heights and adsorption energies. The adlayer–adlayer interaction is crucial for stabilizing the epitaxial quasicrystalline structure. We will also present the first example of quasicrystalline molecular layers. Pentacene adsorbs at tenfold-symmetric sites of Yb atoms around surface-bisected RTH clusters, yielding quasicrystalline order [3]. Similarly, C-60 growth on the five-fold surface of i-Al-Cu-Fe at elevated temperature produces quasicrystalline layer, where the growth is mediated by Fe atoms on the substrate surface [3]. The finding of quasicrystalline thin films of single elements and molecules opens an avenue for further investigation of the impact of the aperiodic atomic order over periodic order on the physical and chemical properties of materials.

Diagnosis and management of green algae in low land paddy fields of Cauvery delta zone, Tamil Nadu

2021 ◽  
Vol 58 (1) ◽  
pp. 33-42
Author(s):  
M Jeya Bharathi ◽  
M Raju ◽  
S Elamathi
Keyword(s):  
Green Algae ◽  
Tamil Nadu ◽  
Rice Cultivation ◽  
Rice Root ◽  
Wetting And Drying ◽  
Alternate Wetting And Drying ◽  
Green Algal ◽  
Algae Growth ◽  
Cauvery Delta ◽  
Soil And Water

Rice is a prime food crop for Asian countries. Wet land rice cultivation contributes maximum grain yield than dry land rice. Cauvery delta is a predominant area for rice cultivation in Tamil Nadu. Green algae growth during Kuruvai (June -August) season is a serious problem in wet land rice. These algae growth create anaerobic condition and prevent rice root respiration. The entire rice root was uprooted and floated on the stagnated water during initial stage. There is no preliminary study for green algae control in rice field. Soil and water samples were collected and analyzed for the nature of occurrence. Laboratory and field experiments were conducted to find out the remedial measures. The results of soil and water sample analysis showed that use of bore well water and dumping of phosphatic fertilizers leads to salt accumulation which favours the green algal growth. The results of the laboratory experiment revealed that the CuSO4 londox power, propiconazole and hexaconazole showed moderate inhibition on 5th day after treatment. The findings from field experiment indicated that use of conoweeder, alternate wetting and drying and CuSo4 drenching @ of 2.5 kg/ha when green algae appearance has just noticed or 5.0 kg/ha when severe growth occurred was effective in managing the green algae. Among all measures, alternate wetting and drying is the best management practices. CuSO4 drenching reduces around 70% of the growth. Even though CuSO4 react negatively with algae growth, soil pH changes and salt concentration play a major role on the CuSO4 action towards green algae. In order to maintain soil health condition, biofertilizer application, crop rotation, green manure trampling to be practised to recover the soil from alkaline pH, removal of accumulated salt and to control the algae growth using CuSO4.

Modeling to support physicochemical enhancement techniques

2021 ◽  
pp. 79-90
Author(s):  
Т. A. Pospelova
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Oil And Gas ◽  
Chemical Modeling ◽  
Comparative Structure ◽  
Water Cut ◽  
Physical And Chemical ◽  
Oil And Gas Companies ◽  
The Impact ◽  
Selection Of

The article discusses ways to increase the oil recovery factor in already developed fields, special attention is paid to the methods of enhanced oil recovery. The comparative structure of oil production in Russia in the medium term is given. The experience of oil and gas companies in the application of enhanced oil recovery in the fields is analyzed and the dynamics of the growth in the use of various enhanced oil recovery in Russia is estimated. With an increase in the number of operations in the fields, the requirements for the selection of candidates inevitably increase, therefore, the work focuses on hydrodynamic modeling of physical and chemical modeling, highlights the features and disadvantages of existing simulators. The main dependences for adequate modeling during polymer flooding are given. The calculation with different concentration of polymer solution is presented, which significantly affects the water cut and further reduction of operating costs for the preparation of the produced fluid. The possibility of creating a specialized hydrodynamic simulator for low-volume chemical enhanced oil recovery is considered, since mainly simulators are applicable for chemical waterflooding and the impact is on the formation as a whole.

scholarly journals The influence of field margins on the presence and spatial distribution of the European mole Talpa europaea L. within the agricultural landscape of northern Poland

2012 ◽  
Vol 64 (3) ◽  
pp. 971-980 ◽  
Author(s):  
Ewa Zurawska-Seta ◽  
T. Barczak
Keyword(s):  
Spatial Distribution ◽  
Agricultural Development ◽  
Agricultural Landscape ◽  
Field Margins ◽  
Talpa Europaea ◽  
Northern Poland ◽  
European Mole ◽  
Arable Fields ◽  
Physical And Chemical ◽  
The Impact

European moles are widespread in both cultivated and uncultivated areas in Poland. Their occurrence and distribution in relation to the physical and chemical characteristics of soil has been already studied in previous research. However, there is still an open question about the impact of the structure of anthropogenic habitats produced by agriculture on moles. The main aim of this study is to assess the influence of different kinds of field margins on the presence and spatial distribution of the European mole Talpa europaea L. in farmlands. Methods included the monitoring of six investigative sites in northern Poland. Observations were made during three six-month periods in 2005-2008 of the presence or absence of moles as recognized by recent molehills and surface tunnels. There was a very clear tendency by moles to occupy areas within arable fields close to field boundaries with wide verges containing ruderal and woodland communities with a spacious zone of ecotones. Narrow boundary strips were avoided by moles. In conclusion, the conducted research confirms that field margins have an impact on the presence and spatial distribution of moles within ploughed lands. Our results may be helpful in improving the relation between agricultural development and biodiversity conservation, and the rational use of nature by humankind.

scholarly journals The Interstellar Medium of Dwarf Galaxies

Galaxies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Christian Henkel ◽  
Leslie K. Hunt ◽  
Yuri I. Izotov
Keyword(s):  
Interstellar Medium ◽  
Dwarf Galaxies ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Ionized Gas ◽  
Green Pea ◽  
Physical And Chemical ◽  
The Impact ◽  
The Universe ◽  
And Chemical Properties

Dwarf galaxies are by far the most numerous galaxies in the Universe, showing properties that are quite different from those of their larger and more luminous cousins. This review focuses on the physical and chemical properties of the interstellar medium of those dwarfs that are known to host significant amounts of gas and dust. The neutral and ionized gas components and the impact of the dust will be discussed, as well as first indications for the existence of active nuclei in these sources. Cosmological implications are also addressed, considering the primordial helium abundance and the similarity of local Green Pea galaxies with young, sometimes protogalactic sources in the early Universe.

scholarly journals ZNAČAJ MIKROBIOLOŠKE ISPRAVNOSTI VODE U ZAŠTITI ZDRAVLJA STANOVNIŠTVA

2021 ◽  
Author(s):  
Ljubica Šarčevic - Todosijevic ◽  
Snezana Đorđevic ◽  
Vera Popovic ◽  
Ljubisa Živanovic ◽  
Bojana Petrovic ◽  
...  
Keyword(s):  
Population Monitoring ◽  
Chemical Pollution ◽  
Microbiological Safety ◽  
Microbiological Pollution ◽  
Physical And Chemical ◽  
The Impact

In addition to physical and chemical pollution of water, from the aspect of the impact of water on the health of the population, monitoring and prevention of microbiological pollution of water, especially water used for drinking, is extremely important. In this paper, the importance of microbiological safety of water in protecting the health of the population is considered.

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