Propaedeutic Study of Biocomposites Obtained With Natural Fibers for Oceanographic Observing Platforms

In response to the pervasive anthropogenic pollution of the ocean, this manuscript suggests the use of biodegradable elastomers in marine applications. The present study characterizes 25 samples of highly biodegradable polymers, obtained blending a base elastomer with natural fibers. Mechanical analysis and Scanning Electron Microscope imaging, reveal how base polymers behave differently depending on the plant fiber chosen, on the external forcing—exposure to water—and on the doses that constitute the final biocomposite. Results suggest that EcoflexTM 00-30 and EcoflexTM 00-50, mixed with potato starch, perform best mechanically, maintaining up to 70% of their maximum tensile strain. Moreover, early signs of degradation are visible on polysiloxane rubber blended with 50% vegetable fibers after 19 hours in distilled water. Analyses demonstrate that highly biodegradable elastomers are good candidates to satisfy the requirements of aquatic devices. Furthermore, the discussed materials can improve the dexterity and biodegradability of marine technology.

Evaluation of a Methoprene Aerial Application for the Control of Culiseta melanura (Diptera: Culicidae) in Wetland Larval Habitats

Eastern equine encephalitis virus (EEEV) is an arbovirus endemic to the eastern United States. Human cases are rare but can be serious. The primary enzootic vector is Culiseta melanura (Coquillett) (Diptera: Culicidae), an ornithophagic mosquito. We conducted an aerial application of a granular methoprene formulation in Hockomock Swamp (Massachusetts), which represents a focus of EEEV transmission. Water collected from inside and outside Cs. melanura crypts was evaluated in bioassays of early fourth instar Cs. melanura larvae using treated and untreated water. Adult eclosion rates were 36% significantly lower in treated compared with untreated water (P < 0.05). Eclosion rates for water collected from inside crypts were significantly higher (62%) than rates from outside crypts (30%) (P < 0.05), indicating higher efficacy outside crypts. We tested whether reduced methoprene efficacy inside the crypts was due to reduced chemical penetration into this habitat. Chemical water analyses confirmed that methoprene concentrations were lower inside the crypts (0.1 ± 0.05 ppb) compared to water from outside crypts (1.79 ± 0.41 ppb). The susceptibility of Cs. melanura to methoprene was also determined to allow for comparison against concentrations observed in water collected from the field (LC-95: 1.95 ± 0.5 ppb). Overall, methoprene-treated water prevented mosquito development for up to 4 wk, but with a reduction in efficacy between 4- and 6-wk post-application. Our results suggest that aerial methoprene applications can effectively treat open water in wetlands but may not provide efficacious control of Cs. melanura due to an inability to penetrate larval habitats.

The effect of water transposition on the quality of water in a tropical reservoir, São Paulo – Brazil

<p>The aim of the present study is to analyze the influence of water transposition from Rio Grande System on the quality of water in Taiçupeba Reservoir, Suzano city, SP. Water samples were collected every two months for one year (from June 2016 to April 2017) in four sampling spots. Physical, chemical and biological water analyses were carried out; Water Quality and Trophic State indices were also applied. There was influence of water transposition from Rio Grande System on the quality of the water in Taiaçupeba Reservoir throughout the assessed period. The quality of the water was similar in all sampling spots, except for P3, which recorded the worst results. Point 3 was located in an urbanized zone of Taiaçupeba sub-basin; therefore, it is likely that the worse water quality in this spot has resulted from contamination by domestic sewage. It is recommended to carry out further studies based on longer sampling period in the same environment.</p>

GEOLOGICAL EVALUATION OF LAKE VAN (TURKEY) FOR URANIUM-THORIUM DEPOSITION

Purpose of this study is to prove most probable existence of economical U-Th mineralisations within Tatvan Basin which have been hidden among foreign international research project manuscripts of Lake Van and to inform the importance of national exploration studies. Lake Van is a pull-apart basin formed within Quaternary Muş-Zagros suture zone with right lateral movement. Calculations on heat transfer below the Tatvan Basin indicate that a constant heat flow is about fourty times the continental average which have been only reported from some oceanic ridges. Data indicate the heat source below Tatvan Basin bottom represents a steadily collapsing cauldron subsidence of Nemrut volcano’s magma chamber. Lake Van surface water has mean 76ppb dissolved uranium content of hyrothermal and authigenic origin. It is calculated that there is at least 50.000 tons of dissolved uranium exists in the Lake Van waters. Ultimate deposition of U-Th mineralisation within euxinic Tatvan Basin have been expected to be a continuous process during geologic history of Lake Van as long as uranium resources remain and its NaHCO3 water functions as dissolving agent Sodic Lake Van waters continuously dissolve uranium from 1) high 3He/4He and U-Th containing hydrothermal fluxes of mantle origin coming up through cauldron subsidence faults of Tatvan Basin, 2) per-alkaline rhyolitic volcanic ash rain of Nemrut volcanism, 3) Bitlis granitoid Massive basement, 4) repeated authigenic disentegrations of U to (Th and 4He) within the sedimentary deposites of Tatvan Basin through its 600.000 years history. Tatvan Basin is the deepest basin with 450m depth, 300km2 flat area and constant unoxic basal water table undisturbed by currents and has the following verifications for Quaternary U-Th depositions in the unconsolidated porous sediments: 1) organic mass rich levels with reducing microbial activities, 2) evaporitic dolomites deposited during low stand lake levels with high U-Th concentrations, 3) varved, mixed-layered clays with high hectorite content, 4) sub-aquaeous, basic-intermediate volcanic basement intrusions with reducing properties, 5) measured very low redox potentials in basal environment, 6) very high density of U-Th. Drilling core sequence and the gamma ray logs from Ahlat Ridge have been used in the foreign literature published since 1974 until now while the existence or non-existence of uranium has not been mentioned. Gamma ray logs of drilling cores and their pore water analyses from Tatvan Basin were carried out abroad but not published yet. Thus gamma ray logs belonging only to shallow Ahlat Ridge sequence where uranium mineral precipitation is not possible is misleading.

Thallium mobility in mining wastes at the Crven Dol locality, Allchar deposit, North Macedonia

&lt;p&gt;In order to better understand the environmental behaviour of thallium, we have chosen the abandoned As&amp;#8211;Sb&amp;#8211;Tl&amp;#8211;Au Allchar deposit (North Macedonia) with unique mineral composition and high thallium grades of the ore. We used pore water analyses, selective extractions, single-crystal and powder X-ray diffraction (PXRD), SEM-EDS, electron microprobe analysis (EMPA), and Raman spectroscopy to determine the distribution and speciation of thallium in waste dump material at the Tl-rich Crven Dol locality in the northern part of the Allchar deposit.&lt;/p&gt;&lt;p&gt;PXRD studies showed that the various solid waste samples are comprised mostly of carbonates (dolomite and calcite), gypsum, quartz, muscovite, kaolinite-group minerals followed by orpiment, realgar, pyrite, marcasite, lorandite, and various iron and calcium arsenates and iron (hydro)oxides, both amorphous and crystalline. Raman spectra, SEM-EDS and EMPA also showed the presence of Ca-Fe-, Ca-Mn-, and Ca-Mg-arsenates.&lt;/p&gt;&lt;p&gt;The main primary source of Tl in the waste is lorandite (TlAsS&lt;sub&gt;2&lt;/sub&gt;), which occurs as prismatic crystals and anhedral grains up to 1 mm and is frequently intergrown with realgar. Other Tl sources, included in either realgar or orpiment, are minor Tl sulphosalts such as fangite (Tl&lt;sub&gt;3&lt;/sub&gt;AsS&lt;sub&gt;4&lt;/sub&gt;), raguinite (TlFeS&lt;sub&gt;2&lt;/sub&gt;), picotpaulite (TlFe&lt;sub&gt;2&lt;/sub&gt;S&lt;sub&gt;3&lt;/sub&gt;) and jankovi&amp;#263;ite (Tl&lt;sub&gt;5&lt;/sub&gt;Sb&lt;sub&gt;9&lt;/sub&gt;(As,Sb)&lt;sub&gt;4&lt;/sub&gt;S&lt;sub&gt;22&lt;/sub&gt;). The Tl dissolved during weathering is precipitated as micaceous subparallel crystals of poorly crystalline to amorphous thallium arsenates (representing previously unknown mineral species), forming porous aggregates up to 100 &amp;#181;m. These Tl arsenates are intergrown with dolomite and Ca-Fe-arsenates and appear as two chemically different phases. The first, more common phase shows a variable Tl:As ratio ranging from ca. 2.1 to 4.1 and a variable Ca content (2.2 to 4.1 at.%). In the second, Tl-richer phase, the Tl:As ratio varies from ca. 5.1 to 8.4. Raman spectra of the Tl arsenates display broad bands and may be divided in the fingerprint region into two relevant ranges, 350&amp;#8211;600 and 700&amp;#8211;900 cm&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;, both attributed to arsenate tetrahedral complexes showing As&amp;#8211;O(&lt;em&gt;X&lt;/em&gt;) symmetric stretching with &lt;em&gt;X&lt;/em&gt; = H&lt;sup&gt;+&lt;/sup&gt; or H&lt;sub&gt;2&lt;/sub&gt;O.&lt;/p&gt;&lt;p&gt;Another relatively common Tl precipitate is dorallcharite [TlFe&lt;sup&gt;3+&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(SO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;(OH)&lt;sub&gt;6&lt;/sub&gt;], crystallizing in the form of tiny, well-formed platelets that are grouped into aggregates up to 400 &amp;#181;m in size. Tl is also accumulated in (probably cryptomelane-type) Mn oxides (up to 3.6 at.%), pharmacosiderite (up to 0.9 at.%), and jarosite (up to 0.9 at.%).&lt;/p&gt;&lt;p&gt;The pore water contained high aqueous concentrations of Tl (up to 660 &amp;#956;g&amp;#183;L&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;) and As (up to 196 mg&amp;#183;L&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;). Although these concentrations are low with respect to their total concentrations in the solid phase (Tl: 0.07-1.44 wt. %; As: 0.72-8.67 wt. %), mild extractions (ammonium nitrate and phosphate) mobilized up to 44% of the total Tl and 23% of the total As, indicating that a large amount of these toxic elements is bound weakly (sorption) to solids and can be easily mobilized into the pore water.&lt;/p&gt;&lt;p&gt;Financial support of the Austrian Science Fund (FWF) [P 30900-N28] is gratefully acknowledged.&lt;/p&gt;

The Quality of Stored Rainwater for Washing Purposes

The use of rainwater for washing clothes is determined by its amount, composition and quality of washing. Raw rainwater is soft and free of pollution. The collected rainwater already contains pollution present in the atmosphere and washed away from roofs and other surfaces. It can also change its quality when stored in tanks. Washing clothes does not require drinking quality water but just clean, safe water that guarantees effective removal of dirt from fabrics. The study determined the physicochemical and microbiological changes of rainwater characteristics during retention. Rainwater was collected in a standard underground tank for 30 days and water analyses were conducted every 10 days. The possibility of tap water replacement in the household with collected rainwater for ecological clothes washing has been assessed.

THE ELEMENTAL CONTENT OF HAIR AS AN INDICATOR FOR NATURAL AND TECHNOGENIC CONDITION OF TASHKENT REGION

The samples of soils, drinking water and hair of habitants of 15 districts in Tashkent region studied using the method of neutron activation analysis. The results obtained from soil and drinking water analyses indicated that contents of Zn, Co, Cu and other elements in a number of districts are higher in comparison with average values throughout the region. This is related to developed industry in these regions. The analysis of the habitants' hair also indicated increased values, which are caused by environmental contamination and working conditions. For generalized assessment of environmental condition it was suggested to use the logarithm of multiplication of the lithophylic elements (Ba, Ca, K, La, Na, Rb, Sc, Sr) content, characterizing the geochemical condition. And similarly, the logarithm of multiplication of potential pollutants, typical for this area, such as Br, Co, Cr, Sb, U, Zn content in soil, water and hair was used as conditional index of overall pollution. It was demonstrated, that fluctuations of lithophylic elements content logarithm value throughout the districts of the region are insignificant and fall within range of 3941, while logarithm values for the potential pollutants vary from 3.1 to 9.3. The distribution of a hypothetical integral pollutant is presented in the cartogram. The correlation analysis conducted has established a relationship between the content of elements in environmental objects and some diseases, indicating that increased or decreased content of elements in the hair is highly likely one of the signs of a particular disease, especially in environmentally disadvantaged districts of the region.

Vulnerable Populations Exposed to Lead-Contaminated Drinking Water within Houston Ship Channel Communities

Recent events have drawn increased attention to potential lead exposures from contaminated drinking water. Further, homes with older infrastructure are at greatest risk due to the presence of the disinfectant chemical chloramine, which can leach lead from older pipes. There is a growing need to determine the extent of lead leaching especially within vulnerable communities and homes with children. This pilot study collected survey data and performed lead analysis on drinking water in the small community of Manchester in Houston, TX. Manchester is characterized by industrial sites, flooding, and a low socioeconomic population. Surveys and water analyses were completed on randomly selected homes (N = 13) and documented perceptions of participants on their drinking water regarding presence and concentration of lead. Lead was discovered in 30.8% of homes ranging from 0.6 to 2.4 (µg/L), all below the US Environmental Protection Agency action level of 15 ppb, but above the water standard goals. These findings further suggest that contaminated water is a broad issue requiring concerted efforts to ensure the health of US residents.