Sediment contamination by heavy metals in a lock-regulated section of the River Neckar

1995 ◽  
Vol 46 (1) ◽  
pp. 101 ◽  
Author(s):  
U Kern ◽  
B Westrich
Keyword(s):  
Heavy Metals ◽  
Principal Component ◽  
Coarse Grained ◽  
Acid Neutralizing Capacity ◽  
High Concentration ◽  
Fine Grained ◽  
Neutralizing Capacity ◽  
Sediment Fraction ◽  
Sediment Layers ◽  
Different Sources

For a lock-regulated reach of the River Neckar at Lauffen, Germany, results from sediment core analysis are presented. It is observed that sediment layers with a high concentration of heavy metals, especially cadmium, are covered by younger, less polluted sediment layers. A principal component analysis separated the parameters measured into three groups: heavy metals from human activities (Cd, Cr, Ni, Pb, Zn), metals from natural sources (Co, Fe, Mn), and inorganic carbon. Within the fine-grained sediment fraction containing particles smaller than 20 μm, a higher concentration of anthropogenic trace metals was found in fine-grained samples than in coarse-grained samples, whereas Co, Fe and Mn showed the opposite tendency. Obviously, this is due to two different sources of fine-grained material: sewage flocs and natural erosion particles. Acid-producing capacity (APC) and acid-neutralizing capacity (ANC) are calculated for both pore water and particulate matter of the sediment. At a depth of 20 cm, APC and ANC are controlled by the sediment matrix. ANC, which is due to calcium carbonate, is 20 times higher than APC, which is predominantly due to reduced sulfur components. Therefore, oxidation of sediment of the River Neckar does not lead to acidification.

scholarly journals Inventory of MSWI Fly Ash in Switzerland: Heavy Metal Recovery Potential and Their Properties for Acid Leaching

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1668
Author(s):  
Wolfgang Zucha ◽  
Gisela Weibel ◽  
Mirjam Wolffers ◽  
Urs Eggenberger
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Acid Leaching ◽  
Acid Neutralizing Capacity ◽  
Mswi Fly Ash ◽  
Mineralogical Characterization ◽  
Recovery Rates ◽  
Leaching Potential ◽  
Geochemical Properties ◽  
Neutralizing Capacity

From the year 2021 on, heavy metals from Swiss municipal solid waste incineration (MSWI) fly ash (FA) must be recovered before landfilling. This is predominantly performed by acid leaching. As a basis for the development of defined recovery rates and for the implementation of the recovery process, the authorities and plant operators need information on the geochemical properties of FA. This study provides extended chemical and mineralogical characterization of all FA produced in 29 MSWI plants in Switzerland. Acid neutralizing capacity (ANC) and metallic aluminum (Al0) were additionally analyzed to estimate the effort for acid leaching. Results show that all FA samples are composed of similar constituents, but their content varies due to differences in waste input and incineration conditions. Based on their geochemical properties, the ashes could be divided into four types describing the leachability: very good (6 FA), good (10 FA), moderate (5 FA), and poor leaching potential (8 FA). Due to the large differences it is suggested that the required recovery rates are adjusted to the leaching potential. The quantity of heavy metals recoverable by acid leaching was estimated to be 2420 t/y Zn, 530 t/y Pb, 66 t/y Cu and 22 t/y Cd.

scholarly journals Petrology and geochemistry of granitoids and their mafic micogranular enclaves (MME) in marginal part of the Małopolska Block (S Poland)

Mineralogia ◽  
2012 ◽  
Vol 43 (1-2) ◽  
pp. 3-127 ◽  
Author(s):  
Anna Wolska
Keyword(s):  
Trace Elements ◽  
Continental Crust ◽  
Coarse Grained ◽  
Granitic Rocks ◽  
Mixing Process ◽  
Na2o Content ◽  
Fine Grained ◽  
Małopolska Block ◽  
First Time ◽  
Different Sources

AbstractGranitic plutons (the Dolina Będkowska valley and Pilica area) were found in a few boreholes in the Małopolska Block (MB). These granitic rocks may represent apical parts (apophyses) of a great magmatic bodies (batholiths) located in deeper level of the Ediacaran/Paleozoic basement. They are described as ‘stitching intrusions’, generated during/after collision in Carboniferous/Permian period (~300 Ma) between the Upper Silesian Block (USB) and the Małopolska Block (MB).These rocks are fresh, unaltered granodiorites that are pale grey in colour. They have holocrystalline, medium- to coarse-grained structure and massive texture. For the first time, several mafic microgranular enclaves (MME), varying in size and colour, were found in the granodioritic host (HG). The occurrence of MME in the host granodioritic rocks is evidence of a mingling process between mafic and felsic magmas.The MME are pale/dark grey in colour, fine-grained rocks with ‘porphyritic’ textures. They consist of large megacrysts/xenocrysts of plagioclase, quartz, alkali feldspars and the fine-grained groundmass of pseudo-doleritic textures (lath-shaped plagioclases, blade-shaped amphiboles/biotites). According to their modal/mineral composition, they represent Q-diorites and tonalites.The MME, similar to the host granodiorites (HG), are I-type rocks, exhibit high Na2O content >3.2 wt%; normative diopside or normative corundum occurs (mainly <1%). They are metaluminous to slightly peraluminous (ASI <1.1) and have calc-alkaline, medium-K to high-K character. They generally belong to magnesian series (#Mg=0.20-0.40) and have low agpaitic index (<0.87). They are low evolved magmatic rocks. The rocks studied are enriched in LREEs (La, Ce, Sm) compared to HREEs. The Eu* negative anomaly and high Sr contents point to varying degrees of plagioclase fractionation connected to the mixing process rather than simple fractional crystallization. Both rocks studied (HG and MME) are characterized by a high content of LILEs (K, Ba, Rb) in normalized patterns and a low HFS/LIL elements ratio (Ta, Nb)/(K, Rb, La). The projection points of the rocks studied plot in different fields of various petrochemical diagrams: mainly in the arc granites that are rare in the pre-collisional granites as well as the syn-subductional to post-collisional granites fields.For the first time, inner textures in rock-forming minerals related to mixing processes are described both in the granodioritic host (HG) and in the MME. Mantled boxy cellular plagioclase megacrysts with ‘old cores’ of labradorite composition, and amphibole aggregates with titanite and opaque minerals, represent peritectic rather than primary residual minerals. The plagioclase, quartz and alkali feldspar megacrysts/xenocrysts were mechanically transferred from the granodioritic host (HG) to MME. The presence of lath-shaped plagioclases, blade-shaped amphiboles/biotites and acicular-shaped apatites in the groundmass of the MME is evidence of undercooling of hot mafic blobs in a relatively cold granodioritic magma chamber. The MME were hybridized by leucocratic melt squeezed from the granodioritic magma in a later stage of the mixing process (quartz and alkali crystals in the interstices in the MME groundmass). In the granodiorites (HG), the spike and spongy cellular zones as well as biotite/amphibole zones in plagioclase megacrysts are connected to the mixing process.Both of the rocks studied are characterized by different amounts of major elements (SiO2, Na2O and K2O), trace elements (Ni, Cr, V, Ti and P), #Mg and modified alkali-lime index (MALI) that is related to their origins from different sources. On the other hand, they have similar chondrite-normalized patterns (for trace elements and REE), LILEs contents (Sr, Ba, Rb), aluminum saturation index (ASI) and isotopic signatures (high 86Sr/87Sr (0.079-0.713) and low 143Nd/144Nd (0.512) values but lower than in continental crust), which are evidence of the strong hybridisation of mafic enclaves by the granodioritic host magma. The parental rocks of both rocks studied have a similar mafic signature but were generated in different sources: the host granodiorites (HG) magma in lower continental crust rocks, and the MME magma in enriched upper mantle. The MME crystallized from strongly hybridized magma of intermediate compositions (Q-diorite, tonalite) rather than from primary mafic magma. The host granodiorites (HG) originated from completely homogenized crustal granodioritic magma which inherited its geochemical signature from ancient arc-rocks in a subduction-related setting

Boron isotope systematics of Higashi-akaishi mantle wedge peridotites (Sanbagawa belt, Japan): implications for fluid recycling in subduction zones

2021 ◽  
Author(s):  
Cees-Jan De Hoog ◽  
Keiko Hattori ◽  
Eleri Clarke
Keyword(s):  
Isotopic Composition ◽  
Subduction Zones ◽  
Isotope Fractionation ◽  
Mantle Wedge ◽  
Greenschist Facies ◽  
Coarse Grained ◽  
High Concentration ◽  
Fine Grained ◽  
Dynamic Recrystallisation ◽  
Mantle Olivine

&lt;p&gt;Boron provides an efficient tracer of fluids in subduction zones, due to its high concentration in surface reservoirs, low concentration in the mantle, and large isotope fractionation. The Higashi-akaishi peridotite body in Sanbagawa UHP belt, Japan, is composed of partially serpentinised dunites and harzburgites, which are interpreted to be exhumed mantle wedge peridotites. Compositions of olivine (Fo90-94, NiO 0.28-0.48 wt%, MnO 0.10-0.16 wt%) and chromite (Cr# &gt;0.7, TiO&lt;sub&gt;2&lt;/sub&gt; &lt;0.4 wt%) confirm its origin as highly refractory fore-arc mantle. Several generations of olivine and serpentine can be recognised in the samples, and were analysed in-situ for their B content and B isotopic composition by SIMS. Coarse-grained primary mantle olivine has low [B] (1-3 &amp;#181;g/g), but is still significantly B-enriched compared to typical mantle olivine, and has &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B of -10 to -3 &amp;#8240;. Lower B contents in olivine cores compared to rims suggests diffusive incorporation of B from slab-derived fluids at high temperature. &amp;#160;Later fine-grained olivine neoblasts, products of dynamic recrystallization, have higher [B] (3-11 &amp;#181;g/g) and higher &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B (-7 to +2&amp;#8240;). Platy antigorite associated with the olivine neoblasts have similar [B] (4-12 &amp;#181;g/g) but higher &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B (-4 to +6&amp;#8240;). Late-stage greenschist-facies overprint resulted in lizardite veining with high [B] (18-52 &amp;#181;g/g) and a narrow range of &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B (-2 to -1&amp;#8240;).&lt;/p&gt;&lt;p&gt;We envisage the following scenario. Coarse-grained mantle olivine acquired B from slab-derived fluids when the peridotites were dragged down by mantle corner flow and positioned near the slab-mantle interface. The values of &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B (-10 to -3&amp;#8240;) are consistent with fluids from dehydrating slab at ca. 110-150 km depth, but are potentially affected by diffusion-controlled kinetic isotope fractionation. High temperatures (&gt; 650-700&amp;#176;C) prevented the peridotites from serpentinisation. Subsequently the rocks were down-dragged in a subduction channel where olivine neoblasts formed first and platy antigorite crystallized later when temperature dropped below 650&amp;#176;C. Both phases show heavier &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B than coarse-grained olivine; the values are consistent with fluids from dehydrating slab at ca. 70-100 km depth. Finally, the peridotites were exposed to crust-derived B-rich fluids with low &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B during exhumation and amalgamation with crustal units, forming lizardite veining during greenschist-facies overprint.&lt;/p&gt;&lt;p&gt;This study shows that mantle olivine may scavenge significant amounts of B from percolating fluids by diffusive re-equilibration or dynamic recrystallisation, lowering the B content of such fluids and potentially modifying their B isotopic composition.&lt;/p&gt;

scholarly journals Comprehensive Risk Assessment of Applying Biogas Slurry in Peanut Cultivation

2021 ◽  
Vol 8 ◽  
Author(s):  
Qingyu Liu ◽  
Zixuan Zhao ◽  
Zhiping Xue ◽  
Ding Li ◽  
Zhining Wen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Human Health ◽  
Organic Fertilizer ◽  
Chemical Properties ◽  
Principal Component ◽  
Permissible Limit ◽  
Peanut Kernel ◽  
Biogas Slurry ◽  
High Concentration

Biogas slurry, a byproduct of biogas plants, is considered a high-quality bio-organic fertilizer. Despite providing nutrients to crops, biogas slurry may contain a high concentration of heavy metals, leading to food safety problems and endangering human health if such metals are absorbed by plants. Therefore, biogas slurry should undergo systematic risk assessment prior to direct use on farmland to ensure its safety for soils and crops. In this study, the risk of applying biogas slurry in peanut cultivation was comprehensively evaluated. Based on nitrogen contents, different concentrations of biogas slurry were applied in peanut cultivation. The results achieved herein showed that the application of biogas slurry as a nutrient supplier in peanut cultivation would significantly affect the physical and chemical properties of soil and characteristics of the plant and the quality of peanuts. Although the heavy metal content of biogas slurry was within the permitted range, it had potential risks to human health and the environment. Principal component analysis (PCA) showed that biogas slurry was the primary source of heavy metals in soil. After the application of biogas slurry, the contents of As and Hg in the soil increased significantly, which were 11.12 and 26.67 times higher than those in the control soil. The contents of Cu, Zn, Pb, Cd, and As in peanut kernel samples under different levels of biogas slurry application were all lower than the maximum permissible limit set by the Standardization Administration of China. In contrast, the content of Hg in peanut kernels was higher than the maximum permissible limit value of 0.02 mg/kg. Peanut had a higher enrichment capacity of Cd and Zn and a higher migration capacity of Pb. The health risk assessment showed that the long-term consumption of peanuts grown with a high dosage of biogas slurry would be harmful to the health of children aged 2–6 years with a large consumption level.

scholarly journals Removal of heavy metals (Cu, Cd and Zn) from contaminated soils using EDTA and FeCl3

2016 ◽  
Vol 18 (1) ◽  
pp. 98-107 ◽  
Keyword(s):  
Heavy Metals ◽  
Contaminated Soils ◽  
Extraction Procedure ◽  
Soil Washing ◽  
Nitrilotriacetic Acid ◽  
Coarse Grained ◽  
Metal Extraction ◽  
Fine Grained ◽  
Solid Ratio ◽  
Fine Grained Soil

<p>Environmental pollution caused by heavy metals from different industrial activities constitutes a serious risk for the environment. Soils contaminated with metals, such as Cu, Cd and Zn, are often subjected to physical or chemical remediation procedures to purify soils from these metals. Typical chelating agents used for metal extraction and soil washing generally include ethylene-diaminetetraacetic acid nitrilotriacetic acid, diethylenetriaminepentaacetic acid and citric acid. The subject study evaluating the potential of soil washing methods using EDTA and ferric chloride on two types of soils (coarse grained, fine grained). The effects of operating parameters, such as liquid/solid ratio, soil washing chemicals and washing time were examined. In extraction procedure of Cd (266 mg kg<sup>-1</sup>), Cu (194 mg kg<sup>-1</sup>) and Zn (497 mg kg<sup>-1</sup>) from contaminated coarse grained soil with using 0.01 M FeCl<sub>3</sub> washing solution (liquid/solid ratio 20) for 2 hours, contaminants were removed 96.66%, 90.02% and 98.25%, respectively. In extraction procedure of Cd (218 mg kg<sup>-1</sup>), Cu (153 mg kg<sup>-1</sup>) and Zn (441.6 mg kg<sup>-1</sup>) from contaminated fine grained soil with using 0.01 M FeCl<sub>3</sub> washing solution (liquid/solid ratio 20) for 2 hours, contaminants were removed 98.18%, 97.48% and 98.05%, respectively. Better removal efficiencies have been obtained by using FeCl<sub>3</sub>. These results confirmed the effectiveness of the soil-washing method with FeCl<sub>3</sub> in remediating heavy metals (Cu, Cd and Zn) from different types of soil.</p>

Correlation between dislocation, grain boundary and interface of duplex SS in stress corrosion cracking(SCC)

1990 ◽  
Vol 48 (4) ◽  
pp. 928-929
Author(s):  
Wang Zheng-fang ◽  
Z.F. Wang
Keyword(s):  
Stainless Steel ◽  
Thermal Cycle ◽  
Secondary Phase ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
Test Environment ◽  
Fine Grained ◽  
Evaluation Test ◽  
Welding Thermal Cycle ◽  
Micro Analysis

The main purpose of this study highlights on the evaluation of chloride SCC resistance of the material,duplex stainless steel,OOCr18Ni5Mo3Si2 (18-5Mo) and its welded coarse grained zone(CGZ).18-5Mo is a dual phases (A+F) stainless steel with yield strength:512N/mm2 .The proportion of secondary Phase(A phase) accounts for 30-35% of the total with fine grained and homogeneously distributed A and F phases(Fig.1).After being welded by a specific welding thermal cycle to the material,i.e. Tmax=1350°C and t8/5=20s,microstructure may change from fine grained morphology to coarse grained morphology and from homogeneously distributed of A phase to a concentration of A phase(Fig.2).Meanwhile,the proportion of A phase reduced from 35% to 5-10°o.For this reason it is known as welded coarse grained zone(CGZ).In association with difference of microstructure between base metal and welded CGZ,so chloride SCC resistance also differ from each other.Test procedures:Constant load tensile test(CLTT) were performed for recording Esce-t curve by which corrosion cracking growth can be described, tf,fractured time,can also be recorded by the test which is taken as a electrochemical behavior and mechanical property for SCC resistance evaluation. Test environment:143°C boiling 42%MgCl2 solution is used.Besides, micro analysis were conducted with light microscopy(LM),SEM,TEM,and Auger energy spectrum(AES) so as to reveal the correlation between the data generated by the CLTT results and micro analysis.

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

Assessment of micro and macro nutrients in poultry feeds available in Dhaka city, Bangladesh.

2017 ◽  
Vol 1 ◽  
pp. 264
Author(s):  
Md Didarul Islam ◽  
Ashiqur Rahaman ◽  
Fahmida Jannat
Keyword(s):  
Heavy Metals ◽  
Adverse Effect ◽  
The Other ◽  
Nutrient Level ◽  
Dhaka City ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Low Concentration ◽  
Feed Formulation ◽  
Macro Nutrients

This study was based on to determine the concentration of macro and micro nutrients as well as toxic and nontoxic heavy metals present in the chicken feed available in Dhaka city of Bangladesh. All macro nutrients, if present in the feed at high concentration have some adverse effect, at the same time if this nutrient present in the feed at low concentration this have some adverse effect too. So that this nutrient level should be maintained at a marginal level. On the other side toxic heavy metals if present in the feed at very low concentration those can contaminate the total environment of the ecosystem. In this study six brand samples (starter, grower, finisher and layer) which was collected from different renowned chicken feed formulation industry in Bangladesh. Those samples were prepared for analysis by wet ashing and then metals were determined by Atomic Absorption Spectroscopy. It was found that 27.7 to 68.4, 57.3 to 121.9, 0.21 to 4.1, 0.32 to 2.1, 0.11 to 1.58, 0.28 to 2.11 and 0.28 to 1.78 for zinc, iron, copper, mercury, cadmium, nickel and cobalt respectively. It was found that essential macro and micro nutrients were present in the feed in low concentration on the other side mercury was present in high concentration in the feed samples.

Evaluation of Hemidesmus indicus root as an antacid by In vitro

2016 ◽  
Vol 5 (04) ◽  
pp. 4524
Author(s):  
Abdullah Shaikh Farooque ◽  
Md. Azharuddin Ismail Atar*
Keyword(s):  
Skin Diseases ◽  
Care Delivery ◽  
Health Care Delivery System ◽  
Acid Neutralizing Capacity ◽  
Standard Drug ◽  
Hemidesmus Indicus ◽  
Neutralizing Capacity ◽  
Loss Of Appetite ◽  
Powdered Drug

Medicinal plants are being widely used, either as single drug or in combination in health care delivery system. Indian Sarsaparilla, Hemidesmus indicus (Family: Asclepiadaceae) is a commonly known Indian Medicinal Plant, which is widely recognized in traditional systems of Medicine. It contains various phytoconstituents belonging to the category glycosides, flavonoids, tannins, sterols and volatile oils. It has been reported as useful in biliousness, blood diseases, dysentery, diarrhea, respiratory disorders, skin diseases, syphilis, fever, leprosy, leucoderma, leucorrhoea, itching, bronchitis, asthma, eye diseases, epileptic fits in children, kidney and urinary disorders, loss of appetite, burning sensation, dyspepsia, nutritional disorders, ulcer and rheumatism. Several studies are being carried towards its activities like analgesic, anti-inflammatory, antiulcer, hepatoprotective, antioxidant and helicobactericidal properties. In our study we have evaluated antacid activity of sariva (Anantmool) by using In-Vitro method, i.e. ANC (Acid Neutralizing Capacity). This evaluation was done by comparing the ANC of sariva macerated & powdered drug with water as blank & standard drug i.e. NaHCO3. Based on this In-Vitro experiment, we can conclude that, the macerated & powdered drug of sariva (Anantmool) evaluated in this study, varied in potency as measured in terms of their ANC. These results having ** i.e. P < 0.01 & Passed the normality test. However, the present study being in-vitro, the effects of antacid may vary In-Vitro; individual variations also contribute to the ultimate effectiveness of as antacid.        

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