Order Mn Research Articles

Bio-tolerance potential and environmental risks assessment of Oreochromis niloticus and Ipomoea aquatica in Agodi Reservoir, Nigeria

The concentration of nine heavy metals in Oreochromis niloticus and Ipomoea aquatica inhabiting Agodi reservoir, Oyo State, Nigeria were investigated for twelve months. The concentrations of the metals were carried out using PG990 Atomic Absorption Spectrophotometer. The Ecological Risk Quotient (ERQ) was calculated using standard methods while the tolerability was determined with Box Plot analysis. The metal bioaccumulation in O. niloticus and I. aquatica followed the order Mn > Fe > Zn > Cu > Co > Pb > Cd > Cr > Ni and Fe > Zn > Mn > Cu > Pb > Cd > Co > Cr > Ni respectively. The results revealed O. niloticus to bioaccumulate the metals more than I. aquatica. Most of the examined metals were higher than the safety limit for the metals concentration in O. niloticus and I. aquatica. Also, I. aquatica had higher tolerability for heavy metals than O. niloticus. In O. niloticus, metal concentration, as well as ERQ, was higher in the wet season while no particular order was observed for I. aquatica. The ERQ result revealed that Cd, Fe, Mn, Zn, Cu and Pb exhibited a high level of ecological risk to both the aquatic flora and fauna as the ERQ values were above the risk limit of one (1). Thus, there is a significant environmental risk associated with heavy metals in the water body.

Pilot groundwater radon mapping and the assessment of health risk from heavy metals in drinking water of southwest, Nigeria

Radon and heavy metals are sources of groundwater pollution and are identified as potential carcinogens. Southwest Nigeria's populace mostly relies on groundwater source for drinking. This study aims to map radon distribution in groundwater of southwest Nigeria and to determine the health risk of radon and heavy metal in drinking water. Radon concentrations of 145 groundwater samples were measured using RAD7 electronic radon detector and heavy metal concentrations of 52 groundwater samples were measured using atomic absorption spectrophotometer. Radon concentration distributions were delineated using geographical information system. Radon concentration of water samples ranges between 1.6 Bq l−1 and 271 Bq l−1 with an average value of 35.9 ± 38.4 Bq l−1. The average groundwater radon concentration is higher than US-EPA recommended level of 11.1 Bq l−1 but lower than the WHO recommended limit of 100 Bq l−1. The estimated average annual effective radiation doses to infants, children, and adults are 29 μSvy−1, 41 μSvy−1 and 92 μSvy−1 respectively. The radon distribution map of the study area reveals regions of high, medium, and low groundwater radon concentrations. The average concentration values of heavy metals in groundwater samples are of the order Mn > Zn > Pb > Cu > Cr > Ni > Cd. 84% of groundwater exhibits good to excellent quality in terms of heavy metal pollution. However, about 16% of the samples which lie in the sedimentary regions of Ogun and Lagos States exhibit poor to very poor quality. Overall, ingestion of groundwater in the study area may not pose a serious health hazards from radon ingestion and heavy metal toxicity.

Assessment of Heavy Metal Levels in Soil and Vegetables in Some Farms Around Mining Sites in Mangu Local Government Area Plateau State, Nigeria

When the mining process is not properly controlled, it can be a source of heavy metals pollution in the environment. The uptake of these heavy metals in edible parts of vegetables can be a direct source of the metals into the human food chain. This study assessed the concentrations of lead (Pb), manganese (Mn), zinc (Zn), copper (Cu), nickel (Ni) and chromium (Cr) in soil and vegetables obtained from nine (9) farms around mining sites in Mangu LGA. Concentrations of heavy metals in soil and vegetables were determined using atomic absorption spectrophotometer (AAS). The results revealed the concentrations of the heavy metals at the farms to be within the recommended maximum levels of world soils but were higher than their respective controls. This implies that the artisanal mining contributed to the increased values of these heavy metals in the environment. Also, the mean concentrations of the heavy metals at Mangu Halle mining site decreased in the order Mn > Zn > Cr > Cu > Ni > Pb > Cd whereas at Alogwom it decreased in the order Mn > Zn > Pb > Cu > Ni > Cr > Cd. The enrichment factor (EF) of the elements showed deficiency to minimum enrichment for all the heavy metals whereas the pollution index (PI) of the metals indicated very slight contamination to moderate pollution. The results of the heavy metals in the vegetables showed that the bioaccumulation of the metals followed a pattern: Zn > Cu > Pb > Cr > Cd > Ni. Levels of Cd, Pb and Ni in the vegetables were observed to be higher than the recommended limit for vegetables whereas Cu, Cr and Zn exhibited lower values than recommended standards. Thus, their consumption might pose health risk to consumers and therefore there is the need for proper monitoring of the illegal mining activities to reduce health risk and the extent of heavy metals contamination.

Assessment of heavy metal contamination within the sediments in some fresh water lakes of Udaipur

Heavy metal concentrations were assessed in sediment samples collected from three lakes of Udaipur, Rajasthan. The aim of the present investigation was to compare the lakes for season wise addition of pollution load. The assessment of heavy metals was done using Contamination factor (CF), Geo accumulation index (Igeo) and Pollution load index (PLI). In summer CF varied from 0.01 to 7.43 i.e low to very high but in winter season all three lakes represented high CF factor. Likewise Igeo index in the sediments for summer ranged between 0.41 to 14.48 mg/kg i.e uncontaminated to moderate to heavy to extreme levels in sediments of lakes and trends were of the order Mn>Zn>Pb>Ni>Cu>Cd. In winter Igeo index ranged between 1.34 to 19.3 mg/kg which is uncontaminated to extreme contamination in bottom sediments and trends were of the order Mn>Zn>Pb>Ni>Cu>Cd. Pollution load index in winter season represented high value i.e more than 1 in both Dudh Talai and Udai Sagar Lake. The proposed study suggested that heavy metal accumulation in sediments during winter was higher than summer season. This has a very significant relevance where the contaminated sediments have one of the most challenging pollution issues owning to the toxicity persistence and bioaccumulation issues of food web.

Heavy Metals and Health Risks Associated with Consumption of Herbal Plants Sold in a Major Urban Market in Southwest, Nigeria.

Background.Although herbal medicines play an important role as a source of medicine, concerns have been raised about the risks posed by consumption of these plants, especially if consumed above permissible levels.Objectives.This study was undertaken to assess the level of exposure, toxicity and health risk associated with the consumption of herbal plants in Ado Ekiti urban market, Nigeria.Methods.Ten commonly consumed herbal plants sold in Ado Ekiti urban market were subjected to heavy metal analysis. Health risk assessment was carried out to determine the estimated daily intake (EDI) of heavy metals, health risk index (HRI), target hazard quotient for non-carcinogenic risk and estimation of cancer risk (ECR).Results. The EDIs for lead (Pb), nickel (Ni), chromium (Cr), copper (Cu) and magnesium (Mn) were above the upper tolerable daily intake reference for all studied plant species in both children and adults, an indication that herbal use poses a short-term to long-term health risk to consumers of these herbal products. The EDI for children was significantly lower compared to that of adults, indicating higher risks for adult consumers of these herbal products. The HRI in children for Pb (Alstonia congensis, Terminalia avicennioides, Aframomum melegueta, Cymbopogon citratus and Napoleona vogelii) were greater than 1; HRI in Cu and Mn also showed an unusually high concentration, an indication that long term exposure to the consumption of these herbal plants poses a serious health risk. The HRI in children and adults follows the order Mn > Cu > Ni > Pb > Cr; cadmium (Cd) was not detected in any of the herbal plants. The ECR for Pb, Ni and Cr present in the herbal plants for children ranged between 10−6 (low) to 10−3 (high), while the ECR for Pb, Ni and Cr for herbal plants for adults ranged between 10−5 (acceptable) to 10−2 (unacceptable). For both children and adults, there is a call for concern due to ECRs above the acceptable range; the consumption of these herbal plants poses a long-term cancer risk.Conclusions.In both children and adults, ECRs for some of the herbal plants in the present study above the acceptable range present a risk to human health. The consumption of such herbal plants poses a long-term cancer risk.Competing Interests. The authors declare no competing financial interests.

Using antioxidant changes in liver and gonads of Oreochromis niloticus as biomarkers for the assessment of heavy metals pollution at Sharkia province, Egypt

The work was aimed to assess the heavy metals concentrations in the Sharkia Governorate, Egypt. The determination of heavy metal bioaccumulation and their antioxidant alterations on Oreochromis niloticus were considered. The gonads and the liver of the fishes were analyzed for essential metals (Cu, Mn, Fe & Zn) and non-essential metals (Pb) levels seasonally and their bioaccumulation factors. The results revealed that concentrations of the metals differ significantly between the gonads and the liver of the sampled fishes. During summer, liver bioaccumulation of the metals was in the order of Mn > Pb > Fe > Zn > Cu at area I and Mn> Pb> Zn> Fe > Cu at area II. However, the degree of tissue alterations in the gonads can accumulate the heavy metals in the following order Mn >Zn>Pb >Fe>Cu and Mn> Pb >Zn> Fe at the same season, for the areas I and II, respectively. The bioaccumulation of heavy metals in the liver tissue was higher than in the gonads of the O. niloticus. The antioxidant changes in the liver and gonads were mildly and moderately damaged, respectively. These indicated that Zn, Cd, Pb, and Fe polluted the Sharkia Governorate in the two selected areas. Elevation of lipid peroxidation in fishes was parallel with increasing the activity of endogenous antioxidants that could be to compensate for the stress.

Determination of Heavy Metals and Bacterial Count of Some Frequently Consumed Spices in Jordan

Background: Many factors contribute to the contamination of spices with heavy metals and bacteria including fertilizers, soil contamination and source of irrigation water. Methods: In this study, four spices already consumed in Jordan (cinnamon, black pepper, cubeb “allspice” and nutmeg) were investigated regarding heavy metals and bacterial contents. India and China (as Asian origin) as well as United States of America (as North American Origin) and Brazil (as South American origin) were considered as the main producers and exporters of spices for most countries of the world as Jordan. Results: results indicated that (Fe) element was came in the first ordered as a major investigated one in Indian nutmeg. Black pepper came as a predominant one in Indian black pepper contrary to that of Chinese one which had (Mn) element as a predominant. (Mn) is the major element in Chinese cubeb, but Indian cubeb contained (Fe) as a major element. It could be detected iron metal (Fe) as the highest heavy metal in either Indian or Chinese cinnamon. By calculating the total heavy metals content, it could be ascendingly ordered the investigated Asian spices as: Chinese cubeb, Chinese nutmeg, Chinese black pepper, Indian cinnamon, Indian cubeb, Indian nutmeg, Indian black pepper and Chinese cinnamon. Three of Chinese spices, i.e., cubeb, nutmeg and black pepper came in the first order considering their total heavy metals content. Meanwhile, in the second order Indian spices (cinnamon, cubeb and nutmeg) was coming with moderate total heavy metals content. The highest level of total heavy metals (over 9 ppm) was detected in both of Indian black pepper and Chinese. Regarding to the total content of heavy metals in four investigated American spices, black pepper possesses the lowest level of total heavy metals and meanwhile the highest level was found in American cubeb. Cubeb and nutmeg contain iron with 1.9 times higher than that of cinnamon spice. In the second order (Mn) element showed a similar trend. It is interested to notice that all of spices in this study had approximately the same level of (Pb) metal. The total heavy metals content in investigated Brazilian spices, black pepper possessed the highest. While cinnamon had the lowest. Three of heavy metals (As, Ti and Li) were also not detected in Brazilian spices similar to those of American ones. As a general trend, black pepper spice either imported from Asian (China and India) or American (USA and Brazil) origin had the highest bacterial count, meanwhile, the lowest count was detected in nutmeg spice imported from the same origins.

Assessment of trace metal contamination in the core sediment of Ramsar wetland(Kabar Tal), Begusarai, Bihar (India).

The concentration of trace metals Mn, Pb, Ni, Zn, and Cu in the core sediment from Kabar Tal wetland was analyzed to understand the level of contamination in the vertical profile. Additionally, total organic carbon (TOC) and available phosphorus (AP) were also analyzed to infer the biogeochemistry of trace metals and the correlation that exists among them. Five core sediments were collected at the end of the monsoon season from different locations in the study area, representing diverse anthropogenic and agricultural activities. The average concentration of trace metals in sediments followed the order Mn > Pb > Ni > Zn > Cu. The trace metal concentration in the surface sediments was higher and decreased with depth in the vertical profile. Contamination factor (CF), geoaccumulation index (Igeo), enrichment factor (EF), and pollution load index (PLI) were used to evaluate sediment quality and the pollution status of the lake sediments. Cu, Zn, and Ni showed minor to moderate enrichment, and Pb showed a severe level of enrichment in all the core sediment samples. However, the sediment quality guidelines' index indicates that the sediments are moderately polluted with copper, zinc, and nickel and severely polluted with lead. There exists a strong positive correlation among Pb-Ni, Ni-AP, and AP-Pb, and a strong negative correlation among TOC-Ni, TOC-Pb, and TOC-AP for all the sediment samples. Additionally, the principal component analysis (PCA) and cluster analysis (CA) suggest that a good similarity exists among Pb, Ni, and Zn. The study indicates that trace metals in wetland sediments have originated from multiple anthropogenic sources like agricultural runoff (fertilizers), direct addition of solid wastes, discharge of untreated wastewater, and long-range transport from the oil refinery in the wetland.

Chemical composition of organically and conventionally grown fruits of raspberry (Rubus idaeus L.) cv. Willamette

The paper presents two-year results of chemical tests of raspberry fruits in organic and conventional cultivation systems. Raspberry plantations were established on the slopes of Jelica Mountain, on soil having very acidic reaction (pH/KCl 3.67-3.76) and optimal contents of humus and total N. In the conventional cultivation system, the soil had a high supply of readily available P2O5 and K2O and microelements, with excessive levels of Ni, and Cr. In the organic system, the content of Ni and Zn increased. The biochemical properties of organic and conventional fruits showed no significant differences, while the influence of the research year and the interaction of the cultivation system showed significant differences in the content of TA and IS. However, higher values of the levels of soluble solids, total acids and sugars contributed to the more appealing taste and aroma of organic raspberry fruits. The contents of microelements and heavy metals in the fruits of both cultivation systems were measured in the following order Mn>Fe>Zn>Cu>Ni>Cr>Co. No significant difference was found in the contents of the examined elements between organic and conventional fruits, except for the statistically higher content of Fe in organic raspberries. The high share of individual elements (especially Ni) in both cultivation systems indicates the need for continuous chemical testing of soil and fruits. Based on the results, it is important to consider the daily intake of each element in relation to body weight and/or maximum daily intake.

Trace metal pollution and its impacts on the macroinvertebrate community assemblage in a tropical reservoir

AbstractThe extent of metal pollution in the sediment of Osinmo reservoir was determined with a view to assessing the impact of heavy metal concentrations on the community assemblage of the macroinvertebrates there‐in. The range of the mean concentrations of heavy metals are as follows: Pb (6.66–7.89 mg/kg), Cu (1.04–2.63 mg/kg), Mn (34.03–61.69 mg/kg), Zn (3.59–8.17 mg/kg) and Ni (0.08–0.1 mg/kg).The mean concentration of the investigated heavy metals in the reservoir sediment followed the order Mn > Pb > Zn > Cu > Ni. Insignificant variation of the heavy metals was observed amidst the three reaches of the reservoir except for Mn which showed a significant difference (p < 0.05). Although the insect groups were generally more sensitive to the sediment parameters than the noninsect group, the community assemblage was observed not to have been significantly impacted by these variations. The values obtained from enrichment analysis of the metals were generally lower than the background values and this indicated that a significant portion of the heavy metals in the sediment was derived from natural sources thus suggesting the existence of a stable ecological community in the Reservoir.

Investigation of magnetic ordering and origin of exchange-bias effect in doped manganite, Sm0.4Ca0.6MnO3

We have carried out detailed investigations of magnetic ordering and the origin of exchange-bias phenomenology in polycrystalline 154Sm0.4Ca0.6MnO3 perovskite compound by employing dc and ac magnetizations, neutron depolarization, and neutron diffraction techniques. The neutron diffraction study reveals a broad charge ordering transition in the temperature range of 275–150 K, manifested by gradually varying structural distortions. DC magnetization and neutron diffraction studies infer a magnetic ordering around 110 K. Below ∼40 K, this compound exhibits a large enhancement of the magnetization and an exchange-bias effect (∼18 kOe at 5 K). The exchange-bias effect shows a characteristic temperature and cooling field dependence and a training effect. The compound undergoes a CE-type (checker-board type) antiferromagnetic (AFM) ordering of Mn3+/Mn4+ spins below 110 K. The large magnetization below ∼40 K arises from the ferrimagnetic (FIM) ordering of a minority (∼5 vol. %) non-perovskite phase of Mn3O4. The appearance of exchange bias is ascribed due to the presence of an interface, formed between the FIM (Mn3O4) phase and the main AFM perovskite phase. Our study has implications in giving new directions in the search of large exchange-bias effects in mixed FIM/AFM bulk systems.

Environmental screening for the assessment of potentially toxic elements content in PGI soils from the Mediterranean region (Italy and Turkey)

To provide a contribution to the Thematic Strategy for Soil Protection, here we present the results of a study focused on the potentially toxic elements (PTE) content in agricultural soils’ representative for the Mediterranean region. To reach this aim, samples of 22 Italian (NE Peloritani Mountains, Sicily) and 18 Turkish (Amik Plain, Hatay) soils were collected and analyzed to evaluate their PTE content. The Italian and Turkish sites have been selected because they represent very important cultivation zones. In Amik Plain (Turkey), the dominant crops consist of cotton, wheat, corn and olives, whereas in NE Peloritani Mountains, Sicily (Italy), an appreciate citrus variety, known as the “Interdonato lemon”, guaranteed by Protected Geographical Indication label, is produced. The collected results include: (1) the assessment of PTE levels in soils; (2) the identification of the PTE sources; (3) the relationships between PTE contents and soil properties (pH, electrical conductivity, organic matter, CaCO3, and clay). Several multivariate statistical methods such as correlation matrix, cluster analysis and main component analysis were applied to individuate the anthropogenic vs natural origin of the PTE sources. The detected PTE levels are in decreasing order Mn > Zn > V > Cr > Cu > Ni > As > Pb > Co > Sb > Se > Cd for the Italian soils, and Mn > Ni > V > Zn > Cr > Cu > Pb > Co > As > Se > Sb > Cd for the Turkish soils. The overall obtained results allowed to define: (a) a main lithogenic source for PTE detected in the Italian soils, except for Zn which origin is also associated to anthropogenic input; (b) a lithogenic origin for all of the PTE detected for the Turkish soils, with an associate anthropogenic contribution for Cr, Ni, V, Cu and V. The results obtained in this work enhance the knowledge in the individuation of PTE pollution sources in agricultural soils of the European Mediterranean region.

Efficiency of pre-oxidation of natural organic matter for the mitigation of disinfection byproducts: Electron donating capacity and UV absorbance as surrogate parameters

Pre-oxidation is often used before disinfection with chlorine to decrease the reactivity of the water matrix and mitigate the formation of regulated disinfection byproducts (DBPs). This study provides insights on the impact of oxidative pre-treatment with chlorine dioxide (ClO2), ozone (O3), ferrate (Fe(VI)) and permanganate (Mn(VII)) on Suwannee River Natural Organic Matter (SRNOM) properties characterized by the UV absorbance at 254 nm (UV254) and the electron donating capacity (EDC). Changes in NOM reactivity and abatement of DBP precursors are also assessed. The impact of pre-oxidants (based on molar concentration) on UV254 abatement ranked in the order O3 > Mn(VII) > Fe(VI)/ClO2, while the efficiency of pre-oxidation on EDC abatement followed the order Mn(VII) > ClO2 > Fe(VI) > O3 and two phases were observed. At low specific ClO2, Fe(VI) and Mn(VII) doses corresponding to < 50% EDC abatement, a limited relative abatement of UV254 compared to the EDC was observed (~ 8% EDC abatement per 1% UV254 abatement). This suggests the oxidation of phenolic-type moieties to quinone-type moieties which absorb UV254 and don't contribute to EDC. At higher oxidant doses (> 50% EDC abatement), a similar abatement of EDC and UV254 (~ 0.9–1.2% EDC abatement per 1% UV254 abatement) suggested aromatic ring cleavage. In comparison to the other oxidants, O3 abated the relative UV254 more effectively, due to a more efficient cleavage of aromatic rings. For a pre-oxidation with Mn(VII), ClO2 and Fe(VI), similar correlations between the EDC abatement and the chlorine demand or the adsorbable organic halide (AOX) formation were obtained. In contrast, O3 pre-treatment led to a lower chlorine demand and AOX formation for equivalent EDC abatement. For all oxidants, trihalomethane formation was poorly correlated with both EDC and UV254. The EDC abatement was found to be a pre-oxidant-independent surrogate for haloacetonitrile formation. These results emphasize the benefits of combining EDC and UV254 measurement to understand and monitor oxidant-induced changes of NOM and assessing DBP formation.

Metal remediation potential of naturally occurring plants growing on barren fly ash dumps.

The present study aimed to elucidate the remediation potential of visibly dominant, naturally growing plants obtained from an early colonized fly ash dump near a coal-based thermal power station. The vegetation comprised of grasses like Saccharum spontaneum L., Cynodon dactylon (L.) Pers., herbs such as Tephrosia purpurea (L.) Pers., Sida rhombifolia L., Dysphania ambrosioides (L.) Mosyakin & Clemants, Chromolaena odorata (L.) King & H.E. Robins along with tree saplings Butea monosperma (Lam.) Taub. The growth of the vegetation improved the N and P content of the ash. Average metal concentrations (mgkg-1) in the ash samples and plants were in order Mn (345.1) > Zn (63.7) > Ni (29.3) > Cu (16.8) > Cr (9.9) > Pb (1.7) > Cd (0.41) and Cr (58.58) > Zn (52.74) > Mn (39.09) > Cu (10.71) > Ni (7.45) > Pb (5.52) > Cd (0.14), respectively. The plants showed fly ash dump phytostabilization potential and accumulated Cr (80.19-178.11mgkg-1) above maximum allowable concentrations for plant tissues. Positive correlations were also obtained for metal concentration in plant roots versus fly ash. Saccharum spontaneum showed highest biomass and is the most efficient plant which can be used for the restoration of ash dumps.

The Impact of Galena Mining in North-Eastern Nigeria on Nearby Food Crops

Aims: To investigate and evaluate trace elements concentration in soils and bioaccumulation on food crops grown on agricultural fields around galena mine area, Wukari, north eastern Nigeria.&#x0D; Study Design: The studied area is situated in the northwestern part of Wukari Local Government Area of Taraba State, North-East Nigeria. The hydrology of the area is conducive for the cultivation of crops and fresh water for fishing. The soils and food crops samples were collected in the month of May, 2018.&#x0D; Methodology: Edible parts of plants such as leaf, stem and seed were collected from Soybeans (Glycine max), Guinea corn (Sorghum bicolor), Millet (Penniselum typhoides), Spinach (Amaranthus) and Tomato (Lycosipinus esculentum). A 1.00 g of the finely ground soil samples were digested with 10 mL of aqua regia (a mixture of 1:3 HNO3/HCl v/v) at 70°C on hot plate for 3 hours in a fume hood and 1.00 g of each sieved plant samples were digested with 10 mL mixture of HNO3: HCIO4 in the ratio 5:1 at 90°C for 30 minutes in a fume cupboard.&#x0D; Results: The concentrations (µg/g DW) of the trace elements in soil are in the order Mn &gt; Fe &gt; Se &gt; Pb &gt; Cr &gt; Cu &gt; Al &gt; As. The bio-accumulation of trace elements in all food crops were in the range: Se (0.250 – 20.88 µg/g DW), Al (0.250 – 0.980 µg/g DW), As (0.070 – 0.620 µg/g DW) and Pb (0.020 – 0.090 µg/g DW). Cr, Cu, Pb, Mn concentrations in food crops were above FAO/WHO permissible limits of 2.30, 40.0, 0.30, 500 µg/g DW respectively.&#x0D; Conclusion: The Health Risk Index of As, Cr and Fe in spinach and Guinea corn were &gt; 1. The study revealed that food crops grown on farmlands around mining areas are not safe for consumption.

Ca treated Palygorskite and Halloysite clay minerals for Ferrous Iron (Fe+2) removal from water systems

Abstract Palygorskite fibers and halloysite nanotubes (HNT) were used for the Fe (II) uptake from aqueous solutions under various experimental conditions. Palygorskite and halloysite samples were characterized using XRD, FTIR, SEM, BET and CEC and then were saturated by exchanging Ca + 2 cations. The Ca-Palygorskite (Ca-Pal) and Ca-Halloysite (Ca-Hall) were characterized as well, and applied in batch kinetic experiments series. It was shown that both Ca-treated clay minerals were more efficient adsorbents for the lowest ferrous concentrations removal (5 mg/L), especially when the highest solid: liquid ratio (20 g/L) have been applied, reaching 99.8% and 91.2% removal with Ca-Pal and Ca-Hall respectively, within 10 min at the optimal room temperature (20 ± 1 °C). The pH value affected the adsorption’s efficiency, as Ca-Pal was more efficient adsorbent at acidic values (4–6), while Ca-Hall efficiency is positively correlated with pH increase (7 ). Moreover, the competitive ions found to prohibit Ca-Hall capacity for Fe (II), following the order Mn K Cu Zn Ba Mg Na, but Ca-Pal is slightly affected by K Na=Mn Zn Cu Mg Ba, highlighting its preference to a Fe cations. According to the thermodynamic analysis the Fe (II) uptake is a physical and spontaneous process, while both Ca-Pal and Ca-Hall fit in Langmuir isotherm instead of Freundlich, indicating monolayer sorption. The exact mechanism of Ca-Pal efficient adsorption was verified and further explained with molecular simulation optimization by Material Studio 4.3.

Sediment metal contaminations in sewage-fed aquaculture system of East Kolkata Wetland, West Bengal, India

Present work aimed to study the contamination of heavy metals (Copper, Lead, Manganese, and Zinc) in sediment from sewage fed aquaculture system of East Kolkata Wetlands, West Bengal, India from July 2016 to March 2017. Composite sediment samples were collected monthly from three sites (S1, S2, and S3) of the Nalban of the East Kolkata Wetlands. The samples were brought to the laboratory, processed, and analyzed. The concentrations of the metals were in the order Mn&gt; Zn &gt; Pb&gt; Cu at S1; Mn&gt; Zn &gt; Cu &gt;Pb at S2 and Zn &gt; Mn &gt; Pb &gt; Cu at S3. The calculated average values of Contamination Factor (CF) were in the order Pb &gt;Cu&gt;Zn&gt;&gt; Mn at S1, Cu Zn &gt; Pb &gt;&gt; Mn at S2, and Pb &gt; Zn &gt; Cu &gt;&gt; Mn at S3. In general, the wetland was rated as low to moderately contaminated. The estimated Pollution Load Index (PLI) values for the wetland also corroborated the inference. Suitable management practices like the proper waiting period for wastewater intake, continuing general cultural practices of maintaining water hyacinth in the marginal areas of the wetland, etc., should be religiously followed to prevent the wetland from further deterioration due to associated risk of pollution. Key words Heavy metal; Sediment pollution; Contamination factor; Pollution load index.

Assessment of mobility and environmental risks associated with copper, manganese and zinc in soils of a dumping site around a Ramsar site

This study reports the environmental fate and ecological hazard of the three heavy metals (HMs), viz. copper (Cu), manganese (Mn) and zinc (Zn) in soil influenced by municipal solid waste (MSW) dumping. The experimental site is situated in the vicinity of Deepor Beel, a Ramsar site located in Guwahati, India. This study assessed (i) the distribution pattern of Cu, Mn and Zn in six geochemical fractionations; (ii) the mobility, bioavailability and toxicity of Cu, Mn and Zn based on eight contamination and ecological indices, and (iii) the impact of Cu, Mn and Zn on soil quality. Altogether, 18 soil samples were collected and analysed from the study site using stratified random sampling. Pollution indices and multivariate statistics were applied on the data to identify the level and source of analysed HMs. Sequential extraction has revealed that the binding strength of Cu, Mn and Zn had a uniform trend. Mobility and potential bioavailability of studied HMs were in the order Mn > Cu > Zn. Analysed HMs were dominantly associated with non-bioavailable fractions. The observed low values of various contamination factors indicated the lesser contamination load posed by these metals. Conversely, their high enrichment factor and geo-accumulation index values indicated the sources of these metals were anthropogenic. Overall, the pollution and ecological indices registered lower contamination. Yet, it would be prudent to adopt efficient MSW management strategies for eliminating any future risk emanating out of this dumping site and posing threat to nearby Deepor Beel and its associated flora and fauna.

Trace elements in Labrador Tea (Rhododendron groenlandicum): How predominant sources to the plants impact the chemical composition of hot water extracts

Labrador Tea (Rhododendron groenlandicum) has been an important food and medicinal plant to First Nations communities in North America for millenia, but little is known of its geochemical properties. Using plants from 10 sites in 4 provinces, including pristine and industrial regions, and employing the metal-free, ultraclean SWAMP laboratory facilities and procedures, we provide an estimate of the natural abundance of trace elements in the leaves, and the extent of their release during hot water extraction. Elements decrease in abundance in the order Mn > Al > Fe > Zn > Cu > Ni > V > Pb > La > Mo > Y > La > Tl > Cd > Th > Ag. The greatest concentrations of conservative, lithophile elements such as Al, La, Th and Y, are found in samples collected on lands reclaimed from open pit bitumen mines in northern Alberta, reflecting elevated inputs of atmospheric dusts. In contrast, micronutrients such as Cu and Zn are remarkably uniform which suggests that these are supplied almost exclusively by plant uptake via roots. Deionized, reverse osmosis water is more effective in removing some elements (e.g. Al, La, Y, Fe, Zn, Cd) whereas others are more readily extracted using groundwater (e.g. Cu, Ni, Pb); V behaves independently of water composition. In both types of water, the elements most readily extracted are plant micronutrients (Mn, Ni, Cu, and Zn) whereas those supplied primarily by dust exhibit much lower yields; Al shows behaviour intermediate between these two extremes. While element concentrations in the infusions increase with increasing concentrations in the leaves, the abundance of potentially toxic chalcophile elements such as Cd, Pb, Sb and Tl in the infusions are extremely low (ng/l). Plants from British Columbia, Ontario and Quebec provide evidence of atmospheric Pb contamination, yielding greater ratios of Pb/La compared to the samples from Alberta where crustal values are found. Given that this plant is common and found across the northern half of the continent, it shows great promise as a tool for biomonitoring of air quality. For consumers, Labrador Tea may represent an important dietary source of Mn.

Group distance magic Cartesian product of two cycles

Let G=(V,E) be a graph and Γ an Abelian group both of order n. A Γ-distance magic labeling of G is a bijection ℓ:V→Γ for which there exists μ∈Γ such that ∑x∈N(v)ℓ(x)=μ for all v∈V, where N(v) is the neighborhood of v. Froncek showed that the Cartesian product Cm□Cn, m,n≥3 is a Zmn-distance magic graph if and only if mn is even. It is also known that if mn is even then Cm□Cn has Zα×A-magic labeling for any α≡0(modlcm(m,n)) and any Abelian group A of order mn∕α. However, the full characterization of group distance magic Cartesian product of two cycles is still unknown.In the paper we make progress towards the complete solution of this problem by proving some necessary conditions. We further prove that for n even the graph Cn□Cn has a Γ-distance magic labeling for any Abelian group Γ of order n2. Moreover we show that if m≠n, then there does not exist a (Z2)m+n-distance magic labeling of the Cartesian product C2m□C2n. We also give a necessary and sufficient condition for Cm□Cn with gcd(m,n)=1 to be Γ-distance magic.