Mn Pollution Research Articles

Evolution of metal pollution in groundwater of Pleistocene aquifers in Ho Chi Minh City in the period 2000 - 2016

Underground water pollution, especially groundwater of the Pleistocene layers has been recognized by many researchers. These records are often based on the results of water quality monitoring of different monitoring networks: the National Monitoring Network, the monitoring network of the Natural Resources and Environment Department of Ho Chi Minh city, the monitoring network of the Saigon Water Supply Company. The records show that in the underground water of the Pleistocene layers appeared metals such as copper, lead (Pb), zinc, arsenic, cadmium, manganese (Mn), aluminum (Al), nickel, mercury... However, the content of many metals has not reached the limit of pollution. In this study, the authors used the monitoring results of the National Monitoring Network for the period 2000 - 2016 and focused on metals such as Al, Mn and Pb in the water of Pleistocene aquifers - It has already exceeded the allowable standards at some monitoring sites. The results show that the content of Mn and Al metals in the Pleistocene aquifers varies significantly between 2009 and 2013, while for Pb - a sharp increase from 2013 to 1016. Causes leading to the development of Al and Mn pollution, mainly due to geological, hydro-geological conditions and impacts caused by heavy groundwater exploitation in the Pleistocene aquifers.

Soil propagule bank of ectomycorrhizal fungi associated with Masson pine (Pinus massoniana) grown in a manganese mine wasteland.

Ectomycorrhizal (ECM) fungal propagule bank could facilitate the regeneration and plantation of seedlings in disturbed area. In this study, Masson pine (Pinus massoniana) seedlings were used to bait the ECM fungal propagule bank buried in the soils collected from a manganese (Mn) mine wasteland and a non-polluted area in China. After 6-month growth, we found the seedlings grown in the Mn mine soil (Mn:3200 mg kg-1) did not display any toxicity symptoms. Based on morphotyping and ITS-PCR sequencing, we identified a total of 16 ECM fungal OTUs (operative taxonomic units) at 97% similarity threshold, among which 11 OTUs were recovered in the Mn mine soils and 14 in the non-polluted soil. Two soil types shared 9 OTUs and both of them were dominated by a Tylospora sp. Based on those soil propagule banks in Masson pine forests reported in previous, we speculated that some Atheliaceae species may be preferred in the soil propagule bank of some pine species, such as Masson pine. In addition, NMDS ordination displayed geographical position effects on soil propagule banks in five Masson pine forest from three sites at regional scale. In conclusion, Masson pine ECM seedlings could grow well in the Mn wasteland as a suitable tree species used for reforestation application in Mn mineland, in addition, Mn pollution did not alter the dominant ECM fungal species in the soil propagule banks.

Metal Accumulation Strategies of Emergent Plants in Natural Wetland Ecosystems Contaminated with Coke-Oven Effluent.

The release of industrial effluents into natural wetlands is a ubiquitous problem worldwide, and phytoremediation could be a viable option for treatment. The present study assessed metal accumulation strategies of three dominant emergent plants [Colocasia esculenta (L.) Schott, Scirpus grossus (L.) f., and Typha latifolia L.] growing in a wetland contaminated with coke-oven effluent. Metals concentration (mgkg-1) in wetland sediment followed the order Mn (408) > Cu (97) > Co (14.2) > Cr (14) > Cd (2.7). Plant tissues (root and shoot) showed metal-specific accumulation at different extents due to plant response against metal utility or toxicity. Bioconcentration factor(BCF) and translocation factor (TF) of metals in plants revealed Cd and Mn pollution could beremediated through phytoextraction (BCF > 1 and TF > 1); however, Co, Cu, and Cr pollution could beremediated through phytostabilization (BCF > 1 and TF < 1).

The migration and transformation regular study of metal manganese in surface soil of Yiwang Industrial Park in Shanxi Province, China

ABSTRACTAll kinds of industries can produce a large amount of the heavy metal Mn emission, especially in the Mn steel plant production process. The assessment of Mn pollution in industrial areas is vital to human health and soil conservation. First, there are 120 samples of 0–5 cm and samples 9 of 0–40 cm of the surface soil collected from outside. Next, the soil column test is applied to study the migration and speciation regularity of Mn in 0–40 cm of soil layer, and then a forecasting model is established to verify and evaluate the Mn pollution in the study area. After the exogenous Mn enters the soil, Mn soon transforms into a more stable form in soil at 0–20 cm depth. But the residual amounts of Mn in deep soil increases with the increase of exogenous Mn. The main speciation of Mn in surface soil includes residual, oxide-bound, and organic-bound forms. Carbonate-bound form is sensitive to the increase of exogenous Mn. The exogenous Mn content has less influence on the content of oxide-bound and organic-bound forms in soils below 20 cm. The prediction model can be used to evaluate the degree of pollution of Mn in surface soil of the study area.

贵州省松桃县锰矿区洞穴动物群落结构与环境因子的关系

PDF HTML阅读 XML下载 导出引用 引用提醒 贵州省松桃县锰矿区洞穴动物群落结构与环境因子的关系 DOI: 10.5846/stxb201709031589 作者: 作者单位: 贵州师范大学,贵州师范大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（30560024）；贵州省科技基金（黔科合LH字LKS[2016]7207号，黔科合支撑[2017]2811号，黔科合重大专项字[2016]3022号） Study on the relationship between animal community structure and cave environment factors in the Da and Xia caves of the Songtao manganese mine, Guizhou Author: Affiliation: Guizhou Normal University,Guizhou Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:主要选取松桃锰矿区周边大洞、下洞为对象，研究洞穴环境因子与洞穴动物群落的关系，探索两洞穴环境中是否存在重金属Mn污染，对比分析两洞穴动物群落结构，探讨不同重金属、环境因子与两洞穴动物群落之间的相关性是否一致。通过采集，共获标本1274号，其中大洞660号，隶属于5门10纲21目24科26种，下洞614号，隶属于4门7纲15目21科26种。群落多样性分析结果显示，多样性指数由高到底的顺序为群落D（2.4745） > C（1.4036） > A（1.3549） > B（1.1935） > E（1.1384） > F（0.7265）。分析大洞、下洞洞穴群落多样性与环境因子Pearson相关系数矩阵得出，大洞土壤中As、Mn与物种数均呈显著正相关，P值分别为0.039、0.029，下洞水体中重金属As与物种优势度呈显著正相关（0.021），重金属Mn与多样性指数呈显著负相关（0.044），温度是影响下洞洞穴群落数量、分布的主要原因。重金属污染评价显示，两洞穴水质污染小，土壤中的重金属除Hg达到极严重污染外，其余重金属均未超过中度污染等级。 Abstract:We investigated the Da and Xia caves in a manganese mine at Songtao County to evaluate the relationship between animal community and cave habitat factors. The heavy metal, manganese (Mn), was tested to verify Mn pollution in the two caves. The animal community structures and their relationships with the cave habitat factors were analyzed and compared between the two caves. A total of 1274 specimens were collected, 660 (5 phyla, 10 classes, 21 orders, and 26 species) from the Da cave and 614 (4 phyla, 7 classes, 15 orders, and 26 species) from the Xia cave. Six communities were grouped (A-F), and their diversity indices were ranked 2.4745 (D), 1.4036 (C), 1.3549 (A), 1.1935 (B), 1.1384 (E), and 0.7265 (F). The results of Pearson correlation revealed that the content of arsenic (As) and Mn in soil correlated positively with species richness in the Da cave. Furthermore, As content was positively correlated with species dominance, and Mn content was negatively correlated with the species diversity index. Temperature was found to be the major factor for animal abundance and distribution. The results indicate that no heavy metal exceeded the moderate pollution level in the water of the two caves, except Hg, which reached high pollution levels. 参考文献 相似文献 引证文献

Adsorption properties of kaolinite-based nanocomposites for Fe and Mn pollutants from aqueous solutions and raw ground water: kinetics and equilibrium studies.

Raw kaolinite was used in the synthesis of metakaolinite/carbon nanotubes (K/CNTs) and kaolinite/starch (K/starch) nanocomposites. Raw kaolinite and the synthetic composites were characterized using XRD, SEM, and TEM techniques. The synthetic composites were used as adsorbents for Fe and Mn ions from aqueous solutions and natural underground water. The adsorption by the both composites is highly pH dependent and achieves high efficiency within the neutral pH range. The experimental adsorption data for the uptake of Fe and Mn ions by K/CNTs were found to be well represented by the pseudo-second-order kinetic model rather than the intra-particle diffusion model or Elovich model. For the adsorption using K/starch, the uptake results of Fe ions was well fitted by the second-order model, whereas the uptake of Mn ions fitted well to the Elovich model rather than pseudo-second-order and intra-particle diffusion models The equilibrium studies revealed the excellent fitting of the removal of Fe and Mn ions by K/CNTs and Fe using K/starch with the Langmuir isotherm model rather than with Freundlich and Temkin models. But the adsorption of Mn ions by K/starch is well fitted with Freundlich rather than Temkin and Langmuir isotherm models. The thermodynamic studies reflected the endothermic nature and the exothermic nature for the adsorption by K/CNTs and K/starch nanocomposites, respectively. Natural ground water contaminated by 0.4mg/L Fe and 0.5mg/L Mn was treated at the optimum conditions of pH6 and 120min contact time. Under these conditions, 92.5 and 72.5% Fe removal efficiencies were achieved using 20mg of K/CNTs and K/starch nanocomposites, respectively. Also, K/CNTs nanocomposite shows higher efficiency in the removal of Mn ions as compared to K/starch nanocomposite.

Manganese adsorption by iron impregnated pumice composite

Manganese (Mn) is often present at high concentrations in ground and surface waters. Industrial discharges are also a major source of Mn pollution in the environment. Adsorption is a widely studied technique to abate Mn levels that various low cost adsorbents have attempted to for this purpose. Pumice is known to be effective adsorbent for removal of organics and heavy metals. Scientific efforts of modifying its surface were applied too, however, iron impregnated Pumice has not been applied to remove Mn yet. In this study the effect of initial Mn concentration and dose of adsorbents on adsorption efficiency of Mn were investigated. A detailed kinetic evaluation is given applyi,ng four isotherm models. Release of iron was monitored to evaluate the stability of new composite. The results of this study showed that Fe impregnated Pumice composite was more effective to remove Mn than Pumice adsorbent. Langmiur and Temkin Istorherms fitted adsorption data obtained in this study at higher correlation coefficients than other models. Relased Fe concentration was found to be much below than the limits of industrial discharges as well as than WHO guideline value for drinking water. These preliminary results indicate that Fe-Pumice composite is a promising and economical adsorbent and further studies are ongoing to enhance its stability and economical aspect by decreasing the dose of the composite to be used.

Manganese and Mn/Ca ratios in soil and vegetation in forests across the northeastern US: Insights on spatial Mn enrichment

Manganese (Mn) cycling in the Critical Zone is important because of its role as an essential nutrient and potential toxicity to plants and organisms. Quantifying Mn enrichment in terrestrial environments has been limited since Mn is monoisotopic. However, elemental ratios of Mn/Ca ratios may be used to determine spatial Mn enrichment and in aboveground and belowground pools. The objectives of this study were to quantify the spatial variation in Mn concentrations and Mn/Ca ratios in foliage, bolewood, forest floor, and mineral soil horizons across the northeastern United States and compare Mn/Ca ratios to estimate enrichment. Forest floor and mineral soil samples were collected from 26 study sites across the northeastern United States and analyzed by strong acid digestion. Foliage and bolewood was collected from 12 of the 26 sites and analyzed for total Mn and Ca. Our results show forest floor and mineral soil horizon Mn concentrations and Mn/Ca ratios were higher at Pennsylvania and New York sites than New Hampshire and Vermont sites. Using a modified isotope equation, enrichment factors (EF) for Mn/Ca ratios were calculated to be ~3.6 in the forest floor, upper and lower mineral soil horizons at sites in New York and Pennsylvania compared to reference sites in New Hampshire and Vermont. Foliar and bolewood Mn concentrations also decreased from Pennsylvania towards New Hampshire. Moreover, foliar and bolewood Mn concentrations were strongly correlated to forest floor, upper, and lower mineral soil Mn concentrations. It was hypothesized that internal cycling (uptake, throughfall, and litterfall) of Mn controls retention of enriched Mn in forests. Geologic influences from a lithologic gradient and soil pH gradient could also influence Mn enrichment in addition to Mn pollution. Ratios of Mn/Ca and other elemental ratios hold promise as geochemical tracers but require further development.

Biochemical Responses of Ten Ectomycorrhizal Fungal Isolates to Manganese

Manganese (Mn) is one of the heavy metals that pollute the environment. However, there are still few studies concerning Mn pollution. Our study focused on the ectomycorrhizal fungi (EMF), an important organism in the forest. We selected ten isolates of EMF, including Pt.2 (Pi solithus tinctorius 2), Cg.1 (Cenococcum geophilum 1), Br (Boletus reticulatus), Sb (Suillus bovinus), Pt.chdx (P. tinctorius chdx), Pt.104 (P. tinctorius 104), Sg (Suillus granulatus), Av (Amanita virgineoides), Sl.1 (Suillus luteus 1), and Sl.chdx (S. luteus chdx), to investigate their responses to Mn stress (0 to 3000 mg L−1) on liquid MMN medium. EMF isolates showed different responses to Mn stress after 60 days growth. According to their growth, they were classified into three groups: sensitive, moderately sensitive, and tolerant. Three isolates showed tolerance to Mn stress. The mycelia of the four sensitive EMF isolates grew slowly along with the increasing Mn level, and the growth was significantly inhibited in 3000 mg L−1 Mn. The accumulation of Mn in EMF mycelium was increased and the secretion of oxalic acid was stimulated by the increasing Mn concentration for all isolates. However, the sensitive isolates secreted significantly more oxalic acid than the tolerant isolates. A scanning electron microscope showed that hyphae were distorted and severely swollen and a transmission electron microscope revealed that Mn enriched in the cytoplasm and organelles of hyphae cells when EMF grew under 3000 mg L−1 Mn stress. In addition, we found that antioxidative enzyme activities, glutathione S-transferase (GST), and superoxide dismutase (SOD) were higher under the stress of Mn. In conclusion, we identified three isolates (Pt.2, Pt.104, and Br) that showed high Mn tolerance. This might demonstrate the great potential of those EMF in the reforestation of Mn mine lands.

Carbofuran Degradation by Biogenic Manganese Oxides.

This work studied the effect of biogenic manganese oxides (Bio-MnOx) on carbofuran degradation.The results showed that 21.05 % and 90.63 % carbofuran, respectively, were degraded in 4 days by Bio-MnOx with and without NaN3 at initial pH 4.80, whereas carbofuran was hardly degraded by chemical manganese oxides in the same condition. Bio-MnOx promoted carbofuran hydrolysis by changing the pH of the environment and encouraged carbofuran phenol cleavage by its oxidization. Both the oxidation of carbofuran phenol by Bio-MnOx and the reoxidation of the released Mn(II) by Mn(II)-oxidizing microorganisms ensured the continuous reactivity of Bio-MnOx and prevented the secondary pollution of Mn(II). Carbofuran phenol was the major transformation product in the degradation and was further oxidized into small organic molecules as monitored by a GC/MS analyzer. This report offers an efficient, feasible, and no-secondary-pollution approach to controlling carbofuran pollution.

Heavy metal distribution and water quality characterization of water bodies in Louisiana's Lake Pontchartrain Basin, USA.

The seasonal variation in physico-chemical properties, anions, and the heavy metal (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) concentration was evaluated in water from nine different rivers in Lake Pontchartrain Basin, Louisiana, USA. The water quality parameters were compared with toxicity reference values (TRV), US Environmental Protection Agency (USEPA) drinking/aquatic life protection, and WHO standards. Among physico-chemical properties, pH, DO, and turbidity were high during spring, while, EC, temperature, and DOC were high during summer and vice versa. The anion study revealed that the concentrations of F-, Cl-, and NO3- were higher during summer and Br- and SO4- were higher during spring. Our research findings showed anion concentration decreased in the order of Cl->SO4->NO3->Br->F-, in accordance with the global mean anion concentration. The dissolved heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb) except Zn were higher during spring than summer. None of the rivers showed any Cd pollution for both seasons. Co showed higher concentrations in Amite River, Mississippi River, Industrial Canal, and Lacombe Bayou during summer. The Cr concentration was higher than WHO drinking water standards, implicating water unsuitability for drinking purposes in all the rivers associated with the Lake Pontchartrain Basin. Cu showed no pollution risk for the study area. Mn and Co were similar to concentration in Lacombe Bayou, Liberty Bayou, Blind River, and Industrial Canal. Mn levels were greater than WHO standards for the Tickfaw River, Tangipahoa River, and Blind River in both seasons. Blind River, Tangipahoa River, Tickfaw River, and Amite River will require more monitoring for determining possible Mn pollution. Ni content in river water during both seasons showed low pollution risk. Liberty Bayou and Industrial Canal concentrations were closer to the WHO regulatory standards, indicating possible risk of Pb pollution in these water bodies. The Zn content was near the USEPA aquatic life standards in summer for all water bodies. None of the rivers showed any risk associated with Cd, Co, Cu, and Ni levels but medium to higher risk to aquatic life from Cr and Zn for both seasons for most of the rivers. Metal fractionation revealed the decreasing order of inert>labile>organic. The high inert fraction in the rivers under study reflects the major contribution of natural sources in Lake Pontchartrain Basin. The labile and organic forms of Cd, Cu, Ni, and Zn pose potential higher risk to the aquatic life in the Lake Pontchartrain Basin.

QUALITY ASSESSMENT OF TWO WATER RESOURCES IN MUNICIPALITY OF KAMENICA (KOSOVO)

In this study the assessment of water quality of two water resources (depth 10-50 meters) in the municipality of Kamenica have been investigated. Concentrations of some ions are determined using UV-VIS spectrometry. Statistical studies have been carried out by calculating of basic statistical parameters and anomalies (extremes and outliers). By comparing with available results of three similar water -samples in Kosovo, it can be summarized that water quality of two water-samples in the municipality of Kamenica is similar to the well waters of Mirosala. From the results of field work and laboratory analyses it was found out that the well water does not fulfil the criteria set by the WHO. The high value of Fe, Mn and turbidity pollutants indicated pollution by natural pollutants and from anthropogenic sources like waste waters.

Preliminary Results on Growing Second Generation Biofuel Crop Miscanthus X Giganteus at The Polluted Military Site in Ukraine

Abstract The semi-field research on using second-generation biofuel crop Miscanthus x giganteus for restoration of former military site in Kamenetz-Podilsky, Ukraine was carried out during two vegetation seasons. Despite high metal pollution of soil, in particular, by Fe, Mn, Ti, and Zr, no growth inhibition was observed. The concentrations followed pattern soil &gt; roots &gt; stems &gt; leaves. Accumulation of particular metals in roots was different: Fe, Mn and Ti were accumulated rather palpably after the first vegetation season and less tangible after the second one. Cu, Pb and Zn were less accumulative in both vegetation seasons, and for As and Pb the accumulative concentrations were very small. Accumulations in the aboveground parts of the plant in comparison to roots were significantly lower in case of Fe, Ti, Mn, Cu, Zn, Sr and even statistically comparable to zero in case of As, Pb and Zr. Calculated translocation ratio of metals in the plant’s parts preferably indicated lack of metals’ hyper accumulation. Generally, no correlations were observed between concentrations of metals in the soil and in the upper plant’s parts. The research confirmed the ability of Miscanthus x giganteus to grow on the military soils predominantly contaminated by metals.

Assessment of metallic pollution status of surface water and aquatic macrophytes of earthen dams in Ilorin, north-central of Nigeria as indicators of environmental health

The functional quality of an aquatic ecosystem is a reflection of the health of the environment. Therefore, the present study evaluates the trace metal contamination (Pb, Cd, Ni and Mn) of water and aquatic macrophytes in Asa, Agba, Unilorin and Sobi (Moro) earthen dams, north-central Nigeria to evaluate the level of anthropogenic impact on the immediate environment. The concentrations of trace metals in samples of water and available macrophytes from the earthen dams were determined by Atomic Absorption Spectrophotometry. Trace metal contamination of surface water in the earthen dams was assessed using metal index (MPI) and metal pollution index (HPI). The biological accumulation factor of trace metals in the aquatic macrophytes was extrapolated from trace metal concentrations in the water and macrophyte samples. The results of the MPI revealed gross metal contamination of the surface water by Pb and Cd (>6.0 for both metals) in the four earthen dams; while Agba and Sobi dams were slightly contaminated by Ni (MPIs=1.43 and 1.14 respectively). All the earthen dams were considered safe from Mn contamination (MPI<1.0). Considering the HPI, the four earthen dams fall within the critical pollution threshold for trace metals (HPI>100), but Asa dam (HPI=2682.4) was the most contaminated. The biological accumulation factor of Mn in the macrophytes indicated Ceratophyllum demersum, Pycreus lanceolatus and Pistia stratiotes as moderate accumulators of Mn, and can be used as bioindicators in monitoring Mn pollution of aquatic ecosystem. The obtained results in this study showed that the earthen dams are polluted by Pb, Cd and Ni which pose human health risks to the inhabitants through drinking water.

Analysis of the Metals in Soil-Water Interface in a Manganese Mine.

In order to reveal the influence of the metals of soil-water interface in a manganese mine (Xiangtan, China), on local water environment, there are six kinds of metals (Mn, Ni, Cu, Zn, Cd, and Pb) characterized by measuring their concentration, correlation, source, and special distribution using principal component analysis, single factor, and Nemero comprehensive pollution index. The results showed that the corresponding average concentration was 0.3358, 0.045, 0.0105, 0.0148, 0.0067, and 0.0389 mg/L. The logarithmic concentration of Mn, Zn, and Pb was normal distribution. The correlation coefficients (between Mn and Pb, Mn and Zn, Mn and Ni, Cu and Zn, Cu and Pb, and Zn and Cd) were found to range from 0.5 to 0.6, and those between Cu and Ni and Cu and Cd were below 0.3. It was found that Zn and Mn pollution were caused primarily by ore mining, mineral waste transportation, tailing slag, and smelting plants, while Cu and Ni mainly originate from the mining industry activities and the traffic transportation in the mining area. In addition, the Cd was considered to be produced primarily from the agricultural or anthropogenic activities. The pollution indexes indicated that metal pollution degree was different in soil-water interface streams as listed in increasing order of pollution level as Zn > Ni > Cu > Pb > Mn > Cd. For all of the pollution of the soil-water interface streams, there was moderate metal pollution but along the eastern mine area the pollution seemed to get more serious. There was only a small amount of soil-water interface streams not contaminated by the metals.

Heavy Metals (Fe, Zn, Mn, Cr, As) Speciation Analysis and Ecological Risk Assessment in the Surface Sediments of WuHe Wetland

This study assessed the ecological risk associated with heavy metals in surface sediments in a specific setting: the Wuhan wetland. Metals were extracted and characterized using the Tessier method, and the morphological distribution characteristics and correlation of Zn, Mn, Fe, Cr, and As were analyzed. The results indicated that heavy metals at the study site mainly exist in residual state forms; the Mn pollution was serious; the potential risk from Cr and As was larger; and the environmental risk from Fe and Zn was lower. In order of potential ecological harm: As &gt; Zn &gt; Cr &gt; Mn. The overall risk of ecological harm was slight, but the individual region has seen moderate ecological damage because of As pollution. Because this element has a significant toxicity level, it is important to remain attentive to the pollution caused by it.

Pollution and health risk of potentially toxic metals in urban road dust in Nanjing, a mega-city of China

Spatial variations in concentrations of a suite of potentially toxic metals (Ba, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and Ca in road dusts (n=99) from urban trunk roads (TR) in Nanjing, a mega-city in China, were established. Metal pollution levels, sources and human health risk (non-carcinogenic) were studied. In contrast to previous studies, we labeled the indicative metals relating to non-exhaust traffic emissions by comparing metal pollution between crossroad and park road dusts, and then anthropogenic sources of metals in TR dusts were assessed combining their spatial pollution patterns, principal component analysis and Pb isotopic compositions. Results showed that the metals were enriched in TR dusts compared to background soil concentrations with mean enrichment factors (EFs) of 2.2–23, indicating considerable anthropogenic influence. The degrees of metal pollution ranged from minimal to extremely high and ranked by Ca>Cu>Pb≈Zn>Cr≈Fe>Ni≈Ba>Mn on average. Pollution of Cr, Cu, Fe, Mn, Ni, Pb and Zn in TR dusts resulted primarily from industrial emissions (e.g., coal combustion and smelting) and high pollution levels were found close to suburb industrial complexes, whereas pollution of Ba and Ca was mainly related to construction/demolition sources and was generally distributed homogeneously. The relatively minor contribution of non-exhaust traffic emissions to metal pollution in TR dusts was considered to be due to overwhelming industrial and construction/demolition contributions, as well as to the dilution effect of natural soil particles. Ingestion appears to be the major route of exposure for road dust for both adults and children, followed by dermal contact. The non-carcinogenic health risk resulting from exposure to the potentially toxic metals in TR dusts was within the safe level based on the Hazard Index (HI), except in pollution hotspots where exposure to Pb, Cr, and Cu may be hazardous to children.

Assessment of metals pollution and health risk in dust from nursery schools in Xi’an, China

Concentrations, pollution and health risks of metals in dust from nursery schools in Xi’an, China were determined. In comparison with local soil, dust samples have elevated metals concentrations except for Mn. The results indicate no distinct pollution of Mn, Ni, As and Ba in the dust, while Cu, Co and Zn are moderate pollution, Pb is significant pollution, and Cr with large pollution range. Most samples presented moderately polluted by metals. The non-cancer risks of the studied metals are within the safe range, and the cancer risks of As, Co, Cr and Ni are also within the currently acceptable range.

Demonstration Project of Wetlands Restoration and Pollution Control - A Case Study in Xiangtan Manganese Mine, China

Demonstration project attempted to restore the terrestrial habitats around wetlands and reduce the manganese (Mn) pollution of wetlands. Project had tested five kinds of trees for phytoremediation in terrestrial habitats, and designed Ecological interception system (EIS) to control the Mn pollution to wetlands. EIS was composed of the surface runoff collection system (SRCS) and the Treatment system (TS). SRCS composed of cobblestones, high-capacity adsorbent fillers, sands and plants. TS composed of three subsurface wetland units processing modules. The results show that: (1)New soil and base fertilizer applied in the plant pits can effectively improve plants survival rate; (2)Koelreuteria paniculata, Elaeocarpus sylvestris and Paulownia can be used for phytoremediation in terrestrial habitats; (3)Canna warszewiczii, Boehmeria, Thalia dealbata and other nine kinds plants in the EIS can absorb the Mn element effectively; (4)EIS can purify the water effectively. The complex project was based on the biological principles, ecological principles and biochemical effects which provides a reasonable ecological engineering model suitable for the restoration of polluted wetlands.

Decreasing concentrations of metals in Sphagnum mosses in ombrotrophic mires of the Sudety mountains (SW Poland) since late 1980s

In this investigation we focus on the evaluation of changes in metal pollution between 1986 until 2011 by Sphagnum species as bioindicators in 100km part of the Sudety mountains influenced by the former Black Triangle Region. Concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in various Sphagnum species all from ombrotrophic bogs in the Sudety mountains (SW Poland). The tested hypothesis was that overall improvements in pollution control in the former Black Triangle Region between 1986 until recent reduced the amount of metals deposited and accumulated by these plants. Concentrations of Cd, Cr, Cu, Fe, Pb and Zn in Sphagnum species were very high in 1986 indicating a heavy pollution of the examined bogs in this period, and significantly higher than in samples collected in 2011. The PCCA ordination showed the similar pattern in all bogs. In 2011 concentration of the Co was significantly higher in hollow species and concentration of Mn was significantly higher in those from hummocks. Differences between hollow/hummock sites were more important than species-specific abilities of Sphagnum mosses to accumulate metals. Species from hollows were better bioindicators of Co and those from hummocks were better bioindicators of Mn pollution.