Estimating the contribution of industrial facilities to annual PM10 concentrations at industrially influenced sites

If measures to reduce the industrial discharge of PM10 shall be planned with high accuracy, a first step must be to estimate the contribution of single industrial facilities to the overall PM10 burden as accurately as possible. In northern Duisburg as an example, an area where iron and steel producing industry is concentrated, PM10 was measured at 4 sampling sites very close to an industrial complex of blast furnaces, a sinter plant, oxygen steel works and a coke oven plant for 9 months in 2006. At two sites metals in PM10 were determined. The results, together with analytical data of urban background sites in the region and data of wind direction and wind speed were used for an estimation of the contribution of single plants to the PM10 burden. A careful analysis of the data showed, that the data of PM10, calcium, iron and zinc measured at two sites close to the industrial area and information about the urban background aerosol were sufficient to calculate the PM10 contribution of the main single plants. The data could be compared with those of modelling.     

Hydroxyiminodisuccinic acid (HIDS): A novel biodegradable chelating ligand for the increase of iron bioavailability and arsenic phytoextraction

The influence of biodegradable chelating ligands on arsenic and iron uptake by hydroponically grown rice seedlings (Oryza sativa L.) was investigated. Even though the growth solution contained sufficient Fe, the growth of rice seedlings gradually decreased up to 76% with the increase of pH of the solution from 7 to 11. Iron forms insoluble ferric hydroxide complexes at neutral or alkaline pH in oxic condition. Chelating ligands produce soluble ‘Fe–ligand complex’ which assist Fe uptake in plants. The biodegradable chelating ligand hydroxyiminodisuccinic acid (HIDS) was more efficient then those of ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS), and iminodisuccinic acid (IDS) in the increase of Fe uptake and growth of rice seedling. A total of 79 ± 20, 87 ± 6, 116 ± 15, and 63 ± 18 mg dry biomass of rice seedlings were produced with the addition of 0.5 mM of EDDS, EDTA, HIDS, and IDS in the nutrient solution, respectively. The Fe concentrations in rice tissues were 117 ± 15, 82 ± 8, 167 ± 25, and 118 ± 22 μmol g⁻¹ dry weights when 0.25 mM of EDDS, EDTA, HIDS, and IDS were added to the nutrient solution, respectively. Most of the Fe accumulated in rice tissues was stored in roots after the addition of chelating ligands in the solution. The results indicate that the HIDS would be a potential alternative to environmentally persistent EDTA for the increase of Fe uptake and plant growth. The HIDS also increased As uptake in rice root though its translocation from root to shoot was not augmented. This study reports HIDS for the first time as a promising chelating ligand for the enhancement of Fe bioavailability and As phytoextraction.     

The effects of biochars from rice residue on the formation of iron plaque and the accumulation of Cd, Zn, Pb, As in rice (Oryza sativa L.) seedlings

A historically multi-metal contaminated soil was amended with biochars produced from different parts of rice plants (straw, husk and bran) to investigate how biochar can influence the mobility of Cd, Zn, Pb and As in rice seedlings (Oryza sativa L.). Rice shoot concentrations of Cd, Zn and Pb decreased by up to 98%, 83% and 72%, respectively, due to biochar amendment, though that of As increased by up to 327%. Biochar amendments significantly decreased pore water concentrations (C_pw) of Cd and Zn and increased that of As. For Pb it depended on the amendment. Porewater pH, dissolved organic carbon, dissolved phosphorus, silicon in pore water and iron plaque formation on root surfaces all increased significantly after the amendments. The proportions of Cd and Pb in iron plaque increased by factors 1.8-5.7 and 1.4-2.8, respectively; no increase was observed for As and Zn. Straw-char application significantly and noticeably decreased the plant transfer coefficients of Cd and Pb. This study, the first to investigate changes in metal mobility and iron plaque formation in rice plants due to amending a historically contaminated soil with biochar, indicates that biochar has a potential to decrease Cd, Zn and Pb accumulations in rice shoot but increase that of As. The main cause is likely biochar decreasing the C_pw of Cd and Zn, increasing the C_pw of As, and increasing the iron plaque blocking capacity for Cd and Pb.     

Biomonitoring spatial and temporal impact of atmospheric dust from a cement industry

The objective of this work was to evaluate the spatial and temporal impact of dust-pollution in the vicinity of a cement industry, located in an area with dry climate. The spatial impact integrated over time was evaluated from the concentrations of Ca, Fe and Mg in in-situ Xanthoria parietina. The temporal pattern was assessed through one-month transplants of the lichen Ramalina canariensis. Four potential sources of atmospheric dust were evaluated: the limestone-quarry; the unpaved roads, the deposit area and the cement mill. Calcium concentration in lichens was considered the best cement-dust indicator. Different types of dust (clinker and grinded-limestone-dust) resulted in different time-patterns of Ca accumulation, which was also related with the different influence that wet and dry periods have in the lichen accumulation process. The dust pollution was found to be deposited locally and dependent on: the nature of dust particles and the volume and frequency of precipitation.     

Magnetic anomalies of forest soils in the Upper Silesia-Northern Moravia region

Previous investigations revealed a strong magnetic anomaly due to soil magnetic enhancement in the industrialized cross-border area of Upper Silesia (Poland) and Northern Moravia (Czech Republic). Since industrial and urban dusts contain magnetic particles, this soil magnetic enhancement is assumed to be of anthropogenic origin, caused by a high concentration of atmospherically deposited magnetic particles, accumulated in topsoil layers. This assumption is proved by investigations of vertical profiles of magnetic susceptibility along a transect crossing the border area of the two countries. The results show that the population of magnetic minerals in the organic horizon is different from that in the mineral horizons. The vertical distribution of magnetic susceptibility and thermomagnetic analysis suggests negligible lithogenic contribution. The observed relationship between magnetic susceptibility and some heavy metals, confirmed by micromorphological observations and microchemical analysis of magnetic particles separated from the organic horizons of forest topsoil, has proved the usefulness of soil magnetometry for pollution study.     

烟花爆竹用氧化剂的研究进展

在调查研究的基础上,分析、总结、研讨用于烟花爆竹的氧化剂的历史、现状及发展方向。分析和讨论氯酸盐类、高氯酸盐类、硝酸盐类以及金属氧化物等氧化剂的物化性质、燃爆性能及各自用于烟火剂的优缺点。研究指出:将不同类型的氧化剂复合使用,当选择的组分及搭配的比例合适时,不仅能使各种氧化剂充分发挥其优点,而且还将产生一些新的实际的性能。同时提出:复合氧化剂是配制燃放效果好、安全性能高、价格低廉的烟花爆竹氧化剂的发展方向。     

A sulfur removal and disposal process through H2S adsorption and regeneration: Ammonia leaching regeneration

An iron oxide solid sponge H₂S adsorbent works by reacting H₂S and turning ferric oxide into ferric sulfide. The ferric sulfide will be converted back into ferric oxide and elemental sulfur when contacting oxygen or air. This study investigates the leaching of elemental sulfur from the solid sponge using anhydrous liquid ammonia as solvent. The leaching treatment expectedly results in effective regeneration of the adsorbent, which is able to lead to a sulfur removal and recovery process suitable for handling the small and mid-sized sulfur production cases, i.e., those less than 10 ton/day sulfur. The leaching does not significantly impair the physical properties, including the adsorbent pellet strength. The adsorption–regeneration (or leaching) cycle could be repeated at least three times. The cumulative sulfur loading can achieve as high as 50% (w/w), three times greater than that in the one-time use. The wash-off in leaching and the spent adsorbent can be made into slurry that is to be injected into underground formations such as depleted oil wells. It is anticipated that this underground injection is safer and more efficient than acid gas injection.     

Quantifying the importance of diffuse minewater pollution in a historically heavily coal mined catchment

There has been considerable progress in developing treatment systems for point sources of minewater pollution in recent years; however, there remains a knowledge gap in the characterisation and remediation of diffuse minewater sources. Data are presented from the River Gaunless catchment, a historically heavily coal mined catchment in the northeast of England. Instream iron (Fe) loadings were monitored alongside loadings arising from point minewater discharges over a 12-month period to assess the dynamic importance of diffuse sources of minewater pollution. In low flow, diffuse sources account for around 50% of instream loading, a proportion which increases to 98% in high flow conditions. The low flow sources appear to be dominated by direct discharge of contaminated groundwater to surface waters in lower reaches of the catchment. In high flow, resuspended Fe-rich sediments, which are both naturally occurring and derived from historic mining, become the dominant diffuse source of Fe in the water column.     

Group size and relative competitive ability: geometric progressions as a conceptual tool

Contrary to the assumptions of many previous theoretical models, group size has recently been shown in experiments to have an effect on the relative (as well as absolute) competitive abilities of group members. Here we introduce a novel and effective mathematical tool for describing how relative competitive ability will change for any two specified individuals within a group as group size changes. We show that there is no simple general rule for describing how relative competitive ability will change with group size. A subsequent empirical test of the model helps to illustrate that very specific knowledge of the system under study is needed in order to produce robust predictions. Received: 23 December 1998 / Received in revised form: 26 July 1999 / Accepted: 2 October 1999     

Arsenic in groundwater and sediment in the Mekong River delta, Vietnam

A study of groundwater and sediment during 2007-2008 in the Mekong River delta in Vietnam (MDVN) revealed that 26%, 74%, and 50% of groundwater samples were above the US EPA drinking water guidelines for As (10 μg/L), Mn (0.05 mg/L), and Fe (0.3 mg/L). The range of As, Fe, and Mn concentrations in the MDVN were <0.1-1351 μg/L, <0.01-38 mg/L, and <0.01−14 mg/L, respectively. Elevated levels of As were found in groundwater at sampling sites close to the Mekong River and in wells less than 60−70 m deep. An inverse relationship was found between As and Mn concentrations in groundwater. Sediment samples from An Giang and Dong Thap had the highest As concentrations (18 mg/kg and 38 mg/kg, respectively). Arsenic sediment occurred mainly in the poorly crystalline Fe oxide phases. Reductive dissolution of the Fe oxide phase is not necessarily the dominant mechanism of As release to groundwater.