Thermal monitoring and analysis of the large-scale field earth-dam breach process

Thermal imaging is a nondestructive testing method for monitoring internal material changes that are indicated by changes in an object’s surface temperature. In this study, field observation using thermographs was applied to monitor and analyze the breach process of large-scale earth dams. The earth dam test site was Landao Creek in Nantou County, Taiwan. Four field tests were performed to monitor and analyze a single earth dam and two successive earth dams. Ponding first occurred at the lowland of the riverbed upstream, and base seepage occurred at the base of the dam downstream; overtopping failure soon followed. Earth-dam failure mode is affected by the topographic characteristics of the riverbed; specifically, lowland areas are prone to ponding upstream, which causes piping and seepage downstream as well as subsequent breaches. Ponding and piping cause water seepage and soil wetting, which are reflected in lower surface temperatures recorded on thermographs. Thermographs can monitor changes in surface temperature to evaluate the potential failure modes of dams. Dam surfaces with large temperature variations may be potential failure areas. If confirmed, this fact may prove useful for failure-mode prediction. This paper proposes a monitoring index to reflect the temperature changes in a given period, and this study verified it empirically.     

Background levels of some major,trace, and rare earth elements in indigenous plant species growing in Norway and the influence of soil acidification,soil parent material,and seasonal variation on these levels

Baseline levels of 43 elements, including major, trace, and rare earth elements (REEs) in several native plant species growing in boreal and alpine areas, are presented. Focus is placed on species metal levels at different soil conditions, temporal variations in plant tissue metal concentrations, and interspecies variation in metal concentrations. Vegetation samples were collected at Sogndal, a pristine site in western Norway, and at Risdalsheia, an acidified site in southernmost Norway. Metal concentrations in the different species sampled in western Norway are compared with relevant literature data from Norway, Finland, and northwest Russia, assumed to represent natural conditions. Except for aluminium (Al) and macronutrients, the levels of metals were generally lower in western Norway than in southern Norway and may be considered close to natural background levels. In southern Norway, the levels of cadmium (Cd) and lead (Pb) in particular appear to be affected by air pollution, either by direct atmospheric supply or through soil acidification. Levels of some elements show considerable variability between as well as within plant species. Calcium (Ca), magnesium (Mg), and potassium (K) are higher in most species at Sogndal compared to Risdalsheia, despite increased extractable concentrations in surface soil in the south, probably attributed to different buffer mechanisms in surface soil. Antagonism on plant uptake is suggested between Ca, Mg, and K on one hand and Al on the other. Tolerance among calcifuges to acid conditions and a particular ability to detoxify or avoid uptake of Al ions are noticeable for Vaccinium vitis-idaea.     

长江流域全氟化合物污染态势与生态效应

简述了PFASs在长江流域上、中、下游水环境中的空间分布格局和时间变化趋势，探讨了其生物蓄积效应、淡水生物毒性效应和生态风险评价。指出，PFASs广泛赋存于长江流域从上游至下游的干流和支流及湖泊之中，其平均值低于我国其他主要流域；PFOA在长江流域内环境浓度最高，而PFOS在近10年环境管控措施下浓度降至极低，PFBS、PFBA和PFHxA等短链物质正作为替代物使用，可能在未来出现升高趋势。长江流域内水生动物（包括食用鱼类）能够从环境中富集PFASs并通过食物链传输，在其血液、肌肉和内脏中蓄积。虽然目前长江流域生态风险评价表明PFASs总体上风险为低级，但局部高浓度地区仍可能对敏感生物造成基因表达受损等毒性效应。     

Aluminium concentrations in Swedish forest streams and co-variations with catchment characteristics

The negative effects of elevated concentrations of inorganic aluminium on aquatic organisms are well documented. Acid deposition is often cited as a main driver behind the mobilisation and speciation of aluminium in soils and surface waters. In the study, we tested the hypothesis that sulphur deposition is the main driver for elevated concentrations of inorganic aluminium in 114 base poor, boreal Swedish streams. However, the deposition of anthropogenic sulphate has decreased substantially since it peaked in the 1970s, and at the current deposition levels, we hypothesise that local site parameters play an important role in determining vulnerability to elevated concentrations of inorganic aluminium in boreal stream waters. Presented here are the results of a principal components analysis of stream water chemistry, acid deposition data and local site variables, including forest composition and stem volume. It is shown that the concentrations of both organic and inorganic aluminium are not explained by either historical or current acid deposition, but are instead explained by a combination of local site characteristics. Sites with elevated concentrations of inorganic aluminium were characterised by small catchments (<500 ha) dominated by mature stands of Norway spruce with high stem volume. Using data from the Swedish National Forest Inventory the area of productive forest land in Sweden with a higher vulnerability for elevated inorganic aluminium concentrations in forests streams is approximately 1.5 million hectares or 7% of the total productive forest area; this is higher in the south of Sweden (10%) and lower in the north (2%). A better understanding of the effects of natural processes and forest management in controlling aquatic inorganic aluminium concentrations is therefore important in future discussions about measures against surface water acidification.     

Exposure and inhalation risk assessment in an aluminium cast-house

To date the exposure, absorption and respiratory health effects of cast-house workers have not been described since most studies performed in the aluminium industry are focused on exposure and health effects of potroom personnel. In the present study, we assessed the external exposure and the absorbed dose of metals in personnel from the aluminium cast house. This was combined with an evaluation of respiratory complaints and the lung function of the personnel. 30 workers from an aluminium casting plant participated and 17 individuals of the packaging and distribution departments were selected as controls. The exposure was assessed by the quantification of total inhalable fume with metal fraction and by the determination of urinary aluminium, chromium, beryllium, manganese and lead concentration. Carbon monoxide (CO), carbon dioxide (CO2), aldehydes and polyaromatic hydrocarbons and man-made mineral fibres concentration were assessed as well. In order to evaluate their respiratory status each participant filled out a questionnaire and their lung function was tested by forced spirometry. Total inhalable fume exposure was maximum 4.37 mg m(-3). Exposure to the combustion gases, man-made mineral fibres and metal fume was well below the exposure limits. Beryllium could not be detected in the urine. The values of aluminium, manganese and lead in the urine were all under the respective reference value. One individual had a urinary chromium excretion above the ACGIH defined biological exposure index (BEI) of 30 microg g(-1) creatinine. There was no significant difference in any of the categories of the respiratory questionnaire and in the results of the spirometry between cast house personnel and referents (Chi-square, all p > 0.05). Exposure in cast houses seem to be acceptable under these conditions. However, peak exposure to fumes cannot be excluded and the potential risk of chromium and beryllium exposure due to the recycling of aluminium requires further attention.     

Disaster Management for Nandira Watershed District Angul (Orissa) India, Using Temporal Remote Sensing Data and Gis

NALCO – the largest exporter of aluminium in India has a power plant of 720 MW capacity in Nandira watershed in Angul district of Orissa. The power plant utilises local coal to generate thermal power and disposes of large amount of ash which accumulates in slurry form at nearby two ash ponds. These ash ponds were breached on 31 December 2000, causing ash accumulation for entire regime of the Nandira river. An attempt has been made towards preparation of recovery and rehabilitation plan for NALCO using temporal Remote Sensing data and GIS. Indian remote sensing satellite data for pre-breach condition 12 December 2000, during breach event 31 December 2000 and post-breach condition 4 and 6 January 2001 has been digitally analysed for Nandira watershed. The satellite data of coarse spatial resolution provides the absence and presence of fresh sediment deposition along Nandira watershed and Brahmani river pertaining to pre-breach and post-breach conditions respectively on regional scales. The temporal comparison of fine resolution has clearly highlighted the aerial extent of damage caused by the disaster for entire watershed on local scales. The GIS has helped in demarcation of freshly accumulated ash at interval of 500 m along the river length as well as in delineation of maximum ash accumulation across the river width. The study has clearly demonstrated the use of temporal Remote Sensing data in conjunction with GIS for disaster management in terms of recovery and rehabilitation plan preparation of the Nandira watershed.     

Determination of aluminium in groundwater samples by GF-AAS, ICP-AES, ICP-MS and modelling of inorganic aluminium complexes

The paper presents the results of aluminium determinations in ground water samples of the Miocene aquifer from the area of the city of Poznań (Poland). The determined aluminium content amounted from <0.0001 to 752.7 μg L(-1). The aluminium determinations were performed using three analytical techniques: graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The results of aluminium determinations in groundwater samples for particular analytical techniques were compared. The results were used to identify the ascent of ground water from the Mesozoic aquifer to the Miocene aquifer in the area of the fault graben. Using the Mineql+ program, the modelling of the occurrence of aluminium and the following aluminium complexes: hydroxy, with fluorides and sulphates was performed. The paper presents the results of aluminium determinations in ground water using different analytical techniques as well as the chemical modelling in the Mineql+ program, which was performed for the first time and which enabled the identification of aluminium complexes in the investigated samples. The study confirms the occurrence of aluminium hydroxy complexes and aluminium fluoride complexes in the analysed groundwater samples. Despite the dominance of sulphates and organic matter in the sample, major participation of the complexes with these ligands was not stated based on the modelling.     

Influence of aluminium on the restoration potential of a terrestrial vascular plant,Portulaca Oleracea L. as a biomonitoring tool of fresh water aquatic environments

In the present study, the influence of aluminium on the regeneration potential of leaf and stem-cuttings of Portulaca oleracea was studied in order to identify a terrestrial plant species as an alternate biomonitoring toolof fresh water environment. The leaves and stem cuttings of theterrestrial plant, P. oleracea grew well in the distilled water producing adventitious and lateral roots. The aluminium treated leaves and stem cuttings showed a reduction in the growthof the adventitious and lateral roots and increase in the decay of leaves and stem cuttings with increasing aluminium concentration. The tolerance index calculated for the leaves and the stem cuttings showed that the leaves were more sensitivethan stems to aluminium. Since all the parameters studied showedconcentration dependent changes, the terrestrial plant, P. oleracea can be considered a suitable biomonitoring tool of fresh water environment besides its usage in the Al toxicity testing.     

Aluminium contamination via assisted leaching from metallic aluminium utensils at neutral pH

Fluoride ion in trace concentrations is found to leach metallic aluminium from utensils even at neutral pH, releasing aluminium hydroxide which is readily soluble in dilute acids. The levels of leaching at different F^- concentrations are given and compared with leaching levels with equivalent concentrations of Cl^-. It is suggested that consumption of water boiled in aluminium utensils may contribute to cumulative aluminium toxicity.