COD and TOC analysis of leachate from a solidified organic waste

Several combinations of binders and absorbent additives were utilized to solidify a typical organic waste, API Separator sludge. The effectiveness of the materials was based on the waste leachability from the solidified samples. COD and TOC analyses were used to determine the organic content of the leachate samples.The ability of the COD and TOC analyses to assess waste leachability was limited. The inability of the COD and TOC tests to differentiate between organic compounds made the results difficult to interpret. This was due to organic contaminants from the solidification materials contributing to the COD and TOC contents of the leachates. Also, the COD test may have be influenced by reduced inorganic compounds contained in the flyash binder and the sludge. Representative samples for the TOC analysis were difficult to obtain for the leachates containing oils or suspended particles. It is recommended that the COD and TOC tests only be used as a screening method for determining solidified organic waste leachability and other methods need to be employed to obtain more accurate results.     

Ecology of the mind and educational research: Chemistry,the universal language of nature

Summary The authors advocate the need for a new approach to chemistry, using educational research to permit a fuller appreciation of the functions of the mind and a better understanding of natural processes. Such studies will, the authors believe, clarify the true relationships between energy, matter and information. Their integration, within a conceptually unitary whole, should allow a wider and more fruitful interpretation of reality. An attempt is made to understand the preferential orientation of bond-electrons that give order to a molecular formation, in terms of a tentative reinterpretation of chemistry as a universal language of nature.Dr Paolo Manzelli, senior author of this paper, is Professor in the Department of Chemistry at the University of Florence and Executive Secretary to the International Committee for the Promotion of Advanced Educational Research (Capire). John Eaton, until very recently Head of Education and Media Studies at Farnborough College of Technology, Hants; is now Vice Principal at East Herts College, Broxbourne, Herts, UK.     

Arsenic in the food chain and assessment of population health risks in Bangladesh

The most consumed food samples of cereals (rice, maize and wheat), vegetables (lentil, brinjal, carrot, bean, potato, tomato, onion and chili), fruits (banana, mango and jackfruit), fish (taki, rui, pangas and tilapia), egg (chicken and duck), milk (cow) and meat (chicken, duck, beef and mutton) were collected from some markets of Bogra district northern part of Bangladesh to evaluate the levels of arsenic (As) and associated health risk to the adult’s and child inhabitants. Arsenic is a highly toxic element, and its presence in food composites is a matter of concern to the world scientists. Target hazard quotients (THQs) and target carcinogenic risk were calculated to evaluate the non-carcinogenic and carcinogenic health risk from ingested arsenic. The highest and the lowest mean concentrations of arsenic were noted in the Tilapia fish [(0.94 mg/kg, wet weight (ww)] and beef (0.012 mg/kg, ww). The daily intakes of arsenic via foodstuffs were 1.92 and 3.30 µg/kg-bw/day for rural adults and children and 1.69 and 3.04 µg/kg-bw/day for urban adults and children, respectively. The result shows the highest THQs of arsenic in cereals and vegetables for both the rural and urban inhabitants which exceed the safe limit (>1) indicating that cereals and vegetables are the main food items contributing to the potential health risk. The estimated target cancer risks from ingesting dietary arsenic all exceeded 10^?6, indicating increased risk of cancer for adults and children in the study area.     

3D MRI measurements of the effects of wind direction on flow characteristics and contaminant dispersion in a model urban canopy

Environmental Fluid Mechanics - Three dimensional velocity fields and contaminant dispersion within an evenly spaced orthogonal array of cubic buildings (height = H) with a central tall...     

The conceptual bases of chemistry and the development of integrated science

Summary A paradigmatic model of the evolution of scientific thought encourages awareness of the provisional nature of present scientific explanations, sensitizing us to aspects of observed reality which they are unable to adequately explain. The self-organizing capabilities of open systems, exemplified by the clock-reactions investigated by Prigogine, not only demonstrate the inadequacies of the present probabilistic scientific interpretations but also point towards a more adequate model of scientific explanation which would place man at the centre of scientific development and encourage the integration of science.Dr Paolo Manzelli, as the senior author of this paper, is Professor in the Department of Chemistry at the University of Florence. John Eaton is responsible for Educational Studies at Farnborough College of Technology.     

EVALUATION OF INFLOW TO MIRROR LAKE,NEW HAMPSHIRE1

ABSTRACT: Measured stream discharge plus calculated ground water discharge (total measured runoff) were compared with runoff calculated by the unit-runoff method for the two largest watersheds of Mirror Lake for 1981–1983. Runoff calculated by the unit-runoff method, using Hubbard Brook watershed 3 as the index watershed, was greater than the total measured runoff into Mirror Lake during periods of high flow and slightly less than the total measured runoff into Mirror Lake during periods of low flow. Annual calculated unit runoff was 17 to 37 percent greater than total measured runoff. Differences in monthly runoff are far greater, ranging from 0 to greater than 100 percent. For high flows the calculated unit runoff is about 2 times greater than total measured runoff. For low flows the northwest basin of Mirror Lake has the greatest ground water contribution compared to the other two basins. In contrast, Hubbard Brook watershed 3 has the least ground water contribution.     

What makes for good and bad neighbours? An emerging research agenda in the study of Chinese environmental politics

Tackling China’s grave environmental problems increasingly turns on questions of sub-national interjurisdictional relations. What are the conditions under which neighbouring localities cooperate in stewardship of the natural environment? What factors give rise to interjurisdictional conflict such as pollution spillovers? Through a combination of empirical and theoretical reflections, a research agenda to better understand these issues is outlined. First, China’s recent innovative approaches to the promotion of interjurisdictional cooperation are examined. An in-depth case study of interjurisdictional ecological protection ‘redline’ zones underscores the difficulties of inculcating environmental neighbourliness between local governments. Yet, a precise diagnosis of the problem remains elusive because too little is known about the underlying drivers of interjurisdictional relations in China. An analytical framework that draws insight from contemporary China studies and comparative environmental governance scholarship is offered for the study of interjurisdictional environmental relations in China.     

Vanadium-Akkumulation beim Stickstoff-fixierenden Wasserstoffbacterium Xanthobacter autotrophicus

früher: Institut für Mikrobiologie der Universität, D-3400 Göttingen     

Heavy metal distribution in an urban wetland impacted by combined sewer overflow

The heavy metal content and distribution in an urban wetland affected by combined sewer overflow (CSO) discharge during dry conditions was evaluated. Metals identified in the CSO discharge were also measured upstream and downstream of the CSO. Metals were detected in the acid-extractable fraction of the wetland sediments and the roots of Phragmites australis plants. Sediment from the banks of a pool created by the CSO, and from a clay bed upstream were found to be moderately contaminated with Cu, Pb and Zn. Micro X-ray fluorescence (μ-XRF) of Phragmites roots from the CSO banks showed a correlation in the spatial distribution of Fe and Mn, attributed to the formation of mineral plaques on the root surface. Micro X-ray absorption near edge spectroscopy (μ-XANES) revealed that Cu and Zn were complexed with the organic ligands phytate and cysteine. The findings indicated that continuous discharge from the CSO is a source of heavy metals to the wetland. Metals bound to sediments are susceptible to remobilization and subsequent transport, whereas those associated with Phragmites roots may be more effectively sequestered. These observations provide insight into the behavior of heavy metals in urban areas where CSOs discharge into wetlands.