Decreasing lead levels in Swedish biota revealed by 36 years (1969-2004) of environmental monitoring

Since the 1980s, lead levels decreased significantly in most marine biota from the Baltic Sea, the Kattegatt and the Skagerrack and in terrestrial biota from south and central Sweden, analysed in the National Swedish Environmental Monitoring Programme. In herring and cod liver, the decrease was 4.2-7.1% annually 1981-2003 and in perch liver and guillemot eggs analysed since the middle of the 1990s the decrease was 10-13%. In kidneys of young starlings from south and central Sweden, lead levels decreased 6.2-12% annually and the annual decrease in liver and kidney from young moose was 8.8% and 6.5%, respectively. In northern Sweden, lead levels decreased in pike liver by 2.8% between 1969 and 1994 and in reindeer liver by 3.5% annually while a significant increase (5% annually 1981-1994) has been detected in arctic char. In some marine biota, there were indications of a larger decrease during the last ten years compared to the whole period. The large decline in lead emission to the atmosphere during the last twenty years, mainly because of decreasing use of leaded gasoline has obviously resulted in decreasing lead levels in biota.     

Indoor air pollution by 2-ethyl-1-hexanol in non-domestic buildings in Nagoya, Japan

2-Ethyl-1-hexanol is a possibly causative chemical in sick building symptoms, although 2-ethyl-1-hexanol has received little attention as a hazardous substance in studies on indoor air pollution. Airborne 2-ethyl-1-hexanol concentrations were measured from 2002 to 2004 in 99 rooms of 42 non-domestic buildings in Nagoya, Japan. The diffusive sampling method is effective for the measurement of a low level of 2-ethyl-1-hexanol in indoor air. The geometric mean (geometric standard deviation) of 2-ethyl-1-hexanol concentrations was 16.5 (5.4) microg m(-3) in indoor air and 1.9 (2.2) microg m(-3) in outdoor air. The maximum concentration of 2-ethyl-1-hexanol in indoor air and outdoor air was 2709 microg m(-3) and 12.4 microg m(-3), respectively. Fewer rooms in a small number of new buildings showed high concentrations of 2-ethyl-1-hexanol, while low concentrations were observed in many rooms of these buildings as well as the other new buildings. The room-to-room concentrations of 2-ethyl-1-hexanol in each building exhibited a wide variation. The geometric mean of the 2-ethyl-1-hexanol concentrations was significantly higher for indoor air than for outdoor air (p < 0.01). The correlation of the 2-ethyl-1-hexanol concentrations between indoor and outdoor air was not significant. Mechanical ventilation was effective in the temporary reduction of indoor 2-ethyl-1-hexanol level. These results suggest that the predominant source of 2-ethyl-1-hexanol was indoor areas.     

泡沫法分离表面活性物质的效率研究

本文介绍泡沫法净化表面活性废水的效率.探讨提浓效率与原水表面活性物质浓度的关系以及pH值与硬度对提浓效率的影响.     

Efficiency of the activated carbon filtration in the natural organic matter removal

The removal and transformation of natural organic matter were monitored in the different stages of the drinking water treatment train. Several methods to measure the quantity and quality of organic matter were used. The full-scale treatment sequence consisted of coagulation, flocculation, clarification by flotation, disinfection with chlorine dioxide, activated carbon filtration and post-chlorination. High-performance size-exclusion chromatography separation was used to determine the changes in the humic substances content during the purification process; in addition, a UV absorbance at wavelength 254 nm and total organic carbon amount were measured. A special aim was to study the performance and the capacity of the activated carbon filtration in the natural organic matter removal. Four of the activated carbon filters were monitored over the period of 1 year. Depending on the regeneration of the activated carbon filters, filtration was effective to a degree but did not significantly remove the smallest molar mass organic matter fraction. Activated carbon filtration was most effective in the removal of intermediate molar mass compounds (range 1,000-4,000 g/mol). Regeneration of the carbon improved the removal capacity considerably, but efficiency was returned to a normal level after few months.     

Pyrosequencing reveals bacteria carried in different wind-eroded sediments

Little is known about the microbial communities carried in wind-eroded sediments from various soil types and land management systems. The novel technique of pyrosequencing promises to expand our understanding of the microbial diversity of soils and eroded sediments because it can sequence 10 to 100 times more DNA fragments than previous techniques, providing enhanced exploration into what microbes are being lost from soil due to wind erosion. Our study evaluated the bacterial diversity of two types of wind-eroded sediments collected from three different organic-rich soils in Michigan using a portable field wind tunnel. The wind-eroded sediments evaluated were a coarse sized fraction with 66% of particles >106 μm (coarse eroded sediment) and a finer eroded sediment with 72% of particles <106 μm. Our findings suggested that (i) bacteria carried in the coarser sediment and fine dust were effective fingerprints of the source soil, although their distribution may vary depending on the soil characteristics because certain bacteria may be more protected in soil surfaces than others; (ii) coarser wind-eroded sediment showed higher bacterial diversity than fine dust in two of the three soils evaluated; and (iii) certain bacteria were more predominant in fine dust (, , and ) than coarse sediment ( and ), revealing different locations and niches of bacteria in soil, which, depending on wind erosion processes, can have important implications on the soil sustainability and functioning. Infrared spectroscopy showed that wind erosion preferentially removes particular kinds of C from the soil that are lost via fine dust. Our study shows that eroded sediments remove the active labile organic soil particulates containing key microorganisms involved in soil biogeochemical processes, which can have a negative impact on the quality and functioning of the source soil.     

Life cycle of meats: an opportunity to abate the greenhouse gas emission from meat industry in Japan

The food industry is one of the world's largest industrial sectors, hence a large contributor of greenhouse gases (GHG) which cause global warming. This study evaluates the life cycle of various types of meat to determine if the GHG emission from the meat industry in Japan could be reduced if the population makes different dietary choices. It was confirmed that the GHG emission of beef was greater than that of pork or chicken. The GHG emission from meat in general also depends on the per capita caloric intake (if meat supplies the recommended animal protein or contributes to it at the present rate). In a healthy and balanced diet (9.2 MJ i.e., 2200 kcal in total, where either mixed meat or chicken or pork or beef contributes 2.2%), the GHG emission is estimated to be 0.28 or 0.17 or 0.15 or 0.77 kg CO? eq/person/day, respectively. A change in consumption patterns (from beef to chicken or pork) and the adoption of a healthy and balanced diet would help to abate about 2.5-54.0 million tons (CO? eq) produced by the meat industry each year in Japan.     

Implementing China's circular economy concept at the regional level: a review of progress in Dalian, China

The circular economy (CE) concept was introduced in China to address environmental degradation and resource scarcity associated with rapid economic development. Chosen as a demonstration city, Dalian has implemented the CE strategy as a means of conserving water, materials, energy and land. This paper outlines some of the regional CE initiatives that have been successful to date in Dalian, including those focusing on conserving energy and water resources and others focusing on reduced industrial emissions. The paper details the approach used in implementing the CE concept in Dalian, tracing the foci and goals of the program, and the sectoral approach used to implement a CE. Although Dalian municipality has achieved many successes in implementing a CE, our paper identifies several challenges that, until recently, have held back complete implementation. These include: the lack of incentives for older industries to 'green' their operations, the lack of financial support to expand the CE concept, and a broad-based need for heightened public awareness and participation in CE initiatives. Our paper then identifies several responses by Dalian municipality to overcome these challenges, including pricing and tax reforms that serve as conservation incentives, the provision of financial support for CE promotion through budget reorganization, and the organization of CE training programs. Our paper concludes that, although CE initiatives have been successful in Dalian, more is possible and more is needed before Dalian can be designated a true 'eco-city'. The approach used by Dalian can provide guidance for other Chinese cities, although it is recognized that each city must tailor its own approach for differing contexts and conditions.     

Leaching from MSWI bottom ash: evaluation of non-equilibrium in column percolation experiments

Impacts of non-equilibrium on results of percolation experiments on municipal solid waste incineration (MSWI) bottom ash were investigated. Three parallel column experiments were performed: two columns with undisturbed percolation and one column with two sets of 1-month-long flow interruptions applied at liquid-to-solid (L/S) ratios of L/S 2L/kg and 12L/kg, respectively. Concentrations of Na, K, Cl(-), Ca, Si, SO(4)(2-), Al, Cu, Ni, Mo, Ba, Pb, Zn, and dissolved organic carbon (DOC) were monitored throughout the entire leaching period; geochemical modeling was used to identify non-equilibrium-induced changes in the solubility control. Despite both physical and chemical non-equilibrium, the columns were found to provide adequate information for readily soluble compounds (i.e., Na, Cl(-), and K) and solubility-controlled elements (i.e., Ca, SO(4)(2-), Ba, Si, Al, Zn, and Pb). The leaching of Cu and Ni was shown to depend strongly on DOC leaching, which was likely affected by physical non-equilibrium during flow interruptions. Consequently, the leaching of Cu and Ni in the undisturbed columns was shown to be by about one order of magnitude lower compared with the interrupted column. The results indicate that the leaching of DOC-related metals in laboratory column experiments may be considerably underestimated compared with full-scale scenarios in which the impacts from non-equilibrium may be significantly lower. The leaching of Mo (or MoO(4)(2-)) may be controlled solely by its availability in the mobile zone, which in turn appeared to be controlled by diffusion from the stagnant zone; no Mo controlling minerals were predicted by the geochemical modeling.     

Hydrothermal treatment of MSWI bottom ash forming acid-resistant material

To recycle municipal solid waste incinerator (MSWI) bottom ash, synthesis of hydrothermal minerals from bottom ash was performed to stabilize heavy metals. MSWI bottom ash was mixed with SiO(2), Al(OH)(3), and Mg(OH)(2) so its chemical composition was similar to that of hydrothermal clay minerals. These solid specimens were mixed with water at a liquid/solid ratio of 5. The reaction temperature was 200 degrees C, and reactions were performed for 24-240h. Generation of kaolinite/smectite mixed-layer clay mineral was found in the samples after the reaction of the mixture of bottom ash, SiO(2), and Mg(OH)(2). Calcium silicate hydrate minerals such as tobermorite and xonotlite were also generated. X-ray powder diffraction suggested the presence of amorphous materials. Leaching tests at various pHs revealed that the concentration of heavy metals in the leachates from MSWI bottom ash hydrothermally treated with SiO(2) and Mg(OH)(2) was lower than that in leachates from non-treated bottom ash, especially under acid conditions. Hydrothermal treatment with modification of chemical composition may have potential for the recycling of MSWI bottom ash.     

Municipal solid waste management in India: From waste disposal to recovery of resources?

Unlike that of western countries, the solid waste of Asian cities is often comprised of 70-80% organic matter, dirt and dust. Composting is considered to be the best option to deal with the waste generated. Composting helps reduce the waste transported to and disposed of in landfills. During the course of the research, the author learned that several developing countries established large-scale composting plants that eventually failed for various reasons. The main flaw that led to the unsuccessful establishment of the plants was the lack of application of simple scientific methods to select the material to be composted. Landfills have also been widely unsuccessful in countries like India because the landfill sites have a very limited time frame of usage. The population of the developing countries is another factor that detrimentally impacts the function of landfill sites. As the population keeps increasing, the garbage quantity also increases, which, in turn, exhausts the landfill sites. Landfills are also becoming increasingly expensive because of the rising costs of construction and operation. Incineration, which can greatly reduce the amount of incoming municipal solid waste, is the second most common method for disposal in developed countries. However, incinerator ash may contain hazardous materials including heavy metals and organic compounds such as dioxins, etc. Recycling plays a large role in solid waste management, especially in cities in developing countries. None of the three methods mentioned here are free from problems. The aim of this study is thus to compare the three methods, keeping in mind the costs that would be incurred by the respective governments, and identify the most economical and best option possible to combat the waste disposal problem.