Concentrations of organic wood preservatives in wood chips produced from wood wastes

We investigated the concentrations of wood preservatives in the wood chips produced in wood-waste processing facilities in 1988, 1998–1999, and 2001–2002. Among the wood preservatives used in the past in Japan, halophenols, including PCP, chlordane, and chlorpyrifos, had comparatively high detection rates and high average concentrations in the wood chips produced in 2001–2002. Aldrin and endrin were rarely detected, and DDT was already in low concentrations in those wood chips. Although several types of wood preservative were contained in the wood chips, their concentration levels depended on the sources of the wood wastes. In chips produced from wooden pallets, wooden forms for concrete working, or wood discarded from nondemolition sources, no organochlorine wood preservatives were detected, and chlorpyrifos and chlorophenols were detected at one order of magnitude lower than the average concentrations in chips produced from wood wastes discarded in house demolitions.     

Climatic Variation and Solute Concentration and Flux in Meltwaters Draining from an Alpine Glacier

Measurements of electrical conductivity and discharge ofmeltwaters in the Gornera, which drains from the 83%glacierised basin containing Gornergletscher, PennineAlps, Switzerland, were undertaken between May andSeptember in both 1979 and 1998. Discharge in theGornera was 43% higher in 1998, average air temperatureduring the ablation season being 2.1 °C warmer andpreceding winter precipitation 28% lower than in 1979. Mean electrical conductivity of meltwater in 1998 wasreduced by 40%. In the same 60 day period in 1998,however, solute flux was augmented by only 2% bycomparison with 1979. Year-to-year climatic variations,reflected in discharge variability, strongly affectsolute concentration in glacial meltwaters, but havelimited impact on solute flux. Climatic conditionstranslate into meltwater quality through inter-relationships between mineral reaction rates, subglacialresidence time in contact with sediment, and discharge. Annual variability in solute flux depends on the extentto which volume of flow can offset decline in soluteconcentration brought about by reducing residence time.     

电厂煤粉炉燃煤中硫的转化规律研究

利用50组燃煤电厂现场测试数据，研究了在煤粉炉燃烧条件下，不同煤种、不同地区烟煤中硫转化为烟气中SO2的份额。研究认为，目前我国电厂煤粉炉燃煤中硫转化为烟气中SO2的份额平均值取0．85是适宜的。     

The influence of seasonal vertical temperature gradients on no‐purge sampling of wells

Seasonal changes in ambient temperature create vertical temperature gradients in shallow groundwater (less than 15 m). These temperature gradients can affect in‐well flow dynamics that impact samples collected using no‐purge sampling methods. In late winter, the shallower water is colder, resulting in thermally mixed conditions and uniform contaminant concentrations. In late summer, the shallower water is warmer, resulting in thermally stratified conditions and contaminant distributions in the monitoring well more consistent with the distribution in the surrounding aquifer. The importance of seasonal temperature gradients on in‐well mixing was evaluated in two shallow monitoring wells in Houston, Texas. In each of the two wells, four vertically spaced passive diffusion samples collected in late winter showed a less than 1.3x difference in trichloroethene (TCE) concentration between depths, while the same sampling conducted in late summer showed greater than a 100x difference in TCE concentration between depths. A simple analytical model originally developed to predict vertical soil temperature profiles can also be used to predict the occurrence of thermally stratified and thermally mixed conditions in monitoring wells as a function of time and well depth. The results of this analysis and modeling suggest that shallow monitoring wells in most of the United States and Canada can have significantly different vertical concentration profiles within the well over the course of a year due to seasonal vertical temperature gradients. This can induce additional intra‐annual temporal variability on passive no‐purge sampling results from these shallow wells, potentially making it more difficult to discern true trends in the data. © 2012 Wiley Periodicals, Inc.     

Reduction of hazardous elements contained in sewage sludge incineration ash

Research and experimental studies were carried out in relation to reduction of hazardous elements contained in sewage sludge incineration ash. A questionnaire survey was conducted in 69 Japanese municipalities with sewage sludge incineration facilities. Selenium content in bag filter ash and ceramic filter ash was relatively higher than that in ash of cyclone and electrostatic precipitators. It was assumed that selenium vaporized in the furnace was due to adsorb in the fly ash on filter when passing through the low-temperature filter. To reduce high boiling point heavy metals in the ash, sewage sludge and incineration ash were heated up using a small muffle furnace. As the result, the chrome and nickel contents were reduced. A decrease in the surface area of ash and the reduction of elements occurred at the same time in sewage sludge and incineration ashes tested in this study.     

Interannual Changes in the C:N:P Ratios of Seston and Zooplankton of a High Mountain Lake in Sierra Nevada,Spain

We investigated the carbon, nitrogen and phosphorus content inthe seston and the zooplankton of a high-mountain lake duringthree years of contrasting physical and chemical conditions.Carbon in seston was ten times higher in 1995 than in 1996 and1997. Phosphorus content in seston was variable for the studyperiod, increasing gradually towards late summer in 1995, butpeaking abruptly in 1996 and 1997, reflecting atmosphericdepositions. Seston C:P were high and did not fit any definitepattern in 1995, and were particularly low after the thaw, increasing towards mid-summer in 1996 and 1997. As the seasonprogressed, major decreases in these ratios occurred coincidingwith important atmospheric inputs in the lake area. ZooplanktonN:P and C:P were negatively associated to the appearance ofrotifers and copepod nauplii in 1995, but positively correlatedto the ontogenetic development of the most abundant species,Mixodiaptomus laciniatus, in 1996. Seasonal variations inzooplankton N:P and C:P ratios showed limited interannual, butlarge intraannual variability. The comparison between the bulkcarbon in seston and zooplankton demands for this elementindicated that zooplankton were above food-quantity thresholdsfor maximum growth in 1995, 1996 and mid-season of 1997,therefore suffering only from food-quantity constraints afterthe thaw (nauplii dominance) and towards late season (adultdominance) in the latter year. The high C:P ratios in sestonrelative to zooplankton in 1995 imply that the zooplankton mayhave faced severe food-quality constraints (in terms ofphosphorus) during this year. Differences between bulkzooplankton and seston elemental nutrients are also discussed inrelation to the competitive abilities of species, andparticularly of Daphnia.     

Effect of irrigation on the survival of total coliforms in three semiarid soils after amendment with sewage sludge

Sewage sludges are increasingly used in soil amendment programmes, although not without risk since they contain, among other potential hazards, high concentrations of total coliform bacteria. In this paper we have studied the effect of irrigation on the survival of total coliforms in three semiarid degraded soils with different agricultural practices. Fresh sewage sludge was added at 50 g kg(-1) soil, and incubated in both the presence and absence of irrigation. The absence of irrigation led to a sharp decrease in the number of total coliforms in all soils, with the bacteria disappearing in 40 days. Irrigation produced a substantial initial increase in the number of coliforms in the three soils, although after 80 days there was none growing in any of the soils. The results showed that there were significant differences in the survival of coliform bacteria due to the presence or absence of irrigation.     

'Stop pub': can banning of junk mail reduce waste production?

According to the new regulations on junk mail management to be adopted in France, both producers and distributors must participate in the recycling process. This case study was carried out in 2000 in four sectors in the Departement of Charente in the south west of France. This report presents the quantities of junk mail in residual waste and in separate collections. The conclusion is that the new regulations may reduce overall domestic waste production by 2-4%, with the impact on separately collected paper being some 20%.     

Redesigning a collection system for "small" consumer electronics

This paper establishes that the collection system within the recycling scheme for consumer electronics in the Netherlands has not been entirely successful in convincing consumers to hand in their used appliances by means of dedicated collection routes. Particularly regarding small appliances, consumers are persisting in their habit of discarding their appliances by means of the refuse bag/bin for regular household waste. Therefore, the current collection system has been unable to direct consumer behavior in the desired direction. Consequently, the layout of the current system is reviewed and redesigned in order to tackle this problem. This design effort applies the Triad model (behavioral model) in the analysis stage and the Morphological Chart method (design tool) in the synthesis stage, and results in a concrete proposal for a new system. Finally, the applicability of this design approach beyond the specific circumstances of the case study presented in this paper is discussed. This case represents only one example of the broader, worldwide challenge to design appropriate collection systems to direct consumer behavior in desired directions. It is argued that the approach presented in this paper could be a valuable contribution to research dealing with this challenge.     

Supercritical methanol for polyethylene terephthalate depolymerization: observation using simulator

To apply PET depolymerization in supercritical methanol to commercial recycling, the benefits of supercritical methanol usage in PET depolymerization was investigated from the viewpoint of the reaction rate and energy demands. PET was depolymerized in a batch reactor at 573 K in supercritical methanol under 14.7 MPa and in vapor methanol under 0.98 MPa in our previous work. The main products of both reactions were the PET monomers of dimethyl terephthalate (DMT) and ethylene glycol (EG). The rate of PET depolymerization in supercritical methanol was faster than that of PET depolymerization in vapor methanol. This indicates supercritical fluid is beneficial in reducing reaction time without the use of a catalyst. We depicted the simple process flow of PET depolymerization in supercritical methanol and in vapor methanol, and by simulation evaluated the total heat demand of each process. In this simulation, bis-hydroxyethyl terephthalate (BHET) was used as a model component of PET. The total heat demand of PET depolymerization in supercritical methanol was 2.35 x 10(6)kJ/kmol Produced-DMT. That of PET depolymerization in vapor methanol was 2.84 x 10(6)kJ/kmol Produced-DMT. The smaller total heat demand of PET depolymerization in supercritical methanol clearly reveals the advantage of using supercritical fluid in terms of energy savings.     

Pilot‐scale demonstration of in situ capping of PCB‐containing sediments in the lower Grasse River

A fish‐consumption advisory is currently in effect in a seven‐mile stretch of the Grasse River in Massena, New York, due to elevated levels of PCBs in fish tissue. One remedial approach that is being evaluated to reduce the PCB levels in fish from the river is in situ capping. An in‐river pilot study was conducted in the summer of 2001 to assess the feasibility of capping PCB‐containing sediments of the river. The study consisted of the construction of a subaqueous cap in a seven‐acre portion of the river using various combinations of capping materials and placement techniques. Optimal results were achieved with a 1:1 sand/topsoil mix released from a clamshell bucket either just above or several feet below the water surface. A longer‐term monitoring program of the capped area commenced in 2002. Results of this monitoring indicated: 1) the in‐place cap has remained intact since installation; 2) no evidence of PCB migration into and through the cap; 3) groundwater advection through the cap is not an important PCB transport mechanism; and 4) macroinvertebrate colonization of the in‐place cap is continuing. Additional follow‐up monitoring in the spring of 2003 indicated that a significant portion of the cap and, in some cases, the underlying sediments had been disturbed in the period following the conclusion of the 2002 monitoring work. An analysis of river conditions in the spring of 2003 indicated that a significant ice jam had formed in the river directly over the capping pilot study area, and that the resulting increase in river velocities and turbulence in the area resulted in the movement of both cap materials and the underlying sediments. The pilot cap was not designed to address ice jam–related forces on the cap, as the occurrence of ice jams in this section of the river had not been known prior to the observations conducted in the spring of 2003. These findings will preclude implementation of the longer‐term monitoring program that had been envisioned for the pilot study. The data collected immediately after cap construction in 2001 and through the first year of monitoring in 2002 serve as the basis for the conclusions presented in this article. It should be recognized that, based on the observation made in the spring of 2003, some of these conclusions are no longer valid for the pilot study area.The occurrence of ice jams in the lower Grasse River and their importance on sediments and PCBs within the system are currently under investigation. © 2003 Wiley Periodicals, Inc.     

Fate of Chlorothalonil, Chlorpyrifos and Profenofos in a Vegetable Farm in cameron Highlands, Malaysia

The fate of chlorothalonil, chlorpyrifos and profenofos in sandy loam soil under tropical condition was studied in a vegetable plot in the Cameron Highlands, Malaysia. The plot was treated with chlorothalonil, chlorpyrifos and profenofos according to normal agricultural practices of the Cameron Highlands. Water (runoff and lysimeter), soil and bedload sediment samples were taken according to a sampling schedule. Residues in water, soil and bedload sediment samples were laboratory analysed to determine amount. Chlorothalonil residues were detected in the range of < 0.01–0.08 mg/kg in the soil, < 0.01–0.02 ng/mL in the leachate, < 0.01–0.02 ng/mL in the runoff and < 0.01–0.11mg/kg in the sediment. Field studies of chlorpyrifos showed residue levels of < 0.01–0.06 mg/kg in the soil, < 0.01–0.07 ng/mL in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.62 mg/kg in the sediment. Residue levels of profenofos were detected in the range of < 0.01–0.02 mg/kg in the soil, < 0.01–0.87 ng/mL in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.35 mg/kg in the sediment. The three pesticides dissipated rapidly, with DT50 (time for 50% loss) of less than two days. The study showed that these pesticides dissipated rapidly under the climatic conditions of the Cameron Highlands in Malaysia.     

Solid waste management associated with the development of 3R initiatives: case study in major urban areas of Vietnam

The purpose of this article is to describe the application and progress of the Reduce-Reuse-Recycle (3R) initiative and its gradual implementation and development in solid waste management in Vietnam through the study of the municipal solid waste management (MSWM) systems of eight major urban cities and provinces. The resulting survey and studies showed that there are big challenges for MSWM in the study areas due to the absence of an appropriate master plan for MSWM; there is a clear need to set up indicators for waste reduction and greenhouse gas emission reduction from waste generators and enterprises involved in MSWM, especially in terms of using 3R activities in the management of industrial waste. The strength and organic combination of institutional frameworks, support measures, and technologies for 3R promotion need to be applied as soon as possible in order to implement MSWM practices using more effective measures; in particular, a reduction in the amount of hazardous substances discarded and improvements in the handling of hazardous waste are required.     

华东废钢产业发展概况及2012年废钢行情分析

对华东地区废钢产业的发展进行概述,回顾了2011年华东地区废钢市场的供求行情,并对2012年废钢市场的供求行情进行分析和预测。     

The Impact of Lake-level Fluctuations on the Sediment Composition

Lithological and granulometric investigations of the surface and short core sediments in L. Martiska (northeastern Estonia) showed that variations in the grain-size parameters and LOI content were influenced by the changes in deposition conditions during the regression and transgression phases monitored in the lake since the 1960s. During the regression and transgression phases displacement of the erosion-transport-accumulation zones in the lake took place depending on the bottom topography. The water level fluctuations are especially clearly reflected in grain-size variations in cores from peripherial area.     

Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition,chlorine content and temperature

Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of fly ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature.Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine content have significant effects on partitioning characteristics by increasing the formation and vaporization of highly volatile metal chlorides. Zinc and cadmium concentrations in fly ash increase with the incineration temperature.     

Characterization of trace constituents in landfill gas and a comparison of sites in Asia

Because landfill gas (LFG) contains an abundance of methane, the utilization of LFG as a renewable energy source is becoming popular in many countries. LFG, however, contains various trace constituents, some of which may pose problems during utilization. For example, siloxanes and halogenated volatile organic compounds (VOCs) can cause difficulties when present in the fuel of gas engines. In addition, many VOCs and mercury have harmful effects on human health, especially on the health of workers at landfill sites and people living near the landfills. Energy recovery from LFG is expected to make great progress in the near future, particularly in Asia, but we found little information on the trace constituents of LFG in this region. Therefore, we sought to characterize the trace components in LFG generated in two landfill sites in China and one site in Japan, to determine the typical concentrations of these trace components in LFG, and to compare their concentrations among landfill sites in Asia. We concluded that the trace components in LFG at the sites studied were mainly siloxanes generated from sewage sludge and harmful benzene, toluene, ethylbenzene, and xylene compounds from petroleum products.     

Healthcare waste management in the capital city of Mongolia

Inconsistencies are present in the management options for healthcare wastes in Mongolia. One of the first critical steps in the process of developing a reliable waste management plan requires the performance of a waste characterization analysis. The objectives of this study were an assessment of the current situation of healthcare waste management (HCWM) and characterization of healthcare wastes generated in Ulaanbaatar. A total about 2.65 tonnes of healthcare wastes are produced each day in Ulaanbaatar (0.78 tons of medical wastes and 1.87 tons of general wastes). The medical waste generation rate per kg/patient-day in the inpatient services of public healthcare facilities was 1.4-3.0 times higher than in the outpatient services (P<0.01). The waste generation rate in the healthcare facilities of Ulaanbaatar was lower than in some other countries; however, the percentage of medical wastes in the total waste stream was comparatively high, ranging from 12.5% to 69.3%, which indicated poor waste handling practices. Despite the efforts for the management of wastes, the current system of healthcare waste management in Ulaanbaatar city of Mongolia is under development and is in dire need of immediate attention and improvement. It is essential to develop a national policy and implement a comprehensive action plan for HCWM providing environmentally sound technological measures to improve HCWM in Mongolia.     

Impact of moisture on volatility of heavy metals in municipal solid waste incinerated in a laboratory scale simulated incinerator

In this work, the impact of moisture on the volatility of heavy metals present in municipal solid wastes (MSW) in a laboratory scale simulated incinerator was studied, using synthetic waste consisting of 5.4 g of wood powder, 2.6 g lava, 1.9 polythene, 0.19 g polyvinyl chloride, and a given quantity of water and heavy metals represented by lead, zinc and copper in forms of metallic, chlorides and oxides. It is found that the presence of high moisture in MSW will greatly reduce the volatilization of heavy metals in MSW in the incineration process. The volatilization behavior of chlorides, oxides and the metallic species with respect to the effect of moistures is quite different. For copper, the presence of moisture in MSW depresses the volatilization of oxides, and increases that of chloride and the metallic species, while in contrast, the volatilization of both lead and zinc is always depressed by the presence of moisture in MSW, regardless of the chemical forms used. The chemical mechanisms, which govern the volatilization behaviors of different chemical forms in the incineration process, are proposed. Hydrolysis, dewatering of hydrolyzed species, sublimation, chemical transformation of less volatiles to more volatiles or reverse, may participate in and affect the volatilization of heavy metals in MSW.     

Promoting the use of crumb rubber concrete in developing countries

The use of accumulated waste materials in third world countries is still in its early phases. It will take courage for contractors and others in the construction industry to recycle selected types of waste materials in the concrete mixes. This paper addresses the recycling of rubber tires accumulated every year in Jordan to be used in concrete mixes. The main objectives of this research were to provide more scientific evidence to support the use of legislation or incentive-based schemes to promote the reuse of accumulated waste tires. This research focused on using crumb tires as a replacement for a percentage of the local fine aggregates used in the concrete mixes in Jordan. Different concrete specimens were prepared and tested in terms of uniaxial compression and splitting tension. The main variable in the mixture was the volumetric percentage of crumb tires used in the mix. The test results showed that even though the compressive strength is reduced when using the crumb tires, it can meet the strength requirements of light weight concrete. In addition, test results and observations indicated that the addition of crumb rubber to the mix has a limited effect toward reducing the workability of the mixtures. The mechanical test results demonstrated that the tested specimens of the crumb rubber concrete remained relatively intact after failure compared to the conventional concrete specimens. It is also concluded that modified concrete would contribute to the disposal of the non-decaying scrap tires, since the amount being accumulated in third world countries is creating a challenge for proper disposal. Thus, obliging authorities to invest in facilitating the use of waste tires in concrete, a fundamental material to the booming construction industry in theses countries, serves two purposes.