Pretreatment of automobile shredder residue (ASR) for fuel utilization.

Automobile shredder residue (ASR) was pretreated to improve its quality for fuel utilization. Composition analysis revealed that ASR components could be classified into four groups: (1) urethane and textile-light fraction and combustibles containing low levels of ash and Cl; (2) plastics and rubber-light or heavy fraction and combustibles containing high levels of Cl; (3) metals and electrical wire-heavy fraction and incombustibles, and (4) particles smaller than 5.6mm with high ash contents. Based on these results, we successively performed sieving to remove particles smaller than 5.6mm, float and sink separations to reject the heavy fraction and plastics and rubber containing Cl, thermal treatment under an inert atmosphere to remove Cl derived from PVC, and char washing to remove soluble chlorides. This series of pretreatments enabled the removal of 78% of the ash and 91% of the Cl from ASR. Sieving using a 5.6-mm mesh removed a considerable amount of ash. Product quality was markedly improved after the float and sink method. Specifically, the sink process using a 1.1 g cm(-3) medium fluid rejected almost all rubber containing Cl and a large amount of PVC. The remaining Cl in char, after heating at 300 degrees C under an inert atmosphere and washing, was considered to be present as insoluble chlorides that volatilized at temperatures above 300 degrees C. Based on a tradeoff relationship between product quality and treatment cost, ASR may be utilized as a form of refuse plastic fuel or char.

Evaluation of carbonization as a thermal pretreatment method for landfilling by column leaching tests.

To evaluate carbonization as a thermal pretreatment method for landfilling, the releasing characteristics of organic and inorganic constituents from carbonization residue derived from shredded residue of bulky waste was investigated by means of batch and column leaching tests. Shredded residue of bulky waste itself and its incineration ash were tested together to compare pretreatment methods. In batch leaching tests at a liquid/solid ratio of 10, the release of organic carbon from carbonization residue was at a remarkably low level. Besides, carbonization contributed to immobilize heavy metals such as chromium, cadmium, and lead within its residue. In column tests, the discharges of organic constituents were lowest from carbonization residue under aerobic conditions due to microbial activity. The leaching of Cd, Cr, Pb, and Cu from carbonization residue was suppressed under anaerobic conditions; however, this suppression effect tended to be weaker under aerobic conditions. From the results showing that the total releasing amounts of organic and inorganic constituents from carbonization residue are so low as to be comparable to that of incineration ash, carbonization can be considered as one of the thermal pretreatment methods of organic wastes.

Improving the quality of waste-derived char by removing ash.

This study characterized and removed ash from waste-derived char to improve the quality of char as fuel. Municipal solid waste (MSW) and automobile shredder residue (ASR) were carbonized at 450 degrees C and at 500 degrees C, respectively, in a rotary kiln with a nitrogen atmosphere for 1h. MSW and ASR char were subjected to sieving and pulverization-sieving to screen incombustibles and the ash-rich fraction, after which float-sink separation, froth floatation, and oil agglomeration were applied to remove ash from the char. The established target quality was (1) less than 30% ash content and (2) more than 20,000 kJ/kg heating value. However, the rate of combustibles recovery had to be lowered to produce a good quality of char along with a high heating value. MSW char attained the targeted quality level using froth floatation or oil agglomeration, whereas, neither separation method was able to make ASR-derived char satisfy the target. Based on the assumption that particle properties of char are determined by the weight ratio of combustibles and ash, the densities of combustibles and ash in char were estimated using the results of float-sink separation, X-ray diffraction (XRD) analysis, and elemental content. To verify the above assumption, an energy dispersive X-ray/scanning electron microscope (EDX/SEM) analyzer was used to observe char particles.

Characteristics of leachate from pyrolysis residue of sewage sludge.

The pyrolysis residue (SP) of sewage sludge (SS) produced at 500 degrees C was subjected to batch and column leaching tests to investigate the release of its organic and inorganic constituents and metals. For comparison, incineration ash (SI) obtained from a SS incinerator was also tested. Pyrolysis and incineration reduced organic matter of SS from 0.78 kg kg(-1)-dry SS to 0.16 and 0.01 kg kg(-1)-dry SS, respectively. Heavy metals remained in SP without being volatilized, although Cd and Pb were transferred into the off-gas during incineration. In the batch leaching test with the leaching liquid-to-solid mass ratio (L/S)=10, the pH of the SS, SP, and SI filtrates was 6.3, 7.9, and 11.0, respectively. The total organic carbon concentrations were in the order SS (877 l mg l(-1))>>SP (99 mg l(-1))>SI (26 mg l(-1)). The SP and SI filtrates met the landfill standard for the Cd and Pb concentrations (<0.3 mg l(-1)). In the column tests, although the SP contained more organic matter than that of SI, its carbon discharge into the leachate under aerobic conditions was similar to that of SI under anaerobic conditions. The leaching of heavy metals, such as Cd, Cr, Pb, and Zn, was also suppressed in SP during the active decomposition of organic matter. We demonstrated that pyrolysis reduces the potential release of pollutants from sewage sludge in landfill, making it a promising method of treating sewage sludge before landfilling.

Characterization of residual carbon influencing on de novo synthesis of PCDD/Fs in MSWI fly ash.

Using 19 samples of fly ash collected from various MSW incineration facilities, residual carbon was characterized by gasifiable fraction at 450 degrees C (C450), and the correlations with de novo synthesis of PCDD/Fs were experimentally examined. Fly ashes were classified into three groups by the ratio of C450 to total residual carbon. By comparison of CO and CO2 generation patterns with those of reference materials, unburnt carbon of solid waste and activated carbon powder injected into flue gas were identified as a carbon source in fly ash. In the experiment of de novo synthesis of PCDD/Fs, the content of PCDD/F synthesis depended on C450 regardless of the origin of carbon. In addition, the model to predict the content of PCDD/F synthesis, DeltaPCDD/F=0.989.Cu.C450, fitted well with experimental values.

Recovery of zinc and lead from fly ash from ash-melting and gasification-melting processes of MSW--comparison and applicability of chemical leaching methods.

Fly ash generated from MSW ash-melting and gasification-melting plants, known as Melting Furnace Fly Ash (MFA), contains considerable amounts of heavy metals such as Pb and Zn. These metals can be recovered using a smelting furnace after "pre-treatment" for removal of unnecessary elements such as Cl, Sn and Si. Chemical methods have been studied for pretreatment in the past. However, they have been discussed only with regard to treatment cost and the concentration of Pb and Zn recovered, but neither applicability to various types of MFA nor the environmental impact have been considered. In this study, acid, alkaline and ammonia/chloride leaching methods were compared from the standpoints of: (1) applicability to MFA, (2) concentration of Pb and Zn recovered, (3) treatment cost, and (4) environmental impact. Twenty-three samples of MFAs were collected and classified into 4 types based on element contents. A Pb and Zn recovery experiment was conducted for the representative MFA of those types. The results showed: (1) MFA from gasification-melting plants cannot be treated by chemical methods; (2) the other MFA can be treated to an acceptable quality by existing smelting furnaces; (3) only MFA from electric resistance ash-melting plants can be treated easily by the water washing method; and (4) alkaline and ammonia/chloride leaching methods were more effective than acid leaching.

Characterization of char derived from various types of solid wastes from the standpoint of fuel recovery and pretreatment before landfilling.

Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In this work, chars derived from various solid wastes were characterized from the standpoint of fuel recovery and pretreatment of waste before landfilling. Sixteen kinds of municipal and industrial solid wastes such as residential combustible wastes, non-combustible wastes, bulky wastes, construction and demolition wastes, auto shredder residue, and sludges were carbonized at 500 degrees C for 1h under nitrogen atmosphere. In order to evaluate the quality of char as fuel, proximate analysis and heating value were examined. The composition of raw waste had a significant influence on the quality of produced char. The higher the ratio of woody biomass in waste, the higher heating value of char produced. Moreover, an equation to estimate heating value of char was developed by using the weight fraction of fixed carbon and volatile matter in char. De-ashing and chlorine removal were performed to improve the quality of char. The pulverization and sieving method seems to be effective for separation of incombustibles such as metal rather than ash. Most char met a 0.5 wt% chlorine criterion for utilization as fuel in a shaft blast furnace after it was subjected to repeated water-washing. Carbonization could remove a considerable amount of organic matter from raw waste. In addition, the leaching of heavy metals such as chrome, cadmium, and lead appears to be significantly suppressed by carbonization regardless of the type of raw waste. From these results, carbonization could be considered as a pretreatment method for waste before landfilling, as well as for fuel recovery.

Application of a gas-solid fluidized bed separator for shredded municipal bulky solid waste separation.

A laboratory-scale gas-solid fluidized bed separator able to separate fractions of 5.6-50mm was used for separation of shredded municipal bulky waste (SBW) into combustibles and incombustibles. In batch-scale tests, it was found that accumulation of SBW in the bottom of the bed significantly reduced the separation efficiency. In this study, stirring was shown to be effective in preventing this accumulation. Flexible sheet materials such as paper and film plastics also significantly decreased the separation efficiency. In batch-scale tests, an overall efficiency of 90% was obtained when flexible materials such as film plastics and paper were excluded from the feed SBW. In continuous feeding tests, purities of the float and sink fractions attained 95% and 86% efficiencies, respectively, with an overall efficiency of 79%. The effect of feedstock shape on separation efficiency was also investigated. This study revealed that large particles can be properly separated on the basis of density, while the shape of the material significantly influenced behavior in the fluidizing bed.

Water-soluble characteristics of chlorine in char derived from municipal solid wastes.

Chlorine in char derived from municipal solid waste (MSW) was characterized and quantified based on its water solubility: easily water-soluble, hardly water-soluble, and non-water-soluble chlorine. For that, a four-cycle process of water-washing, heating or carbonation were carried out. In order to confirm the characteristics of non-water-soluble chlorine, additional thermal treatment and an alkali-acid washing process were applied to washed char. It was found that a large particle size of char (0.5-1.0 mm) significantly contributed to the amount of non-water-soluble chlorine. Pulverization and HNO3-HF digestion were performed to identify a factor to interfere chlorine release from char with a large particle size. Pulverization was proven ineffective for release of non-water-soluble chlorine, whereas approximately 32% of non-water-soluble chlorine was extracted by HNO3-HF digestion. Therefore, the presence of non-water-soluble chlorine is likely to originate from its chemical property rather than simply from its physical one.

Flow analysis of metals in a municipal solid waste management system.

This study aimed to identify the metal flow in a municipal solid waste (MSW) management system. Outputs of a resource recovery facility, refuse derived fuel (RDF) production facility, carbonization facility, plastics liquefaction facility, composting facility, and bio-gasification facility were analyzed for metal content and leaching concentration. In terms of metal content, bulky and incombustible waste had the highest values. Char from a carbonization facility, which treats household waste, had a higher metal content than MSW incinerator bottom ash. A leaching test revealed that Cd and Pb in char and Pb in RDF production residue exceeded the Japanese regulatory criteria for landfilling, so special attention should be paid to final disposal of these substances. By multiplying metal content and the generation rate of outputs, the metal content of input waste to each facility was estimated. For most metals except Cr, the total contribution ratio of paper/textile/plastics, bulky waste, and incombustible waste was over 80%. Approximately 30% of Cr originated from plastic packaging. Finally, several MSW management scenarios showed that most metals are transferred to landfills and the leaching potential of metals to the environment is quite small.

Influence of residual carbon on the decomposition process of PCDD/Fs in MSWI fly ash.

In heating treatment of fly ash to reduce PCDD/Fs, cooling process is important to inhibit de novo formation of PCDD/Fs. In this study, assuming that residual carbon is the dominant factor of de novo synthesis, the relation between PCDD/Fs and residual carbon was examined. Firstly, by using MSWI fly ash which was treated in an actually operated facility, both the content of PCDD/Fs and residual carbon were decreased as heating temperature increased. At temperatures higher than 400 degrees C, the reduction rate of residual carbon was higher than 20% and more than 95% of PCDD/Fs was decomposed. In order to simulate a heating treatment process, fly ash was heated at different temperatures and gas atmospheres, oxygen or nitrogen. Heated fly ash was placed for 2 h at 300 degrees C in oxygen to promote de novo synthesis, or cooled immediately. As a result, good correlation between PCDD/Fs and residual carbon was found, therefore it was shown experimentally that residual carbon was the main factor for PCDD/Fs formation by de novo synthesis in fly ash.

Behavior of metals in ash melting and gasification-melting of municipal solid waste (MSW).

In this study, metal behavior in ash-melting and municipal solid waste (MSW) gasification-melting facilities were investigated. Eight ash-melting and three MSW gasification-melting facilities with a variety of melting processes and feedstocks were selected. From each facility, melting furnace fly ash (MFA) and molten slag were sampled, and feedstock of the ash-melting processes was also taken. For the ash melting process, the generation rate of MFA was well correlated with the ratio of incineration fly ash (IFA) in feedstock, and this was because MFA was formed mostly by mass transfer from IFA and a limited amount from bottom ash (BA). Distribution ratios of metal elements to MFA were generally determined by volatility of the metal element, but chlorine content in feedstock had a significant effect on Cu and a marginal effect on Pb. Distribution ratio of Zn to MFA was influenced by the oxidizing atmosphere in the furnace. High MFA generation and distribution ratio of non-volatile metals to MFA in gasification-melting facilities was probably caused by carry-over of fine particles to the air pollution control system due to large gas volume. Finally, dilution effect was shown to have a significant effect on metal concentration in MFA.

The excitatory action of the newly-discovered mammalian tachykinins, neurokinin alpha and neurokinin beta, on neurons of the isolated spinal cord of the newborn rat.

The actions of two new mammalian tachykinins, neurokinin alpha and neurokinin beta, were examined using the isolated spinal cords of newborn rats. Depolarizing responses of spinal motoneurons were recorded extracellularly from the lumbar ventral root during application of neurokinin alpha or neurokinin beta at concentrations ranging from 3 X 10(-8) M to 10(-6) M. The potencies of various tachykinins in depolarizing the motoneurons showed the following order: physalaemin greater than neurokinin beta divided by kassinin divided by substance P greater than neurokinin alpha. When the synaptic transmission in the spinal cord was blocked by tetrodotoxin, the depolarizing action of neurokinin alpha and neurokinin beta was markedly reduced but not completely abolished. The depolarizing action of neurokinin alpha and neurokinin beta was depressed by a substance P antagonist, [D-Arg1, D-Pro2, D-Trp7,9, Leu11]SP. The possibility that neurokinin alpha and neurokinin beta act as neurotransmitters in the mammalian spinal cord is discussed.

Structural changes in oxidative modification of low-density lipoprotein: investigation using lipid peroxidation products, surface charge, and spectrophotometric patterns.

It is well recognized that oxidative modification of low-density lipoprotein (LDL) accelerates atherogenesis of the arterial vascular wall. In this study, we examined the relationship between various methods of measuring the extent of oxidation, namely lipid peroxidation products, surface charge, and spectrophotometric patterns. LDL was isolated from fresh human normal plasma by centrifugation and was oxidized by incubating with copper ions. Apolipoprotein B was isolated from the LDL solution. We also prepared artificial lipid particles composed of cholesterol linolenate, triolein, and phosphatidylcholine. Our results suggest that lipid peroxidation begins drastically in 30-60 min, while the abolition of the positive charge on apoliproproteins is accelerated after 60 min. We found a characteristic change in the spectrophotometric pattern during the process and conclude that the spectrophotometric absorption ration at 232 and 203 nm is a useful measure of in vitro oxidation of LDL.

A new enzymatic method for the determination of inulin.

A new enzymatic method for the determination of inulin in plasma and urine, using inulase (EC 3.2.1.7), fructokinase (EC 2.7.1.4), phosphoglucoisomerase (EC 5.3.1.9) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) is described. The assay is based on the hydrolysis of inulin or Inutest (INutest which is the injectable form of inulin), by inulase and the determination of fructose released. The assay was linear up to 2 g/L of Inutest. The within-batch and between batch coefficients of variation were 2.3% and 2.2%, respectively. Recovery of added Inutest from plasma and urine was 98-102%. There was no interference from glucose (27.7 mmol/L), fructose (1.7 mmol/L) or mannose (1.7 mmol/L). When inulin clearance (using this method) and thiosulphate clearance were compared in 37 patients the inulin clearance was 9.3 mL/min (12%) lower than the thiosulphate clearance. We conclude that this enzymatic method is a simple and specific method.

Resident's concerns and attitudes towards Solid Waste Management facilities.

Because of limited space, the siting and construction of a new SWM facility is a big challenge in Japan. An SWM facility should be socially accepted as well as environmentally and economically sound. This study aimed to investigate people's concerns about SWM facilities and their attitudes towards such facilities. A questionnaire was designed based on literature reviews and was sent to residents in three municipalities with different backgrounds. The questions covered concerns on the impact of an SWM facility, management aspects, unfairness of facility siting, and attitudes to facility construction. Of the many concerns, "pollution and health effect" had the highest rating, followed by "reliability", "damage to nature" and "cost". The rating was different between municipalities, reflecting their geographic and social backgrounds. Using factor analysis, correlations among concerns were analyzed, and five principal components were extracted, namely "pollution", "nuisance", "facility management", "planning of facility", and "merit/demerit". Although obvious correlations were not found between individual items of concern and attitudes to construction of a facility, the discriminant analysis indicated dominant concerns of attitudes, but the disagreement between actual impact and citizens were found. As for attributes, the "opposed" attitude decreased for residents who had visited an SWM facility, even if they had only seen it from outside.

Material and heavy metal balance in a recycling facility for home electrical appliances.

Collection and recycling of home electrical appliances was started in Japan in 2001 under a new recycling law. The law is aimed at promoting material recycling and at reducing the amount of waste to be landfilled. End of life products are processed by manual disassembly, shredding, and separation in 38 recycling facilities. The authors conducted a questionnaire survey and interviewed at some facilities to obtain information on process flow and material balance. By using the detailed records offered by one facility and by estimating the composition of recovered components, the material balance in the facilities was determined for four typical recycling processes. The heavy metal content of the recovered components was analyzed, then metal flow in the process was determined for each scenario. As a result, it was concluded that emissions to the environment of most heavy metals have been substantially reduced by the new recycling system, while a modest improvement in the rate of material recovery has been achieved.

Metal distribution in incineration residues of municipal solid waste (MSW) in Japan.

This study aimed to identify distribution of metals and the influential factors on metal concentrations in incineration residues. Bottom ash and fly ash were sampled from 19 stoker and seven fluidized bed incinerators, which were selected to have a variety of furnace capacity, furnace temperature, and input waste. In the results, shredded bulky waste in input waste increased the concentration of some metals, such as Cd and Pb, and the effect was confirmed by analysis of shredded bulky waste. During MSW incineration, lithophilic metals such as Fe, Cu, Cr, and Al remained mainly in the bottom ash while Cd volatilized from the furnace and condensed to the fly ash. About two thirds of Pb and Zn was found in the bottom ash despite their high volatility. Finally, based on the results obtained in this study, the amount of metal in incineration residues of MSW was calculated and the loss of metal was estimated in terms of mass and money. A considerable amount of metal was found to be lost as waste material by landfilling of incineration residues.

Effects of modified low density lipoprotein and hypoxia on the expression of endothelial leukocyte adhesion molecule-1.

OBJECTIVES: Expression of endothelial leukocyte adhesion molecule (ELAM-1 or CD62E) plays a role as an early event of atherogenesis. It is well known that interleukin-1 (IL-1) expresses ELAM-1 on vascular endothelial cells. We have examined pathological factors that induce ELAM-1 expression on cultured endothelial cells. METHODS: Examined factors were native low density lipoprotein (LDL), oxidized LDL, glycated LDL, hypoxia, and IL-1. Peroxidation of LDL was performed by ultraviolet radiation. Hypoxia was reproduced by adding a hypoxic cell-culture medium that was deoxygenated by use of a vacuum pump and nitrogen gas. Endothelial cells were harvested from a porcine aorta and were allowed to proliferate to be subconfluent in slide chambers. Expression of ELAM-1 was evaluated by counting the number of cells that were characterized by positive staining with the immunohistochemical technique. RESULTS: Without any stimulants, about 6.9% of the endothelial cells expressed ELAM-1. Weakly oxidized LDL (12 pmol/micrograms protein) significantly expressed ELAM-1 (14.8%) after an incubation period of 1 hour. Glycated LDL induced significant expressions (12.6%) in a fructosamine concentration of 65 pmol/micrograms protein. A one-hour incubation with a hypoxic culture medium expressed ELAM-1 in 16.3% of the cells. Native LDL did not cause any significant increases in the percentage. IL-1 expressed ELAM-1 in 30% of the cells even with as low a concentration as 3.1 U/ml. CONCLUSIONS: The present study shows that not only IL-1 but also weakly oxidized LDL, glycated LDL, and hypoxia may be possible factors that cause the expression of ELAM-1.

[Personal laboratory data management system using optical card].

This paper describes the development and state of the medical optical card system. Recently, computerized medical information systems have been developed in many hospitals and they allow quick access and automatic processing of the patient's data in medical practice and research. However, the use of the information stored by such a system has been limited to each hospital while it is not rare for a patient to change hospitals. It is desirable to develop a personal medical data management system which allows the patient to carry his own medical records for a long period of time, and hospitals to share the information about the patient. The optical card is a transportable information medium with a large capacity. Since data are recorded optically with a laser beam, the card is tolerant to environmental factors such as static electricity, magnetism and impact which injure other transportable media such as IC card, magnetic stripe card and floppy disk. Therefore, the optical card suits our purpose. We developed a prototype of the medical optical card system. In our system, the card can contain character data, numerical data, two-valued image data and electrocardiographical data. In order to share laboratory data among different database systems, we defined a data descriptive language which enables complete and compact data description without any external code tables. The recorded patient data are presented in the original multi-window system, which allows the doctor to see any combination of any part of the patient's information simultaneously.