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1.
Twenty four waste cellular phones, manufactured between 2002 and 2011, were selected in order to determine the total heavy metal content in each of their parts (printed circuit boards (PCBs), plastic housing (PH) and liquid crystal display monitors (LCDs)) and compare the results with the permissible limits set by the 2003 Directive on Restriction of Hazardous Substances (RoHS). All the selected samples were pulverized and digested with strong acids. Inductively coupled plasma-mass spectrometry was used to measure the heavy metal content in each sample. The results revealed that concentration levels of the examined heavy metals were higher in PCBs, followed by PH and LCD in that particular order (PCB > PH > LCD). With the exception of Pb and Cr present in PCBs of mobile phones released before the year 2006, all the other metal concentrations were according to the Directive. Concentration levels of Cd, Hg were lower than the permissible limits set by the EU, either before or after the validity of the 2003 RoHS Directive. Considering their significant heavy metal content, coupled with their large quantities produced worldwide in an annual rate, waste cellular phones need to be treated under an environmentally sound management scheme, prioritizing recycling and at the same time eliminating the possibility of any harm.  相似文献   

2.
The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline–manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc–carbon batteries, on average, contained the highest levels.  相似文献   

3.
The EU RoHS Directive (2002/95/EC of the European Parliament and of the Council) bans the placing of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants on the EU market. It necessitates methods for the evaluation of RoHS compliance of assembled electronic equipment. In this study mounted printed circuit boards from personal computers were analyzed on their content of the three elements Cd, Pb and Hg which were limited by the EU RoHS directive. Main focus of the investigations was the influence of sample pre-treatment on the precision and reproducibility of the results. The sample preparation steps used were based on the guidelines given in EN 62321. Five different types of dissolution procedures were tested on different subsequent steps of sample treatment like cutting and milling. Elemental analysis was carried out using ICP-OES, XRF and CV-AFS (Hg). The results obtained showed that for decision-making with respect to RoHS compliance a size reduction of the material to be analyzed to particles ?1.5 mm can already be sufficient. However, to ensure analytical results with relative standard deviations of less than 20%, as recommended by the EN 62321, a much larger effort for sample processing towards smaller particle sizes might be required which strongly depends on the mass fraction of the element under investigation.  相似文献   

4.
Cathode ray tube (CRT) glass is considered a hazardous material due to its lead toxicity. In addition, current disposal practices are being phased out due to their adverse environmental impacts. In this project, CRT glass was used as a fine aggregate replacement in concrete. Life-cycle material characterization was conducted by evaluating the durability and strength of the CRT-Concrete. Leaching tests were also conducted to investigate whether the material meets drinking water limits for Pb. Test results show that the plastic state of the CRT-Concrete was affected by the angularity of the glass particles. Moreover, the compressive strength of CRT-Concrete met and exceeded that of the control specimen. However, CRT-Concrete was susceptible to expansive alkali-silica reactions when more than 10% CRT replacement was used. Environmental leaching results show that lead concentrations from CRT-Concrete are below the drinking water limits depending on the CRT volume replacement and if biopolymers are used.  相似文献   

5.
Grout and glass formulations were developed for the stabilization of highly radioactive tank sludges. These formulations were tested in the laboratory with a surrogate and with a sample of an actual mixed waste tank sludge. The grout formulation was tested at wet-sludge loadings of 50–60 wt%, giving a volume increase of about 40–50 vol%. Dried sludge was vitrified into glass at waste oxide loadings of 40–50 wt%, giving a volume decrease of about 50–60 vol%. The Resource Conservation and Recovery Act (RCRA) metals included in surrogate testing were Ag, Ba, Cd, Cr, Ni, Pb, Se, Tl and Hg. Since vitrification would volatilize, not stabilize mercury, it was not included in the surrogates vitrified. The actual sludge sample was only characteristically hazardous for mercury by the toxic characteristic leaching procedure (TCLP) but exceeded the Universal Treatment Standard (UTS) limit for chromium. The grout and glass formulations stabilized these RCRA metals within UTS limits. In addition, a grout leachability index of about 9–10 was measured for both 85Sr and 137Cs, meeting the recommended requirement of >6. The glass leachability index was estimated to be >18 for cold cesium and strontium.  相似文献   

6.
The within-site correlations between soil respiration rates,lead (Pb), mercury (Hg) and cadmium (Cd) concentrations andorganic matter quality variables were investigated at four sites in southern Sweden. The aim was to study whether the within-site variation in heavy metal concentrations could beused to monitor biological effects of regional deposition of heavy metals. Two sites in the south-west, one in the mid-southof the country, and one in south-east were investigated. At the south-eastern, least contaminated, site there were no correlations between soil respiration rate, and either organicmatter quality variables or heavy metal concentrations. At the remaining sites, negative correlations were found between Pb andsoil respiration rate. However, at two of these three sites there was a covariation with cellulose that could account for these correlations. The within-site variation of pH and total nitrogen (N) was low, and did not show any correlative general trends with either respiration rate or heavy metals. Meta analysis showed that negative correlations between Pb or Hg, on the one hand, and cellulose or hemicellulose on the other weregenerally found in within-site investigations. However, this does not necessarily explain the correlation between Pb and soil respiration, as was shown for the southernmost site. A PLS model of soil respiration rates at this site, using allmeasured variables, including heavy metals, explained more variation than a model developed using only mor layer thickness,pH, carbohydrate, ash and nitrogen concentrations, as independent variables. Thus there is a risk of toxic effects from Pb even at the levels found in south-western Sweden today(>120 g Pb * g dw-1). However, since the correlationsbetween heavy metals and cellulose were not significantly different at the different sites, random sampling variation could not be ruled out as an explanation of the different results for the different sites. The causes of the correlationbetween organic matter quality and heavy metals have not yet been clarified. Analysis of mor samples incubated in thelaboratory for 2 yr with 1200 g Pb * g dw-1 or 5 gHg * g dw-1 did not show any differences in carbohydrate composition, compared to control samples. This shows that within-site studies of correlations between respiration rate and heavy metals have to be combined with studies of metal additions to soils and analysis of organic matter quality beforeany valid conclusions can be made.  相似文献   

7.
In recent history the volume of electronic products purchased by consumers has dramatically escalated. As a result this has produced an ever-increasing electronic waste (E-waste) stream, which has generated concerns regarding the E-waste’s potential for adversely impacting the environment. The leaching of toxic substances from obsolete personal computers (PCs) and cathode ray tubes (CRTs) of televisions and monitors, which are the most significant components in E-waste stream, was studied using landfill simulation in columns. Five columns were employed. One column served as a control which was filled with municipal solid waste (MSW), two columns were filled with a mixture of MSW and CRTs, and the other two were filled with MSW and computer components including printed wire boards, hard disc drives, floppy disc drives, CD/DVD drives, and power supply units. The leachate generated from the columns was monitored for toxic materials throughout the two-year duration of the study. Results indicate that lead (Pb) and various other heavy metals that were of environmental and health concern were not detected in the leachate from the simulators. When the samples of the solids were collected from underneath the E-waste in the columns and were analyzed, significant amount of Pb was detected. This indicates that Pb could readily leach from the E-waste, but was absorbed by the solids around the E-waste materials. While Pb was not observed in the leachate in this study, it is likely that the Pb would eventually enter the leachate after a long term transport.  相似文献   

8.
Copper waste is iron-rich hazardous waste containing heavy metals such as Cu, Zn, Co, Pb. The results of leaching tests show that the concentration of these elements exceeds the Turkish and EPA regulatory limits. Consequently, this waste cannot be disposed of in its present form and therefore requires treatment to stabilize it or make it inert prior to disposal. Vitrification was selected as the technology for the treatment of the toxic waste under investigation. During the vitrification process significant amounts of the toxic organic and inorganic chemical compounds could be destroyed, and at the same time, the metal species are immobilized as they become an integral part of the glass matrix. The copper flotation waste samples used in this research were obtained from the Black Sea Copper Works of Samsun, Turkey. The samples were vitrified after being mixed with other inorganic waste and materials. The copper flotation waste and their glass-ceramic products were characterized by X-ray analysis (XRD), scanning electron microscopy and by the toxicity characteristic leaching procedure test. The products showed very good chemical durability. The glass-ceramics fabricated at 850 degrees C/2 h have a large application potential especially as construction and building materials.  相似文献   

9.
Sewage sludge from the extended aeration municipal wastewater treatment plant of Kalamata (Greece), dewatered and dried was tested for potential land application. Experiments were carried out simulating rainfall, one low-rate high-duration at 20 mm/d, and one high-rate low-duration at 6.6 mm/d. Leachate was collected and analyzed as a function of accumulated rainfall. The sludge was found suitable for agricultural uses on the basis of the relevant EEC Directive. Leachates contained P and heavy metals well above the allowable limits for discharge, implying that transport through the soil can be decisive on the likelihood of groundwater contamination. High-rate low-duration rain events give higher contaminant concentrations in the accumulated leachates.  相似文献   

10.
Our aim was to clarify the chemical bonding type and stability of heavy metals in industrial waste slag (IWS) by using Fourier transform infrared (FT-IR) spectroscopy. The chemical composition of the IWS sample used in this study was an Al/Si ratio of 0.50 with Fe, Pb, and other minor heavy metals present. The IR peak position of the Si-OSi( M) band (M: Al, Pb, or Fe) was lower for IWS (971 cm−1) than for synthetic Si-Al glass with an Al/Si ratio of 0.5 (1029 cm−1). This implies the formation of covalent Si-O-Pb and Si-O-Fe bonds in the IWS, which caused a shift in the peak position toward a lower wavenumber. FT-IR spectra of synthetic Si-Al-Pb and Si-Al-Fe glasses with various Pb/Si and Fe/Si ratios with a constant Al/Si ratio of 0.5 showed that the peak position of the Si-O-Si(M) band continuously shifted toward lower wavenumbers with increasing Pb/Si and Fe/Si ratios. This suggests that covalent Si-O-Pb and Si-O-Fe bonds are formed in IWS. The comparison of peak positions of the Si-O-Si(M) band between IWS and Si-Al-Fe glass indicated that not only Pb but also other minor heavy metals such as Cu and Cr were included by covalent bonds into the structure of IWS. Therefore, we concluded that most of the heavy metals in IWS formed covalent Si-O-M bodings and were chemically stable.  相似文献   

11.
Tannery waste is categorized as toxic and hazardous in Malaysia due to its high content of Cr (in excess of 500 mg/kg) and other heavy metals. Heavy metals, when in high enough concentrations, have the potential to be both phytotoxic and zootoxic. Heavy metals are found as contaminants in tannery sludge. This investigation aimed to identify the fate of chromium, cadmium, copper, lead, and zinc concentrations in tannery sludge throughout a 50-day composting cycle. The results of this study showed a general increase in the removal of Cr, Cd, Pb, and to a much smaller extent Zn and Cu, manifested by a decrease in their overall concentrations within the solid fraction of the final product (the decreases were likely the result of leaching). Furthermore, in using a sequential extraction method for sludge composting at different phases of treatment, a large proportion of the heavy metals were found to be associated to the residual fraction (70-80%) and fractions more resistant to extraction, X-NaOH, X-EDTA, X-HNO3 (12-29%). Less than 2% of the metals were bound to bioavailable fractions X-(KNO3+H2O).  相似文献   

12.
The performance of four dioxin emission monitors, including two long-term sampling devices, the Dioxin-MonitoringSystem (DMS) and AMESA (the adsorption method for sampling dioxins and furans), and two semireal-time continuous monitors, the resonance ionization with multimirror photon accumulation time-of-flight mass spectrometer (RIMMPA-TOFMS) and the jet resonance-enhanced multiphoton ionization (jet-REMPI) system were tested. A package boiler burning a simulated chlorinated hazardous waste was used for a total of nine tests. Reference samples were collected during each test and analyzed for polychlorinated dibenzodioxins and dibenzofurans (PCDDs/Fs) using gas chromatography mass spectrometry. The PCDD/F concentrations of the reference samples measured by EPA Method 23 ranged from 0.9 to 6.0 ng toxic equivalence (TEQ)/dry standard cubic meter. The relative accuracies achieved by DMS, AMESA, and jet-REMPI varied from 22.6% to 78.2%, with 100% data completeness. The RIMMPA-TOFMS produced no quantifiable results due to various difficulties associated with the instrument during the testing. The two long-term samplers were easy to install and operate and provided a cumulative, averaged emission for the sampling period. The operations of the two semi-real-time continuous monitors were relatively complex, but one of them provided on-site, real-time data for PCDD/F emissions from measurement of a TEQ correlative indicator compound. This article summarizes results from the individual Environmental Technology Verification reports for the four dioxin monitors. This work was presented, in part, at the Fourth International Conference on Combustion, Incineration/Pyrolysis and Emission Control (i-CIPEC)  相似文献   

13.
Incineration of municipal solid waste (MSW) is a waste treatment method which can be sustainable in terms of waste volume reduction as well as a source of renewable energy. In the process fly and bottom ash is generated as a waste material. The ash residue may vary greatly in composition depending on the type of waste incinerated and it can contain elevated levels of harmful contaminants such as heavy metals. In this study, the ecotoxicity of a weathered, untreated incineration bottom ash was characterized as defined by the H14 criterion of the EU Waste Framework Directive by means of an elemental analysis, leaching tests followed by a chemical analysis and a combination of aquatic and solid-phase bioassays. The experiments were conducted to assess the mobility and bioavailability of ash contaminants. A combination of aquatic and terrestrial bioassays was used to determine potentially adverse acute effects of exposure to the solid ash and aqueous ash leachates. The results from the study showed that the bottom ash from a municipal waste incineration plant in mid-Sweden contained levels of metals such as Cu, Pb and Zn, which exceeded the Swedish EPA limit values for inert wastes. The chemical analysis of the ash leachates showed high concentrations of particularly Cr. The leachate concentration of Cr exceeded the limit value for L/S 10 leaching for inert wastes. Filtration of leachates prior to analysis may have underestimated the leachability of complex-forming metals such as Cu and Pb. The germination test of solid ash and ash leachates using T. repens showed a higher inhibition of seedling emergence of seeds exposed to the solid ash than the seeds exposed to ash leachates. This indicated a relatively low mobility of toxicants from the solid ash into the leachates, although some metals exceeded the L/S 10 leaching limit values for inert wastes. The Microtox® toxicity test showed only a very low toxic response to the ash leachate exposure, while the D. magna immobility test showed a moderately high toxic effect of the ash leachates. Overall, the results from this study showed an ecotoxic effect of the solid MSW bottom ash and the corresponding ash leachates. The material may therefore pose an environmental risk if used in construction applications. However, as the testing of the solid ash was rather limited and the ash leachate showed an unusually high leaching of Cr, further assessments are required in order to conclusively characterize the bottom ash studied herein as hazardous according to the H14 criterion.  相似文献   

14.
Medical waste from hospitals and other healthcare institutions has become an imperative environmental and public safety problem. Medical waste in Greece has become one of the most urgent environmental problems, because there are 14,000 tons produced annually, of which only a small proportion is incinerated. In the prefecture of Attica there is only one modern municipal medical waste incinerator (started 2004) burning selected infectious hospital waste (5-6 tons day(-1)). Fly and bottom residues (ashes) are collected and stored temporarily in barrels. High values of metal leachability prohibit the landfilling of these ashes, as imposed by EU directives. In the present study we determined quantitatively the heavy metals and other elements in the fly and bottom ashes of the medical waste incinerator, by inductively coupled plasma emission spectrometry (ICP) and by energy dispersive X-ray analysis (EDAX). Heavy metals, which are very toxic, such as Pb, Cd, Ni, Cr, Cu and Zn were found in high concentrations in both fly and bottom ashes. Metal leachability of fly and bottom ashes by water and kerosene was measured by ICP and the results showed that toxic metals in both ashes, such as Pb, Cr, Cd, Cu and Zn, have high leaching values. These values indicate that metals can become soluble and mobile if ash is deposited in landfills, thus restricting their burial according to EU regulations. Analysis of polychlorinated biphenyls and polycyclic aromatic hydrocarbons in fly and bottom ashes showed that their concentrations were very low. This is the first known study in Greece and the results showed that incineration of medical waste can be very effective in minimizing the most hazardous and infectious health-care waste. The presence of toxic metals with high leachability values remains an important draw back of incineration of medical waste and various methods of treating these residues to diminish leaching are been considered at present to overcome this serious technical problem.  相似文献   

15.
In southern Sweden, where exposure to long range distributedheavy metals is about the highest in Scandinavia, depositionsof cadmium (Cd) and lead (Pb) decreased about 20 and 70%,respectively, between mid-1980s and mid-1990s, as estimated bytheir concentrations in moss. Concentrations of Cd and Pb in tissues of the pied flycatcher (Ficedula hypoleuca) and bank vole (Clethrionomys glareolus) were also lower in 1996and 1997 compared to 1981 and 1982. It is concluded that the decreased deposition rate of these elements in southern Sweden had caused decreased exposure, and thus also to decreased potential risk of detrimental effects on insectivorous birds andherbivorous mammals. There was no indication that breeding results of pied flycatcher was influenced by the decreased deposition of toxic metals.  相似文献   

16.
A study of the effects of LCD glass sand on the properties of concrete   总被引:1,自引:0,他引:1  
In order to study the recycling of discarded liquid crystal display (LCD) glass into concrete (LCDGC), a portion of the usual river sand was replaced by sand prepared from discarded LCD glass. Three different mix designs were regulated by the ACI method (fc(28)=21, 28, and 35MPa) with 0%, 20%, 40%, 60%, and 80% LCD glass sand replacements investigated; their engineering properties were determined. Test results revealed that, when compared to the design slump of 15cm, the 20% glass sand concrete for the three different mix designs kept good slump and slump flow. Furthermore, a slump loss ranging from 7 to 11cm was observed for specimens with 60% and 80% glass sand replacement for the design strengths of 28 and 35MPa. The compressive strengths of the concrete with glass sand replacement were higher than the design strengths. Moreover, the durability of the concrete with 20% glass sand replacement was better than that of the control group. Surface resistivity for specimens with different amounts of LCD glass sand replacement was also higher than that in the control group for mid to long curing ages. The sulfate attack in concrete with different amounts of glass sand replacement caused less weight loss than in the control group. Moderate chloride ion penetration was observed for glass sand concrete. Furthermore, the measured ultrasonic pulse velocities for LCD glass sand concrete specimens were higher than 4100m/s, which qualified these specimens as good concrete. OM and SEM indicate that the dense C-S-H gel hydrate was produced at the interface between the glass sand and cement paste. The test results indicate that the addition of 20% LCD glass sand to concrete satisfies the slump requirements and improves the strength and durability of concrete. This suggests that LCD glass sand can potentially be used as a recycled material in concrete applications.  相似文献   

17.
Sorption capacities were evaluated for the dissolved stormwater (SW) pollutants onto two tree mulches and jute fiber. SW spiked with predetermined concentrations of copper (Cu), cadmium (Cd), hexavalent chromium (Cr +6), lead (Pb), zinc (Zn), and benzo[a]pyrene (B[a]P), naphthalene (NP), fluoranthene (FA), 1,3‐dichlorobenzene (DCB), and butylbenzylphthalate (BBP) were used in this study. Each medium removed close to 100 percent of all the pollutants at the concentrations studied. Sorption capacities (μg/g) of the three organic media were in the order of jute > hardwood mulch > softwood mulch, and on a mole basis, both the heavy metals and the toxic organics were sorbed by the three media in an identical sequence: Cr +6 > Cu, Zn > Cd > Pb; and NP > DCB > FA > B[a]P > BBP. Sorption capacities of the hardwood wood mulch and jute fiber for the pollutants were correlated with distinctive physical properties of the pollutants. © 2005 Wiley Periodicals, Inc.  相似文献   

18.
Environmentally safe disposal of end-of-life (EoL) or discarded mobile phone is a serious problem on account of their ever increasing number and toxic metals contents. In the present work, metal toxicity of mobile phone plastics, printed wire boards (PWBs) and batteries were assessed through dynamic batch leaching using Milli Q (MQ) water. Phone plastics failed Toxicity Characterization Leaching Procedure (TCLP) and Waste Extraction Test (WET) for Pb as the cumulative amount of Pb leached from plastics (5.33 mg/l) exceeded the regulatory limits (5.0 mg/l) used in characterizing a waste as hazardous. Similarly, the average cumulative amount (21.83 mg/l) of Ni leached from PWBs exceeded the regulatory limit of 20 mg/l and thus PWBs failed WET. Metals leached from batteries in small amounts (Cr: 0.40 mg/l and Ni: 0.15 mg/l). The presence of Fe in the batteries and its precipitation as oxides/hydroxides in the leaching solution hindered the leaching of other metals in MQ water. Both plastics and PWBs should be treated as hazardous waste and should not be disposed in open landfills. Further, MQ water leaching could provide good simulation of metals leaching from the mobile phones disposed at landfill sites.  相似文献   

19.
Disposal of PC monitors and TV sets is a growing problem, with over 40% of the weight of these systems comprised of waste glasses with high Pb (funnel) or Ba–Sr concentrations (panel), making them unsuitable for recycling and manufacturing new glass. A possible way to re-use these glasses is in the manufacturing of clay bricks and roof tiles. This possibility was appraised by laboratory simulation of the brickmaking process and technological characterization of unfired and fired products. The recycling of both funnel and panel glasses into clay bodies is technologically feasible, resulting in a substantially reduced plasticity behaviour during shaping–drying (implying a reduction of mechanical strength), and a promotion of sintering during firing. No significant release of Pb, Ba, and Sr was observed during the firing and leaching test for the carbonate-poor body; in contrast, some Pb volatilization during firing and Sr leaching were observed for the carbonate-rich body. Additions of 2 wt.% appear to be practicable, while 5 wt.% glass induces unacceptable modifications of technological properties. The recommended amount is within 2 and 4 wt.%, depending on the characteristics of the clay bodies. The main constraint is that the glass must have a particle size below the limit of the pan mills used in brickmaking (<1 mm).  相似文献   

20.
Vitrification of electric arc furnace dusts   总被引:6,自引:0,他引:6  
Electric arc furnace baghouse dust (EAFD), a waste by-product of the steelmaking process, contains the elements that are volatilized from the charge during the melting (Cr, Pb, Zn, Cu and Cd). The results of leaching tests show that the concentration of these elements exceeds the regulatory limits. Consequently, EAFD cannot be disposed of in ordinary landfill sites without stabilization of the heavy metals. In this work, the vitrification of EAFD, from both carbon and stainless steel productions, were studied. The vitrification process was selected as the inertizing process because it permits the immobilization of the hazardous elements in the glass network and represents an environmentally acceptable method for the stabilization of this waste. Classes of various compositions were obtained by mixing EAFD with glass cullet and sand. The EAFD and the glass products were characterized by DTA, TG, X-ray analysis and by the TCLP test. The results show that the stability of the product is influenced by the glass structure, which mainly depends on the Si/O ratio. Secondary crystallization heat-treatment were carried out on some samples. The results highlighted the formation of spinel phases, which reduced the chemical durability in acid media. The possibility to recover Zn from carbon steel production EAFD was investigated and about 60-70% of metal recovery was obtained. The resulting glass show higher chemical stability than glasses obtained without metal recovery.  相似文献   

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