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Municipal solid waste incineration (MSWI) fly ash has become a challenge for waste management because it is rich in heavy metals and its output is increasing sharply year by year. A novel binder system for MSWI fly ash solidification/stabilization was produced by blending MgO and silica fume in this work. And several tests including compressive strength, toxicity leaching behavior, hydration products, pore structure and micromorphology of MgO-SiO2-H2O (M–S–H) binders without and with MSWI fly ash were conducted. Results showed that the compressive strength of MSWI fly ash-blended samples varied from 1.8 MPa to 29.3 MPa, and the maximum leaching concentration of Pb, Zn and Cd were 0.052 mg/L, 1.02 mg/L, 0.098 mg/L, which all met the national standard limitation on the landfill site. Besides, M–S–H binders could buffer against the harsh acid environment at a certain degree, which would provide a proper low alkalinity environment for immobilization of heavy metals such as Pb, Zn and Cd in MSWI fly ash. Meanwhile, the microstructure and morphology characteristics analysis results demonstrated that the favorable ion exchange and high specific surface area of hydration product contributed much to the excellent immobilization and adsorption characteristics on heavy metals, so it can be deduced that M–S–H binders mainly fixed the heavy metals by the physical encapsulation and chemical bonding. Overall, this work demonstrated that the application potential of M–S–H as immobilization binders in the field of sustainable construction materials and hazardous waste management, and providing a new way for the development and utilization of magnesium resources.

Estimation of construction waste generation (CWG) at the field scale is a crucial but challenging task for effective construction waste management (CWM). Extant field-scale CWG modeling approaches have faced difficulties in obtaining accurate results due to a lack of detailed CWG data, and most of them fail to consider the complex relationship among predictive variables. This study attempts to tackle this issue by proposing a novel CWG modeling approach that integrates improved on-site measurement (IOM) and a support vector machine (SVM)-based prediction model. To achieve this goal, 206 ongoing commercial construction sites were investigated to obtain the predictor values and waste generation rates (WGRs) of five types of waste (i.e., inorganic nonmetallic waste, organic waste, metal waste, composite waste, and hazardous waste) generated at three construction stages (i.e., the understructure stage, superstructure stage, and finishing stage). The data were introduced to the SVM to develop the relationships between predictive variables and WGRs. An actual commercial building under construction was used to demonstrate the applicability of the proposed approach. The results showed that the superiority of the IOM can be used as a basis to implement robust CWG data collection. In addition, the SVM-based WGR prediction model (SWPM) can obtain more accurate prediction results (R2 = 86.87%) than the back-propagation neural network (R2 = 75.14%) and multiple linear regression (R2 = 61.93%).

Non-hazardous industrial waste (NHIW), primarily consisting of manufacturing process residues, has long been overlooked in waste reporting, regulation, and reuse. Limited information about NHIW generation with spatial and sectoral details has impeded the systematization of reuse efforts to move towards a resource-efficient economy. In this article, we develop a methodological framework that makes the best use of fragmented and limited observational data to infer the confidence intervals of NHIW generation by sector, location, and year across the United States. The framework decomposes the quantity of NHIW into two factors: the activity level (economic output) and the waste intensity factor (waste tonnage generated per unit of output). It statistically infers the probability distribution of the waste intensity factor and extrapolates waste tonnages to the entire country. In our demonstrative application of the method, we provide an updated estimate for spent foundry sand and find that its total amount in the United States decreased from 2.2-7.1 million tons in 2004 to 1.4-4.7 million tons in 2014. The spatial distribution, however, was highly uneven, with over 90% of the waste generated in 10% of the counties, indicating great variations in reuse potentials and benefits among regions. Our methodological framework makes a significant departure from existing estimations that usually rely on averaging limited observations or expert judgments biased by subjectivity. Detailing spatial and sectoral distributions and temporal trends in NHIW generation and reuse benefits, our study could inform more systematic strategies on waste and materials management to build a circular economy.

Waste printed circuit boards (WPCBs) contain a variety of valuable and hazardous materials. Recycling WPCBs is an important subject not only for environmental protection but also for sustainable development of resources. In this work, a new method combined low-temperature alkaline smelting with liquid-liquid phase separation is proposed to separate and recycle metal mixture in pyrolysis residue of WPCBs of mobile phones. During the low-temperature alkaline smelting process, amphoteric metals Al, Pb, Si, Sn, and Zn are firstly separated and recycled from the metal mixture with the separation rates of 99.5%, 81.6%, 97.8%, 88.4% and 95.7%, respectively. To separate the remaining metal mixture mainly containing elements Cu, Fe, Cr, Ni, Au and Ag, a liquid-liquid phase separation system is designed. As a result, the noble metals Au and Ag are concentrated in the copper-rich substance to form a high-value group, while the elements Ni and Cr distribute in the iron-rich substance. The iron-rich substance can be reused in the liquid-liquid phase separation process. In the super-gravity field, the recycling rates of the metals Au, Ag, Cr and Ni reach 98.1%, 99.8%, 95.6% and 75.4%, respectively. Furthermore, the iron-rich substance can be reused back to the liquid-liquid separation system. The copper-rich substance enriched by the noble metals can be efficiently recovered with low energy consumption and less pollution. This work provides an environmentally friendly and efficient route for separating and recycling the metal mixture in WPCBs.

The trend of the market of electric vehicles (EVs) in Korea is increasing because of reduction in heavy fine dust and economic benefit for purchasing EVs. With increasing number of EVs, the recycling of end-of-life battery of EVs is important to recover valuable metals such as Li and Co etc. and to control hazardous substances such as Pb, Cd and Cu. The current status on recycling policy and recycling technology of end-of-life battery of EV was explained in several countries including China, Europe, and Korea. It is necessary to immediately prepare the regulation on the storage, transportation and recycling of end-of-life battery of EV in Korea because of the safety management of end-of-life battery of EV. The new recycling scheme for the management of end-of-life batteries of EV by EPR system is proposed to secure recycling and stability because primary battery in internal combustion engine (ICE) vehicles is managed by the EPR system in Korea. For recycling of end-of-life battery of EVs, the technologies and the recycling level in Korea were compared with other countries. To develop the technical guidelines for the recycling of end-of-life battery of EV, it is proposed to set up an international committee on the recycling of end-of-life battery of EV as a new initiative in the Basel Convention.

The EU's publication of the 2017 End-of-Life Vehicle Recycling and Recovery results reported that the UK failed to meet its targets. The Commission's data showed that the UK only achieved a rate of 94.1% falling short of the 95% target. The treatment of automotive shredder residue (ASR) using pyrolysis technologies offers a potential solution to this shortfall. The pyrolysis products could contribute to the target as well as supporting the circular economy package. However, there are questions about their hazardous nature and whether they qualify as secondary products. ASR, from a commercial plant, was processed through a pilot-scale pyrolysis unit, which separated the char into two fractions: coarse ≥0.1 mm and fine ≤0.1 mm. These were chosen as potential commercial products. Chars were produced from two processing temperatures of 800 and 1000 °C. These temperatures maximise gas production and produce the best "quality" char in terms of limiting organic contamination. It was found that the toxicity of the chars changed with both processing temperature and size fraction; with the maximum total PAHs concentration in the fine fraction at 800 °C. The coarse fractions were shown to be non-hazardous. It is suggested that some form of post-separation may be required to remove the hazardous component. The implication was that non-separated char could be classified as hazardous even if its overall characteristics were not, due to the role of dilution. If there were any questions about the status of the char this could prevent the use of ASR to meet the higher ELV target. [Abstract copyright: Copyright © 2020 Elsevier Ltd. All rights reserved.]

In this study, the feasibility of using municipal solid waste incineration fly ash (MSWIFA) as additive for the strengthening of pretreated cement-stabilized soil was evaluated. Results indicated that the leaching concentrations of chromium and lead in MSWIFA after the water washing process and addition of 4% ferrous sulphate were reduced by 67% and 89%, respectively, which was lower than the limit value of Identification standard for hazardous waste (GB 5085.3-2007). After pretreatment, MSWIFA samples with ratios of 5% and 10% were blended into cement-stabilized soil with ordinary Portland cement (OPC) content of 10%, 15% and 20%. The unconfined compressive strength (UCS), internal friction angle and cohesion of the cement-stabilized soil increased with OPC and pretreated MSWIFA (PFA) content. The same effect was observed on UCS after the addition of 10% PFA as replacement of 5% OPC. In the subsequent X-ray powder diffraction test, scanning electron microscopy and leaching tests, the leaching concentrations of heavy metals in cement-stabilized soil became far lower than the limit value under the synergistic effects of the physical encapsulation of hydration products and stabilization of chemical agents. The incorporation of PFA as a supplementary material can effectively accelerate the formation of hydration products and can thus provide cleaner options for foundation reinforcement.

A recycling and disposal technology for municipal solid waste incinerator (MSWI) fly ash using high temperature sintering process was evaluated in an industrial scale facility with daily disposal capacity of 100 t/d. The emission, mass balance and distribution characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as well as heavy metals (HMs) were assessed during two test runs. The PCDD/Fs emission from stack varied in range of 0.019 to 0.025 ng I-TEQ /Nm3, below international standards. The PCDD/Fs in the sintered product was reduced to 0.002–0.008 μg I-TEQ/kg from 2.593 to 2.704 μg I- TEQ/kg of the original MSWI fly ash (Mix-FA). However high concentration of 14.3 μg I-TEQ/kg were found in the secondary fly ash (Sec-FA). Therefore, a large share of PCDD/Fs just desorbed from the ash and the destruction efficiency (DRE) for PCDD/Fs was only 8.9%. The distribution characteristics of investigated HMs were primarily dependent on the evaporative properties. The results of HMs leaching test for the sintered product were considerably below the Chinese legal limits. The HMs leaching toxicity test for Sec-FA indicated which is a hazardous waste presented high risk to the environment. The use of the sintered product as construction material need further assessment on its long term HMs leaching behavior.

An environmentally benign vacuum pyrolysis (VP) approach is employed to recover Li and Co from spent LiCoO2-based lithium-ion batteries (LIBs). First, the electroactive materials were separated from the current collector by the VP method from 623 to 823 K with an attempt to choose an appropriate temperature. Then, the as-received cathode materials were mixed with different amounts of graphite from the anode to selectively convert LiCoO2 to Co or CoO and Li2CO3 by carbothermic reduction under vacuum and at 873 to 1273 K. After carbothermic reduction, the pyrolyzed powder was leached in water to separate Li2CO3 from Co/CoO. By alternating the C/LiCoO2 mass ratio and the pyrolysis temperature, a recovery rate reaches over 93% for Li and 99% for Co. Finally, the recovered CoO and Li2CO3 were used to regenerated LiCoO2 that delivered a specific capacity of 145 mAh g−1 at 1C and retaining 93% of the initial capacity after 100 cycles. Overall, a multi-vacuum-pyrolysis approach offers a closed-loop route for the management of spent LIBs without using any hazardous chemicals.

Polyvinyl chloride (PVC) products comprise a large portion of plastic wastes and cause severe environmental burdens in thermal recycling such as toxic release and disposal difficulties. Selective separation methods for PVC containing hazardous chlorine are required for the development of suitable disposal or material recycling processes. However, separating PVC selectively from municipal plastic waste mixtures is difficult due to their similar hydrophobic surface and appearance densities. This study presents a one-step, selective separation technique for PVC using H2O2 solution under ultrasonic irrigation to promote the selective development of hydrophilicity only on the PVC surface. The combined treatment helped to decrease air bubbles attached on the PVC surface because of increased wettability, which allowed the treated PVC to settle on the bottom of the flotation reactor. However, the remaining plastic wastes were easily floated off because they maintained their hydrophobicity. The combined treatment with a low concentration of 3% H2O2 and ultrasonic irrigation for 30 min afforded 100% purity and recovery of the PVC separated from the municipal plastic waste mixture. This proposed treatment is therefore a promising and inexpensive way to improve plastic recycling quality through selective PVC separation by the selective development of hydrophilicity on its surface.

The production of lithium-ion battery is around 9100 million sets in 2016 and is believed to further increase consecutively. This fact triggers the generation of spent cathode materials which contain metals of both valuable and hazardous. Their recycling corresponding to life cycle sustainability of lithium-ion battery has attracted significant attention. However, most technologies for recycling waste lithium-ion batteries are dependent on metallurgical based processes where secondary pollution is inevitable. This research demonstrates a process to directly regenerate LiNi1−x−yCoxMnyO2 cathode material by incorporating methods of mechanochemical activation and solid-state sintering, which can restore the layered structure and improve the lithium ion diffusion without introducing extra impurities. By understanding the effects of sintering temperature, the optimal conditions for direct regeneration of cathode materials with obvious improvement on electrochemical performance can be obtained. As a result, this research proves the possibility of direct regeneration of nickel-containing waste cathode materials with minimized chemical consumption.

E-waste management is a challenging task not only due to its rapidly growing volume but more staggeringly because of its hazardous nature. This study examined the waste electrical and electronic equipment management in the educational institutions and governmental sector offices of Addis Ababa. Through purposive sampling method, the study involves 72 sample respondents from General Service Department office and 6 higher governmental officials. The study realized the purchase of both used and working electronic equipment. The major causes of e-waste generation are rapid obsolescence rate and breakage of electronic equipment. The X2 test result (13.066, p = .042) was statistically significant in terms of the causes of electronic waste among the selected offices. The rapid technological advancements, reduce in the performances of electronic equipment, poor utilizations and handlings brought the generation of obsolete and broken e-waste. The most common e-waste disposal method was storing. Hence, 81.7% of e-waste are simply stored. Other e-waste disposal methods such as reusing, refurbishing and recycling activities were flimsy. The absence of recycling possibilities and lack of awareness about the possibilities and values of recycling e-waste were some of the hindering factors. The administrative, economic and socio-cultural related factors challenging e-waste management. What is more, there were absence of e-waste legislation, shortages of storage facilities, absence of recycling and refurbishing centres. Therefore, the study proposes a workable e-waste management model and theory. Hence, Extended Producer Responsibility Model and Actor Network theory might be adopted and practiced within the realities of today’s Addis Ababa.

Printed circuit boards (PCBs) comprise valuable metals, precious metals, and hazardous materials. Thus, they are considered both attractive secondary sources of metals and environmental pollutants. This study is based on the selective separation of Pb-Sn, Sn-Cu, and Cu-Zn alloys, where supergravity separation was used to concentrate precious metals (i.e., Ag, Au, and Pd) from PCBs in Cu-Zn alloy and final residue. The temperature and gravity coefficient were found to have great influence on the concentration of precious metals in said alloy and residue. At the optimized temperature of 1300 °C, gravity coefficient of 1000, and separation time of 5 min, the Ag, Au, and Pd contents in the Cu-Zn alloy increased by 1.65, 2.05, and 1.54 times, respectively, compared to their concentrations in the original PCBs, while those in the final residue increased by 0.63, 1.02, and 2.62 times, respectively. By combining an appropriate hydrometallurgical process with the present supergravity separation and concentration of precious metals, this clean and efficient process provides a new pathway to recycle valuable metals and prevent environmental pollution by PCBs.

The long-term dynamics of leachate leakage from hazardous waste landfills (HWLs) and its influence on the surrounding groundwater and human health urgently requires decision-making processes for long-term HWL management and risk control. This study, based on the DMFU model, which is described in the literature as simulating the performance degradation of a landfill's main functional units, constructs a comprehensive model by coupling the HELP, EPACMTP, and Dose-Effect modules to investigate the long-term emissions of leachate from HWLs and their potential influence on groundwater quality and human health. Our results showed that the leakage rate over a long time period (50–1000 years) is 10 times higher than that of either a short (0–10 years) or medium (10–50 years) period. Due to the substantial increase in leakage rate, the negative influence on regional groundwater quality and human health changes from “insignificant” in the short term to “slight but acceptable” in the medium term, and finally to “substantial and unacceptable” in the long term. Studies also reveal that the uncertainty of risk increases over time. The information gained from this research provides useful insights into the long-term dynamics of leachate leakage, its risk consequences, and associated uncertainty, which can help landfill owners or risk managers make better decisions regarding the after-closure management of landfills.

There are approximately 15 million people engaged in waste collection or recycling activities in the world. Some of these dump sites are informal and people work in environments that are labor-intensive, unregulated, unregistered, low-paid, unrecorded, and environmentally hazardous. A systematic review was conducted to assess consequential health conditions and occupational risks that affect waste collectors in Brazil. The search was limited to Brazil because although the government closed dump sites, open-air dumping-the worst type of waste disposal-still occurs in about half of the country; moreover, Brazil is the only country to systematically collect data on the occupation, with an estimated 229,568 recyclable collectors of all types country-wide, which offers relevant and pertinent data on the topic. The results of the search indicated that nearly every region has individuals that work as recyclable collectors. As expected, the sites are full of occupational hazards to the workers that can include: long working hours; exposures to physical, chemical, mechanical, biological, ergonomic and social agents; and frequent work accidents. Exposure to these risks can result both in physical and psychological illnesses. In view of these findings, public policies could be strengthened by supporting and providing incentives to municipalities, schools, universities, health professionals, and all others who will contribute to the closure of open-air waste or poor waste disposal systems. Moreover, an improved awareness should be provided to the general population about environmental education and correct disposal of garbage. The goal of healthy waste disposal conditions ultimately decreases environmental and public health effects, while improving the working conditions, quality of life, and health outcomes for recyclable collectors.

The utilization of the stream of waste secondary nickel-metal hydride (Ni-MH) and lithium-ion (Li-ion) cells, representing annually about 33% of all consumer batteries and accumulators placed on the Polish market, will soon become a big challenge for both legislators and plants dealing with the recycling of this type of hazardous waste. It is due to the fact that no company in Poland operating on the market has a complete technology for the processing of a full stream of waste chemical energy sources produced in this country. Until now, the most commonly used techniques of processing this type of waste were pyrometallurgical process. In this paper, the quantitative and qualitative characteristics of the stream of waste batteries and accumulators collected at separate collection points are presented. The results of metal recovery: caesium, lanthanum, cobalt, iron, manganese, nickel and zinc from the stream of waste Ni-MH cells, type R6 (AA), using hydrometallurgical methods are also offered. The paper demonstrates that one-stage leaching at an initial temperature of 25.0 °C, with 3 M H2SO4 and at the solid to liquid ratio of s/l = 1/10, within 75 min, at a mixing speed of 500 rpm and in a strongly acidic environment should be adopted as optimal parameters for acid leaching of the paramagnetic fraction created after mechanical machining of Ni-MH battery, for which the leaching rates of individual metals were as follows: Ce - 97.7%, La - 88.7%, Co - 79.4%, Fe - 68.5%, Mn - 91.9%, Ni - 66.2% and Zn - 100%.

Fly ash commonly accumulates a significant amount of heavy metals and most of these heavy metals are toxic and easily leached out to the environment, posing risks to human health. Thus, fly ash has been classified as a type of hazardous waste and requires proper treatment before disposal in specific landfill sites for hazardous waste. In this study, a hydrometallurgical process developed to recover copper and zinc performed in pilot scale close to industrial scale followed by a landfill compliance leaching test of the ash residue is evaluated. LIX860N-I and Cyanex 572 gave high selectively for extractions, a yield efficiency of 95% and 61% was achieved for copper and zinc respectively. Results of pilot experiments reveals that the combining metal recovery recycling and landfill disposal of the ash residue in a local regular landfill was demonstrated to be a technically and economically effective strategy. Specifically, the economic and environmental aspects of a scenario, in which the fly ash generated in Guangzhou is processed were systematically assessed. the assessment results show that a 7.15 million US$ of total expense reduction, a less energy cost of 19k GJ as well as 2100 tons less CO2 emissions could be achieved annually comparing to the current alternative, direct disposal of the fly ash as hazardous waste. The results reveal that the hydrometallurgical process has industrial application potential on both economic and environmental aspects and further optimization of the process can give more accurate assessment of the cost and environment effect. In addition, leaching tests and evaluation of solid residue according to the regulations specific to the country should be studied in future.

Continuous growth of the shipping industry and infrastructure has consumed large amounts of zinc-rich paint (ZP) for the protection of steel structures against corrosion. Consequently, a growing amount of waste zinc-rich paint residue (ZPR) is being generated from anticorrosion spraying. ZPR is classified as hazardous waste in most industrialized countries, but it contains considerable amounts of organic compounds with high calorific value and zinc species that can potentially be recycled. Most of the ZPR generated is not properly treated, and this study presents a simple and efficient process for recycling ZPR. The zinc in ZPR was recovered via a hydrometallurgical route through oxidative alkaline leaching and electrowinning. The results show that the leaching ratio of zinc was greater than 98% at 95 °C, NaOH concentration of 250 g/L, liquid/solid ratio of 10:1, air flow rate of 0.6 L/min, and leaching time of 1.5 h. The appropriate minimum concentration of zinc for electrowinning was determined to be 10 g/L. Adding 50 mg/L of gelatin to the electrolyte significantly refined the grain and the optimum current density was determined to be 200 A/m2. Fern shaped cathode zinc powders with a purity of 99.8% were obtained. A high current efficiency (92.7%) was also obtained with energy consumption of 2330.3 kWh per ton of zinc produced. The composition and thermal analysis of the leaching residue suggest that co-processing in cement kiln may be suitable for disposing the leaching residue of ZPR. The experimental results show that the proposed process is promising for ZPR recycling.

The overall objective of this work is to determine the composition, characterization and production rate of Greek dental solid waste (DSW). This information is important to design and cost management systems for DSW, for safety and health considerations and for assessing environmental impact. A total of 141 kg of DSW produced by a total of 2542 patients in 20 dental practices from Xanthi, Greece was collected, manually separated and weighed over a period of four working weeks. The waste was separated in 19 sub fractions, which were classified in 2 major categories, according to Greek regulations: Domestic-type waste comprising 8% and hazardous waste comprising 92% by weight of total DSW. The latter was further classified in infectious waste, toxic waste and mixed type waste (infectious and toxic together), accounting for 88.5%, 3.5% and 0.03% of total DSW by weight, respectively. The overall unit production rates (mean ± standard error of the mean) were 381 ± 15 g/practice/d and 53.3 ± 1.4 g/patient/d for total DSW, 337 ± 14 g/practice/d and 46.6 ± 1.2 g/patient/d for total infectious DSW, 13.4 ± 0.7 g/practice/d and 2.1 ± 0.1 g/patient/d for total toxic DSW and 30.4 ± 2.5 g/practice/d and 4.6 ± 0.4 g/patient/d for domestic-type waste. Daily DSW production was correlated with daily number of patients and regression correlations were produced. DSW was subject to laboratory characterization in terms of bulk density, calorific value, moisture, ash and volatile solids content. Measured calorific values were compared to predictions from empirical models.

Rejects from selective collection are municipal solid waste (MSW) not used for recycling and are, therefore, destined for the landfill in Brazil. Knowledge of the composition and generation of this waste is important for strategically planning public policies that minimize its generation and its negative environmental impacts. However, this portion of MSW is not very well known. Therefore, the aim of this study was to analyze the rejects from the sorting process of the selective waste collection in the municipality of Blumenau, in the State of Santa Catarina, southern Brazil. The studied rejects came from the largest cooperative in the city, and its composition was sorted into 17 categories of 101 samples over the course of one year, with a total of 3893 kg of analyzed rejects. The waste collected by the selective collection of the municipality was evaluated monthly to determine which part of this quantity became rejects and to determine the composition and seasonality of these rejects. The study found that 30.5% of the waste sorted by the cooperative was rejected. Among these rejects, the presence of materials that could be marketed by the cooperative was verified. Hazardous and/or legally prohibited waste were also identified, as were organics, construction and demolition waste, health care waste, electronics, textiles, footwear, batteries, and bulbs. Seasonal analysis indicated a concerning constant generation of health care waste. Aside from that, there was an increase in the generation of waste from electrical and electronic equipment (EEE) during the Christmas period, when a large part of the population discards their EEE. This information is important for the enforcement of the MSW management structure as well as for educational campaigns aimed at the correct separation of waste that should be sent for selective collection.

Municipal solid waste incineration (MSWI) fly ash constitutes a hazardous waste. The possibilities for managing this waste comprise disposal at underground deposits or at above-ground landfills after cement stabilisation, application of the FLUREC process, thermal treatment in a dedicated furnace or thermal co-treatment together with combustible hazardous waste. A comparative life cycle assessment (LCA) study was conducted in order to assess the environmental impact of these five MSWI fly ash disposal options with regard to two different time horizons (100years, indefinite). The uncertainties of the input parameters were propagated by Monte Carlo simulations (MCS). As could be shown by the discernibility analysis, the FLUREC process has the lowest impact in more than 90% of the MCS results. In case long-term emissions (beyond 100years) are neglected, the second lowest impact is caused by thermal co-treatment in more than 90% of the MCS results. Consideration of long-term emissions indicates the disposal at underground deposits as second best option. Furthermore, it is shown that stabilisation with cement has the second highest and thermal treatment in a dedicated furnace has the highest environmental impact, mostly due to high CO2 emissions. Therefore these two treatment options should be avoided in the future. Besides the comparative evaluation of the different options, it could be shown that uncertainty analysis is useful to determine the relevance of long-term emissions for the ranking of different systems.

Malaysian authorities has planned to minimize and stop when applicable unsanitary dumping of waste as it puts human health and the environment at elevated risk. Cost, energy and revenue are mostly adopted to draw the blueprint of upgrading municipal solid waste management system, while the carbon footprint emissions criterion rarely acts asa crucial factor. This study aims to alert Malaysian stakeholders on the uneven danger of carbon footprint emissions of waste technologies. Hence, three scenarios have been proposed and assessed mainly on the carbon footprint emissions using the 2006 IPCC methodology. The first scenario is waste dumping in sanitary landfills equipped with gas recovery system, while the second scenario includes anaerobic digestion of organics and recycling of recyclable wastes such as plastic, glass and textile wastes. The third scenario is waste incineration. Besides the carbon footprint emissions criterion, other environmental concerns were also examined. The results showed that the second scenario recorded the lowest carbon footprint emissions of 0.251t CO2 eq./t MSW while the third scenario had the highest emissions of 0.646t CO2 eq./t MSW. Additionally, the integration between anaerobic digestion and recycling techniques caused the highest avoided CO2 eq. emissions of 0.74t CO2 eq./t MSW. The net CO2 eq. emissions of the second scenario equaled -0.489t CO2 eq./t MSW due to energy recovery from the biogas and because of recycled plastic, glass and textile wastes that could replace usage of raw material. The outcomes also showed that the first scenario generates huge amount of leachate and hazardous air constituents. The study estimated that a ton of dumped waste inside the landfills generates approximately 0.88m3 of trace risky compounds and 0.188m3 of leachate. As for energy production, the results showed that the third scenario is capable of generating 639kWh/t MSW followed by the second scenario with 387.59kWh/t MSW. The first scenario produced 296.79kWh/t MSW. In conclusion, the outcomes of this study recommend an integrated scenario of anaerobic digestion and recycling techniques to be employed in Malaysia.

Recycling of waste materials is desirable to reduce the consumption of limited primary resources, but also includes the risk of recycling unwanted, hazardous substances. In Austria, the legal framework demands secondary products must not present a higher risk than comparable products derived from primary resources. However, the act provides no definition on how to assess this risk potential. This paper describes the development of different quantitative and qualitative methods to estimate the transfer of contaminants in recycling processes. The quantitative methods comprise the comparison of concentrations of harmful substances in recycling products to corresponding primary products and to existing limit values. The developed evaluation matrix, which considers further aspects, allows for the assessment of the qualitative risk potential. The results show that, depending on the assessed waste fraction, particular contaminants can be critical. Their concentrations were higher than in comparable primary materials and did not comply with existing limit values. On the other hand, the results show that a long-term, well-established quality control system can assure compliance with the limit values. The results of the qualitative assessment obtained with the evaluation matrix support the results of the quantitative assessment. Therefore, the evaluation matrix can be suitable to quickly screen waste streams used for recycling to estimate their potential environmental and health risks. To prevent the transfer of contaminants into product cycles, improved data of relevant substances in secondary resources are necessary. In addition, regulations for material recycling are required to assure adequate quality control measures, including limit values.

This paper presents a literature review on the incorporation of municipal solid waste incinerated bottom ash as raw material in several markets, other than those where it is conventionally used, such as geotechnical applications and road pavement construction. The main findings of an ample selection of experimental investigations on the use of the bottom ash as precursor of alkali-activated materials, as an adsorbent material for the removal of hazardous elements from wastewater and landfill gases, as soil replacement in agricultural activities, as partial or complete substitute of raw materials for the manufacture of ceramic-based products, as landfill cover and as biogas production enhancer, were gathered, collated and analysed.

This study aims to evaluate the environmental impacts and benefits of state-of-the-art technologies for proper e-waste handling using Jordan as a case study. Life Cycle Assessment (LCA) was employed to evaluate five advanced management systems represent state-of-the-art treatment technologies, including sanitary landfilling; proper recycling of metals, materials, and precious metals (PMs); and incineration of plastic and the hazardous portion of printed circuit boards (PCBs). Six e-waste products that contribute the most to the e-waste in Jordan were included in the assessment of each scenario, which resulted in 30 total cases of e-waste management. The findings indicated that landfills for the entire components of the e-waste stream are the worst option and should be avoided. The most promising e-waste management scenario features integrated e-waste processes based on the concept of Integrated Waste Management (IWM), including recycling materials such as non-PMs and PMs, incinerating plastic and the hazardous content of PCBs using the energy recovered from incineration, and using sanitary landfills of residues. For this scenario, the best environmental performance was obtained for the treatment of mobile phones. Incineration of the portion of hazardous waste using energy recovery is an option that deserves attention. Because scenario implementation depends on more than just the environmental benefits (e.g., economic cost and technical aspects), the study proposes a systematic approach founded on the IWM concept for e-waste management scenario selection.