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Rapid global urbanization and economic growth have significantly increased solid waste volumes, with hazardous waste posing substantial health and environmental risks. Co-processing strategies for industrial solid and hazardous waste as alternative fuels highlight the importance of integrated waste management for energy and material recovery. This study identifies and characterizes solid and hazardous industrial wastes with high calorific values from various industrial processes at Nirma Industries Limited. Nine types of combustible industrial wastes were analyzed: discarded containers (W1), plastic waste (W2), spent ion exchange resins from RO plants (W3), sludge from effluent treatment in soap plants (W4), glycerine foot from soap plants (W5), rock wool puff material (W6), fiber-reinforced plastic waste (W7), spent activated carbon (W8), and spent cartridges from reverse osmosis plants (W9). Physical characterization, proximate and ultimate analysis, heavy metal concentration evaluation, and thermogravimetric analysis were conducted to assess their properties, revealing high calorific values exceeding 2500 kcal/kg. Notably, W1 and W2 exhibited the highest calorific values (∼10,870 kcal/kg), followed by W6 and W8 (∼6000 kcal/kg) and W9 (∼8727 kcal/kg). Safe heavy metal levels are safe, and high calorific values support the prospects of energy recovery and economic and environmental benefits, reducing landfill reliance and enhancing sustainable waste management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The presence of polybrominated diphenyl ethers (PBDEs) in consumer products, waste treatment processes, and treated ashes poses a significant environmental threat. Due to the lack of research on the removal of PBDEs during waste incineration, this study investigated the effectiveness of a Hazardous Waste Thermal Treatment System (HAWTTS) utilizing reburning of sludge and fly ash (SFA) with gasification-moderate or intense low-oxygen dilution (GASMILD) combustion for PBDE removal. The closed-loop treatment of sludge and ash within the HAWTTS provides a potential pathway for near-zero PBDE emissions. The GASMILD combustion addresses potential combustion issues associated with fly ash recirculation. The system achieved an impressive overall removal efficiency of 98.4% for PBDEs, with minimal stack emissions (2.45 ng/Nm³) and a negative net discharge rate (-1.02 μg/h). GASMILD combustion played a crucial role (92.7%-97.6% destruction) in addressing challenges associated with high-moisture feedstocks and SFA residues. Debromination of highly brominated PBDEs occurred within the incinerator, resulting in an increased proportion of lower brominated PBDEs in the bottom slag compared to the feedstock. Air Pollution Control Devices (APCDs) achieved a total PBDE removal efficiency of 74.4%. However, the hydrophobic nature of PBDEs limited removal efficiency in scrubbers (36.0%) and cyclonic demisters (37.86%). This study demonstrates that reintroducing SFA into the GASMILD combustion process offers an effective and environmentally sustainable strategy for reducing net PBDE levels in hazardous waste. This approach also provides additional benefits such as energy conservation, reduced carbon emissions, and lower operating costs associated with secondary treatment of thermally treated byproducts., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Sheng-Lun Lin reports financial support was provided by National Science and Technology Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aims to improve the quality of fuel with high calorific value namely Sfuel - a commercial high-quality refuse-derived fuel (RDF) from hazardous waste via modifying the process design and operating parameters of thermal conversion process. The study analyses key parameters of RDF quality, such as calorific value and heavy metal content, before and after process modifications based on the combination of experimental and simulation using Aspen Plus. In this study, the temperature and pressure of the simulation system are varied from 100 to 700 °C and from 1 to 5 bar, respectively. Findings indicate that there are a total of eleven heavy metals and 179 volatile compounds in the "Sfuels". The quality of the targeted product is greatly improved by the metal evaporation at high temperatures and pressures. However, the calorific value of RDF significantly decreases at 700 °C due to a large amount of the carbon content being evaporated. Although the carbon content at high temperatures is significantly lost, the heat from the vapour stream reactor outlet, which is reused to preheat the nitrogen gas stream supplied to the system, reduces energy consumption while improving the thermal conversion efficiency of the system. Besides, low pressure along with high temperature are not the optimal conditions for quality Sfuels improvement by thermal conversion. Results also indicate that electric heating is more economically efficient than natural gas heating., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Brick kiln co-treatment is a novel industrial hazardous wastes (IHWs) utilization process. However, the effects of chlorine (Cl) in wastes on heavy metals (HMs) during this process are overlooked. This study investigated the stabilization/solidification (S/S) and volatilization, as well as long and short-term leaching, of HMs in Cl-containing bricks. The results indicated enhanced formations of stable mineral phases (NiFe 2 O 4 , Ni 2 SiO 4 , Cd 3 Al 2 Si 3 O 12 , CdSiO 3 , FeCr 2 O 4 , Cr 2 O 3 , CuFe 2 O 4 , and CuAl 2 O 4 ) in bricks at a low sintering temperature (800 °C) due to the affinity between Cl and HMs. By comparing HM concentrations before and after sintering in bricks, the study observed that Cl's presence significantly elevated the volatilization rates for Cd and Cu by 30.8% and 14.2%, respectively. In contrast, the effect on volatilization for Ni and Cr was not significant. Additionally, utilizing the NEN 7375 method, the cumulative leaching rates of Ni, Cd, Cr, and Cu over a 64-day experiment under extremely acidic conditions were 0.22%, 7.18%, 0.01%, and 1.46%, respectively. Similarly, higher short-term leaching rates of Cd (4.03%) and Cu (5.73%) than those of Ni (0.94%) and Cr (0.08%) were observed. This finding might be attributed to the lower stability of the Cd and Cu solid phases under acidic environments compared to those of Ni and Cr. Surface wash-off, dissolution, and diffusion were the processes governing HM leaching from bricks. The 10-year projections revealed a minimal release of HMs during future extended leaching, implying the successful S/S of HMs. This study provides a reference for assessing the environmental impacts of brick kiln co-processing of Cl-containing IHWs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Hazardous waste rotary kiln incineration, as the most effective and comprehensive technology to reduce and detoxify waste, generally faces problems such as low load rate and short continuous operating periods. However, there are few studies on the actual operation of such facilities and evaluation of their technical efficiency. Based on the 77-week time-series data of the case company, this study introduces in-depth key operating parameters and evaluates long-term technical efficiency through the data envelopment analysis (DEA) method. The results show that the continuous operating period of the rotary kiln incineration facility can reach more than half a year, with an average load rate of 91.7%. In the analysis of 9 input indicators, the amount of injected activated carbon could not be effectively evaluated due to the lack of relevant standards and online real-time monitoring of dioxins, which might become a weak link in the control of flue gas pollution. The average comprehensive technical efficiency of rotary kiln incineration facilities was 0.939, of which the average pure technical efficiency was 0.949 while the average scale efficiency was 0.989. With 33 of the 77 decision-making units being invalid, there is scope for improvement. The amount of incineration could be increased by 5.34%, and among the input variables, dosage of urea, calcium hydroxide and lye with a relatively high improvement ratio. Based on the results, targeted suggestions were proposed to advance the scientific and precise compatibility of hazardous waste, strengthen the control of dioxin emissions, and promote the intelligent control of the entire process., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Healthcare waste produced in healthcare activities entails higher risk of infection and injuries than municipal waste. In developing countries healthcare waste has not received much attention and has been disposed of together with municipal wastes. Modern method of disposal of healthcare waste have been introduced to most healthcare institutions mismanagement and increased in production in public health centres in Ethiopia is important issues. The aim of the study was to assess the type of healthcare waste generation and quantification in selected public health centres in Addis Ababa, Ethiopia., Methods: An institution based cross-sectional study were conducted from January to February 2018. Fifteen health centres in Addis Ababa City Administration were selected for this study. Data were collected by using by different color plastic bags (Black plastic bags for non-hazardous wastes, Yellow plastic bags for hazardous wastes and Yellow safety box for needles and Red bags for pharmaceutical wastes and toxic wastes). The collected wastes were measured by weighing scale and were written to data entry sheet. To assure the data quality calibration of weighing scale was made by the standard weight every morning. EPI INFO TM7 and IBM SPSS were used for data entry, cleaning and analysis., Results: The mean healthcare waste generation was 10.64+5.79Kg/day of which 37.26% (3.96+2.20Kg/day) was general waste and 62.74% (6.68+4.29) was hazardous waste from the studies health centres. Total hazardous waste; sharps, infectious, pathological and pharmaceutical wastes constitutes mean (±SD) 0.97 ±1.03, 3.23 ± 2.60, 2.17±1.92 and 0.25 ±0.34 kg/day respectively. Healthcare waste 29.93% and 0.32% were generated from delivery and post-natal case team and nutrition and growth monitoring case team respectively. The annual mean+ SD of healthcare waste generation rate per health centres were 3807.53+ 2109.84 Kg/year., Conclusion: The finding in this study showed there was an increased in hazardous healthcare waste in amount as compared to the WHO standard 85% non-hazardous waste and 10% hazardous waste and 5% toxic wastes. The healthcare waste management practices about segregation, collection, transportation and disposal at the source is crucial to decrease in quantity. Generally unselective handling and disposal of healthcare wastes is a concern., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Menelik Legesse Tadesse. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

In this study, the behavior of heavy metal transformation during the co-thermal treatment of hazardous waste incineration fly ash (HWIFA) and Fe-containing hazardous waste (including hazardous waste incineration bottom slag (HWIBS) and electroplating sludge (ES)) was investigated. The findings demonstrated that such a treatment effectively reduced the static leaching toxicity of Cr and Pb. Moreover, when the treatment temperature exceeded 1000 °C, the co-thermal treated sample exhibited low concentrations of dynamically leached Cr, Pb, and Zn, indicating that these heavy metals were successful detoxified. Thermodynamic analyses and phase transformation results suggested that the formation of spinel and the gradual disappearance of chromium dioxide in the presence of Fe-containing hazardous wastes contributed to the solidification of chromium. Additionally, the efficient detoxification of Pb and Zn was attributed to their volatilization and entry into the liquid phase during the co-thermal treatment process. Therefore, this study sets an excellent example of the co-thermal treatment of hazardous wastes and the control of heavy metal pollution during the treatment process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Incineration technology has been widely adopted to safely dispose of hazardous waste (HW). While the incineration process causes the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Due to its extreme toxicity, many scholars have been committed to determining the PCDD/F formation process and reducing emissions in incinerators. Previous studies ignored the impact of incineration and fluctuation of feeding materials on PCDD/F formation in hazardous waste incinerators (HWIs). In this study, differences in PCDD/F formation between HWIs and municipal solid waste incinerators (MSWIs) were pointed out. The incineration section in HWIs should be carefully considered. Laboratory experiments, conventional analysis and thermogravimetry experiments were conducted. An obvious disparity of PCDD/F formation between 12 kinds of HWs was found. Distillation residue was found with remarkably higher PCDD/F concentrations (11.57 ng/g). Except for the Cl content, aromatic rings and C-O bond organics were also found with high correlation coefficients with PCDD/F concentrations (>0.92). And PCDD/Fs were formed through a chlorination process and structure formation process. All of these are helpful to further understand the PCDD/F formation process during HW incineration, optimize the operation conditions in HWIs and reduce the emission pressure of PCDD/Fs in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The escalating generation of hazardous waste (HW) has become a pressing concern worldwide, straining waste management systems and posing significant health hazards. Addressing this challenge necessitates an accurate understanding of HW generation, which can be achieved through the application of advanced models. The Transformer model, known for its ability to capture complex nonlinear processes, proves invaluable in extracting essential features and making precise HW generation predictions. To enhance comprehension of the key factors influencing HW generation, visualization techniques such as SHapley Additive exPlanations (SHAP) provide insightful explanations. In this study, a novel approach combining classical deep learning algorithms with the Transformer model is proposed, yielding impressive results with an R 2 value of 0.953 and an RMSE of 7.284 for HW prediction. Notably, among the five key fields considered-demographics, socio-economics, industrial production, environmental governance, and medical health-industrial production emerges as the primary contributor, accounting for over 50% of HW generation. Moreover, a high rate of industrial development is anticipated to further accelerate this process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Precisely predicting the amount of household hazardous waste (HHW) and classifying it intelligently is crucial for effective city management. Although data-driven models have the potential to address these problems, there have been few studies utilizing this approach for HHW prediction and classification due to the scarcity of available data. To address this, the current study employed the prophet model to forecast HHW quantities based on the Integration of Two Networks systems in Shanghai. HHW classification was performed using HVGGNet structures, which were based on VGG and transfer learning. To expedite the process of finding the optimal global learning rate, the method of cyclical learning rate was adopted, thus avoiding the need for repeated testing. Results showed that the average rate of HHW generation was 0.1 g/person/day, with the most significant waste categories being fluorescent lamps (30.6 %), paint barrels (26.1 %), medicine (26.2 %), battery (15.8 %), thermometer (0.03 %), and others (1.22 %). Recovering rare earth element (18.85 kg), Cd (3064.10 kg), Hg (15643.43 kg), Zn (14239.07 kg), Ag (11805.81 kg), Ni (4956.64 kg) and Li (1081.45 kg) from HHW can help avoid groundwater pollution, soil contamination and air pollution. HVGGNet-11 demonstrated 90.5 % precision and was deemed most suitable for HHW sorting. Furthermore, the prophet model predicted that HHW in Shanghai would increase from 794.43 t in 2020 to 2049.67 t in 2025., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Chromium ore processing residue (COPR) is classified as hazardous solid waste because of the leachable Cr(VI). Cementitious materials are often used to solidify and stabilize heavy metals. However, most of them focus on the leaching concentration of particles after solidification and stabilization and lack research on leaching characteristics. This study investigated the leaching characteristics of heavy metals in three simulated environments (HJ557-2010, HJ/T299-2007, TCLP) after immobilizing COPR with composite binders. Industrial solid waste coal fly ash and lead-zinc smelting slag are used to prepare composite binders through alkali activation technology. Compressive strength, particle leaching toxicity, acid neutralization capability, and semi-dynamic leaching test are used to evaluate the performance of the solidified body. The solidified body can be applied to building materials or treated as general industrial waste. Heavy metals are mainly released from the matrix by surface washing at a low rate. The analysis results, including XRD, FTIR, and SEM-EDS, show that chemical binding and physical encapsulation are the main immobilizing mechanisms to realize the coordinated disposal of Zn and Cr(VI)., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Incense sticks ash is one of the most unexplored by-products generated at religious places and houses obtained after the combustion of incense sticks. Every year, tonnes of incense sticks ash is produced at religious places in India which are disposed of into the rivers and water bodies. The presence of heavy metals and high content of alkali metals challenges a potential threat to the living organism after the disposal in the river. The leaching of heavy metals and alkali metals may lead to water pollution. Besides this, incense sticks also have a high amount of calcium, silica, alumina, and ferrous along with traces of rutile and other oxides either in crystalline or amorphous phases. The incense sticks ash, heavy metals, and alkali metals can be extracted by water, mineral acids, and alkali. Ferrous can be extracted by magnetic separation, while calcium by HCl, alumina by sulfuric acid treatment, and silica by strong hydroxides like NaOH. The recovery of such elements by using acids and bases will eliminate their toxic heavy metals at the same time recovering major value-added minerals from it. Here, in the present research work, the effect on the elemental composition, morphology, crystallinity, and size of incense sticks ash particles was observed by extracting ferrous, followed by extraction of calcium by HCl and alumina by H 2 SO 4 at 90-95 °C for 90 min. The final residue was treated with 4 M NaOH, in order to extract leachable silica at 90 °C for 90 min along with continuous stirring. The transformation of various minerals phases and microstructures of incense sticks ash (ISA) and other residues during ferrous, extraction, calcium, and alumina and silica extraction was studied using Fourier transform infrared (FTIR), dynamic light scattering (DLS), X-ray fluorescence (XRF), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and inductively coupled plasma-optical emission spectroscopy (ICP-OES). DLS was used for analyzing the size during the experiments while FTIR helped in the confirmation of the formation of new products during the treatments. From the various instrumental analyses, it was found that the toxic metals present in the initial incense sticks ash got eliminated. Besides this, the major alkali metals, i.e., Ca and Mg, got reduced during these successive treatments. Initially, there were mainly irregular shaped, micron-sized particles that were dominant in the incense sticks ash particles. Besides this, there were plenty of carbon particles left unburned during combustion. In the final residue, nanosized flowers shaped along with cuboidal micron-sized particles were dominant. present in If, such sequential techniques will be applied by the industries based on recycling of incense sticks ash, then not only the solid waste pollution will be reduced but also numerous value-added minerals like ferrous, silica, alumina calcium oxides and carbonates can be recovered from such waste. The value-added minerals could act as an economical and sustainable source of adsorbent for wastewater treatment in future., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Medical wastes include all solid and liquid wastes that are produced during the treatment, diagnosis, and immunisation of animals and humans. A significant proportion of medical waste is infectious, hazardous, radioactive, and contains potentially toxic elements (PTEs) (i.e., heavy metal (loids)). PTEs, including arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg), are mostly present in plastic, syringes, rubber, adhesive plaster, battery wastes of medical facilities in elemental form, as well as oxides, chlorides, and sulfates. Incineration and sterilisation are the most common technologies adopted for the safe management and disposal of medical wastes, which are primarily aimed at eliminating deadly pathogens. The ash materials derived from the incineration of hazardous medical wastes are generally disposed of in landfills after the solidification/stabilisation (S/S) process. In contrast, the ash materials derived from nonhazardous wastes are applied to the soil as a source of nutrients and soil amendment. The release of PTEs from medical waste ash material from landfill sites and soil application can result in ecotoxicity. The present study is a review paper that aims to critically review the dynamisms of PTEs in various environmental media after medical waste disposal, the environmental and health implications of their poor management, and the common misconceptions regarding medical waste., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2023. Published by Elsevier Ltd. All rights reserved.)

The control of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from the flue gas in hazardous waste incinerators (HWIs) is an intractable problem. To figure out the formation mechanism of PCDD/Fs and reduce the emission, a field study was carried out in a full-scale HWI. Ca(OH) 2 & (NH 4 )H 2 PO 4 or CH 4 N 2 S & (NH 4 )H 2 PO 4 were injected into the quench tower, and the detailed inhibition effect on PCDD/Fs formation by the inhibitors coupled with quench tower was studied. Gas and ash samples were collected to analyze PCDD/Fs. XPS, EDS characterization and Principal component analysis were adopted to further analyze the de novo and precursors synthesis. The PCDD/Fs emissions reduced from 0.135 ng I-TEQ/Nm 3 to 0.062 or 0.025 ng I-TEQ/Nm 3 after the injection of Ca(OH) 2 & (NH 4 )H 2 PO 4 or CH 4 N 2 S & (NH 4 )H 2 PO 4 , respectively. The quench tower was found mainly hindering de novo synthesis by reducing reaction time. CP-route was the dominant formation pathway of PCDD/Fs in quench tower ash. Ca(OH) 2 & (NH 4 )H 2 PO 4 effectively inhibit precursors synthesis and reduce proportions of organic chlorine from 4.11% to 2.86%. CH 4 N 2 S & (NH 4 )H 2 PO 4 show good control effects on both de novo and precursors synthesis by reducing chlorine content and inhibiting metal-catalysts. Sulfur-containing inhibitors can cooperate well with the quench tower to inhibit PCDD/Fs formation and will be effective to reduce dioxins formation in high chlorine flue gas. The results pave the way for further industrial application of inhibition to reduce PCDD/Fs emissions in the HWIs flue gas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The results of a quantitative analysis of asbestos content in the ground with varying degrees of concentration of this mineral as a result of natural phenomena such as rock weathering, contamination by the manufacture of asbestos and cement products, and the many years of use of "eternit roofs" are presented. Preliminary thermal treatment, soil grinding and sieving were used for the determinations, followed by electrostatic separation in order to obtain the concentration of asbestos in a smaller volume. It was used for microscopic preparations for the identification and planimetry of asbestos. A polarizing optical microscope was used in the qualitative and quantitative analysis. The levels of re-emission of asbestos dust into the air as a result of the exploitation of contaminated soil were estimated. Polluted land in industrially areas, at a distance of up to 1200 m, contains 0.0003 % to 0.02 % asbestos. The content of 0.01 % asbestos does not require remediation in the absence of soil use. It may cause <500 fibres/m 3 . Removing the facade of asbestos-cement panels from the building at a distance of up to 10 m resulted in concentration <0.007 % of free asbestos in the ground, and for used roofs <0.001 % from above the distance of 3 m. This means that land in the vicinity of buildings with facade or roofing made of a-c products can be safely exploited. The direct discharge of rainwater from the gutter into the ground, however, contaminates it well above this value and those places should be treated as hazardous waste due to the presence of asbestos fibres in unbound form, containing <9,8 %. Ultimately, the size of the threat depends on many factors and can be comparable with the pollution of industrial production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author. Published by Elsevier B.V. All rights reserved.)

Health care waste is a global problem. While most health care waste is harmless, some of it is hazardous. The volume of hazardous waste generated worldwide is enormous, and its disposal can be environmentally damaging. This article discusses how such waste disposal is regulated and the problems that currently exist with waste disposal regulation. The article also offers possible national and international regulatory solutions., (Copyright 2022 American Medical Association. All Rights Reserved.)

This study proposed a decision support system (DSS) for optimizing transportation routing and disposal hub location for Thailand's local administrative organizations' hazardous waste management. The first step is to choose the origin and destination, as well as to collect data for each route. Each route's decision criteria were based on traffic quality and risk measures from the perspective of users. An analytic hierarchy process (AHP) was used to compute effective weights for decision criteria. To achieve optimal routing, AHP weights were combined with a zero-one goal programming technique. The DSS operates systematically and successfully, taking into account both transportation risk and socioeconomic factors, and provides appropriate routes. Overall, this waste management system may provide useful information to decision-makers for prioritizing disposal site alternatives and implementing feasible waste management actions. The zero-one location design was then used to determine the best hub location. Based on two scenarios of six and fifteen CoG hubs, the results revealed that the best model for managing a case company's hazardous waste was to establish 15 hubs scattered throughout the country for collecting points and then transporting them to the waste disposal plant in Phitsanulok province. Locating the hub near sink points would reduce transportation costs and backhaul issues, reducing the environmental impact of GHG emissions and increasing system efficiency. Implications: The problem of waste pollution has become increasingly serious all over the world, particularly in developing countries that face significant pollution control challenges. End-of-life wastes cause economic, health, and environmental problems if they are not properly managed. As the world's population and living standards rise, so does the amount of waste produced. The environmental impact is significant, with massive amounts of waste generated each year with only basic or minimal treatment to mitigate its impact. As a result, there is an urgent need for a method that can precisely optimize transportation routing and disposal hub location for Thailand's local administrative organizations' hazardous waste management (LAOs). The proposed decision support system (DSS) may provide useful information to decision-makers in prioritizing disposal site alternatives and implementing feasible waste management actions.

Electroplating sludge is a hazardous waste and its recycling is a hot topic. Electroplating sludge usually contains plenty of transition metals and multi-hetero atoms, which are potential resources. For the first time, this work synthesized spinel catalyst from Zn- and Cr-containing electroplating sludges by a simple calcination method, and applied the obtained catalysts in CH 3 OH production by CO 2 catalytic hydrogenation. The spinel was doped by various heteroatoms, including Fe, Mn, Cu, and even S. According to detailed characterizations, the metal doping increased the low-temperature conversion efficiency of CO 2 but decreased the CH 3 OH selectivity at the same time. After a further doping of S, although CO 2 conversion efficiency was slightly decreased, the selectivity of CH 3 OH was significantly increased. After all, the optimized catalyst attained a conversion efficiency of 8.6% (CO 2 ) as well as a selectivity of 73.3% (CH 3 OH) at 250 °C and 3 MPa. As a result, above results realized high-value-added utilization of hazardous waste and producing valuable product at the same time, which was in favor of circular development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Electroplating sludge is a hazardous waste and secondary metal resource because of its heavy metal content, which poses a huge threat to environmental safety if not properly disposed. An innovative process of oxidizing roasting followed by water leaching and smelting reduction to recover Cr, Cu, and Ni from electroplating sludge was proposed in this research, in which other two hazardous wastes of spent cathode carbon combustion dust and copper refining slag were co-treated. The NaF from spent cathode carbon combustion dust could convert Cr 2 O 3 to Na 2 CrO 4 using the oxidizing roasting process, resulting in a Cr recovery through the subsequent water leaching. The Na 2 CrO 4 formation was promoted by CaO owing to it transferring the Cr spinel phase of FeCr 2 O 4 [1+] to CaCrO 4 and then to Na 2 CrO 4 . Under optimal conditions, the Cr recovery reached 97.1 %, and most 'F' was solidified into CaF 2 . In the next smelting reduction of the leaching residue, the Cu and Ni were recovered mainly in the form of Cu-Ni alloy. The addition of copper refining slag promoted their recovery, due to it modifying the molten slag and alloy structures and increasing the Cu-Ni alloy separation from molten slag. Some generated high-melting-point Cu-Ni-Fe and Ni-Fe alloys were converted to a Cu-Ni alloy with a low melting point in presence of Co from the copper refining slag, simultaneously with which the Fe was transferred out from Cu-Ni-Fe and Ni-Fe alloys and combined with Co to form a Fe-Co alloy. It increased Cu-Ni alloy droplets aggregation from molten slag and decreased their contents in the residual slag. Under optimized conditions, the Cu and Ni contents in the residual slag decreased to 0.37 and 0.06 wt%, respectively. Besides, the residual slag mainly composed of CaO, CaF 2 and SiO 2 could be used to prepare building materials rendering it harmless., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Cement kiln collaborative disposal technology can not only dispose of hazardous waste but also provide energy for the cement industry. However, the addition of hazardous waste may promote the formation of dioxins in cement kilns. In this study, typical hazardous solid wastes, such as solidified fly ash, electroplating sludge, and industrial residue, were co-processed in a cement kiln with different feeding positions and different feeding amounts. The concentrations of dioxins in the flue gas, clinker, and precalciner furnace slag were investigated. The effect of adding mixed hazardous solid waste on the formation of dioxin was also studied. The results showed that the concentration of dioxin in the flue gas without added hazardous waste was 1.57 ng/m 3 , and the concentration varied from 1.03 to 6.49 ng/m 3 after the addition of hazardous waste. In addition, the concentration of dioxin in the flue gas and solid samples increased substantially when the co-processing ratio doubled. The large amount of Cu in solidified fly ash promoted the formation of dioxins, while the higher S content in the electroplating sludge suppressed the formation of dioxins. Compared with the addition of single hazardous waste, the concentration of dioxin in precalciner furnace slag increases by about 300%. Furthermore, the distributions of isomers in the clinker and precalciner furnace slag were similar. 1,2,3,4,6,7,8-HpCDD and OCDD accounted for a large proportion of the mass concentration, and the contribution rate ranged from 48.7 to 82.0%. Most importantly, correlation analysis showed that the concentration of dioxin was closely related to the copper content, hazardous waste types and additive proportion, with correlation coefficients of 0.79, 0.83, and 0.89, respectively. This study provides a basis for exploring the high environmental benefits of disposing of hazardous solid waste by co-processing in cement kilns., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

There are increasing worldwide concerns about the negative impacts of healthcare waste generated in hospitals, especially in low- and middle-income countries. Hazardous type of waste can contribute to adverse effects both in human populations and the environment because of its physical, chemical, and biological characteristics. A comprehensive view on increasing waste in the world has not been conducted to understand the breadth of the issue; thus, this paper sought to provide an analysis of hospitals' healthcare waste generation rate. Comparisons were made with Wilcoxon and Kruskal-Wallis tests for simple and multiple comparisons, to analyze nonparametric data, with post hoc by Nemenyi test. Median values indicated that hospital waste was the highest in North and South America (4.42, 1.64 kg/bed/day, respectively) and was almost nonexistent in Oceania (0.19 kg/bed/day), while the median rates for hazardous waste were the highest in Oceania (0.77 kg/bed/day). Africa was almost the lowest producer of waste in each category (0.19 and 0.39 kg/bed/day for hospital and hazardous waste, respectively). Over time, linear regression indicated that hazardous waste in Asia and Europe has increased, while in Oceania, the total waste also increased. Interestingly, in North America, it was observed a reduction in the generation for both total and hazardous waste. This information highlights the importance of understanding continent-specific characteristics and rates, which can be used to create a more individualized approach to addressing healthcare waste in the world., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Arsenic (As)-bearing gypsum sludge, one of the most prominent hazardous wastes, has created a myriad of critical problems in human health, waters, soils, and sediments at the global scale. Unfortunately, the reclamation and disposal of As-bearing gypsum sludge have been rarely investigated. This paper aims to explore a novel technology for simultaneous value-added utilization and harmless exploitation of As-bearing gypsum sludge. In the experiment, As-bearing gypsum sludge and anthracite were mixed, granulated, and then roasted in Ar atmosphere. Based on the thermodynamic analysis and experimental results, the As migration mechanism in the As-bearing gypsum sludge was determined during the roasting process. Under optimal conditions, 90% of As phase was volatilized and then recovered in the form of elemental As 99.5 , and it could act as a chemical product. In addition, As 99.5 could be further processed into high-purity As and As 2 O 3 using existing chlorination-rectification-reduction process and oxidation process, respectively, which can be widely used in the treatments of semiconductor material, pigment, and wood. Residual As primarily occurred as Fe-As compounds, but the leached As concentration in the toxicity characteristic leaching procedure was only 0.008 mg/L. Correspondingly, a new As immobilization method that generates Fe-As compounds (α-Fe and AsFe 2 ) is first proposed and then verified, which may be widely used for simultaneous As-bearing solid wastes reduction and improved harmlessness. This paper is significant for development of the metallurgical, mining, acid, and thermal power industries, minimizing its environmental risk., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

An integrated gasification-flameless combustion-melting process was approached by a twin-cyclonic flow in a hazardous waste thermal treatment plant. A series of advanced scrubber, cyclonic demister, activated carbon adsorption, and baghouse processes were equipped for the end-of-pipe treatment. The untreated filterable particulate matter, CO, and NOx levels were only 283, 47.1, and 15.9 mg/Nm 3 , indicating the flameless combustion inhibited their formation by narrowing the post-combustion zone. The filterable particle mass-size distribution was equally contributed by nucleation, accumulation, and coarse formations, while their number concentration was predominated by nucleation (99.6%). That could enhance the adsorption of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) on ultrafine particles. Both total mass and toxic equivalent concentrations of PCDD/Fs were reduced 99.9% by the new air pollution control system when a slight reformation occurred during scrubbing. However, the escaped PCDD/Fs were mainly distributed on the ultrafine particles, which should be further inhibited by either increasing their sizes or equipping backup filtrations. Finally, the new process concentrates the PCDD/Fs into the scrubbing sludge, which could be recirculated back into the thermal process. This study not only reveals the emission risk of the ultrafine particle-bound PCDD/Fs, but also provides an effective process to remove them for industrial application., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In this study, wastes originating at each production station during refrigerator manufacturing were identified and classified based on a waste tree. A mass balance study revealed a total waste production factor of 0.046 kg/kg of a product of which 75.3%, 23.9%, and 0.8% were non-hazardous wastes (NHWs), packaging wastes (PWs), and hazardous wastes (HWs), respectively. Wastes produced during refrigerator manufacturing were grouped under 35 different waste codes. Waste codes that contributed more than 5% by weight were 15 02 02 (contaminated absorbent material), 15 01 10 (contaminated packaging), 16 02 13 (electronic cards), 07 02 14 (polyol) and 08 05 01 (isocyanates), 19 08 13 (treatment sludge), 16 02 15 (capacitors), and 13 01 13 (hydraulic oil) for HWs, 12 01 01 (ferrous metal), and 16 02 16 (components) for NHWs, and, finally, 15 01 03 (wooden), 15 01 01 (paper&cardboard), and 15 01 02 (plastic) for PWs over 5 years. Scrap costs were used as a surrogate to determine production stages that generated high amounts of metal and plastic wastes. Logarithmically, increasing and decreasing trends were observed for PWs and NHWs over the study period, respectively. HW amounts did not exhibit a statistically significant trend. Twenty-eight BATs (best available techniques) were identified that could be applied in refrigerator manufacturing for waste minimization and management. Among those, 8 of them were proposed for further improvement for waste management in the facility., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The amount of generated waste, which increases every year, is a serious problem of the modern world. In particular, attention should be paid to hazardous waste and methods of its disposal. One of the most used in this context is thermal treatment in dedicated incinerators equipped with a rotary kiln. Conducting the process requires, inter alia, supplying the furnace with a batch of batch material with appropriate parameters. Improper operation in this regard may cause negative environmental effects and operational problems. The key here is to select different types of hazardous waste and compose batch portions. The paper presents an application that optimizes the work of waste incineration plant operators. At the same time, this tool can be described as ensuring security at this stage of the process. The application implements an ant colony algorithm that selects the optimal solution to the problem, which has been formulated here as the types and masses of the batch mixture components with given parameters. The application has been tested in the laboratory and real conditions with satisfactory results.

Dental amalgam from dental clinics in Kosova is an uncontrolled source of mercury. The environmental legislative framework related to its use does not fully provide measures that reduce amalgam use and the release of its waste into the environment. This paper highlights issues related to environmental policy covering mercury amalgam waste management. Existing national regulations on hazardous waste management in Kosova consider the waste from dental health care as hazardous. Currently, however, no regulations restrict the use of dental amalgam or specifically oblige the generators of amalgam to treat or dispose of waste properly, thus leading to inconsistent legislation. New regulations, revised hazardous waste management standards, and new infrastructure for waste treatment and disposal, in compliance with EU regulations, should be developed to create a holistic approach that prevents the adverse effects of amalgam waste. Integr Environ Assess Manag 2021;17:1037-1044. © 2021 SETAC., (© 2021 SETAC.)

Industrial waste salt is classified as hazardous waste to the environment. The organic impurity and its occurrence in industrial waste salt affect the salt resource utilization. In this paper, composition quantitative analysis, XRD, TG-DSC, SEM/FIB-SEM coupled with EDS, FTIR, XPS and GC-Ms were chosen to investigate the organic impurity and its occurrence in industrial waste salt. The organic impurities owe small proportion (1.77%) in the specimen and exhibit weak thermal stability within the temperature of 600°C. A clear definition of organic impurity, including 11 kinds of organic compounds, including aldehyde, benzene and its derivatives etc., were detected in the industrial waste salt. These organic impurities, owing (C-O/C-O-C, C-OH/C = O, C-C/CHx/C = C etc.)-containing function group substance, are mainly distributed both on the surface and inside of the salt particles. Meanwhile, the organic substance may combine with metal cations (Ni2+, Mg2+, Cu2+ etc.) through functional groups, such as hydroxide, carbonyl etc., which increases its stability in the industrial waste salt. These findings provide comprehensive information for the resource utilization of industrial waste salt from chemical industry etc., Competing Interests: The authors of this paper have read the journal’s policy and have the following competing interests: Zongwen Zhao, Wenbin Xu, Zhongbing Wang, Weining Qin, Xinglin Guo, and Jiang Long are paid employees of Dongjiang Environmental Co., Ltd. Jie Lei is paid employees of Green Eco-Manufacture Co., Ltd. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Thailand is facing a management crisis of both urban and rural household hazardous waste (HHW). The collection and disposal of these wastes threaten both the environment and human health. The objective of the study was to investigate the characterization and quantification of household hazardous waste at source by all local administrations in Nakhon Nayok province, Thailand. The quantity of HHW in the household waste stream constitutes 2.53% of total household wastes (about 2.90 t/day). Most HHWs were generated in the local administration level (3.2%) followed by the subdistrict (2.9%) and municipality level (1.2%). The characterization of HHWs included paint products (20.1%), household batteries (17.4%), and unused medicines (14.1%). HHW characterization can be grouped as automobile products from municipalities (38.5%), paint and its containers from the subdistricts (43.08%), and pesticides from the more rural local administrations (24.73%). Albeit the amount of HHW waste found in the household waste stream is relatively small compared to the overall waste stream, it can still cause significant damage to human health and environment. This is because the elements and compounds that comprise hazard wastes are toxic at very low levels. Programs are needed to increase appropriate management of HHW to mitigate human health and environmental contamination risks. Reducing and separating HHW at source can minimize these problems during both normal and pandemic situations. Implications : The study of household hazardous waste (HHW) characterization and quantification is very importance for HHW management, especially study at source. In this study we found the smallest province in Thailand can produce HHW volume nearly three tons per day. The trend in consumption of household products may be increase. The government should therefore be more focused on HHW at source management in both normal and pandemic situations.

Cigarette butt (CB) is a crucial litter in urban communities because it may contain various toxicants. Due to serious limitations on incinerating or landfilling CB, recycling of this hazardous waste is essential. The objective of this study was to investigate the most important challenges in CB collection and recycling. To this end, a search was done on Scopus, PubMed, and Web of Science by defining a search protocol and identifying appropriate keywords. At the end of the screening process, 52 appropriate papers were selected. In this review, all methods for the CB recycling were considered. This review showed that nine categorizations of different products have been produced from the recycling of CBs, but three important challenges were identified for the recycling of this hazardous waste. It should be noted that finding solutions to these challenges may be helpful in better management of CB as a toxic litter.

This paper describes the modeling approach and example results for a newly introduced computational simulation tool to evaluate waste destruction in thermal incineration systems. The Configured Fireside Simulator (CFS) is a software simulator, originally developed for the Department of Defense to evaluate operations of the chemical demilitarization incinerators processing the chemical warfare agent stockpile of the US. The software was later adapted for use by the U.S. Environmental Protection Agency (EPA) to provide for the ability to run "what if" scenarios of waste streams contaminated with chemical/biological (CB) threat agents in four specific incinerators, including the EPA's pilot-scale Rotary Kiln Incinerator Simulator (RKIS) facility, as well as three commercial incinerators based on design criteria for actual operating facilities. These commercial incinerators include a Medical/Pathological Waste Incinerator, a Hazardous Waste Burning Rotary Kiln, and a Waste-to-Energy Stoker-type combustor. The CFS uses three-dimensional computational fluid dynamics coupled with detailed chemical kinetic data for destruction of chemical warfare agents, coupled with kinetic data for biological agent destruction derived from bench- and pilot-scale experiments to predict the way agent-containing materials will behave under full-scale combustion conditions in several different incinerator types. The objective of this paper is to describe the CFS software, how it works, and potential applications of this software to real-world situations. This software could be a valuable tool for researchers, regulators, and industry to evaluate potential operating conditions to help guide testing activities and develop operational scenarios for difficult-to-manage waste streams. Although this software has been under development for several years, this paper represents the software's first introduction to the scientific community in the peer-reviewed literature. Implications: Adapting the Configured Fireside Simulator that was originally developed for the Department of Defense to evaluate operations of the chemical demilitarization incinerators processing the chemical warfare agent stockpile of the US to provide for the ability to run "what if" scenarios on civilian waste streams contaminated with CB agents is a useful tool for national preparedness. Such a model could be used in planning and response efforts to provide a better understanding of incineration capacity, development of feed strategies, and assessment of throughput limitations for CB incidents as well as other difficult-to-test waste streams and contaminants.

Vitrification is an effective solidification method for heavy metal-containing wastes. However, most investigations focused on the formation of glass matrix. Seldom report discussed the influence of co-existing crystals on heavy metal stabilizations. In this work, Ca-Al-Si phase was formed in the glass matrix by adjusting the composition of feeding ingredient and melting temperature. As a result, when molar ratio of CaO/(SiO 2 +Al 2 O 3 ) was lower than 0.97 and reaction temperature was bigger than 1300 °C, small-size Ca-Al-Si phase (Ca 2 Al 2 SiO 7 and CaAl 2 Si 2 O 8 ) was homogeneously distributed in vitreous matrix. At the same time, Cr, Zn, and Pb leaching concentrations were the lowest, far lower than the leaching standard values. According to theoretical calculations, Zn and Pb replaced Ca atom; Cr replaced Al atom in Ca-Al-Si phase under thermal conditions. These replacements resulted in the fixation and stabilization of heavy metals. When the CaO/(SiO 2 +Al 2 O 3 ) molar ratio was bigger than 1.00, neither glass nor Ca-Al-Si was formed. Similarly, when the melting temperature was decreased, Ca-Al-Si phase formed a bigger size. Both these went against the stabilization, resulting in high leaching concentrations of heavy metals. The main of this work will help the development of high-temperature melting for the treatment of hazardous wastes.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are very toxic chemicals which are emitted in waste incineration and whose exposure has important adverse effects for the human health. In 2019, adipose tissue samples were collected from 15 individuals with a median age of 61 years, who had been living near a hazardous waste incinerator in Constantí (Spain). The content of PCDD/Fs in each sample was analyzed. The results were compared with data from previous studies, conducted before (1998) and after (2002, 2007 and 2013) the facility started to operate, and based on populations of similar age. In 2019, the mean concentration of PCDD/Fs in adipose tissue was 6.63 pg WHO-TEQ/g fat, ranging from 0.95 to 12.95 pg WHO-TEQ/g fat. A significant reduction was observed with respect to the baseline study (1998), when a mean PCDD/Fs concentration of 40.1 pg WHO-TEQ/g fat was found. Moreover, the current level was much lower than those observed in the 3 previous studies (9.89, 14.6 and 11.5 pg WHO-TEQ/g fat in 2002, 2007 and 2013, respectively). The body burdens of PCDD/Fs were strongly correlated with age. The significant reduction of PCDD/Fs levels in adipose tissue fully agreed with the decreasing trend of the dietary intake of PCDD/Fs by the population of the zone (from 210.1 pg I-TEQ/day in 2018 to 8.54 pg WHO-TEQ/day in 2018). Furthermore, a similar decrease has been also observed in other biological, such as breast milk and plasma. The current data in adipose tissue, as well as those in other biological monitors, indicate that the population living near the HWI is not particularly exposed to high levels of PCDD/Fs. However, biomonitoring studies cannot differentiate the impact of the HWI emissions from food consumption patterns. This question can be only solved by conducting complementary investigations and contrasting the results of monitoring and epidemiological studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this work, hydrophilic molecularly imprinted nanospheres (MINs) were synthesized via surface imprinting technology and subsequently utilized as dispersant sorbent in matrix solid phase dispersion (MSPD) for the extraction of rhodamine B (RhB) as the illogical food additive dye from different foodstuffs, followed by HPLC analysis. By considering hydrophilicity of target analyte, the sol-gel route was chosen for the preparation of MINs in aqueous media at mild conditions. Most importantly, both synthesis and extraction steps were designed and performed in the line of green chemistry and hazardous waste was eliminated to minimize detrimental impact on the operator health and the environment. The reputable experimental design methodology was adopted to assist the condition optimization of MSPD, which comprehends the significance of the factors and their interactions with the least experimental runs. Under optimized MINs-MSPD-HPLC conditions, the detection limit of RhB was down to 0.14 μg kg -1 and excellent linearity over the wide range of 0.5-10000 μg kg -1 was attained. Furthermore, endogenous RhB was found in the tested food samples with relative standard deviations (RSDs) of ≤4.6%, and satisfactory recoveries were from 83.6 to 96.9%. The simple green MINs-MSPD method holds great potential for determination of trace RhB in complicated solid/semi-solid samples, showing rapidity, accuracy and reliability., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest with regard to the contents of this manuscript., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: The inhalation anesthetics are potent greenhouse gases. To reduce the global environmental impact of the health care sector, technologies are sought to limit the release of waste anesthetic gas into the atmosphere., Methods: Using a photochemical exhaust gas destruction system, removal efficiencies for nitrous oxide, desflurane, and sevoflurane were measured at various inlet concentrations (25% and 50%; 1.5%, 3.0%, and 6.0%; and 0.5%, 1.0%, and 2.0%, respectively) with flow rates ranging from 0.25 to 2.0 L/min. To evaluate the economic competitiveness of the anesthetic waste gas destruction system, its price per ton of carbon dioxide equivalent was calculated and compared to other greenhouse gas abatement technologies and current market prices., Results: All inhaled anesthetics evaluated demonstrate enhanced removal efficiencies with decreasing flow rates (P < .0001). Depending on the anesthetic and its concentration, the photochemical exhaust gas destruction system exhibits a constant first-order removal rate, k. However, there was not a simple relation between the removal rate k and the species concentration. The costs for removing a ton of carbon dioxide equivalents are <$0.005 for desflurane, <$0.114 for sevoflurane, and <$49 for nitrous oxide., Conclusions: Based on this prototype study, destroying sevoflurane and desflurane with this photochemical anesthetic waste gas destruction system design is efficient and cost-effective. This is likely also true for other halogenated inhalational anesthetics such as isoflurane. Due to differing chemistry of nitrous oxide, modifications of this prototype photochemical reactor system are necessary to improve its removal efficiency for this gas.

Because of the urgent need to protect the environment, it has become vital to deal with the dangers and particularities associated with the growth in hazardous industrial waste. Governments have begun to expand their investments in the environmental protection industry and have tightened enterprise environmental management requirements. The 13th Five-Year Plan period in China, in particular, increased the focus on the environmental supervision and enterprise environmental management. Because of the specific qualities of many types of hazardous waste, most enterprises do not have the ability to process hazardous waste and therefore must outsource the disposal to third-party contractors. However, choosing suitable hazardous waste disposal enterprises (HWDE) can be difficult. Therefore, to assist in the selection of appropriate hazardous waste disposal enterprises, this paper developed a comprehensive evaluation index system for hazardous waste disposal enterprises (EISHWDE). As multi-criteria decision-making problems involve qualitative evaluations that have semantic ambiguity, hesitant fuzzy linguistic term sets (HFLTS) were introduced to increase the accuracy of the evaluation process, an analytic hierarchy process (AHP) used to determine the objective indicator weights, and PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluation) employed to determine the final order for the selected enterprises. This research developed a scientific evaluation model that industrial waste enterprises (IWE) and related organizations could use to objectively and systematically select suitable hazardous waste disposal enterprises. Then, the problems of uncertainty and fuzzy semantics in the evaluation process were solved, and the weight of each selection criteria and the ranking of alternative enterprises are given., Competing Interests: The authors declare no conflict of interest.

The leaching concentrations of different metals in stainless steel pickling residue (SSPR) were determined and the toxic metals were treated using Na 2 S∙xH 2 O, FeSO 4 ∙6H 2 O, and phosphoric acid. A modified European Community Bureau of Reference (BCR) sequential extraction was used to identify the speciation of the concerned metals. Results showed that SSPR contains a large amount of Ca (58.41%), Fe (29.44%), Cr (3.83%), Ni (2.94%), Mn (2.82%) and some of Al, Cu, Mg, Zn. Among them, Cr and Ni were the most toxic metals in SSPR, thus the raw SSPR falls into hazardous waste category due to the leaching amount of Cr. In addition, the leached Cr was identified as Cr 6+ (MgCrO 4 ) in the waste. BCR test revealed that risk assessment code (RAC) of Cr and Ni were 33.29% and 61.7%, indicating they posed "high" and "very high" risk to the environment, respectively. After fixing by Na 2 S∙xH 2 O and FeSO 4 ∙6H 2 O, the leaching concentrations of Cr and Ni were less than 1.5 and 0.5 mg/L, respectively. After fixing by Na 2 S∙xH 2 O and FeSO 4 ∙6H 2 O the treated SSPR can be safely reused as roadbed materials, concrete and cement aggregates. This study provides a useful implication in treatment and beneficial reuse of heavy metal-containing hazardous wastes., (Copyright © 2020. Published by Elsevier B.V.)

Hazardous waste landfills (HWLs) usually mean the end of non-reusable, non-recyclable and non-recoverable wastes derived from industrial activities. A number of hazardous compounds and toxic elements, such as PCDD/Fs, Cd, Cr, Hg, Pb and As, is associated to these wastes. The HWL of Castellolí (Catalonia, Spain) treats a variety of hazardous wastes, which include bottom ashes from waste incinerators and asbestos potentially containing those toxicants. In 2007, our group began a surveillance program inside the HWL and in nearby villages focused on assessing the environmental levels of PCDD/Fs and toxic elements. Here we summarize the most updated results, corresponding to data from samples collected between 2015 and 2018. The levels of most trace elements (As, Cd, Cr, Ni and Pb) in soils, as well as those of Cd and Pb in air, were significantly higher (p < 0.01) inside the HWL than outside. However, no relevant differences were noted in the concentrations of trace elements when comparing the results of villages near the HWL with those located farther. With respect to PCDD/Fs, a progressive decrease was observed between the first (2007) and most recent (2018) surveys. The human health risks associated with the exposure to trace elements and PCDD/Fs exposure were within acceptable ranges according to national and international legislations (HQ < 1 and Cancer risk < 10 -5 )., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Hazardous waste disposal is a serious environmental concern in China. Therefore, in this study, industrial trials were conducted in a low-temperature thermal degradation facility, a tunnel kiln, and a shaft kiln to effectively treat dioxins in municipal solid waste incineration (MSWI) fly ash. The results indicated that the low-temperature thermal degradation facility efficiently decomposed polychlorinated dibenzo-p-dioxins and dibenzofurans in the MSWI fly ash. Additionally, the concentrations of dioxins in the treated fly ash and exhaust gas were lower than the suggested standard limits and the degradation ratio of dioxins was ∼99%. Therefore, treated fly ash characterized by acceptable dioxin risks could be utilized for the production of non-fired building materials. The results from the tunnel kiln indicated complete decomposition of the dioxins in the firing and insulating sections. However, the addition of fly ash in the tunnel kiln increased the concentration of dioxins in the flue gas. This can be primarily attributed to the heterogeneous catalytic synthesis reaction in the low-temperature section of the tunnel kiln. The results from the shaft kiln indicated degradation of at least 22% of the dioxins in the ash. The dioxin concentration in the flue gas was lower than the national standard while that in the clinker was within a reasonable limit. Furthermore, the environmental risks were significantly reduced at fly ash addition ratios lower than 3%., Competing Interests: Declaration of competing interest None., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Chromium (Cr)-bearing electroplating sludge is a hazardous solid waste and has a detrimental effect on human health and the environment. In this study, an alkali-activated slag binders, namely, formed by the reaction of blast furnace slag (BFS) with alkali, was applied to the stabilization/solidification (S/S) of electroplating sludge. The effects of liquid-solid ratio, water glass modulus ratio (molar ratio of SiO 2 to Na 2 O), water glass dosage, and electroplating sludge amount on the compressive strength and Cr leachability of binders were analyzed. The related mechanism of the S/S of electroplating sludge was discussed on the basis of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy coupled with energy-dispersive spectrometry (SEM-EDS). Results showed that the compressive strength of the alkali-activated slag binder first increased and then remained stable with the increase in liquid-solid ratio, water glass modulus ratio, and water glass dosage. By contrast, the leaching concentrations of Cr(VI) and total Cr decreased with the increase in liquid-solid ratio, water glass modulus ratio, water glass dosage, and curing time. In addition, XRD, FTIR, and SEM-EDS revealed that the hydration products of the binders were mainly low-crystallinity and dense calcium silicate hydrate gels, and Cr(VI) had been effectively immobilized in the structure. The reduction in Cr(VI) by the reductive components in the BFS boosted the stabilization of Cr-bearing electroplating sludge. Overall, the BFS binders containing electroplating sludge had relatively high compressive strengths and low Cr(VI) leaching concentrations. The physical encapsulation, chemical bonding, and absorption contributed the Cr immobilization during the S/S process of electroplating sludge., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The assessment of heavy metal contents in environmental sectors is important to estimate the carcinogenic and non-carcinogenic doses and risks for the mankind associated with it. The present work deals with the assessment of the risk exposure related to heavy metal contents in groundwater and soil samples to two different age groups via three different transits, i.e., ingestion, inhalation and dermal. The concentrations of heavy metals (Zn, Cd, Cu, Pb and Cr) were measured in the villages of lower Himalayas of Reasi district by using microwave plasma atomic emission spectrometer. The calculated mean contamination factors of heavy metals in soil samples were as: Zn, 0.73; Cu, 0.70; Pb, 0.74; and Cr, 0.33; which led to pollution load index less than unity. The overall carcinogenic risks have been varied from 6.4E-08 to 5.1E-07 in soil samples and from 7.3E-06 to 1.1E-04 in ground water samples and were found to be well within the range prescribed by USEPA (Screening level ecological risk assessment protocol for hazardous waste combustion facilities, appendix E: toxicity reference values, US Environmental Protection Agency, Washington, D.C., 1999). The mean values of heavy metal contents except lead and chromium in water samples were found to be less than the values prescribed by various agencies. Geo-accumulation Index showed that Pb contribute to the highest contamination (0 < I geo  < 1) among the other heavy metals. Cluster analysis and principal component analysis identified that Zn, Cu, Pb and Cr had a relationship and the presence of these heavy metals could be related to vehicle emissions, traffic sources and industrial sources. The overall mean values of the non-carcinogenic doses and associated hazard risks in soil and water samples calculated for children were found to be higher than the adults which may be due to hand to mouth activities.

Background This review intends to explore the household hazardous waste (HHW) generation rates, HHW management, and people's awareness regarding HHW in Asian countries based on the economic levels using the available published articles. Methods This is a systematic review of the scientific literature based on several databases, namely Scopus, ProQuest, PubMed, Sage Journals, and Elsevier's Science Direct from 2008 to 2018. Results HHW generation rates in various Asian cities do not seem to be influenced by the countries' financial status, except for e-waste. The variety in HHW generation rates among Asian countries might be due to various reasons, which include differences in (1) sampling frame/locations; (2) sampling size; (3) study duration; (4) seasons; (5) study year; and (6) HHW definition/composition. Governmental intervention programs on HHW management have been implemented in some of the Asian countries, mostly in high and upper-middle income groups although misconducts are still found. There is a tendency for economically developed countries to ship their e-waste to less-developed countries, where the system relies heavily on the informal sectors where unsafe treatments are often discovered. Low level of awareness regarding HHW risks is mostly identified in the lower-middle income group. However, even though high and upper-middle income groups have a better awareness of HHW, many people do not entirely follow the recommended practices. Conclusion The lack of enforced regulation and proper treatment infrastructure may lead to HHW being mixed with general household waste, which is found in many Asian countries, despite their income levels. In addition, a good awareness of HHW does not guarantee proper handling of it.

In the present study, biochar particles (BPs) produced by the co-pyrolysis of sewage sludge and corncobs at temperatures of 300, 500, and 700°C were characterized. The Pb 2+ adsorption properties and the heavy metal leaching toxicity rates of the BPs were investigated. It was found that the adsorption kinetics of the Pb 2+ can be accurately described by a pseudo-second-order model, and the equilibrium adsorption data were well represented by both the Langmuir and the Freundilich Equations. The toxicity characteristic leaching procedure (TCLP) results indicated that the leaching concentrations of all the heavy metals were below the set limit of China's national standard (Identification Standard for Hazardous Waste Extraction Toxicity Identification, China National Standard, GB 5085.3-2007). The results of this study can successfully provide scientific support for future corncob treatment and sludge pollution control.

More than 34 old glasswork sites in the southeastern part of Sweden pose a permanent threat to human and environmental health due to the presence of toxic trace elements in open dumps with glass waste. The possibility of leaching of trace elements from different fractions of the disposed waste needed to be assessed. In the present investigation, leachate from a mixture of soil and waste glass of particle sizes of less than 2 mm (given the name fine fraction) was characterized by analyzing the pH (7.3), total organic content (TOC < 2%), organic matter content (4.4%), moisture content (9.7%), chemical oxygen demand (COD, 163 mg/kg) and trace elements content, being the values in accordance to the Swedish guidelines for landfilling of inert materials. However, very high trace elements content was found in the fine fraction as well as in all colors of waste glass, whose values were compatible to hazardous waste landfill class. Tests with Lepidium sativum growing in the fine fraction as substrate revealed chronic toxicity expressed as inhibition of root biomass growth in 11 out of 15 samples. Additionally, leachate from fine fractions posed acute toxicity to genetically modified E. coli (Toxi-Chromotest). This study highlights the importance of combining physicochemical characterization with toxicity tests for both solid waste and leachate obtained from different waste fractions for proper hazardousness assessment supporting decision making on remediation demands., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This study evaluates the potential use of a new limestone calcined clay cement (LC 3 ) for stabilization/solidification of zinc contaminated soil. LC 3 is a new ternary blend manufactured by the replacement of 50% cement clinker by locally available two supplementary cementitious materials (SCMs) - limestone and calcined clay. The incorporation of LC 3 is evaluated on the soil spiked with 0.5% and 1% of Zinc (Zn) at curing times of 3, 7, 14, 28 and 56 days. pH, strength and leachability properties of the solidified/stabilised soil are measured for both mechanical and environmental conditions. Additionally, sequential extraction procedure (SEP), X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) analysis are performed to elucidate the mechanisms of Zn immobilization in the soil. The results show that the leachable Zn concentrations in the stabilised soil are well below the corresponding hazardous waste management regulatory limit after the curing time of 14 days. The soil pH and unconfined compressive strength of the stabilised soil increase with curing time. The SEP results confirm that LC 3 considerably reduces the acid soluble fraction (F1) and increase the residual fraction (F4). The XRD and SEM results indicate that formation of Tri-calcium Silicate 3CaO·SiO 2 , Portlandite Ca(OH) 2 , Ettringite Ca 6 Al 2 (SO 4 ) 3 (OH) 12 .26 H 2 O and Wulfingite Zn(OH) 2 are the primary mechanisms for the immobilization of Zn in the LC 3 stabilised soil., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Thousands of small clinics in Pakistan are generating dispersed medical waste, unlike large hospitals, small clinic waste management is often ignored. This study was conducted on 135 small clinics in Hyderabad, Pakistan, with the aim to determine small clinics' waste management practices in contrast to rules, level of knowledge, the environmental impact of disposal methods, and motivating factor analysis to understand the current situation from multiple perspectives. Overall, the waste generation rate was calculated to be 2.01 kg/clinic/day and the hazardous waste generation rate was 0.89 kg/clinic/day, whereas the general waste generation rate was 1.12 kg/clinic/day. The hazardous waste generation rate percentage is found to be higher than those found in large hospitals by 20%. The waste management practice among surveyed clinics was deplorable; none of the clinics were completely following hospital waste management rules of 2005 and thus the absence of proper segregation, storage, transportation, and disposal was commonly encountered during the study. Clinic staff possessed low level of knowledge and awareness, and acquired no training about waste management practice and rules, moreover, frequent employee turnover was noticed too. Additionally, two hypotheses were checked for creditability of motivating factors with an exploratory factor analysis to check their contribution to motivating clinic staff to practice sound healthcare waste management. Out of 10 indicators, nine were found in support of the hypotheses. Hence, it was discovered that active government involvement and financial support in providing training and inspecting small clinics could help in improving the condition. The findings of the present study can play a vital role in documenting evidence, and for policymakers and governments to plan solid waste management of small clinics and other healthcare facilities.

Advocates for civil rights, environmental justice, and movements promoting social justice require data and may lack trust in public authorities, turning instead to academic scientists to help address their questions. Assessing historical exposure to toxic chemicals, especially in situations of a specific industrial source of pollution affecting a community, is critical for informing appropriate public health and policy responses. We describe a community-driven approach to integrate retrospective environmental hazard exposure assessment with community organizing to address concerns about the extent of exposure to toxic metals in a predominantly working-class, Latinx community living near a now-closed lead-acid battery smelter facility. Named the "Truth Fairy Project" by leaders of the community organization East Yard Communities for Environmental Justice, this community-university partnership aimed to assess prenatal and early-life exposures to toxic metals through biomarkers of exposure in baby/deciduous teeth. This partnership integrated community mobilization with empirical research, informing residents about toxic metal exposures and improving the community's capacity to respond to a public health crisis.

The Central and Eastern Europe region is faced with longstanding environmental health problems as well as emerging health threats from pollution caused by the region's recent period of rapid industrialization. As researchers in the region continue to work to address these problems, they could find unique approaches by increasing collaborations between biomedical and non-biomedical scientists and by more closely following the Superfund Research Program model of pursuing basic research, then connecting with stakeholders in the region to share and apply new knowledge. To build upon and leverage research in the region, researchers and stakeholders should work to formalize the bi-annual meeting of the Central and Eastern European Conference on Health and the Environment into a more cohesive organization and make efforts to connect to broader global networks that aim to spread research results and applications around the world. By taking these steps to connect to the broader world of environmental health research, the CEE region stakeholders can reduce pollution-related disease, minimize costs of hazardous waste remediation, and help grow the economy in their region.

This study reports on the assessment of the impact of antimony mine wastes from Xikuangshan (XKS) Antimony Mine in Lengshuijiang City, Hunan Province. We focus on the leaching of a number of potentially toxic elements (PTEs) from residues from the processing of antimony ore. The PTE content of ore processing waste and solutions generated by leaching experiments were determined for a suite of PTEs associated with the ore mineralization. These were Sb, As, Hg, Pb, Cd and Zn. As anticipated, high concentrations of the PTEs were identified in the waste materials, far exceeding the standard background values for soil in Hunan Province. For Sb and As, values reached >1800 mg·kg -1 and >1200 mg·kg -1 , respectively (>600 and >90 times higher than the soil background). The leaching of Sb, As, Hg, Pb, Cd and Zn decreased with an increase in grain size and leachable portions of metal ranged between 0.01% to 1.56% of total PTE content. Leaching tests identified the release of PTEs through three stages: a. alkaline mineral dissolution and H + exchanging with base cation; b. oxidation and acid production from pyrite and other reducing minerals; and c. the adsorption and precipitation of PTEs.

Reuse of waste is one of the main principles of sustainable development and circular economy. Secondary alkaline lead slag is a hazardous waste generated in the recycling process of lead-acid batteries that may be suitable in construction materials. The environmental impact of the use of lead slag as a partial replacement of fine aggregates in the cement-based stabilization/solidification (S/S) process for the preparation of concrete was studied in this paper. Solidified products containing 10%, 15%, 20%, and 25% slag were laboratory tested by unconfined compressive strength (UCS) analyses and the Toxicity Characteristic Leaching Procedure (TCLP). At the same time, the leachability of toxic elements from solidified products with a high percent of slag was evaluated under environmental conditions for during one year. The results of the UCS and TCLP indicated that utilization of this type of slag in cement-based applications may be justified with its controlled addition. However, the described application of the slag was disputed due to the high release of As under high alkaline environmental conditions. Eh-pH analyses and the geochemical modeling using the software PHREEQC were evaluated, as well as the mechanism of pollutant (Pb, As) immobilization (precipitation, adsorption) as a function of pH conditions.