Disposal Methods Research Articles

Economic assessment of municipal solid waste management in midsized metropolitan areas of Brazil

This paper addresses the incipient number of studies regarding municipal solid waste management in Brazil, where the federal law requires the inclusion of waste pickers in waste management and proposes waste diversion targets far from being attained. Therefore, decision-makers can make the best choice economically among alternative technological roadmaps that meet the legal requirements. The proposed alternatives combine biowaste treatments (open composting, closed composting, anaerobic digestion), recycling and final disposal methods (landfill and incineration) for a metropolitan region with two million inhabitants. The results show that incineration can lower the costs for the citizens, and the cost increase is modest if anaerobic digestion is chosen if no profit is intended after 20 years (IRR=0%). However, higher profit (8% and 16% IRR) causes a significant increase in the service fees, which could encourage the use of composting facilities with lower environmental performance. Furthermore, the high waste diversions scenarios have lower service fees than the low diversions counterparts because of the increase in revenue from sales of recyclable materials and employing 5,697 instead of 2,138 pickers to work at sorting facilities, therefore highly recommended.

Study of hydrocyclone with flushing water device for sand washing of municipal sludge

Municipal sludge particles with size range between 0.045 and 0.2 mm were difficult to be precisely separated due to fine size distribution and high content of organic matter, resulting in low sand recycling efficiency. In view of the above problems, this paper proposed a flushing water device which was settled at the cone section of conventional hydrocyclone, aiming to utilize the supplementary water to strengthen the shear force field. Comparative test results showed that the organic matter content in the underflow product was significantly reduced after the addition of flushing water. Using the organic matter content and the sand recovery rate as the response index, the prediction models were established by using response surface optimization test. The influence order of different parameters on the response index was apex diameter, flushing device position and flow rate. Finally, an underflow product with organic matter content of 3.96 % and sand recovery rate of 48.03 % was obtained under the conditions of optimized parameter combinations. The research results can contribute to the development of a new method of residual sludge disposal that improves the sand washing efficiency and the cost-effectiveness of sludge treatment.

Assessment of Knowledge and Practice Regarding Disposal of Unused and Expired Drugs in Medical Professionals in a Tertiary Care Teaching Hospital in Eastern India: A Cross- Sectional, Questionnaire-based Study

Background: Despite the effect of drugs on human body getting wide attention worldwide the effect of disposed drugs on the environment is largely neglected. Since the doctors working in a teaching hospital are the major stakeholder in ensuring proper and safe disposal of drugs their knowledge, attitude and practice regarding drug disposal was assessed in this study.Methods: A pre-validated questionnaire was given to the doctors working in a tertiary care teaching hospital through Google form from 1st June,2023 to 31st July 2023. Their responses were recorded in a Microsoft excel form and analyzed. Results: It was observed that while buying medicines 87.5% of physicians check the date of expiry but only 78.9% do that while receiving physician’s sample from the medical representatives. Among the participants in this study 97.2% declared that medicines remain unused in their homes. In case of unused drugs, 45.8% donate them to patients or hospitals, and 29.2% throw them away with household garbage whereas in case of expired medicines majority (56.9%) throw them away. Among the participants 38.9% had never instructed their patients about the proper disposal methods. Conclusion: To ensure proper drug disposal programs should be initiated to increase awareness about the danger of improper drug disposal not only in general population but in medical community also.

Assessment of Behaviour among Households towards Solid Waste Management in GHMC

Background: Rapid urbanization has made domestic waste management a crucial environmental challenge in Hyderabad, which generates 5,500 to 6,000 metric tons of waste daily. Despite regulations, improper disposal practices persist, posing risks to public health and sustainability. Research Methodology: This mixed-methods study used surveys of 404 households and secondary data to assess household waste management behavior in GHMC. Statistical tools like Chi-square tests and ANOVA were used to analyze the influence of demographic factors. Results: Significant variations in waste management practices were found across demographics. Improper disposal methods, such as roadside dumping (mean = 3.43, p-value = 0.13) and burning (mean = 3.17, p-value = 0.572), are prevalent among older adults and higher-income households (mean = 3.44, p-value = 0.002). Conversely, younger individuals (<20 years, mean = 3.36, p-value = 0.084) and lower-income groups (<₹10,000, mean = 3.13, p-value = 0.805) show better adherence to sustainable practices like the 3R's and composting (mean = 3.32, p-value = 0.013). Education level also influences waste management behavior, with primary education correlating with better practices (mean = 3.41, p-value = 0.315). Conclusion: Targeted interventions are needed to address improper disposal practices among older and higher- income groups. Positive trends in waste facility utilization and e-waste disposal are noted, but burning and burying waste remain common. Enhanced educational campaigns and infrastructure improvements are essential for sustainable waste management. Keywords: Solid Waste Management, Household Behavior, Urbanization, Environmental Sustainability, Waste Segregation, Greater Hyderabad Municipal Corporation (GHMC), Recycling, Waste Reduction, Education, Public Health.

Medication Disposal Patterns and Practices with Awareness of Environmental Contamination Caused by Pharmaceuticals among the General Public in Malaysia.

The proper disposal of pharmaceuticals has become a prime concern in contemporary healthcare and environmental management. The evolving awareness highlights the ecological and public health risks associated with pharmaceutical waste. Therefore, evaluating medication disposal patterns and public awareness regarding pharmaceutical-related environmental issues is crucial for promoting responsible practices. The primary aim of this study is to identify the determinants of participation in the Medicine Return Program (MRP) among Malaysians. This cross-sectional study employed snowball sampling and an online questionnaire, disseminated via multiple social media platforms. Results: Out of 389 respondents, 46% were 18 to 29 years old, 61% were female, and 69.7% attained a tertiary educational level. Most of them (71.5%) reported disposing of their unused medicines into the rubbish bin, indicating that this disposal method is prevalent among Malaysians. Only 26.2% participated in the MRP program. The study revealed that 73.0% of respondents were aware of pharmaceutical-related environmental contamination. Furthermore, significant associations were demonstrated between a factor of receiving advice from healthcare professionals (p < 0.001), awareness level on environmental pharmaceutical contamination (p < 0.001) and MRP (p < 0.001) and willingness to participate in MRP (p < 0.001) with MRP support. This study provides valuable insights on Malaysian pharmaceutical disposal practices and the factors influencing MRP participation. These findings can inform targeted interventions and public health campaigns to improve medication disposal behaviors and reduce pharmaceutical waste's environmental impact.

Electrocatalytic upcycling of plastic waste: Progress, challenges, and future

AbstractThe escalating accumulation of plastic waste has been developed into a formidable global environmental challenge. Traditional disposal methods such as landfilling and incineration not only exacerbate environmental degradation by releasing harmful chemicals and greenhouse gases, but also squander finite resources that could otherwise be recycled or repurposed. Upcycling is a kind of plastic recycling technology that converts plastic waste into high‐value chemicals and helps to avoid resource waste and environmental pollution. Electrocatalytic upcycling emerges as a novel technology distinguished by its mild operational conditions, high transformation efficiency and product selectivity. This review commences with an overview of the recycling and upcycling technology employed in plastic waste management and the respective advantages and inherent limitations are also delineated. The different types of plastic waste upcycled by electrocatalytic strategy are then discussed and the plastic waste transformation process is examined together with the mechanisms underlying the electrocatalytic upcycling. Furthermore, the structure‐activity relationships between electrocatalysts and plastic waste upcycling performance are also elucidated. The review aims to furnish readers with a comprehensive understanding of the electrocatalytic techniques for plastic waste upcycling and to provide a guidance for the design of electrocatalysts towards efficient plastic waste transformation.

Kinetics analysis of copper extraction from copper smelting slag by sulfuric acid oxidation leaching

Copper smelting slag (CSS) is generally produced from the pyrometallurgy of copper sulfide concentrate, the current storage disposal methods of CSS not only occupy precious land and pollute the environment, but also waste resources. To recover copper from the CSS and explore the atmospheric pressure oxidative leaching kinetics of copper extraction from CSS with sulfuric acid was investigated intensively. In this study, the effect of particle size, sulfuric acid concentration, temperature, liquid-to-solid ratio, and hydrogen peroxide added amount were investigated comprehensively. The results indicated that the decrease of particle size and increase of other parameters can significantly promote the leaching of copper. Under the optimum conditions, 90.7 % of the copper in the CSS was effectively leached, other copper in the leaching slag mainly existed in the form of fine-grained embedded copper sulfide. The dominant phase of the leaching slag is magnetite, which could be further recovered by conventional magnetic separation. Moreover, the kinetics of copper atmospheric pressure oxidative leaching in CSS were further expounded. The results indicated that the copper leaching kinetic conforms to the shrinking core model, and the overall leaching reaction was controlled by the internal diffusion control with an activation energy of 11.22 KJ/mol. The apparent reaction order of sulfuric acid and particle size are determined to be 0.965 and 0.478 respectively. Finally, the kinetics model equation is established for copper at normal pressure as:1-23η-1-η2/3=0.032·CH2SO40.965·r0-0.956·t. This research could provide an alternative solution for the efficient utilization of CSS.

EDUKASI BAHAYA DAN CARA DISPOSAL MINYAK JELANTAH

Used cooking oil has confirmed to be harmful to our health and environtment. In Indonesia, used cooking oil commonly reuse for cooking and dispose directly into the environment. Reusing used cooking oil will increase the risk of cardiovascular disease and cancer and discharging it directly into environment causes water and soil pollution. However, a lack information has been delivered to the community. This article reported community service activity conducted at Desa Pacarkembang Tambaksari Surabaya that has been purposed to increase the community’ knowledge on the dangers and proper disposal of the used cooking oil. A total of 33 participants joined the event. 30 of them had filled the pre and post event questionnaire assessed knowledge in dangers and proper disposal of the used cooking oil. The results showed that there was a rise in number of participants who had positive knowlede on the potential harm and proper disposal method of used cooking oil. A continuous campaign and public education will increase the community knowledge and awareness in maintaining their health and environment.

Development and Application of Unsealed Borehole Leakage Detection Device Based on Flow Method

Poor sealing of gas extraction boreholes is one key to restrict gas extraction efficiency. In this paper, a novel borehole sealed quality detection device for the gas extraction of a coal mine is developed based on the theory of air leakage. By comparing the amount of gas extracted at different test points, it is possible to determine whether there is air leakage around the borehole, and the specific leakage position and leakage amount. Moreover, this device has the advantages of simple operation and a short test period. Based on the above analysis, a corresponding air leakage disposal method was proposed to handle the leaky boreholes. Field tests showed that the air–gas mixture flow in the test borehole was reduced by a factor of approximately 1.55 and the concentration of pure seam gas was increased approximately six times after the disposal of the air leaks. The combination of the leakage disposal method and the leakage detection device can accurately seal the borehole at the position of the leak, thus effectively ensuring the effectiveness of gas extraction from the borehole. The findings have important implications for improving the efficiency of gas extraction in coal mining operations.

Microwave pyrolysis of polypropylene, and high-density polyethylene, and catalytic gasification of waste coffee pods to hydrogen-rich gas

Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy.

Characterization of heat-processed artificial lightweight aggregates from polyethylene terephthalate plastic waste

Plastic waste is an undeniable source of pollution that threatens the existence of the earth’s flora and fauna. The bulk of plastic waste generated globally does not go through the proper methods of disposal but is carelessly discarded into the aquatic or terrestrial environment. Current recycling efforts are largely inadequate and disposal in landfills is still fraught with environmental and land use challenges. The proper disposal of plastic waste, as well as mitigating the environmental, social, and health impacts of extracting natural aggregates can be achieved by incorporating plastic waste as aggregates in the construction industry. This paper presents a characterization of aggregates manufactured from polyethylene terephthalate plastic waste using thermal/mechanical methods. From the cost analysis, 24,341.67 Ugx (6.09 USD) was spent to produce 1 kg of PET aggregates. Morphological, intrinsic and mechanical characteristics of the produced aggregates were established using standard procedures and equipment. The results of morphological characterization indicate an irregular shaped aggregate with smooth surface, a dense graded aggregate with a fineness modulus of 4.25, flakiness index of 26%, elongation index of 16% and particle index of 13. Intrinsic characterization yielded particle density of 1330 kg/m3, bulk density of coarse aggregates of 715 kg/m3 and water absorption of 0.445%. Mechanical characteristics of aggregates were evaluated, with compressive strength of 50Mpa, Aggregate Crushing Value of 37%, Ten Percent Fines Value of 71KN, Aggregate Impact Value of 24% and Aggregate Abrasion Value of 20%. The characteristics of PET aggregates confirm their suitability for application in structural lightweight concrete and rigid pavement. The produced PET aggregates can be considered in mix design as a total or partial replacement of natural aggregates in concrete.

Review of Disposal Methods and Directions for the Use and Processing of Sewage Sediments

International expertise in the neutralization, recycling and use of municipal wastewater sedimentation is reviewed. Information is provided on the main areas of neutralization and disposal of wastewater residues used in Asian and European countries. Thermal disinfection of non-flammable components, foreign, harmful and dangerous substances of sewage sediment is proposed, during which the biocoke is formed. The possibility of using the biocoke as a safe organic fertilizer was noted.

When missing becomes murder: An analysis of missing-femicide cases from the Republic of Ireland.

Many femicide cases are initially reported as missing persons to the police. Women who go missing have a greater risk of being a victim of homicide. This study explores the circumstances surrounding the disappearance and killing of women and girls in the Republic of Ireland from 1962 to 2023. A total of fifty-four cases were analysed, 52 cases were homicides. Most femicides occurred during 1990-1999 (n = 13; 24%) and 2000-2009 (n = 17; 32%). Twenty-five victims knew the offender and the leading cause of death was strangulation with 27 cases. Dumping/leaving the body on open ground with little or no concealment was the predominant method of disposal. The leading risk factors were the engagement of the victim in a fight or row before disappearance and domestic violence. The 'suicide narrative' should be treated with extreme caution in the disappearance of women.

A Review of Grease Trap Waste Management in the US and the Upcycle as Feedstocks for Alternative Diesel Fuels

As byproducts generated by commercial and domestic food-related processes, FOGs (fats, oils, and grease) are the leading cause of sewer pipe blockages in the US and around the world. Grease trap waste (GTW) is a subcategory of FOG currently disposed of as waste, resulting in an economic burden for GTW generators and handlers. This presents a global need for both resource conservation and carbon footprint reduction, particularly through increased waste upcycling. Therefore, it is critical to better understand current GTW handling practices in the context of the urban food–energy–water cycle. This can be accomplished with firsthand data collection, such as onsite visits, phone discussions, and targeted questionnaires. GTW disposal methods were found to be regional and correspond to key geographical locations, with landfill operations mostly practiced in the Midwest regions, incineration mainly in the Northeast and Mid-Atlantic regions, and digestion mainly in the West of the US. Select GTW samples were analyzed to evaluate their potential reuse as low-cost feedstocks for biodiesel or renewable diesel, which are alternatives to petroleum diesel fuels. Various GTW lipid extraction technologies have been reviewed, and more studies were found on converting GTW into biodiesel rather than renewable diesel. The challenges for these two pathways are the high sulfur content in biodiesel and the metal contents in renewable diesel, respectively. GTW lipid extraction technologies should overcome these issues while producing minimum-viable products with higher market values.

A Comprehensive Approach to Biodiesel Blend Selection Using GRA-TOPSIS: A Case Study of Waste Cooking Oils in Egypt

The transition to sustainable energy sources is critical for addressing global environmental challenges. In 2017, Egypt produced about 500,000 tons of waste cooking oil from various sources including food industries, restaurants and hotels. Sadly, 90% of households choose to dispose of their used cooking oil by pouring it down the drain or into their village’s sewers instead of using proper disposal methods. The process involves converting waste cooking oil (WCO) into biodiesel.This study introduces a multi-criteria decision-making approach to identify the optimal biodiesel blend from waste cooking oils in Egypt. By leveraging the grey relational analysis (GRA) combined with the technique for order preference by similarity to the ideal solution (TOPSIS), we evaluate eight biodiesel blends (diesel, B5, B10, B20, B30, B50, B75, B100) against various performance metrics, including carbon monoxide, carbon dioxide, nitrogen oxides, hydrocarbons, particulate matter, engine power, fuel consumption, engine noise, and exhaust gas temperature. The experimental analysis used a single-cylinder, constant-speed, direct-injection eight cylinder diesel engine under varying load conditions. Our methodology involved feature engineering and model building to enhance predictive accuracy. The results demonstrated significant improvements in monitoring accuracy, with diesel, B5, and B20 emerging as the top-performing blends. Notably, the B5 blend showed the best overall performance, balancing efficiency and emissions. This study highlights the potential of integrating advanced AI-driven decision-making frameworks into biodiesel blend selection, promoting cleaner energy solutions and optimizing engine performance. Our findings underscore the substantial benefits of waste cooking oils for biodiesel production, contributing to environmental sustainability and energy efficiency.

Research Trends and ‘Space-Sky-Ground-Underground’ Monitoring Technology Analysis of Landslide Hazard

Landslide is a typical geological disaster distributed in most countries worldwide. Due to long-term natural weathering and human engineering disturbances, the instability of landslides is prone to occur. Once monitoring and disposal methods are implemented inappropriately, they can lead to landslide hazards, seriously threatening the safety of people’s lives and property. For a long time, extensive research on landslide monitoring has been conducted from various countries, providing crucial technical support for reducing the incidence and severity of landslide hazards. However, considering the complex geological conditions of actual landslides and the direct impact of internal and external factors such as rainfall, storms, and earthquakes, the early warning accuracy of landslide hazards is still relatively low. Therefore, based on advanced research achievements, it is significant to carry out research on the current status and development trends of landslide monitoring technology. Based on the Web of Science core database, this study quantitatively analyzes the advanced research achievements in global landslide monitoring in the past decade using bibliometric analysis. A systematic analysis of landslide monitoring technology development is conducted according to each study’s publication time, keywords, and countries. On this basis, a multi-dimensional monitoring system for landslides was proposed, which utilizes the complementary advantages of multi-dimensional monitoring technology to achieve all-round, high-precision, and real-time monitoring of landslides. Finally, taking the Xinpu landslide in the Three Gorges Region of China as an example, a multi-source and multi-field-monitoring experiment was conducted. The application of landslide multi-field-monitoring technology provides an essential reference for monitoring, early warning, as well as the scientific prevention and control of landslide hazard.

Management of Plastic Wastes through Recent Advanced Pyrolysis Processes

Plastics are predominant in numerous sectors like packaging, agriculture, hardware, electronics, and many others. Annual plastic demand has been rapidly growing in the last few decades because of the increasing dependency on plastics. As a consequence, massive amounts of plastic waste are being generated every year. These plastic wastes are non-biodegradable, and hence their disposal poses a serious threat to the ecosystem and causes significant environmental problems such as endangering the safety of marine life, wildlife, air, water, and soil, etc. A large portion of plastic waste ends up in landfills, and only a small fraction is recycled. The continuous dependence on landfills as the main disposal method for plastic waste is costly and ineffective. Common solutions to plastic waste management are incineration and recycling; however, incineration emits harmful pollutants and greenhouse gases that contribute to ozone layer depletion and global warming; moreover, recycling is expensive and inefficient. As an alternative to recycling and incineration, the pyrolysis process can convert plastic wastes into more valuable fuel products. Pyrolysis is a thermal process that converts raw material into pyrolysis liquid, solid wax, and non-condensable gases in the absence of oxygen. This process is attractive because it is economical and energy-efficient, and it can be used to convert various types of plastic waste into valuable products. In recent years, there have been significant developments in pyrolysis applications in liquid fuel production from plastic wastes. This work reviews recent advances in and challenges for the pyrolysis process for converting plastic wastes into a valuable alternative fuel, focusing on studies of advanced pyrolysis processes published over the last five years. The paper also highlights the numerical modeling of pyrolysis of plastic wastes and the potential impact of pyrolysis on the future of sustainable waste-management practices of plastics.

An In-depth Analysis of Fashion Merchandise Packaging: Evaluating Environmental Awareness and Challenges among Consumers and Retail Managers in Nairobi City County, Kenya

Recently, the Government of Kenya implemented a ban on single-use plastic and imposed strict regulations on environmental sustainability for packaging. This has led to challenges for consumers and fashion retail managers in Nairobi City County as they adapt to new packaging innovations from manufacturers. A study was conducted to assess the level of environmental awareness among consumers and fashion retail managers regarding fashion merchandize packaging. The study also aimed to identify the packaging challenges faced by both consumers and fashion retail managers in fashion retail outlets. The results of the study are intended to assist consumers, fashion retail managers, and the Kenyan government in standardizing eco-friendly packaging materials and providing training on proper disposal methods to ensure a clean environment.

Elimination of microplastics, PFAS, and PPCPs from biosolids via pyrolysis to produce biochar: Feasibility and techno-economic analysis

Biosolids from municipal wastewater treatment contain many contaminants of emerging concern, including microplastics (MPs), per- and polyfluoroalkyl substances (PFAS), pharmaceuticals and chemicals from personal care products (PPCPs). Many of these contaminants have very slow biotic or abiotic degradation rates and have been shown to have human and ecological health impacts. Application of biosolids to agriculture, a common disposal method, can result in extended environmental contamination. An approach for eliminating the contaminants is pyrolysis, which can also generate biochar, enhancing carbon sequestration as a side-benefit. We pyrolyzed biosolid samples from an operating facility at various temperatures from 400 to 700 °C with a 2-hour residence time. We then evaluated contaminant removal, which in many cases was 100 %, with only a few residuals. No trace of PFAS was detectable even at 400 °C. Overall mass removal of PPCPs, including PFAS, was over 99.9 %. MP removal via pyrolysis ranged from 91 to 97 %. The biochar contains significant amounts of Fe and P, which make it a useful fertilizer amendment. The techno-economic analysis indicates that pyrolysis may generate significant cost savings, and revenue from the sale of biochar, sufficient to more than cover the investment and operating costs of the dryer and pyrolysis unit.

Evaluating the economic and environmental benefits of deploying a national-scale, thermo-chemical plastic waste upcycling infrastructure in the United States

Emerging chemical technologies can upcycle plastic waste by producing high-value polymers and other products. In this work, we study the economic and environmental benefits of deploying an upcycling infrastructure in the continental United States for producing low-density polyethylene (LDPE) and polypropylene (PP) from post-consumer plastic waste. Our analysis is based on a computational framework that integrates techno-economic analysis, life-cycle assessment, and value chain optimization. Our results demonstrate that the infrastructure could generate a market of nearly 20 billion USD per year and that this market is robust to various externalities. Our analysis also indicates that the infrastructure can achieve a plastic-to-plastic degree of circularity of 34% relative to residential plastic waste production, and leads to significant environmental benefits over alternative waste disposal methods, including 69%–75% lower greenhouse gas emissions than waste-to-energy systems and 38 million tonnes of avoided landfill waste per year.