Waste Recovery Research Articles

ТЕРМОХИМИЧЕСКАЯ РЕКУПЕРАЦИЯ ТЕПЛОТЫ В ГАЗОТУРБИННОЙ УСТАНОВКЕ

Natural gas every year wins an increasing share in the global fuel balance. Countries where cheap natural gas is available are seeking to increase the efficiency of its use in order to increase the volume of its use. One of the most promising methods for increasing the efficiency of natural gas is the heat recovery of gas waste. The subject of the study is a gas turbine plant due to the fact that the number of power plants with gas turbines tends to increase. In this paper, options for increasing the efficiency of using natural gas in gas turbines at a constant flow rate are investigated. Variants of implementation of thermochemical heat recovery of gas wastes based on steam reforming of methane and thermal heat recovery of gas wastes based on steam generation are considered. The results of a study based on a mathematical model of a gas turbine plant using thermal and thermochemical waste gas heat recovery are presented.
 A constructive calculation of the methane steam reforming reactor has been carried out. The design and regime parameters of the heat exchanger are determined. A 3D-model of the conversion reactor has been developed, which provides high gas density and the possibility of thermal elongation of heat exchange tubes

Learning in the Biosphere Reserve in Entlebuch, Switzerland: Environmental Sustainability and Social Management

The present study corresponds to the second stage of an investigation on the diagnosis and proposal for the application of destination criteria from an environmental approach in rural communities in the State of Morelos, with the objective of designing strategies for permanent intervention through training. on the use and management of solid waste for sustainable use and strategies for the reduction and recovery of recyclable waste, including environmental awareness campaigns. The Academic Body CAMOR 145-Management of Tourist and Cultural Heritage-CONACyT, responsible for the research, has defined two major initiatives, one of training through the visit to the Biosphere Reserve in Entlebuch, Switzerland and another of action, through the organization of a congress oriented towards the definition of social management needs, with a view to proposing activities for the application of the tourism sustainability criteria proposed by the Global Sustainable Tourism Council (GSTC) in order to provide guidance to communities on management strategies and safeguarding of the tourist heritage in their regions.

From rubbles to digital material bank. A digital methodology for construction and demolition waste management in post-disaster areas

In 2020, European countries generated 807 mln tons of construction and demolition waste (CDW), accounting for 37.5% of total waste production. The UE Waste Framework Directive of 2008 established as a priority goal to increase the percentage of reuse, recycling and recovery of nonhazardous construction waste to a minimum of 70% by 2020. Pending the report that will define compliance with this goal, the average percentage currently stands at around 50%, of which only 3% involves upcycling operations. This doctoral research defines an operational methodology aimed at implementing digital processes for circularity in the AEC sector, with a focus on post-earthquake emergency Italian contexts. The treatment of CDW in earthquake-affected areas for the purpose of recovery/reuse, in a perspective of circularity, represents an underexplored field and limited, as in the rest of UE, to downcycling operations. By defining planning strategies and digital tools and procedures, the research aims to facilitate the reuse of building elements from post-earthquake demolition and reconstruction operations. The final output of the research consists of a cloud database, a Digital Material Bank (DMB), of informed building elements from post-earthquake selective demolition operations that can be reused in the construction market as a secondary raw material. The CDW management of the 2016 Central Italy earthquake is identified as the scope of application, with a focus on the situation in the Marche region. Finally, the main limitations and possible future scenarios of the research are reported.

UiO-66-NH2/chitosan with microalgae platform for gold valorization from waste microelectronics

The combination of UiO-66-NH2/chitosan (CTS) and microalgae was effective in precious metal recovery of electronic wastes (E-wastes) from discarded microchips. Herein, zirconium-based metal–organic frameworks were introduced to bind metal ions from the E-waste. Thus, UiO-66-NH2 was linked to CTS as examined by Fourier-transform infrared spectroscopy (FT-IR). Au(III) leachate solutions were prepared via acidic treatments from the microcomputer chips that were used to test metal binding using UV–Vis absorption spectroscopy. The prepared UiO-66-NH2/CTS was tested to recover Au(III) ions from the liquid phase waste, which exhibited higher adsorption capacity than UiO-66, UiO-66-CTS, and UiO-66-NH2. The inclusion of microalgae in UiO-66-NH2/CTS system enhanced gold adsorption efficiency and binding of Au(III) ions onto UiO-66-NH2/CTS and UiO-66-NH2/CTS/microalgae attained equilibrium within a few hours. UiO-66-NH2/CTS showed an adsorption capacity of ∼ 576 mg/g, which increased to ∼ 671 mg/g after the introduction of microalgae of Spirulina maxima. The pH effect on Au(III) binding revealed that electrostatic interactions between the negatively charged UiO-66 particles and gold anions decreased the adsorption capacities at higher pH values. The findings highlighted the potential use of UiO-66-NH2/CTS and microalgae for effective gold recovery from the E-waste.

Valuation of Plastic Waste as a Community Circular Economy Strategy in the Municipality of Choco–Colombia

A business solution is proposed for the accumulation of waste in the Municipality of Choco without prior treatment through the establishment of a center for the reception, classification, recovery and use of solid plastic waste in the Municipality of Quibdo, which would optimize and expand the management of plastic waste. In this study, the basic diagnosis of the practices that are currently carried out in Quibdo is evaluated with the appropriation of the knowledge of the population, the technical structuring of the conditions of production of plastic wood is carried out from the management of plastic waste, recognition of the market for waste generated as an alternative for development and sustainable growth and the financial feasibility of the project and the profitability of each of the investment plans for its implementation. The results of the investigation include the identification of weaknesses and opportunities in waste management practices and the proposal of two investment plans for the establishment of the center. It is concluded that investment plan 2 would require 46,590.50 USD less than investment plan 1, equivalent to a 2.21% return compared to investment plan 1.

Analysis of gas-solid two-phase flow characteristics of mobile shot blasting machine recovery device based on CFD-DEM

The shot blasting machine recovery device is an important part of the operation of the shot blasting machine to recover solid particles and reduce environmental pollution. The recovery efficiency of solid particles has an important influence on their processing efficiency and service life. The computational fluid dynamics and discrete element method (CFD-DEM) simulation method is applied to study the gas-solid two-phase flow characteristics and solid particle recovery efficiency of shot pellet recovery unit. The results show that the simulation results of outlet and inlet wind speeds and pressures are in good agreement with the experimental data, which verifies the accuracy of the simulation model. The existence of particle phase divides the recovery pipeline into inner high-speed flow area and outer low-speed flow area, which has little influence on the air flow distribution inside the recovery bin. The results of solid particle recovery efficiency show that with the increase of incident angle, the recovery efficiency of waste particles and shot particles first decreases and then increases, and the recovery efficiency is the lowest when the incident angle is 30°. With the increase of particle formation rate, the efficiency of shot recovery first increases and then decreases. When the particle formation rate is 2000 n/s, the efficiency of shot recovery is the highest, which has little influence on the efficiency of waste recovery.

Is Loose-Fill Plastic Waste an Opportunity for Thermal Insulation in Cold and Humid Tropical Climates?

This paper addresses the plastic waste management challenge by proposing a sustainable solution for the building sector. The proposed solution uses Loose-Fill Plastic Waste (LFPW) as a thermal insulation material, the world’s first in plastic waste recovery. To investigate the potential of this new path, an experimental study was conducted on test cells in Reunion Island’s cold and wet climate. It was revealed that LFPW (size between 3 and 4 mm with 8 cm thickness) can reduce surface temperatures by nearly 3.2 °C, with a maximum difference by almost 22.2 °C. The thermal phase shift is significant (190 mn) and comparable to conventional thermal insulation solutions. The study results suggest that LFPW can provide an effective and economical solution to the challenge of plastic waste management while promoting sustainable development.

Analysis of Environmental Sustainability through a Weighting Matrix in the Oil and Gas Industry

In the oil sector, various strategies are applied to mitigate harmful effects on the environment. These strategies include, among others, compensation plans, the measurement and control of the carbon footprint and/or water footprint, the recovery of waste from activities and processes, and Environmental Management Systems (EMS). An EMS provides a formal framework that enables more efficient work on environmental issues, thereby improving performance. It aims to raise awareness of the environmental impacts associated with the oil industry in different areas through the use of weighting matrices. Additionally, it seeks to conduct sustainable studies and optimize the direct activities involved in the exploitation of hydrocarbons as a natural resource. Factors considered in decision making include ensuring that the strategy does not compromise the well-being of future generations, has economic viability, and does not hinder any oil sector activities such as exploration, drilling, production, or processing of derivatives. The purpose of this is that it allows for the creation of decision matrices based on weighting methodologies that outline possible correlations between specific activities of the oil sector such as water use, effects on soils and landscapes, greenhouse gas emissions, solid waste, liquid effluents, hazardous waste, and toxic waste, among others. The decision matrices can also help elucidate the relationship of these activities with mitigation strategies to provide a decision-making tool for environmental management plans so that activities are implemented in a way that can mitigate impacts on water, soil, and air resources. The results of this study were classified using a traffic light matrix, based on the level of technical congruence, using an optimal (green), regular (yellow), medium (orange), and at-risk (red) scale. The environmental impact of “alteration of the geoform of the land” was positioned in the at-risk category due to its assessment by experts in relation to the activity of “land adaptation”. In the medium category, a total of 23 impacts were identified, while 10 impacts fell into the regular category. These results were evaluated in the context of the environmental, social, and economic sustainability of the oil industry.

Fermentation broth of food waste: A sustainable electron donor for perchlorate biodegradation

Microbial reduction has been considered an effective way to remove perchlorate (ClO4-), during which, additional electron donors and carbon sources are required. This work aims to study the potential of fermentation broth of food waste (FBFW) serving as an electron donor for ClO4- biodegradation, and further investigates the variance of the microbial community. The results showed that FBFW without anaerobic inoculum at 96 h (F-96) exhibited the highest ClO4- removal rate of 127.09 mg/L/d, attributed to higher acetate and lower ammonium contents in the F-96 system. In a 5 L continuous stirred-tank reactor (CSTR), with a 217.39 g/m3·d ClO4- loading rate, 100% removal efficiency of ClO4- was achieved, indicating that the application of FBFW in the CSTR showed satisfactory performance for ClO4- degradation. Moreover, the microbial community analysis revealed that Proteobacteria and Dechloromonas contributed positively to ClO4- degradation. Therefore, this study provided a novel approach for the recovery and utilization of food waste, by employing it as a cost-effective electron donor for ClO4- biodegradation.

A review of the applicability of Environmental Management Systems in waste management in the medical sector of Zimbabwe.

Environmental Management Systems (EMS) are currently the cornerstone of achieving sustainability globally. Nevertheless, the question is applicability of EMS in the medical sector. Hence, the review focused on applicability of EMS in medical waste management Zimbabwe. EMS involves overall processes that facilitate reduction of dire impacts of company's activities while increasing performance. EMS framework consists of environmental policy, planning, implementation, checking, review and improvement stages. To examine applicability of EMS in management of medical sector waste, published secondary sources with information related to the topic were utilised. Analysis of strengths and opportunities of EMS was used as a base to examine its applicability in medical waste management. Zimbabwean medical sector consist of hospitals and primary healthcare facilities. Medical waste includes pathological, pharmaceutical, cytotoxic, radioactive, chemical, sharp, infectious and general waste. However, twenty-first century witnessed expansion of medical institutions to accommodate COVID-19 patients, resulting in generation of construction and demotion waste. Medical institutions in Zimbabwe are accountable for solid waste management at generation source although municipalities are responsible for conveying solid waste to landfills. Solid waste from medical sector is disposed through traditional strategies namely landfilling, incineration, open pits and open burning, resulting in water, air, and soil contamination. However, EMS can reduce quantity of solid waste disposed through waste reuse, recycle and recovery. Moreover, achievement of integrated approach, effective legislation, policies and inclusive participation in medical waste management is adopted through use of EMS. Therefore, EMS were utilised to develop an integrated sustainable medical waste management model to achieve sustainability.

Bibliometric analysis on the applicability of anaerobic digestion in organic solid waste

Anaerobic biological treatment can comprise a viable route of CH4 production through the energy recovery of organic solid waste (OSW). This work therefore presented a bibliometric analysis of research trends on the theme "Applicability of biological treatment via Anaerobic Digestion in Organic Solid Waste", considering experimental articles published from 2018 to 2022 in the Web of Science database™; the analysis used VoSviewer software to define research trends, and found that the main terms addressed in the mapped scientific articles were anaerobic, waste, sludge, waste food, municipal waste, anaerobic co-digestion, sewage sludge, organic fraction, co-digestion and biogas. As a product of such mapping, an Interaction Network Diagram was constructed comprising the main terms in addition to a theoretical foundation on anaerobic digestion and biochemical and microbiological aspects about the process.
 Keywords: anaerobic co-digestion, clean energy, food waste, microbial intercropping.

Greenhouse Gas Reduction Potential based on Waste Recovery Factor in Gading and Dukuh Setro Subdistrics, Surabaya

People’s growth and their activities increase waste generation. Therefore, efforts to reduce waste are needed, including community-based reduction efforts. This research is located in Gading and Dukuh Setro sub-districts in Surabaya City. The purpose of this study was to measure the potential for waste reduction and greenhouse gas reduction. Measurement of waste generation, waste composition, and waste density was based on SNI 19-3964-1994. The researcher conducted sampling in low, middle, and high-income areas, covering 83 families. Greenhouse gas emissions were estimated using the LandGEM (U.S. EPA) method based on the waste disposed at landfill, considering the existing reduction conditions and optimal material recovery. Solid waste generation in 2022 per year was 4.695,58 tons. The largest composition of waste consisted of biodegradable waste (37.13%), plastic waste (25.73%), and diapers and sanitary napkins (18.25%). The average density of loose waste was 152.42 kg/m3. The existing reduction had 1.47% waste bank reduction activity and 0.72% composting reduction activity, for a total reduction of 2.19%. The average optimal reduction was 52.7%, whereas the optimal reduction in the waste bank was 17.5%. The optimal composting reduction was 35.2%. Thus, the existing scenario in 2032 obtained reductions from total landfill gas of 725,498 Gg/year, methane of 193,788 Gg/year, carbon dioxide of 531,710 Gg/year, and NMOC of 8,330 Gg/year. Meanwhile, the optimal scenario for 2032 obtained reductions from total landfill gas of 239.067 Gg/year, methane of 63.857 Gg/year, carbon dioxide of 175.209 Gg/year, and NMOC of 0.412 Gg/year

Recent advances in hydrogen production from biomass waste with a focus on pyrolysis and gasification

Energy consumption was skyrocketing along with fast economic development as well as continuous global population growth. Furthermore, environmental concerns about greenhouse gas emissions were also increasing, which indicated that these issues could be resolved by the development and utilization of renewable and clean energy. Among many renewable kinds of energy, hydrogen was considered the cleanest generating water because it was the only combustion product, allowing for truly zero pollutant emissions. As a result, developing efficient hydrogen generation technologies that utilized biomass feedstock, and ensured clean energy produced with low-carbon emissions was critical in helping fight against global warming as well as obtain waste recovery. In this paper, recent investigation advances in the generation of hydrogen from biomass pyrolysis and gasification were comprehensively reviewed in this regard. Also, the most recent studies on biomass pyrolysis and gasification in the use of biomass waste to produce hydrogen, with an emphasis on technical problems, efficiency, and mechanism were summarized. Following that, challenges and opportunities were presented for enhancing the efficiencies of the process and the quality of the products, which was significant to obtain sustainable and green development. Importantly, even though several advances and innovations in generating hydrogen from biomass were made using existing technologies, more scientific advances were needed to make it economically competitive as well as environmentally friendly for industrial production on large scale. Overall, the entire article gives a consolidated overview of the optimal condition suggested for superior H2 yield, and %volume from various biomass.

GA−BP Prediction Model for Automobile Exhaust Waste Heat Recovery Using Thermoelectric Generator

Thermoelectric generator (TEG) has important applications in automotive exhaust waste heat recovery. The Back propagation neural network (BP) can predict the electrical generating performance of TEG efficiently and accurately due to its advantage of being good at handing nonlinear data. However, BP algorithm is easy to fall into local optimum, and its training data usually have deviation since the data are obtained through the simulation software. Both of the problems will reduce the prediction accuracy. In order to further improve the prediction accuracy of BP algorithm, we use the genetic algorithm (GA) to optimize BP neural network by selection, crossover, and mutation operation. Meanwhile, we create a TEG for the heat waste recovery of automotive exhaust and test 84 groups of experimental data set to train the GA−BP prediction model to avoid the deviation caused by the simulation software. The results show that the prediction accuracy of the GA−BP model is better than that of the BP model. For the predicted values of output power and output voltage, the mean absolute percentage error (MAPE) increased to 2.83% and 2.28%, respectively, and the mean square error (MSE) is much smaller than the value before optimization, and the correlation coefficient (R2) of the network model is greater than 0.99.

Applicability of the Life Cycle Assessment Model in Solid Waste Management in Zimbabwe.

Solid waste increase is inevitable globally due to anthropogenic activities. This adds burden to waste management systems in developing countries including Zimbabwe. Currently, life cycle assessment (LCA) model is used to achieve sustainability and circular economy (CE) in solid waste management. Therefore, the main goal of this paper was to unearth LCA model applicability in solid waste management in Zimbabwe. Data sources were retrieved from databases like Scopus, ScienceDirect and Springer, although government documents were also used. In Zimbabwe, organic and inorganic solid waste is generated from various sources, namely industries, institutions and households. Solid waste management in Zimbabwe is based on traditional linear approach where waste is collected and disposed through landfilling, burning, incineration, burying, open pits or illegally. Most disposal approaches occupy base of waste management pyramid, hence posing detrimental impacts to human health, terrestrial, aquatic and atmospheric ecosystems. Management approaches are far from Agenda 21, Sustainable Development Goals (SDGs), Zimbabwe Vision 2030 and National Development Strategy 1 demands. Literature revealed that LCA model can be utilised to achieve sustainable solid waste management in countries like Zimbabwe. LCA model is essential in management of solid waste in Zimbabwe, since it assists decision makers in selecting management approaches with less environmental health impacts. Moreover, LCA enables application of waste material reuse, recycle, repairing and recovery, thus narrowing the gap to achieve CE and economic growth in Zimbabwe. Owing to LCA model implementation of waste management legislation and policies which support energy recovery and circular economy became easier in Zimbabwe.

Social Assessment of Healthcare Waste Management

Circular economy targets clearly define recovery and recycling as predominant actions for future waste management. However, circularity-oriented actions might not be easily implemented for some types of waste. Healthcare sectors generate non-hazardous municipal waste (up to 80–85 % of all generated waste according to the World Health Organization data) and hazardous infectious waste. Due to public health and the spread of infection risks, healthcare waste treatment needs to be organized in a special manner and moreover, recovered materials need to be tested repeatedly. The present paper aims to analyse the social aspects of health care waste recovery technologies along the supply chain (gate-to-gate approach) – from health care waste collection at medical care institutions to recovered materials at treatment plants. Rotoclave and chemical treatment healthcare waste treatment technologies were analysed as case studies. Methodological approach of the study is based on the UNEP/SETAC guidelines for social life-cycle assessment (S-LCA) of products and questionnaire-based indicators. The results of the assessment will bring the framework for improvement of social aspects of healthcare waste management.

Sequential Methodology for the Selection of Municipal Waste Treatment Alternatives Applied to a Case Study in Chile

Most municipalities in developing countries lack technical and economic resources to improve their municipal solid waste management (MSWM) system. Therefore, tools are needed that enable the most appropriate solutions to be identified to put waste to better use. This study presents an easy-to-apply sequential methodology for the analysis of MSWM alternatives. The method consists of two stages: (1) screening available technologies based on a small set of key variables; (2) ordering the selected alternatives by a combination of multicriteria methods that integrate local priorities. For this second stage, a basic series of technical, environmental, economic and social indicators is proposed. The methodology is applied to a case study where current management is limited to mixed municipal solid waste (MSW) disposal in a landfill without gas recovery. Seven options for implementing energy recovery in landfill, using mechanical plants to recover part of recyclable material, treating the organic fraction, and employing refuse-derived fuel and/or waste to energy incineration, were evaluated together with the current situation and considering four scenarios. The results identify various alternatives that allow the sustainability of MSWM in the case study to improve. Notwithstanding, today, it is necessary to introduce economic instruments that discourage final disposal to make municipal waste recovery viable.

Life Cycle Assessment of Pilot-Scale Bio-Refining of Invasive Japanese Knotweed Alien Plant towards Bio-Based Bioactive Compounds

Japanese knotweed is an invasive alien plant species with characteristic rapid expansion in Europe and North America and resistance to extermination. It displaces autochthonous biodiversity and causes major damage to infrastructure, thus causing global ecological and economic damage. The Japanese knotweed plant is usually eradicated using various chemical, biological, or mechanical techniques, which at a large scale include heavy equipment, usually followed by incineration. Therefore, excavation is preferred to eradication techniques, and as a biomass waste recovery method due to the extraction of high-value biocompounds. This is supported by the fact that the Japanese knotweed possesses various bioactive compounds with beneficial effects on human health. Its rhizome bark extract produces strong and stable antioxidant activity over time, as well as apoptotic, antibacterial, and other beneficial activities. In this work, an environmental impact assessment, including greenhouse gas footprint, acidification, eutrophication, and ecotoxicity for extraction route of the Japanese knotweed rhizome bark, is performed. A comparative case study between the lab-based and proposed pilot-scale production of active added-value extract was evaluated. The results show the pilot-scale production exhibits lower environmental burdens, mainly due to greater electricity requirements for the lab-scale alternative.

Reducing the environmental impacts of Brazilian chicken meat production using different waste recovery strategies

Chicken meat has achieved significant index rates worldwide, with Brazil leading production and exports. The agribusiness significance has led to strengthening attention to the environmental burdens produced by the poultry industry. This research considered reducing the environmental impacts in the life cycle of Brazilian chicken meat regarding strategies for recycling waste from the production process. An attributional cradle-to-gate life cycle assessment was performed, with the functional unit of 1 kg of slaughtered and unpacked chicken meat. The two suggested scenarios used: i) chicken bedding for biogas production and ii) chicken carcass waste as meat meals in feed production. Handling poultry litter for biogas production avoided methane and ammonia emissions, reducing over 50% of the environmental indicators of Climate Change, Terrestrial Acidification, and Freshwater Eutrophication. Reuse poultry waste to produce meat meals reduced from 12% to 55% in all impact categories, decreasing emissions from carcasses destined for decomposition in landfills and using less raw materials from bovine sources. Investigating the environmental performance of the chicken meat production chain encouraged the circularity of natural resources and waste recovery strategies in the system boundary, thus helping to accomplish Sustainable Development Goals 7, 9, 12, and 13 of the UN Agenda 2030

Development of an innovative hybrid thermo-chemical recycling method for CFRP waste recovery

Disposal of carbon fibre reinforced polymer (CFRP) waste in landfill is a significant environmental issue. Cost-benefit and life cycle assessments have demonstrated that pyrolysis and chemical recycling are among the most effective waste treatment strategies. This paper presents the development of a novel low-temperature pyrolysis combined with solvolysis pre-treatment as an effective recycling method for CFRP composite wastes. In this research, the process parameters were meticulously determined to ensure the simultaneous achievement of increased material utilisation and energy efficiency. The kinetic analysis results demonstrate that the pre-treated CFRP, unlike its untreated counterparts, displays an additional preliminary reaction stage, facilitating a higher level of breakdown at lower temperatures. Moreover, solvolysis pre-treatment increased retention of the fibres' mechanical properties by reducing the heat consumption during recycling. With a proper pre-treatment prior to thermal deterioration, the strength of the recycled fibres was preserved at up to 90.53% of their virgin state, which is 10.21% higher than the strength of recycled fibres recovered via thermal degradation only. To demonstrate the practicality of this research, a commercial bike's fork and airplane scraps made of CFRP composites were successfully recycled using the hybrid approach developed in this research. The results validate the effects of chemical pre-treatment and also demonstrate the efficacy of coating removal on the mechanical characteristics of carbon fibres recovered from various types of CFRP for real-world applications.