Waste Technology Research Articles

Life cycle assessment of food waste energy and resource conversion scheme via the integrated process of anaerobic digestion and hydrothermal carbonization

Anaerobic digestion is the mainstream method for energy conversion of food waste, but dewatering and resource utilization of its digestate is the downstream technical obstacle. In this study, an energy and resource utilization scheme via the integrated process of anaerobic digestion and hydrothermal carbonization of food waste is proposed, among which the hydrothermal carbonization not only is used to remove water from digestate in a non-phase change manner with low energy consumption but also convert digestate into hydrochar. Moreover, the scheme has the least environmental impact compared to the anaerobic digestion and composting treatment by life cycle assessment. In particular, it has a lower impact potential (−141.46 kg CO2 eq) than anaerobic digestion (−38.87 kg CO2 eq) for the global warming category, indicating that the addition of hydrothermal carbonization can bring better environmental benefits. This study provides a reference for the development of disposal technology for food waste.

One‐step conversion of sulfate lithium into high‐purity lithium hydroxide crystals via bipolar membrane crystallization

AbstractTo date, bipolar membrane electrodialysis (BMED) is being developed as a competitive technology for waste lithium‐ion battery recovery. However, the purity and concentration of lithium hydroxide generated from a BMED plant could not meet the product criteria for ternary lithium batteries, thus requiring additional condensation, purification, evaporation, and crystallization procedures. Herein, bipolar membrane crystallization (BMC) was proposed for the one‐step conversion of sulfate lithium into high‐purity lithium hydroxide monohydrate crystals. By mediating a continuous saturated feedstock in the salt compartment, it is possible to convert Li2SO4 into 5+ mol/L LiOH at a current density higher than 500 A/m2. Therefore, this unique design allows the production of 99.9% LiOH∙H2O by taking the principle of water dissociation in the bipolar membrane and the simultaneous crystallization procedure. This proof‐of‐concept study proves the feasibility and competitiveness of the BMC for waste lithium recovery by abandoning the condensation and evaporation procedures.

Language Translation from English to Malay in Solid Waste Engineering

Engineering translations are dense with technical jargon and terms that necessitate linguistic and field expertise. The challenges arise from the requirement that the target texts be idiomatic and retain the same phrasing order, meaning, and nuances as the source text, which a layperson cannot translate directly. The Malay language is Malaysia’s official language. Because Malay is the official language in the governing and executive constitutions, the research instrument should be available in Malay. The purpose of this research is to translate from English to Malay a qualitative risk framework for solid waste engineering. On three psychometric scales, 26 items were translated using a back-translation method involving eight linguistic experts. The Malaysian Institute of Translation and Books (ITBM) provided the primary translation, which was then reviewed by a panel of experts as a secondary translation. Next, content validation on a 5-point Likert scale was conducted with five civil engineering field experts to assess instrument structure and reliability agreement. To represent the expert validation process, a descriptive analysis of mean score agreement was performed. The studies discovered deviation losses in forward (8.98%) and backward (17.95%) translation. The results also revealed experts produce accurate translations, particularly the equivalents of engineering expressions, acronyms, measurements, and terminology. Eventually, expert consensus on six aspects was achieved for 27.8/30 (92.7%) and affirmed that the framework is valid and thus applicable. This paper recommends that translation requires quality control, which comprises three processes: conversion to the target language, comparison, and reconciliation by subject matter experts.

Complex technological process for production of apple distillates and evaluation of its quality indicators.

The research presented in the paper is related to solving an important and urgent problem in the wine industry – use of waste and by-products of production as secondary raw materials. In the course of the experimental part, generally accepted and special research methods and techniques were used; the peculiarities of the extraction and fermentation processes were studied. This is the first time when, in the technology of manufacturing apple distillates, a method was used to reduce the amount of the resulting head fraction during fractional distillation, and the prospects for the reuse of a new by-product of fractional distillation – an intermediate fraction – were scientifically substantiated, as well as diffusion juice obtained from apple pomace was involved at the fermentation stage. The uniqueness also lies in the fact that all the techniques are combined into a single integrated approach. As a result, a scientifically sound, improved and cost-effective technology for production of apple distillates with complex processing of secondary raw materials of winemaking has been developed, which makes it possible to increase the level of economic feasibility and efficiency of the industry, and is the basis for innovative economic development aimed at import substitution. The paper reflects the basic technological layout of the developed technology, describes its operations and stages, as well as studies of the main quality indicators (physical-and-chemical, organoleptic indicators and comparative analysis of the tasting test with the consumer focus group) of apple distillates obtained by integrated waste technology.

Characterizing the bending behavior of underground utility tunnel roofs in a fabricated composite shell system

The traditional underground utility tunnel system is characterized by a lengthy construction period, material waste, and poor engineering quality. This study proposes the prefabricated composite shell system underground utility tunnel as a new type of prefabricated underground utility tunnel system. This system uses 20 mm thick high-performance cement-based materials as permanent templates, with steel reinforcement skeletons placed in the cavity between the two side molds, and concrete can be poured after on-site hoisting and positioning to form an integrated tunnel. This study first systematically introduces the system design method of the prefabricated composite shell system underground utility tunnel and clarifies its component and connection structures. Then, bending tests are conducted on the composite shell tunnel top plate specimens, and a cast-in-place top plate specimen is selected as a control group. A suitable bearing capacity calculation formula for composite shell top plates is derived and proposed based on test phenomena and results analysis. The results showed that the prefabricated outer template and internal cast-in-place concrete of the composite shell top plate specimen have good collaborative performance. Its bearing capacity, stiffness, and failure phenomena are consistent with those of cast-in-place components, as are its mechanical properties. In addition, the proposed bearing capacity calculation formula for a composite shell top plates is highly accurate and can guide the design of such components.

Domestic Waste Management Study of Community Based in Kupang City

This research aims to find the existing waste management system and create a development model of waste technology management. Besides, this study will focus specifically on the variables that influence participatory community-based waste management technology. This study uses descriptive analysis crosstab and chi-square. The data collected using distributing questionnaires and interviews with respondents randomly. The results of this study are mostly waste generated by society and less managed well. The integration of variable dimensions of public participation can cultivate people’s willingness to reduce waste generation. Community participation can increase recycling and composting activities that waste going into a landfill can be reduced. Variable work and income results have a relationship with the waste that the people in Kupang did sorting. Simultaneously, the variables age, gender, education, type of housing, and the number of people do not have a significant relationship with waste sorting. Not all respondents addressed the garbage by the janitor, so most of them deal with their waste by burning and dispose of vacant land.

Energy Efficient Technology for Processing Fine-grained Carbonaceous Wastes into Spherical Carbon Adsorbents

The technical and technological processing features of fine-grained carbonaceous technological waste into environmentally friendly products with significant energy and resource saving were introduced. The article defines products which are the recycled highly efficient and competitive spherical activated carbons produced by high-speed pelletisation in aqueous medium with various hydrocarbon binders. The article describes the step-by-step manufacturing of spherical pellets by high-speed components mixing in aqueous medium. The main production parameters of spherical activated carbons (SAC) from the introduced raw materials, the formulation (ratio of components), the conditions for pelletisation and subsequent high-temperature carbonization and activation were identified. The parameters of the porous structure, sorption properties and technical features of the obtained materials were assessed according to the methods typical for the validation of activated carbons. It was confirmed that the characteristics of developed SAC were not inferior to industrial activated carbons in terms of porous structure and sorption properties, and significantly exceed them in terms of percentage of ash and endurance capability.

Process Performance and Functional Microbial Community in the Anaerobic Digestion of Chicken Manure: A Review

Anaerobic digestion is one of the most widely used treatment methods for animal manure. Chicken manure has high methane production potential and is thus a suitable substrate for biogas plants. However, high nitrogen content inhibits the metabolism of anaerobic microorganisms and thus hinders methane production from chicken manure. Enhancing the performance of anaerobic digestion for chicken manure is indeed a long-standing challenge. This review presents new insights into maintaining methanogens’ activities, the decomposition of acetate, and the dynamics of methanogenic pathways under high ammonia stress. This review also analyzed the possible strategies for alleviating ammonia inhibition effects, including supplementing trace elements, co-digestion with nitrogen-less materials, in-situ ammonia removal, and long adaptation of anaerobic consortia to ammonia stress. The insights obtained in this paper may provide helpful information for a better understanding of anaerobic digestion technology for chicken manure and other nitrogen-rich waste and wastewater.

Assessment of the Multidimensional Performances of Food Waste Utilization Technologies in China

In recent years, China has made great efforts to carry out source-separation in municipal solid waste management; in particular, the utilization of food waste has received increasing attention. Food waste-utilizing technologies, including anaerobic digestion, aerobic biological treatment, and insect feed conversion, are currently applied in China. However, in the existing cases, there were several disadvantages, such as a low rate of utilization, significant environmental impacts, poor economic benefits, etc., as well as a lack of systematic analysis and comprehensive assessment of the performances of food waste utilization technologies. In this study, a four-dimensional performance assessment method (resource efficiency, environmental impact, economic feasibility, and social effect, with 21 indicators) was established for assessing the life cycle process of food waste utilization technologies. We collected detailed information of 14 typical food waste utilization cases in China, and the results showed that the average scores of anaerobic digestion and insect feed conversion were 58.39 and 59.65, higher than those of the aerobic biological treatment (49.16). The highest scores among all subdivision technologies were centralized black soldier fly conversion and mesophilic wet anaerobic digestion, which were 67.14 and 60.82, respectively. With respect to the technologies of different treatment capacities and distribution modes, i.e., centralized and decentralized technologies, the resource efficiency and economic benefit scores of the former were 13% and 62% higher than those of the latter, whereas the environmental impacts and social effect scores of the latter were 8% and 34% greater than those of the former, respectively. In practice, the utilization technology of food waste should be chosen according to local conditions, such as the physical and chemical properties of food waste, the classification of municipal solid waste, financial affordability, collection and transportation distance, etc.

Plasma-chemical waste processing: numerical analysis and experiment. Part 1: Medical-biological waste and fuel biomass

The paper presents the results of thermodynamic calculations and experimental studies of plasma processing of biomedical waste and fuel biomass, including waste from the woodworking industry and agriculture, which have shown the promise of using plasma-chemical technology for processing various wastes with production of combustible gas and inert mineral material. Comparison of the experimental results and calculations showed their satisfactory agreement. Both in calculations and in experiments, no harmful impurities were found in the products of plasma processing of the investigated wastes.

Where are demolition wastes going: reflection and analysis of the February 6, 2023 earthquake disaster in Turkey

On 6 February 2023 at 09.17 BST, an earthquake measuring 7.8 on the Richter scale struck the southern border of Turkey near Syria, causing massive casualties and building damage. Badly damaged buildings need to be demolished, bringing a large amount of demolition waste, which, if not properly disposed of, can be a burden on the environment. In this study, damage to buildings in the quake-hit areas of Turkey is investigated, including reinforced structures and masonry structures. Based on this, the amount of demolition waste produced and the proportion of waste components are estimated roughly. Ultimately, the paper puts forward the strategy of recycling demolition waste after the earthquake and the application scenario planning of recycled products. Conclusively, the amount of demolition waste generated after the earthquake ranges from 450 to 920 million tons, providing new ideas for post-disaster reconstruction work. Besides, post-disaster waste management, safe demolition and environmentally friendly disposal and recycling technologies for demolition and construction wastes will bring good economic and environmental benefits, help the reconstruction of disaster areas, and provide a model for the resource utilization of construction and demolition waste worldwide.

Utilization of Yard Land for Healthy Gardens Based on TOGA Waste Technology as an Effort to Support Independent Community Health Post the COVID-19 Pandemic

This article is based on the Community Service Program through the Thematic Village Development Community Service program at Gorontalo State University. The aim is to accelerate the achievement of SDGs (Sustainable Development Goals) Point 3 (ensure a healthy life and encourage prosperity for all people at all ages) in Mohungo Village, Tilamuta District, Gorontalo Regency, Gorontalo Province after the COVID-19 pandemic. The solution offered from this program is the development of healthy gardens in yards using TOGA (Family Medicinal Plants) waste technology. TOGA waste is a technology for utilizing used consumables as a means for planting TOGA. Implementation of activities includes observation and surveys, outreach and education, making healthy parks, and launching programs. Based on the stages of the activities that have been carried out, it can be concluded that the implementation of making a Toga waste garden is very beneficial for the community and the government, namely by increasing public knowledge, especially PKK mothers, in utilizing plastic waste as a planting medium and planting family medicinal plants. Community involvement in assisting each stage and process from start to finish is a form of community concern for the environment.

Chemical recycling technologies for PVC waste and PVC-containing plastic waste: A review

The extensive production and consumption of plastics has resulted in significant plastic waste and plastic pollution. Polyvinyl chloride (PVC) waste has a high chlorine content and is the primary source of chlorine in the plastic waste stream, potentially generating hazardous chlorinated organic pollutants if treated improperly. This review discusses PVC synthesis, applications, and the current types and challenges of PVC waste management. Dechlorination is vital for the chemical recycling of PVC waste and PVC-containing plastic waste. We review dehydrochlorination and dechlorination mechanisms of PVC using thermal degradation and wet treatments, and summarize the recent progress in chemical treatments and dechlorination principles. This review provides readers with a comprehensive analysis of chemical recycling technologies for PVC waste and PVC-containing plastic waste to transform them into chemicals, fuels, feedstock, and value-added polymers.

Development of Sustainability Assessment Criteria in Selection of Municipal Solid Waste Treatment Technology in Developing Countries: A Case of Ho Chi Minh City, Vietnam

Municipal solid waste (MSW) management is a significant problem for developing countries due to lack of sufficient infrastructure, poor management capacity, and low level of waste treatment technology. This study proposes three main groups of criteria, i.e., social, economic, and environmental, that can be used as an effective tool to assess the sustainability of MSW treatment technologies, considering Ho Chi Minh City, Vietnam as a case study. The sustainability assessment criteria consist of a list of indicators which consider potential waste treatment plants. The indicators and technologies then undertake a selection process from identifying assessment goals and key aspects to data collection and consultation of experts. The findings from the previous phase will be used to select the most preferred waste technology through AHP and normalization approaches. As a result, 12 selected indicators are as follows: investment cost, treatment cost, operation and maintenance costs, revenue/benefits, job creation, community consensus, support policy, community health, air pollution, water pollution, greenhouse gas emissions, and land quota. Among three MSW facilities selected, i.e., landfill, compost, and waste-to-energy incineration, waste-to-energy is determined as the best alternative solution for Ho Chi Minh City in a given context of approximate 70% of landfilling being applied. The selection process and indicators found can guide decision-makers and policy on selecting MSW treatment technologies in developing countries. Additionally, Ho Chi Minh City’s governors benefit from finding the most appropriate waste technology. A technology adoption roadmap and its implementation plan should be thought thoroughly to address challenges in MSW management in the city.

Supercritical water gasification of organic solid waste: H2 yield and cold gas efficiency optimization considering modeling uncertainties

Supercritical water gasification (SCWG) is one of the typical hydrothermal treatment technologies for organic solid waste. However, the current SCWG optimization methods perform deterministic optimization without considering the uncertainty of the model for calculating the objective function, which leads to low reliability of the optimization results. Therefore, an optimization framework that considers the prediction uncertainties of SCWG data-driven models is proposed to optimize the H2 yield and cold gas efficiency of organic solid waste SCWG. An ensemble prediction model integrating random forest, gradient boosting regression, and K-nearest neighbor algorithms by the stacking learning method are built to predict SCWG gas yields. The cold gas efficiency prediction model is constructed based on the gas yield prediction models. The SCWG optimization models are constructed by combining the H2 yield and cold gas efficiency prediction models. The uncertainties in the H2 yield and cold gas efficiency prediction models are analyzed and integrated into the optimization models. The case studies were conducted to test the proposed framework. The optimization results were verified by the results of similar experimental conditions. It demonstrates that the proposed framework can obtain the robust results of the organic solid waste SCWG optimization, which can provide a reference for SCWG optimization.

Effect of loading-induced damage on chloride ingress behavior of recycled aggregate concrete: A comprehensive review

The recycling technology of construction and demolition wastes is an inevitable choice towards the sustainable development of the construction industry, aiming at addressing the problems of raw materials shortage and waste disposal. The utilization of recycled coarse aggregate (RCA) in new concrete production has been identified as an effective way to reasonable application of natural resources replacement and environmental preservation. In service, external mechanical loading can easily cause the initiation and interconnectivity of microcracks inside concrete, specifically the complex multiple interface structures of recycled aggregate concrete (RAC) due to the old adhered mortar at the surface of RCAs, which can remarkably accelerate the process of water penetration and aggressive ions penetration into concrete. Thus, knowledge of mass transport properties in the loading-induced damaged RAC contributes to the durability evaluation of RAC and its extensive application in the practical engineering. This paper reviews the previous findings on the mechanical loading effects on the chloride transport properties of RAC. The effects of loading-induced damage on microstructure evolution of RAC as well as the damage characteristics were discussed. The research progress on the chloride ingress behavior of RAC subjected to mechanical loading was highlighted from the viewpoint of testing method, loading devices and numerical calculation, and the modified effects on the transport properties were further analyzed. On this basis, the future research on the durability-related properties of RAC would be finally proposed, which is helpful to further perfect theoretical development and technological innovation of RAC durability in the aggressive environment.

Pestle Analysis on Zero Waste Implementation in Crude Palm Oil Industries for Sustainable Development Concept

Nowadays, to match the dynamics of the marketplace and provide the expected product qualification, industrial manufacturing systems are always developing. One of the most issues which have a large influence on the product that would be accepted by the market is environmental issues. Implementing an environmentally friendly concept through the process could be one of the best solutions to counter the issue and it expectedly meets the requirement of the company's operational permit. In regards of the palm oil industry, is an essential source of national income and has an important role in creating opportunities for employment and developing rural areas in Indonesia, yet it also potentially can cause natural environmental degradation. This means the production process of CPO should be in line with ecological guidelines and legislation that could be used to attain more beneficial impacts on global market competitiveness, social and economic development, and better impacts in maintaining the environment as well. This research tried to critically evaluate the implementation of the zero waste technology scheme for Roundtable Sustainable Palm Oil (RSPO) mandatory in Crude Palm Oil (CPO) industries and its impact on the company's future position. Using PESTLE analysis then, it can recommend the best possible ways to treat the waste as an excess of the production process

Techno-Economic and Life Cycle Analyses of Thermochemical Upcycling Technologies of Low-Density Polyethylene Waste

Techno-Economic and Life Cycle Analyses of Thermochemical Upcycling Technologies of Low-Density Polyethylene Waste

СТРОИТЕЛЬНЫЕ МАТЕРИАЛЫ И МИНЕРАЛЬНЫЕ ВЯЖУЩИЕ ВЕЩЕСТВА НА ОСНОВЕ ГИДРАТИРОВАННЫХ ЗОЛОШЛАКОВЫХ ОТХОДОВ УГЛЕСЖИГАЮЩИХ ЭЛЕКТРОСТАНЦИЙ И ОТХОДОВ УГЛЕОБОГАЩЕНИЯ

The results of scientific research on the development of a comprehensive technology for processing waste from coal mining and coal refining, including in building materials and mineral binders, are presented. The technology of extraction of underburning, slag sand, iron-containing concentrate and microspheres has been tested in production conditions.

Environmental impacts and optimization simulation of aerobic anaerobic combination treatment technology for food waste with life cycle assessment

After the implementation of waste sorting policy in Shanghai, the amount of food waste (FW) separation and treatment demand has increased significantly. It is necessary to establish the life cycle assessment (LCA) to assess the environmental impacts of various treatment technologies comprehensively, thus provide support for sorting, recycling, treatment and disposal strategies of FW. In this study, a local FW treatment plant in Shanghai, using typically aerobic anaerobic combination treatment technology was selected to analyze the environmental impacts with LCA. The process mainly included pretreatment, power, aerobic composting, anaerobic digestion, and further process systems. LCA results showed that the environmental impacts mainly came from the power and aerobic composting systems on the fine particulate matter formation and eutrophication, and freshwater ecotoxicity and terrestrial acidification, respectively. Considering the carbon footprint, the aerobic composting system contributed 3.61E + 02 kg CO2 eq and represented the largest source of carbon emission. The soil conditioner yielded both environmental benefits on eutrophication and terrestrial ecotoxicity, and ecological benefits of 75.33 million CNY per year being the major revenue for the treatment plant. It also suggested that the biogas generation capacity of anaerobic digestion could be increased to achieve electricity self-sufficiency, thus save about 7.12 million CNY per year in electricity costs, and avoid corresponding environmental impacts caused by coal-fired. In summary, the aerobic anaerobic combination treatment could be further optimized and applied in FW treatment to reduce the environmental impacts, and enhance resource recovery and secondary pollution control.