Waste Recycling Research Articles

Removal of multiple metals from real wastewater combining sludges with carbon black and chitosan: Integrating sustainable remediation and waste recycling

Removal of multiple metals from real wastewater combining sludges with carbon black and chitosan: Integrating sustainable remediation and waste recycling

Thermochemical recycling of mixed plastic wastes through pyrolysis and steam cracking – Assessment of centralized vs. Decentralized approaches

Thermochemical recycling of mixed plastic wastes through pyrolysis and steam cracking – Assessment of centralized vs. Decentralized approaches

Electrochemical separation of chromium/collagen from wet blue in a single step: recycling of tannery waste to promote a circular economy

Electrochemical separation of chromium/collagen from wet blue in a single step: recycling of tannery waste to promote a circular economy

Recent progress on recycling and upcycling of PET plastic waste into high-value-added materials for versatile applications

Recent progress on recycling and upcycling of PET plastic waste into high-value-added materials for versatile applications

Recycling of materials industrial waste into a new composite alloy using sintering technique

Recycling of materials industrial waste into a new composite alloy using sintering technique

Shell-like Ni(OH)2 loaded with Pd nanoparticle catalyst mediated efficient electrocatalytic upcycling of polyethylene terephthalate plastics to glycolic acid.

Shell-like Ni(OH)2 loaded with Pd nanoparticle catalyst mediated efficient electrocatalytic upcycling of polyethylene terephthalate plastics to glycolic acid.

Agricultural waste recycling by farmers: A behavioral study

Agricultural waste recycling by farmers: A behavioral study

Material flow analysis of construction and demolition waste recycling under circular economy

Material flow analysis of construction and demolition waste recycling under circular economy

Recycling waste for energy: Reusing methyl orange dye-adsorbed polythiophene/Fe3O4 nanorods/reduced graphene oxide nanocomposite as a supercapacitor electrode

Recycling waste for energy: Reusing methyl orange dye-adsorbed polythiophene/Fe3O4 nanorods/reduced graphene oxide nanocomposite as a supercapacitor electrode

Utilization of Hydrilla Through Earthworm Cultivation to Enhance Amino Acid Content and Promote Waste Recycling

ABSTRACT This study examines the valorization of the invasive aquatic weed Hydrilla verticillata through earthworm (Eisenia fetida) cultivation, highlighting improvements in amino acid profiles and sustainable waste recycling. Earthworms cultured on Aquatic weed Hydrilla verticillata displayed significantly elevated concentrations of several essential amino acids compared to control worms. Notably, lysine increased by 40% (from 4.5 ± 0.17 to 6.3 ± 0.66 g/100 g), leucine by 57.14% (from 4.2 ± 0.12 to 6.6 ± 0.46 g/100 g), and isoleucine by 70.37% (from 2.7 ± 0.70 to 4.6 ± 0.32 g/100 g). Among non-essential amino acids, glutamic acid showed a 54.5% rise (from 4.4 ± 1.00 to 6.8 ± 0.78 g/100 g), and alanine increased by 32.1% (from 2.8 ± 0.34 to 3.7 ± 0.36 g/100 g). The dominant essential and non-essential amino acids were leucine and glutamic acid, respectively. These augmentations are credited to the protein-rich nature of Hydrilla, suggesting that worms cultured on this weed can serve as high-quality protein sources for livestock feed. Vermicomposting of Hydrilla aids in managing its ecological overgrowth, turning a challenging weed into a value-added contribution for organic waste recycling and sustainable animal nutrition. Keywords: H.verticellata, Eisenia fetida, Vermicompost, Amino acid Profile.

Influence of waste management infrastructure on source segregation of medical waste at a major referral hospital in Western Kenya

Medical wastes generated by healthcare facilities, such as sharps, and chemical, pathological, infectious, and pharmaceutical wastes, are hazardous and have been known to cause various infections such as Hepatitis B, Hepatitis C, and Human-Immune Virus (HIV). Various studies in MW have established that source segregation is an effective step in managing hospital waste and, therefore, the most important step in reducing health hazards and environmental pollution. Hospitals are therefore required to put in place sufficient infrastructure such as personal protective equipment, storage as well as waste transportation equipment at strategic points within each department or floor. Jaramogi Oginga Odinga Teaching and Referral Hospital (JOOTRH) is a major facility in western Kenya, generating approximately 68% of medical waste in Kisumu County. A recent public health study in western Kenya established that 72% of cleaners at JOOTRH were treated for sharps injuries while needle prick injuries accounted for 69% of wounds that occurred among waste recyclers in common dumping sites in Kisumu County. The purpose of this study was to establish the influence of waste management infrastructure on source segregation of medical waste at the JOOTRH. This was a descriptive survey that involved a sample size of 112 nursing officers, 41 doctors, 13 laboratory technicians, 20 clinical officers, and eight heads of departments. Semi-structured questionnaires and interview schedules were used to collect data from healthcare workers and heads of departments, respectively. Findings showed that Hospital waste management infrastructure (β=.513) has a significant (p<0.05) influence on source segregation of medical waste, and contributes approximately 38.4% unit changes in source segregation of medical waste at JOOTRH (R2=.384). The study concludes that delays in procurement processes have led to instances of inadequacies in PPE and waste collection containers, causing cases of waste-related injuries. The study findings should inform policy formulation for effective source segregation of medical waste generated by healthcare facilities, thereby reducing associated injuries.

Impact behavior of recycled aggregate concrete modified with nano-silica and fiber

This study proposes a multidimensional reinforcement framework integrating three mechanisms: nano-silica (SiO2) interfacial reconfiguration, fiber toughening, and dynamic response regulation. The effects of pre-soaking recycled aggregates in nano-SiO2 solutions at concentrations of 0%, 1.0%, and 2.0% and incorporating steel fibers (0%, 1.0%, 2.0%) or polyvinyl alcohol (PVA) fibers (0%, 0.1%, 0.2%) into recycled aggregate concrete (RAC). The impact resistance of treated specimens was evaluated under different strain rates using the split Hopkinson pressure bar (SHPB) method. Fracture patterns were analyzed, and dynamic stress-strain relationships were examined to assess the evolution of dynamic compressive strength and dynamic growth factor. Results indicated that higher impact velocities led to greater specimen damage, while increased nano-SiO2 concentrations and fiber reinforcement enhanced structural integrity. Pre-treatment with nano-SiO2 accelerated the peak stress occurrence in the dynamic stress-strain response, whereas fiber incorporation substantially increased peak stress. Both dynamic compressive strength and dynamic growth factor exhibited a linear relationship with strain rate, suggesting that nano-SiO2 and steel fibers collectively enhanced impact resistance.The application of RAC in protective engineering relies on nanoscale pretreatment and fiber reinforcement technologies to enhance the recycling of construction and demolition waste (CDW), enabling its conversion into high-value applications.

Pemberdayaan PKG-PAUD Kecamatan Gunungpati dalam Memanfaatkan Daur Ulang Sampah Kertas dan Plastik untuk Alat Pembelajaran

Each school in Gugus PAUD 1, Gunungpati Sub-district, Semarang City already has a Waste Bank, although it is small and simple. The waste collected comes from around the school and store from each student. The collected waste then sold to collectors. The existence of this waste bank makes it possible to recycle it into playground equipment/games or learning tools, because learning in PAUD is playing while learning. The purpose of the Community Service activities in Gugus PAUD 1 Gunungpati District Semarang City is to improve the competence of PAUD teachers in recycling paper and plastic waste into play tools and educational games. The method applied was theory and practice. Evaluation was conducted from administrative evaluation in the form of attendance and participation. Academic evaluation by project assessment then applications in the teaching and learning process. The results are PAUD teachers' skills and understanding of recycling paper and plastic waste increased after the workshop, as well as attitudes and behavior towards waste recycling increased, all in the high category.

Rehabilitation of Urban Parks with Recycling of Construction and Demolition Waste in Mexico City

Mexico City has experienced a rapid urbanization process, which has led to a socio-environmental crisis characterized by the generation of construction and demolition waste (CDW). The generation of CDW has been favored by the growth of the construction industry, the decrease in the useful life of buildings and an increase in the number of new buildings. To reduce the environmental impacts of CDW, recycling initiatives have been developed, offering alternatives for sustainable urban development. This study examines the use of recycled materials from CDW for urban park rehabilitation, focusing on the production of sustainable urban furniture. CDW as recycled material can be useful because it reduces the need for new resources, preserves land for future urbanization, protects the environment, and reduces transportation costs and energy needs A bibliographic analysis explored urban growth trends, CDW management methods, and the benefits of urban green spaces. As part of the project, urban furniture such as benches and planters was manufactured using recycled aggregates from CDW. The results demonstrate the functionality and sustainability of these elements, while providing recommendations on optimal aggregate sizes and compaction techniques. The urban furniture built using CDW (to manufacture benches, planters, jogging tracks and gabions), turned out to be totally functional, meeting the expectations of use This approach represents a viable alternative to natural fine aggregates, contributing to sustainable city development.

Solid Waste Management Practices and Profitability Among Santa Rosa Market Vendors: Basis for Restructuring Program

This study aimed to examine the relationship between solid waste management practices and profitability among market vendors in Santa Rosa City, specifically focusing on the dry and food sections of the public market. The research sought to assess the vendors' level of knowledge, practices, and the extent to which these factors influence their business profitability. Furthermore, the study intended to propose a restructuring program to improve waste management practices and enhance vendors' profitability. The study employed a descriptive-correlational research design. 74 market vendors, who were of legal age and had been engaged in vending, were selected through purposive sampling. A structured survey questionnaire was utilized to gather data regarding their knowledge, practices, and profitability related to solid waste management. The statistical tools used in analyzing the data included frequency and percentage distribution, weighted mean, and Pearson Product-Moment Correlation Coefficient. The findings revealed that market vendors possess a moderate level of knowledge regarding proper solid waste management, while their practices ranged from moderate to low, particularly in waste segregation and recycling. The study also found a significant relationship between the vendor's knowledge and solid waste management practices. Moreover, it was concluded that proper waste management practices have a positive influence on the profitability of market vendors, as they help reduce operational costs, attract more customers, and maintain a clean and healthy market environment. Based on the findings, the study recommended the development of a restructuring program focused on intensive information dissemination campaigns, provision of waste management facilities, regular monitoring, and training activities to improve the waste management practices of market vendors in Santa Rosa City. The study emphasized that strengthening solid waste management practices is essential not only for environmental sustainability but also for increasing business profitability. Keywords: Solid Waste Management, Practices and Profitability, market vendors in Santa Rosa City, development restructuring program based on the findings

Estimating the costs and amount of recyclable polyvinyl chloride plastic waste associated with discarded Icodextrin.

There is limited data characterizing healthcare waste associated with peritoneal dialysis (PD). In Canada, Icodextrin for continuous cycling PD (CCPD) is only available as 2.5L bags for one-time use, and any remaining volume that is not used for a dwell is discarded. The environmental impact of this practice has not been well characterized. As such, we sought to estimate the costs associated with discarded Icodextrin and associated polyvinyl chloride (PVC) plastic waste production within our renal program. We conducted a cross-sectional audit of all patients utilizing CCPD in the Alberta Kidney Care South program in Canada in 2022. Icodextrin fill volume data were captured and the costs associated with Icodextrin use were calculated. Among patients on CCPD, the average fill volume for Icodextrin was 1273 mL, suggesting that an average of 1227 mL was discarded. In fact, 88% of patients used dwell volumes ≤1.5L. In 2021, our program spent $1.27 million CAD on Icodextrin for CCPD. Given that an average of 49% of each 2.5L bag was discarded, we estimate that the annual value of wasted Icodextrin among patients being treated with CCPD in our program was $622,300 CAD, or $3036 CAD per patient. Annual PVC waste was calculated to be 25.9 kg per patient, and we estimate that PVC waste could be reduced by 35% if there was access to 1.5L Icodextrin solutions. Our work suggests that the availability of Icodextrin bags that are better aligned with volumes used by patients could reduce healthcare costs and PVC waste.

Service Learning in Environmental Education: University students facilitating waste recycling awareness among school children in Malaysia

On 11 May 2024, a service-learning program on waste recycling literacy was held at a suburban primary school in Sabak Bernam, Malaysia, involving 55 pupils and 32 university students. The program featured an innovative card game for teaching waste sorting and recycling, which participants found informative and exciting. Additionally, an upcycling activity was included, deemed beneficial by the students. Integrating recycling literacy into school curricula can foster environmentally responsible behavior and support long-term sustainability goals.

Highly efficient and rapid dechlorination of polyvinyl chloride via microwave pyrolysis

Polyvinyl chloride (PVC) waste recycling is challenging due to its high chlorine content, which generates hazardous chlorinated pollutants if treated improperly. A safe and promising PVC dechlorination method is urgently needed to address this issue. Several dechlorination methods have been reported at the laboratory scale; however, each method has its downsides, and none has been proven at the commercial scale. We present, for the first time in the literature, an effective microwave pyrolysis process that can dechlorinate PVC rapidly without the requirement of a solvent/microwave absorber. High dechlorination efficiency up to 99.6% was achieved within 96 s. This process releases hydrogen chloride and generates hydrocarbon-containing liquid and a dechlorinated residue. Dielectric analysis revealed that the untreated PVC was readily heated under microwaves due to the polar chlorine group in its structure. Thermogravimetric analysis confirmed that there were two pyrolysis stages and dechlorination was achieved after the first pyrolysis stage. Fourier-transform infrared (IR) analysis showed that all the bands corresponding to the stretching of C-Cl bonds were not detected in the dechlorinated residue. All these results prove that microwave pyrolysis is a promising process for PVC dechlorination, and it could be the game changer that makes PVC recycling commercially viable.This article is part of the discussion meeting issue ‘Microwave science in sustainability’.

Reinforcing Cotton Recycled Fibers for the Production of High-Quality Textile Structures.

The textile industry is under increasing pressure to adopt sustainable practices due to the significant environmental impacts associated with fiber production, including high energy consumption, water usage, and substantial greenhouse gas emissions. The recycling of textile waste, particularly cotton, is a promising solution that has the potential to reduce landfill waste and decrease the demand for virgin fibers. However, mechanically recycled cotton fibers frequently demonstrate diminished mechanical properties compared to virgin fibers, which limits their potential for high-quality textile applications. This study explores the use of cross-linking agents (citric acid (CA) and sodium hypophosphite (SHP)), polymers (polyethylene glycol (PEG), chitosan (CH), carboxymethyl cellulose (CMC) and starch (ST)), and silicas (anionic (SA) and cationic (SC)) to enhance the mechanical properties of recycled cotton fibers. The treatments were then subjected to a hierarchical ranking, with the effectiveness of each treatment determined by its impact on enhancing fiber tenacity. The findings of this research indicate that the most effective treatment was starck (ST_50), which resulted in an enhancement of tenacity from 14.63 cN/tex to 15.34 cN/tex (+4.9%), closely followed by CA-SHP_110/110, which also reached 15.34 cN/tex (+4.6%). Other notable improvements were observed with CMC_50 (15.23 cN/tex), PEG_50 (14.91 cN/tex), and CA_50 (14.89 cN/tex), all in comparison to the control. In terms of yarn quality, the CA-SHP_110/110 treatment yielded the most substantial reductions in yarn irregularities, including thin places, thick places, and neps with decreases of 36%, 10%, and 7%, respectively. Furthermore, CA_50 exhibited moderate enhancements in yarn regularity, thin places (-12%), thick places (-6.1%), and neps (-8.9%). The results of this study demonstrate that combining CA with SHP, particularly when preceded by the heating of the solution before the addition of the fibers, results in a substantial enhancement of the structural integrity, strength, and overall quality of recycled cotton fibers. This approach offers a viable pathway for the improvement of the performance of recycled cotton, thereby facilitating its wider utilization in high-quality textile products.

ELECTROMECHANICAL EQUIPMENT AND AUTOMATED CONTROL SYSTEM FOR THE PYROLYSIS PROCESS OF RUBBER AND POLYETHYLENE WASTE

The amount of waste generated as a result of our daily lives and industrial processes continues to grow and has already become a problem in some regions and cities. We must understand that untreated waste, which accumulates in tons every day, negatively impacts both the biosphere of our planet and citizens' health. Areas that can no longer be measured in hectares but only as a percentage of our country's total land are condemned to pollution for decades. This article is dedicated to researching and developing effective methods for the utilization of rubber and polyethylene waste through pyrolysis [1-6]. In the modern world, the issue of waste recycling is becoming increasingly relevant due to the constant increase in waste and its negative environmental impact [6-15]. Improper waste management not only worsens the ecological condition but also leads to the loss of valuable resources. The goal of the article is to address this problem by creating an automated control system for the pyrolysis process. The main object of research is a pyrolysis plant that converts rubber and polyethylene waste into combustible gases, liquid pyrolysis products, and carbon black. This technology not only reduces the amount of waste but also provides an additional source of energy, which is an important step toward energy independence. The study thoroughly analyzes various types of raw materials, their characteristics, and their influence on the pyrolysis process. Significant attention is paid to developing an automated control system to optimize the process and enhance the efficiency and safety of the plant’s operation. The research encompasses both theoretical aspects and practical calculations and system modeling.