Portion Of Waste Research Articles

Analysis of Introducing Plastic Waste Enzymatic Recycling for Sustainable Waste Management in Latvia

Economic growth, urbanisation, and consumer consumption habits have contributed to the yearly increase in the municipal solid waste amount. A significant portion of household waste consists of plastic materials and packaging, which currently cannot be fully and endlessly recycled, does not decompose in nature, and degrades into micro- and nanoparticles entering the soil, air, aquatic environments, and organisms. According to an OECD report from 2022, the amount of plastic waste produced globally is expected to triple by 2060, with around half being landfilled and less than one-fifth being recycled. As waste volumes are going to increase, the need to ensure appropriate waste recycling technology is addressed in this study by introducing enzymatic plastic waste recycling in Latvia. Enzymatic recycling has an advantage over mechanical recycling technology because it can depolymerise plastics without degrading the quality of the material. The methodology applied in this study includes data analysis of the waste amount in Latvia, analysis of the existing plastic recycling plant operation, life cycle assessment of existing and proposed methods, and socio-economic impact evaluation. The proposed solution meets the objectives of promoting sustainable plastic waste recycling through the introduction of enzymatic recycling; therefore, it aligns with the European Union’s targets to follow circular economy principles.

Co-Pyrolysis of biomass and plastic waste: Process prediction and optimization based on Artificial Intelligence and response optimizer surrogate model

Co-pyrolysis process prediction and optimization has been done through different artificial intelligence processes and response optimizer surrogate model. Neural network and machine learning-based different prediction models have been evaluated to predict the co-pyrolysis output based on the experimental data from literature. While multi-objective optimization has been done through response optimizer. According to prediction models results, CatBoost Regressor (CatB) and Extreme Gradient Boosting (XGB) models’ performance is better than other (seven) models with CatB co-efficient of determinant (R2) 0.92–0.98 while it is 0.91–0.98 for XGB in different scenarios. Therefore, CatB and XGB both models can provide an optimal result for co-pyrolysis prediction. Surrogate-model for multi-objective optimization results concluded that lower portion of biomass waste and higher plastic waste in the feedstock has the optimum co-pyrolysis process output around 550 °C and 60 min of resident time for higher portion of liquid yield with lower gases production. Overall higher portion of the plastic waste in feedstock at high temperature and low resident time promotes more liquid yield. While solid (biochar) production is optimal when there is a higher amount of biomass waste in the feedstock at lower temperature, and longer resident time.

Comparing plaque removal efficacy of biodegradable toothbrush and nonbiodegradable toothbrush in children of 8-10 years of age: A randomized clinical study.

In the 21st century, we are surrounded by plastic, disposal of which has a detrimental effect on the environment. Around 700 million plastic toothbrushes are sold which contributes to a large portion of plastic waste. To aid in the restoration of the environment, there is a need to replace plastic toothbrushes with recyclable toothbrushes. The purpose of the study was to evaluate and compare the plaque removal efficacy of biodegradable toothbrushes and nonbiodegradable toothbrushes in children 8-10 years of age. Ninety children 8-10 years old from school were included in the study. Toothbrush types to groups A (nonbiodegradable toothbrush, Colgate® Palmolive India Ltd.), B (Biodegradable toothbrush, Bamboo India), and C (Biodegradable toothbrush, Palette™ India) were randomly allocated and plaque score was evaluated using plaque disclosing agent and Turesky Modification of Quigley Hein Index at day 1, 7, and 14. The data were analyzed using unpaired "t" and analysis of variance to find the significance of study parameters between the groups and paired t-test was used to find the significance of study parameters within the group (pre- and postbrushing). The comparison of plaque scores pre- and postbrushing in all groups manifested reduction from day 1 to 14. However, Group B showed a significant reduction of plaque on day 14 with a difference of 0.50 which is statistically significant with a P < 0.001. According to the results, it can be concluded that a biodegradable toothbrush has adequate plaque removal efficacy. Therefore, the use of biodegradable toothbrushes can be recommended which will reduce nonbiodegradable waste.

Ultra‐strong and biodegradable nanocomposite fibers of poly(butylene adipate‐co‐terephthalate)/cellulose nanocrystal prepared by dry‐jet wet spinning

AbstractFiber‐based products constitute a significant portion of plastic waste and cause environmental damage. In particular, discarded sanitary masks and fishing gear disintegrate into microfiber plastics, posing a significant threat to human health and ecosystems. In this study, we developed robust biodegradable nanocomposite fibers of poly(butylene adipate‐co‐terephthalate) (PBAT)/cellulose nanocrystals (CNCs) (1 and 2 wt%) through dry‐jet wet spinning, by using dimethyl sulfoxide (DMSO) as a common solvent. The control PBAT fibers exhibit remarkable mechanical performance with tensile strength and toughness of 160.0 MPa and 43.0 MJ m−3, respectively. CNC addition has a toughening effect with slightly reduced strength but enhanced toughness (148.8 MPa and 69.0 MJ m−3, respectively, for 2 wt% CNC); their mechanical performances are superior to those of previously reported PBAT‐based materials. The remarkable performance of the fibers is attributed to a highly oriented structure with a total draw ratio of 15 after post‐hot drawing. The control and nanocomposite fibers exhibit spot‐like patterns in 2D wide‐angle x‐ray diffraction patterns with Herman's orientation factor of 0.54–0.58. The theoretical Hansen solubility parameter confirmed the poor chemical affinity between the PBAT and CNC. Nonetheless, the rheological characterization revealed that well‐dispersed CNCs with DMSO produced a physical network in the PBAT matrix, resulting in the toughening effect. Such robust nanocomposite fibers consisting of fully biodegradable components are promising alternatives to nondegradable nylon and polyester fibers.Highlights Robust biodegradable nanocomposite fibers of PBAT and CNC are prepared. Nanocomposite fibers are dry‐jet wet spun using DMSO as a common solvent. PBAT fibers exhibit strength and toughness of 160.0 MPa and 43.0 MJ m−3. 2 wt% CNC toughens the PBAT fibers with an enhanced toughness of 69.0 MJ m−3. Rheological results confirm the toughening effect of well‐dispersed CNC in PBAT.

Facile Recycling Strategy of Dyed Polyester Waste by Template-Based Synthesis of UiO-66 for Value-Added Transformation into Self-detoxifying Fabrics.

Polyethylene terephthalate (PET) accounts for a significant portion of textile waste, and recycling strategies for this material have attracted much attention. This study proposes a facile and innovative PET recycling method applicable to environmental remediation that involves the conversion of dyed PET fabric waste into a value-added fabric. Herein, a template-based synthesis approach capable of growing a UiO-66 metal-organic framework (MOF) directly on a dyed PET fabric is reported. The advantage of this process lies in its simplicity, where the partial hydrolysis of PET followed by a zirconium chloride treatment results in the successful growth of UiO-66 on a dyed PET fabric with the concurrent removal of the dye without additional steps. The catalytic performance of the UiO-66-grown fabric was evaluated through the degradation of dimethyl 4-nitrophenyl phosphate (DMNP), a nerve agent simulant. The fabric produced by the simple metal treatment (Zr@PEThyd) exhibited excellent DMNP degradation performance with t1/2 = 43.3 min and maintained functional stability after a harsh washing procedure, an outcome attributed to the surface-assisted UiO-66 growth that ensured good bonding stability. The developed process is innovative in that it uses dyed PET waste as a template for the direct growth of UiO-66, simplifying the process without compromising the catalytic functionality. This research provides an informative option for a sustainable textile recycling strategy by transforming dyed PET waste into an advanced self-detoxifying material.

Household food waste in Surakarta City, Indonesia: Quantity, global warming potential (GWP), and management

Households represent one of the main contributors to food waste in urban areas. Surakarta is one of the cities in Indonesia where a significant portion of household food waste is disposed of in landfill sites. The piles of food waste can become an environmental issue if left unmanaged, as they generate greenhouse gas emissions that contribute to global warming. The aim of this research is to determine the quantity, emission estimations, and management of household food waste in Surakarta City. A total of 151 household samples had their food waste collected over a period of 7 days. The method for measuring the quantity of food waste involved direct measurements using a scale, calculating food waste emissions using the GWP formula, and collecting management data through a questionnaire. The research results indicate that, on average, households dispose of 0.499 kg/week of food waste and estimate food waste emissions to be 0.789 kg CO2e/week. In addition to being discarded, some food waste is managed as animal feed and fertilizer. Implementing proper and sustainable management can lead to a reduction in the quantity of food waste sent to landfills.

A Systematic Review of Pre-Post Studies Testing Behaviour Change Interventions to Reduce Consumer Food Waste in the Household

Since the United Nations announced their Sustainable Development Goal 12.3 to halve per capita food waste by 2030, prevention has become an international focus. Consumers are responsible for a significant portion of food waste, and much of this waste is avoidable by improving food management routines and planning in the household. There is a growing body of research focused on developing and evaluating domestic behaviour change interventions which can improve these behaviours. However, evidence of intervention efficacy on a household level is inconsistent, and best-practice approaches for researchers, policymakers, and practitioners have not been identified. Furthermore, the magnitude of this problem across environmental, social, and economical aspects of life necessitates meaningful long-term change. Many reviews have synthesised household food waste intervention studies, yet there is a gap exploring whether new habits can or will stick. We identify 16 peer-reviewed articles applying behaviour change interventions in the household, with a pre–post design to measure food waste both before and after implementation. The review reveals a paucity of studies that evaluate intervention efficacy relative to their baseline, as well as a significant longitudinal evidence gap. Our recommendation for further research is for the robust replication of effective short-term interventions to be tested longitudinally. Overall, this review outlines potential areas for prioritisation to enable large-scale sustained household behaviour changes in the fight against food waste.

A strategy for industrial waste mitigation—thermal treatment of non-woven polyester fabric debris on ultrahigh-porosity MgO under CO2 atmosphere

Unproperly treated industrial waste creates serious environmental pollution that requires immediate remediation strategies. Non-woven polyester fabrics are widely used in a variety of industrial applications; thus, their debris becomes a major portion of industrial waste. To contribute to advanced industrial waste treatment processes, this study investigated catalytic thermal treatment of non-woven polyester fabric debris on a novel ultrahigh-porosity MgO material under a CO2 environment. The ultrahigh-porosity MgO was synthesized from hydromagnesite via a series of thermal reactions, having a surface area of 208.8 m2 g−1, total pore volume of 0.34 cm3 g−1, and average pore diameter of 2.37 nm. Using the MgO as the catalyst for thermolysis of non-woven polyester fabric debris in CO2 promoted thermal cracking of volatilized species evolved from the non-woven polyester fabric debris thermolysis, thereby increasing the gas product yield and decreasing the liquid product and wax yields. In addition, dehydrogenation and reverse water gas reaction was promoted by the MgO catalyst, leading to more than higher syngas production (up to 16.1 wt% syngas yield) compared to non-catalytic thermolysis (up to 8 wt% syngas yield). The selectivity toward esters was increased, while the selectivities toward benzoic and phthalic acids were decreased, most likely due to the MgO promoting decarboxylation and esterification reactions during the thermolysis. Moreover, the ultrahigh-porosity MgO catalyst was reusable for at least two consecutive cycles. It is hoped that the applicability of the novel material as a catalyst is widened for advanced treatment processes to minimize negative effects of industrial wastes on the environment.

Operational process stability in pilot dry anaerobic digester of source‐sorted organic fraction municipal solid waste

AbstractThe organic fraction of municipal solid waste (OFMSW) is a major portion of solid waste in Malaysia, with 44.5% of the total waste being food waste‐derived sources. This study investigates the performance of dry anaerobic digester (DAD) operation using the pilot dry anaerobic digester (PDAD), a plug flow reactor, in treating source‐sorted organic fraction municipal solid waste (SS‐OFMSW) for biogas production. A commercial Malaysian food waste (CMFW) sample has been used to represent SS‐OFMSW. The anaerobic digestion was performed in a semi‐continuous operation using a 15 m3 PDAD with organic loading rates (OLRs) ranging from .63 to 5.46 kg volatile solid (VS)/m3·day under mesophilic conditions. The maximum methane composition was achieved at 56.0% at OLR 5.17 kg VS/m3·day with specific methane production (SMP) of .57 m3·CH4/kg VSfed and gas production rate (GPR) 5.27 m3·gas/m3·digester·day. As indicated by a pH and alkalinity ratio, the PDAD system was stable ranging from pH 6.7 to 8.3, alkalinity ratio of .3 with an inclination of total ammonia nitrogen (TAN) up to 1056 mg/L. The SMP achieved is between 1.58 and .4 m3·CH4/kg VSfed and potentially to fuelled 475 MW commercial biogas plant fed by CMFW. The DAD deployment strengthened the circular economy and decarbonization initiatives.

Sustainability Assessment of Construction and Demolition Waste Material

Construction and demolition waste (C&amp;DW) constitutes a substantial portion of waste generated during construction activities, ranging from 15 to 30% globally. This waste category poses environmental threats, impacting health and the environment, particularly in Nigeria. This research investigates the environmental and economic implications of C&amp;DW in the Nigerian construction industry, systematically addressing types, causes, and disposal methods. The study explores potential reuse through Circular Economy (CE) strategies. The literature review encompasses CE principles and Construction Waste Management in Nigeria. Employing quantitative research methods, questionnaires were administered to a selected group, revealing respondents' recognition of economic benefits from proper waste management. However, a lack of incentives and facilities for diverse disposal methods emerged as a significant challenge. Recommendations include government regulations, incentives for recycling facilities, and educational initiatives emphasizing the advantages of a circular economy. Emphasis is placed on effective information dissemination to stakeholders. This research contributes valuable insights for industry professionals, policymakers, and government entities, offering a foundation for sustainable waste management practices in the Nigerian construction sector.

Hospital food management: a multi-objective approach to reduce waste and costs

Food waste contributes significantly to greenhouse emissions and represents a substantial portion of overall waste within hospital facilities. Furthermore, uneaten food leads to a diminished nutritional intake for patients, that typically are vulnerable and ill. Therefore, this study developed mathematical models for constructing patient meals in a 1000-bed hospital located in Florida. The objective is to minimize food waste and meal-building costs while ensuring that the prepared meals meet the required nutrients and caloric content for patients. To accomplish these objectives, four mixed-integer programming models were employed, incorporating binary and continuous variables. The first model establishes a baseline for how the system currently works. This model generates the meals without minimizing waste or cost. The second model minimizes food waste, reducing waste up to 22.53 % compared to the baseline. The third model focuses on minimizing meal-building costs and achieves a substantial reduction of 37 %. Finally, a multi-objective optimization model was employed to simultaneously reduce both food waste and cost, resulting in reductions of 19.70 % in food waste and 32.66 % in meal-building costs. The results demonstrate the effectiveness of multi-objective optimization in reducing waste and costs within large-scale food service operations.

Comparative Study of Hydrogen Production from Organic Fraction of Municipal Solid Waste and Its Challenges: A Review

The growing interest in hydrogen production arises from its higher energy density, making it an attractive option for energy storage and fuel applications. However, hydrogen production relies heavily on fossil fuels, producing substantial CO2 emissions. Meanwhile, the organic fraction of municipal solid waste (OFMSW), which constitutes a significant portion of solid waste, predominantly ends up in landfills, leading to methane emissions. Harnessing hydrogen from OFMSW offers an opportunity to offset methane emissions and promote cleaner hydrogen production compared to conventional methods. Various pretreatment methods and production techniques have been explored for hydrogen production from OFMSW, including bio-photolysis, photo-fermentation, microbial electrolysis, and dark fermentation. This study presents a comparative analysis of these methods, evaluating their efficiency, scalability, and potential challenges for hydrogen fuel production from OFMSW. By exploring these avenues, this study found the current hydrogen fuel production scenarios where OFMSW contributes a small portion due to the limited yield. Microbial electrolysis can help to improve the yield and feedstock quality. This study recommends further investigation into the advancement of sustainable hydrogen production and provides insights into overcoming the obstacles associated with this promising field.

Socio-environmental sustainability and Upcycling of health service waste towards sustainability: Reuse of Spundbond Meltblown Spundbond (SMS)

This work aimed to define the steps for the Safe Capture of postconsumer Spundbond Meltblow Spundbond (SMS) non-woven fabric, and to estimate the generation of this material providing conditions for new uses through upcycling in a Surgical Center of a public hospital for means of application in socio-environmental projects. This is a descriptive, exploratory longitudinal study with a quantitative approach. As a result, a proposition was obtained for a new separation system for specific medical waste that is difficult to recycle, called Safe Capture in the Operating Room, as well as the implementation of SMS reuse in new products developed through upcycling, such as ecobags for make available to patients at the University Hospital of Londrina- HU. With the estimated generation of 140.89 grams per surgery or 18 SMS blankets of different sizes, the possibility of planning a storage infrastructure for this material for use in socio-environmental projects was envisaged through the development of products based on upcycling with focus on the circular economy, in this case reported and already implemented, the creative sewing workshop in partnership with the State Penitentiary of Londrina-PEL 02 where 3000 ecobags are made per month to store the belongings of patients, which caused a reduction of a portion of waste that would go to the infectious waste collector and, at the same time, replaced the use of plastic bags with ecobags, reducing costs. Currently, the possibility of using SMS has been expanded to other application niches such as interior design and the pet market, in partnership with the Veterinary Hospital of the State University of Londrina, which will revert part of the income from sales of pet products so that the Muda Project have a self-management for the purchase of new equipment and trimmings for the manufacture of products.

Guava processing waste: Biological activity profile of a natural and sustainable source of phenolic antioxidants

Guava (Psidium guajava L.) is a widely-consumed tropical fruit that can be industrially processed and generate several food products. However, about 30% of the total volume of processed guava is lost as processing waste, a homogenous fraction containing peels, seeds, and residual pulp. The valorization of the discard fraction is necessary in upcycling due to its richness of bioactive components. Therefore, the phenolic composition and biological activity of guava's processing waste and its pulp counterpart were investigated. Guava's pulp (22.32 mg gallic acid equivalents (GAE)/g) and waste (21.99 mg GAE/g) contained similar levels of total phenolic content (TPC), with the majority of phenolics occurring in the free and esterified forms. Besides, a strong positive correlation was observed between TPC and the antioxidant activity of extracts. Through HPLC-UV-MS-TOF analysis, 27 phenolic compounds were identified across the pulp (25) and waste (18) portions, with a predominance of gallic, vanillic, and ellagic acids and their derivatives. While free and esterified phenolic fractions showed higher efficiency as α-glucosidase inhibitors (84.94–98.85%), pancreatic lipase was better inhibited by the insoluble-bound phenolics in the extracts (41.55–43.31%). Guava waste's insoluble-bound phenolics strongly protected supercoiled DNA against hydroxyl radicals (80.09%). Oxidation protection by guava phenolics was also observed towards human LDL-cholesterol (10.82–22.98%), an indication of their potential cardioprotective effect. As such, guava processing waste demonstrates nutraceutical potential and should be considered as a value-added ingredient in functional foods and other related applications.

Bioplastic from Peel and Rind of Tropical Fruits in Southeast Asia: A Mini-Review

Southeast Asian (SEA) countries have faced numerous challenges in managing their increasing amount of agricultural waste, particularly fruit waste. Fruit waste, like peel and rind, constitutes a substantial portion of total waste generated in SEA countries due to the high consumption of fruits in the region. In addition, inadequate waste management infrastructure, lack of proper disposal methods, and low awareness among the public have exacerbated the problem. The overproduction of plastic waste has become a global environmental issue, and SEA countries are not exempt from this problem. However, using bioplastics made from fruit peel and rind can reduce the dependence on traditional plastics. This paper aims to provide a mini-review regarding bioplastic production from fruit waste (peels and rinds) generated from tropical fruit of SEA countries. Moreover, this mini-review aims to evaluate their potential to replace traditional plastics in various industries. One potential method to solve this issue is converting fruit waste into bioplastics, which can provide a sustainable and eco-friendly alternative to conventional plastics. Bioplastics, derived from renewable sources such as fruit waste, are biodegradable, compostable, and can reduce carbon footprint. The findings of this paper indicate that fruit waste from peel and rind is a promising source of raw materials for bioplastic production in SEA countries. Bioplastics' fruit waste properties are comparable to conventional plastics and their applications. Furthermore, using fruit waste for bioplastic production can address the region's waste management issue. In conclusion, bioplastics from fruit waste have great potential to replace traditional plastics in SEA countries. Fruit waste provides a sustainable and cost-effective alternative raw materials for bioplastic production. Implementing fruit waste utilization for bioplastic production can contribute to developing a circular economy and aid in managing regional waste.

Effectiveness of waste concrete powder in fabricating compressed stabilized earth blocks: Strength, durability and thermal assessment

The construction industry's rapid expansion has led to the accumulation of substantial quantities of waste concrete powder (WCP), which constitutes a significant portion of construction and demolition waste. This study seeks to explore the potential of utilizing WCP in conjunction with cement to manufacture compressed stabilized earth blocks (CSEB) with enhanced mechanical properties. CSEB has long been recognized as an environment-friendly and viable alternative to traditional building blocks that harm the environment. By incorporating WCP into the production process, we can achieve recyclability and sustainability in our construction practices. In order to identify the optimal amount of stabilizers, 15 different combinations of cement and WCP were considered. These included three cement contents (4%, 6%, and 8% by weight of dry soil) and five waste concrete powder (WCP) contents (0%, 5%, 10%, 15%, and 20% by weight of dry soil). Compressed stabilized earth blocks (CSEB) performance was evaluated in terms of strength, durability, and thermal properties. Strength characteristics were determined through unconfined compression and flexure tests, while durability characteristics were evaluated using water absorption, wet compressive strength, submersion, and efflorescence tests. CSEBs without WCP displayed a maximum dry compressive strength of 6.67 MPa, while those with optimal WCP replacement reached a higher strength of 10.68 MPa using the same cement amount. Comparable outcomes were seen in the flexure test, with optimal WCP replacement resulting in a peak strength of 1.92 MPa compared to 1.12 MPa without WCP. In terms of durability, WCP-absent samples showed 13% water absorption, reduced to 10.5% with higher WCP content. Wet compressive strength was relatively lower for all samples, but those with optimal WCP performed best at 4.83 MPa. These fabricated samples also exhibited no efflorescence or damage from submersion. Thermal conductivity, determined using the simplified Lee's method, demonstrated a gradual increase in conductivity as WCP content was increased. However, the obtained values remained within comparable range of fired clay bricks. Furthermore, to investigate the supplementary cementitious behavior of WCP in CSEB, microstructural and thermal analyses were conducted. Scanning electron microscope images revealed a higher concentration of C–S–H gels in the 20% WCP-8% cement combination. The findings suggest that CSEB blocks stabilized with WCP could help to reduce construction and demolition waste while also providing a more stable and sustainable alternative to traditional building blocks.

Intermediate Technologies: The Key to Eradicating Post-harvest Losses (PHLs) in Sub-Saharan Africa (SSA)

Post-harvest losses (PHLs) in Sub-Saharan Africa (SSA) pose a significant threat to food security and economic stability. PHLs account for a substantial portion of food waste and economic losses. This paper explores the potential of intermediate technologies in addressing this challenge. Intermediate technologies, including hand-operated, pedal-operated, and solar-powered devices, offer adaptable and cost-effective solutions tailored to the needs of smallholder farmers who make up the majority of SSA's agricultural sector. These technologies bridge the gap between labor-intensive traditional methods and high-end, expensive equipment. They enhance efficiency, reduce labor, and have the potential to revolutionize post-harvest processes. Additionally, emerging innovations, such as harnessing energy from footsteps and raindrop energy offer promising avenues for further enhancing the sustainability and efficiency of post-harvest operations in resource-constrained environments. Intermediate technologies represent not only tools but also catalysts for transformation. They hold the key to reducing PHLs, fostering economic growth, ensuring food security, and leading to sustainable agriculture in SSA. By harnessing these technologies' adaptability and resource efficiency, SSA can move closer to a more sustainable and prosperous future.

Performance and emission characteristics of a CI engine with post-treated plastic pyrolysis oil and diesel blend

Conversion of waste plastics into energy products is an effective waste management technique as they constitute a considerable portion of solid waste at present. In this study, distilled diesel fraction of Plastic Pyrolysis Oil (PPO) named Distilled Plastic Diesel (DPD) was hydrotreated named hydrotreated plastic diesel (HPD) and blended with commercial diesel fuel by 15:85 ratio (wt%), defined as HPD15, to experimentally investigate the performance and emission characteristics of a compression ignition (CI) engine. The experiment was done in 4-cylinder, 4-stroke diesel engine with an eddy current dynamometer testbed at full load (100 % engine load) and an engine speed of 1200–2400 rpm with 300 rpm intervals. The results are compared with neat diesel fuel data at the same operating conditions. This study found that HPD15 performed better or comparable with diesel fuel. Overall, the brake power (BP) and brake thermal efficiency (BTE) of HPD15 were higher than diesel fuel by a maximum of about 4.77 % and 3.77 %, respectively. Brake specific fuel consumption (BSFC) of HPD15 was lower at all operating speeds (by a maximum of about 4.66 %) and brake specific energy consumption (BSEC) was lower in most of the operating speeds (by a maximum of about 3.77 %). This study also revealed that CO2 at some operating speeds and NOx emission at all operating speeds for HPD15 are lower than diesel fuel. However, CO and unburnt hydrocarbon (UHC) emission are slightly higher for HPD15 than diesel at all speeds. Overall, HPD15 can be recommended as a suitable alternative for diesel fuel without any engine modification.

Residents’ waste management practices in a developing country: A social practice theory analysis

Waste management has become a growing concern globally and caused rising environmental costs in developing countries. The efficiency of a waste management system depends on many factors, including residents’ waste management practices and a governmental commitment to sustainable waste management. This study employs the social practice theory to qualitatively examine residents’ perspectives on waste management in the context of Vietnam as a developing country where a massive portion of plastic waste originates from household disposal. The research involves conducting twelve focus groups in five different research locations, including two largest cities and three coastal and marine protected areas. Data analysis is performed using inductive and deductive coding principles and an interpretivist approach. The findings reveal residents’ classification of sustainable and unsustainable waste management practices, and the factors that facilitate or impede sustainable waste management practices from residents’ perspectives. According to residents, while adequate technical infrastructures can facilitate sustainable waste management practices, it is the social context that motivates or demotivates and can mould a practice into a habit. The study therefore provides useful implications for sustainable waste management systems that would require the government's effective leadership and coordination of technical infrastructures as well as the orchestral efforts from involved social institutions, including families, communities, businesses, formal and informal waste sectors, and social organisations.

Agro-waste Mediated Biosynthesis of Zinc Oxide Nanoparticles and their Antibacterial Properties: Waste to Treat

Background: Biogenic fabrication of metal oxide nanoparticles has been gaining interest over conventional methods. Biological methods make use of plant materials and microbial agents as reducing as well as capping agents. The present work reports the biosynthesis of ZnO NPs from agricultural wastes produced in every household. Objective: A significant portion of municipal solid organic waste (MSOW) consists of agricultural waste. Utilization of this agricultural waste towards cleaning water of pathogens through the synthesis of nanoparticles has far-reaching implications, such as curbing soil pollution and water pollution. Method: Preliminary confirmation was done by the visual formation of a pale yellow/dirty white precipitate of ZnO NPs. These were further characterized by different spectroscopic techniques, such as FT-IR, SEM, EDAX, and HRTEM. Results: The HRTEM study revealed that NPs obtained had sizes between 30-52 nm. Fabricated ZnO NPs were analyzed for their antibacterial activity by disk diffusion method, and they exhibited striking antibacterial activity against E. coli and bacillus subtilis. Conclusion: Exploring the potential of waste and its conversion into a value-added product is a novel step. ZnO nanoparticles were successfully synthesized from agricultural wastes through an environmentally friendly synthetic route, and the synthesized ZnO NPs were found to be potent in inhibiting the growth of bacteria.