Zero-waste Strategy Research Articles

Solid Waste Management (SWM) Challenges and Solutions by using Zero Waste Strategy: Karachi as a Case Study

This paper introduces an abridgment of solid waste conditions and their management issues in Karachi. Approach that can be usedto reduce the municipal waste and the management of solid waste produced by the residents of Karachi city is Zero Waste Strategy. Zero waste strategy is a focused approach of conserving all the resources. This approach is beneficial by means of responsible production, valuable consumption, reuse and recovery of product, packaging and materials without burning and with the least discharge to air, water or land that cause an adverse effect on our environment and human health. The budget allocated by governmental bodies for solid waste management is adequate but not allocated properly to the local bodies. Bin services are provided throughout the city is enough but the locations selected for this purpose are not appropriate. Zero waste strategy (ZWS) helps to reduce the solid waste by providing a proper route, with an appropriate recycling plan, adequate management of resources, and public behavior related to solid waste. The research concludes by proposing zero waste strategy (ZWS) as an effective solution of highlighted issues for the management of solid waste in Karachi city. The current research is entirely unique and could affect the society in value-added manner.

Preliminary Studies of Slag and Ash from Incinerated Municipal Waste for Prospective Applications

The assessment of the possibility of using incinerated municipal waste, which is classified as non-hazardous, is a priority of the European zero waste strategy. The aim of this work was to identify the properties of slag and ash to develop a simple, targeted way of using post-process waste. The material was analyzed by microscopic methods in terms of composition and internal structure. Gas and water permeability tests were carried out. Slag and ash texture was obtained using densimetric methods. BCR sequential extraction was carried out to assess the impacts of the waste on the water and soil environment. It was shown that individual fractions were characterized by different compositions and pore contents. The increase in the waste layer density resulted in porosity reduction of the slag and post-process ash, which had a significant impact on permeability. The increase in density index from 0.92 to 0.98 resulted in reduction of the filtration coefficient by two orders of magnitude. The obtained results showed that the division into fractions is important for prospective applications of incinerated municipal waste. With very low permeability and negligible leachability of heavy metals, the characteristics of slag and ash predispose them to support the needs of specialized hydrotechnical construction.

Zero-waste strategy by means of valorization of bread waste

To impose the zero-waste strategy through the diverse valorization route, this study used bread waste (BW) as the model compound. To realize these grand technical challenges, BW was enzymatically hydrolyzed to obtain a monomer sugar compound (glucose), and glucose was used as the carbon substrate in heterotrophic cultivation of Euglena gracilis ( E. gracilis ). Cultivation of E. gracilis using cultivation medium derived from BW was evaluated from a perspective of an economic viability . In addition, the more production of the target compound (paramylon, β-1,3-glucan) stemmed from E. gracilis was achieved (1.93 g L −1 d −1 ; 24% higher productivity than that of control). To approach zero waste disposal, bread waste residue (BWR) derived from enzymatic hydrolysis of BW was valorized into syngas . To offer a greener pyrolysis platform for BWR, CO 2 was used as a raw material. Here in this study, the mechanistic functionality of CO 2 was disclosed. In detail, CO 2 reacted with volatile matters (VMs) evolved from BWR, thereby resulting in CO 2 reduction. Simultaneously, reduced CO 2 also led to oxidation of VMs. Such consecutive gas-phase-reactions (GPRs) played a critical role to enhance CO formation. Lastly, the identified GPRs induced by CO 2 were tried to expedite the reaction kinetics in the presence of 5 wt% of Ni/SiO 2 catalyst. As a result, the molar concentrations of H 2 and CO in gaseous pyrolytic products derived from catalytic pyrolysis in CO 2 environment were 2- and 6-times higher, respectively, than that from pyrolysis without catalyst in N 2 environment. • Zero waste disposal platform for food waste (FW) was experimentally practiced. • Glucose derived from FW was used as carbon substrate for the growth of E. gracilis . • High yield of paramylon was achieved from E. gracilis grown with FW medium. • FW residue after glucose extraction was further valorized into energy. • CO 2 was converted into gaseous fuel in catalytic pyrolysis of FW residue.

Combining pH-triggered adsorption and photocatalysis for the remediation of complex water matrices

Adsorption and photocatalysis are water remediation techniques with unique advantages and limitations that can make them complementary: while adsorption is a cheap and fast process that simply transfers the pollutant to another phase, photocatalysis is a slow and costly procedure that however can degrade recalcitrant pollutants. Here, we propose a sequential treatment based on reversible and selective adsorption, followed by heterogeneous photocatalysis. In particular, the reversible and selective adsorption of dye molecules was achieved by polyaniline (PANI)-based hybrid adsorbents. The role of the dye content, adsorbent dose, solution pH and electrolyte composition was investigated. By tuning the adsorption pH, an effective regeneration of the spent adsorbent could be achieved by the triggered release of the adsorbate in an aqueous solution and under mild conditions. Moreover, the separation of multi-dye mixtures (methyl orange and methylene blue) was proven, also in consecutive cycles. The selective recovery of one of the components could enable dye recycling. An ensuing photocatalytic step using a commercial photocatalyst could be adopted to either degrade the leftover solution or the regeneration solution. The release of a single pollutant in aqueous solvent, with controlled composition and tunable concentration, allows performing photocatalysis more efficiently. This combined approach enables a fast and effective treatment of the effluent and an easy regeneration of the spent adsorbent with ensuing treatment of the regeneration solution for a zero-waste strategy.

Enhanced Tetracycline Removal from Highly Concentrated Aqueous Media by Lipid-Free Chlorella sp. Biomass.

Microalgae are used as a lipid source for different applications, such as cosmetics and biofuel. The nonliving biomass and the byproduct from the lipid extraction procedure can efficiently remove antibiotics. This work has explored the potential use of Chlorella sp. biomasses for tetracycline (Tc) removal from highly concentrated aqueous media. Non-living biomass (NLB) is the biomass before the lipid extraction procedure, while lipid-extracted biomass (LEB) is the byproduct mentioned before. LEB removed 76.9% of Tc at 40 mg/L initial concentration and 40 mg of biomass, representing an adsorption capacity of 19.2 mg/g. Subsequently, NLB removed 68.0% of Tc at 50 mg/L and 60 mg of biomass, equivalent to 14.2 mg/g of adsorptive capacity. These results revealed an enhanced removal capacity by LEB compared with NLB and other microalgae-based materials. On the other hand, the adsorption kinetics followed the pseudo-second-order and Elovich models, suggesting chemisorption with interactions between adsorbates. The adsorption isotherms indicate a multilayer mechanism on a heterogeneous surface. Additionally, the interactions between the surface and the first layer of tetracycline are weak, and the formation of the subsequent layers is favored. The Chlorella sp. biomass after the lipid extraction process is a promising material for removing tetracycline; moreover, the use of this residue contributes to the zero-waste strategy.

Yard waste prediction from estimated municipal solid waste using the grey theory to achieve a zero-waste strategy.

Yard waste is one of the key components of municipal solid waste and can play a vital role in implementing zero-waste strategy to achieve sustainable municipal solid waste management. Therefore, the objective of this study is to predict yard waste generation using the grey theory from the predicted municipal solid waste generation. The proposed model is implemented using municipal solid waste generation data from the City of Winnipeg, Canada. To identify the generation factors that influence municipal solid waste generation and yard waste generation, a correlation analysis is performed among eight socio-economic factors and six climatic factors. The GM (1, 1) model is utilized to predict individual factors with overall MAPE values of 0.06%−10.39% for the in-sample data, while the multivariable GM (1, N) grey model is employed to forecast the quarterly level of municipal solid waste generation with overall MAPE values of 5.64%−7.54%. In this study, grey models predict quarterly yard waste generation from the predicted municipal solid waste generation values using only twelve historical data points. The results indicate that the grey model (based on the error matrices) performs better than the linear and nonlinear regression-based models. The outcome of this study will support the City of Winnipeg’s sustainable planning for yard waste management in terms of budgeting, resource allocation, and estimating energy generation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-19178-y.

Almond hulls waste valorization towards sustainable agricultural development: Production of pectin, phenolics, pullulan, and single cell protein

This research aimed to valorize almond hulls based on a zero-waste strategy towards sustainable agricultural developments for the recovery and production of valuable compounds. For this purpose, the potential to produce four products, including pectin (AHP), phenolic compounds (AHPC), pullulan (PUL), and single-cell protein (SCP), was examined. The acidic extraction factors were optimized using a Box-Behnken design for the simultaneous extraction of AHP and AHPC, and the obtained results showed that the maximum AHP (26.32% w/w) and AHPC (6.97% w/w) yields were achieved at 90 °C, pH of 1.4, 58.65 min, and liquid–solid ratio (LSR) of 20.13 v/w as the optimum point. In the next step, the solid residues that remained from the AHP and AHPC extraction process (PESR) were treated with cellulase enzyme and ultrasound and were used for simultaneous microbial production of PUL (34.29–24.56 g/L) and biomass containing SCP (19.31–13.44% w/w). Furthermore, the obtained results showed that AHP was low methylated (26.40%), rich in galacturonic acid (67.88%), and high in molecular weight (595.299 kDa). Also, the investigations of structural properties of AHP and PUL confirmed the presence of chemical structures of these polysaccharides in the formed supernatants. In addition, the AHPC showed considerable antioxidant activity compared with ascorbic acid (ASC) and BHA.

A zero-waste strategy to synthesize geopolymer from iron-recovered Bayer red mud combined with fly ash: Roles of Fe, Al and Si

Bayer red mud (RM) was treated with carbothermal reduction for iron recovery, and then the fly ash-based geopolymer was synthesized from the iron-separated RM residue and fly ash with a mass ratio of 25:75. Under the optimized conditions, the recovery efficiency of iron and the total iron content in the iron concentrate could reach the maximum of 51.48 and 54.13 wt%, respectively. The leaching efficiencies of alumina and silica reached the maximum values of 11.45 wt% (Al2O3) and 2.62 wt% (SiO2) after the the iron recovery process, therefore, a compressive strength of 43.35 MPa of the geopolymer was achieved. The effects of Fe element in iron-separated RM residue as well as the transformation of Al and Si elements on the properties of geopolymer were analyzed by Mössbauer spectroscopy, X-ray diffraction, and linear regression model. The presence of iron had a negative impact on the strength of geopolymer, and the enhanced alumina and silica leaching efficiencies by the carbothermal reduction process had dominantly positive effects on the compressive strength. Density Functional Theory (DFT) calculation demonstrated that Fe3+ could substitute Al3+ in the geopolymer networks, and the intensity of the covalent interaction of Fe-O bond was lower than Al-O bond, which indicated that Al-O bond was more stable than Fe-O bond in geopolymer regarding to long-term stability.

Long-term alkaline volatile fatty acids production from waste streams: Impact of pH and dominance of Dysgonomonadaceae

Alkaline co-fermentation of primary sludge and external organic waste (OW) was studied to elucidate the influence of substrate ratios and long-term system robustness and microbial community dynamics using batch and semi-continuous reactors. Volatile fatty acid (VFA) production increased with increasing OW fraction in the substrate due to synergistic effects of co-degradation. VFA production at pH 10 increased up to 30,300 mgCOD/L (yield of 630 mg COD/gVSfed) but reduced over time to ≈10,000 mgCOD/L. Lowering pH to 9 led to the restoration of VFA production with a maximum of 32,000 mg COD/L (676 mg COD/g VSfed) due to changes in microbial structure. VFA was composed mainly of acetic acid, but propionic acid increased at pH 9. The microbial community was dominated by Bacillaceae (34 ± 10%) and Proteinivoracales_uncultured (16 ± 11%) at pH 10, while Dysgonomonadaceae (52 ± 8%) was enriched at pH 9. The study demonstrated a zero-waste strategy that turns organic wastes into bio-based products.

Removal of minocycline from high concentrated aqueous medium by nonliving and lipid-free Chlorella sp. biomass

This work evaluated the removal of minocycline (MC) by the nonliving Chlorella sp. biomass (NLB) and modified by a lipid extraction procedure (LEB). Both biomasses have different morphology (NLB: globular-like; LEB: flakes and blocks) and size distribution. The pH showed a significant synergistic influence on MC removal (p < 0.05). MC initial concentration (C0) and biomass dosage significantly interact, suggesting that LEB agglomeration decreased removal. NLB removed 90.8 ± 1.3% of MC and LEB 80.8 ± 1.4% at C0 = 53.89 mg/L, 50 mg of biomass and pH 10. The adsorption kinetics and isotherms suggested multilayer formation by physical and chemical adsorption on heterogeneous and macroporous surfaces. According to results, NLB as an adsorbent had an economic disadvantage because of production costs despite good removal efficiency. However, it is possible to take advantage of the biomass after removing value-added compounds (LEB) as a zero-waste strategy.

From resource circularity policies to the zero-waste strategy

Over the last twenty years, waste management policies were aimed to mitigate environmental impacts; but in most cases the results of these policies had been the downcycling. The upcycling and the transition to circularity are good solutions to remedy the impacts of linear patterns of production and consumption. However, the only way to reduce environmental pressure is not through recycling but through reusing and avoiding waste production. In this direction, designers could play a significant role thanks to strategies such as those of Design for Longevity and Design for Deconstruction. Even if there are still few decision-making tools to support an effective evaluation of waste in the design phase, the above-mentioned strategies could lead designers towards a Zero Waste Strategy.

The zero-waste design for the municipal solid waste management in Baghdad city

Zero-waste is ideological for facing waste difficulties in our community. The purpose is to start developing and performed in different areas including waste management and treatment, mining, construction, and city development. The zero-waste idea has been welcomed by policymakers because it animates sustainable production and consumption, best recycling, and resource improvement. Experts in waste management systems, however, understand and implement it in different ways. The present study aims to imagine a zero-waste strategy within Baghdad city based on the available data and published in the literature to get an optimum resource recovery from generated waste, by assuming a recycling factory working at a capacity of 7500 tons/day, in three basic units (composting unit 5000 ton/day, composting unit 1500, ton/day, and inert materials unit 1000 ton/day), theses expected capacities of each unit built on Baghdad municipality percentages of each type of waste (57% organic materials, 23% energy sources materials, and 20% for inert materials such as construction waste). From the findings can be concluded that Baghdad city can reach the desired goal (zero-waste) by recycling its waste and implementing a comprehensive management system that includes education, sustainable production, and consumption. Very few investigations have been observed in the fields of zero-waste design, this study shows that the field of zero-waste knowledge is various, and a zero-waste concept is continually growing through different strategies, plans, procedures, and policies. The judgments of this study propose that zero-waste programs are applied in many countries without any holistic zero-waste strategy. The study indicates that countries might be ready to reach zero-waste purposes of explaining general zero-waste plans and by uniting and promoting zero-waste actions (in cities and manufacturers).

Facility Disruptions in a Closed-loop Supply Chain Featuring Warranty Policy and Quality-based Segmentation of Returns

This paper focuses on a closed-loop supply chain that deals with disruptions in the distribution centers, and optimizes the network in two dimensions of sustainability: economic and environmental. Economically, the proposed network maximizes the profits of the customers, manufacturers and distributors. Three avenues for cost minimization are designed for the customer by adding the warranty periods, the reworking options, and the incentives for returning the used items. Non-dominated solutions via the Reservation Level-driven Tchebycheff procedure are found by appropriate choice of facility establishment and suitable allocation links considering the disruption in the distribution centers.Environmentally, the model adopts a zero-waste strategy by embedding various return-segmentation policies and a secondary chain. The backward flow depends on the customers' choice of reworking, the validity of the warranty contract, and the quality of the returns. The test results indicate that due to various revenue options, the manufacturing and distribution centers prefer returns with medium-range quality, while due to the incentives offered for the recyclable items, the customers benefit the most from returning the items with the lowest quality. The tests on the probability of disruptions indicate that establishing a minimum number of the manufacturing and/or distribution sites without disruption leads to better overall performance.

Evaluating emissions reductions from zero waste strategies under dynamic conditions: A case study from Boston

In 2018 and 2019 the City of Boston (Massachusetts, USA) conducted zero waste and carbon neutral planning efforts. Here we present the results of an accompanying analysis of the impacts of zero waste strategies on greenhouse gases (GHG) emissions associated with waste treatment. Emissions analysis in the waste sector is complicated by the contribution of significant indirect impacts that can exhibit temporal and spatial heterogeneity. For example, lifecycle GHG analysis of waste-to-energy combustion grants credits for the emissions avoided due to electricity generated from organic waste (biogenic carbon) that displaces electricity generation that could be carbon-emitting. As electricity grids decarbonize, this credit approaches zero. Long-term emissions planning needs to account for such dynamics to realistically assess the GHG mitigation potential associated with alternative waste management strategies. Here, we seek to capture these dynamics in a forward-looking analysis of waste sector emissions under a zero-waste strategy for the City of Boston. Using publicly available data sets such as EPA’s Waste Reduction Model (WARM), we show that the implementation of zero waste strategies reduces the combustion of plastics and biomass in waste-to-energy (WtE) combustion facilities and associated GHG emissions. While WtE has been considered less-carbon intensive than other forms of waste treatment and fossil-based electricity generation, our analysis shows that more renewables will eventually eliminate the perceived GHG benefits associated with waste-to-energy combustion. While our approach provides policymakers with an understanding of the impacts of decisions in a dynamic context, we also identify common knowledge gaps in conducting forward-looking waste-GHG assessments.

Waste management in a university campus

In this study, we discussed how can be the management hierarchy and management process in a university campus. Erciyes University is in the middle of the Anatolia Region that has about 60.000 population. The university has faculty /institutional administrations and hospital-related buildings and research centers. It has an area of about 20 m2 for each person on the campus. The university is responsible in terms of legislative directives that are in operation. The waste directive is published by the university in 2017 that shares the responsibilities and distributes the tasks for each unit on the university campus. In Turkey, zero waste projects and zero waste legislation are also in operation by 2019. The importance of waste management strategy is important for Sustainable Development Goals (SDG) that is published by the United Nations and put in consideration of Times Higher Education (THE) which is one of the most confidential ranking systems for universities. There is also, environmental assessment system for university campuses, the Green-Metric. One of the grading subjects of the Council of Higher Education (YÖK) in Turkey is the zero waste strategy on the campus. Therefore, the operation of a zero-waste strategy gains importance.

Lean–Green Improvement Opportunities for Sustainable Manufacturing Using Water Telemetry in Agri-Food Industry

Water has become a critical resource due to increased manufacturing activities. However, there is a lack of detailed information on water management and consumption by industries. In the recent bibliography, lean–green was established as a good approach for achieving sustainability in manufacturing industries, but few studies have aimed to achieve both operational and environmental improvements in water consumption. In this paper, we present a multi-case study in the agri-food industry in which water consumption in company activities is monitored, allowing them to improve their industrial processes based on lean–green practices, leading to a zero-waste strategy for this critical resource. The aim of this paper is to demonstrate the importance of having detailed knowledge regarding water consumption in order to discover, in a lean–green context, new improvement opportunities which could remain hidden by the current way of analysing consumption.

Towards the circular economy: Analysis of barriers to implementation of Turkey's zero waste management using the fuzzy DEMATEL method.

Zero waste has an important position in the circular economy model in terms of manufacturing recyclable products instead of products to be consumed quickly, reducing the amount of waste, developing and implementing recycling/reuse technologies, and thus ensuring resource efficiency. A zero-waste strategy is one of the basic steps to achieve the goal of the circular economy. The number of studies conducted on Turkey's zero waste management strategies referring to the circular economy is quite limited. To fill this gap in the literature, this study aims to identify the potential barriers which have an important role in zero waste management practices in Turkey. Through a broad literature review and expert opinions, 12 key barriers for zero waste implementation in Turkey have been defined in view of circular economy principles. Then, fuzzy DEMATEL methodology is employed to examine which is the most influential barrier affecting zero waste management success and to identify the interdependence of these barriers. The results indicate that uncertainty of the goals and tactics relevant to the circular economy and lack of financial and economic aid are key causal barriers that affect Turkey's zero waste management.

Sufficiency Economy Philosophy: An Enabler for Zero Waste City

Waste has become a critical problem in cities around the world. Each year, the world generates 2.01 billion tonnes of municipal solid waste, with at least 33 percent of that not managed in an environmentally safe manner. The currently consumption-driven lifestyle also produces a huge volume of waste each day threatening the world sustainability. Moreover, the ongoing depletion of natural finite resources is also leading the globe to an uncertain future. The purpose of this article is to study the zero-waste concept and the characteristics of zero waste city, to study the principles of sufficiency economy philosophy, and to review the role of sufficiency economy in waste reduction and how it contributes to zero waste city. Documentary study and literature review were used for data collection. The result showed that ineffective waste management including landfill and incineration can be one major cause of waste. Also, overconsumption can be another cause that exacerbates the current waste situation. A zero-waste strategy and the concept of zero waste city can contribute to waste prevention with its proactive-reduce, reuse, and recycle (3R)-principle and to the reduction of wastes sent to landfills and incinerators. Sufficiency Economy Philosophy can also contribute to waste reduction at the consumer side. With the zero-waste strategy and sufficiency economy philosophy, we can achieve waste and pollution reduction and preserve our environment, as well as create sustainability for the future generations.

Gender Inequality in the Global Warming Era: The Disparate Impact of Climate Change on Female

The climate change crisis has gained unprecedented urgency in the most recent decade. Overall, climate change has already led to and will continuously lead to environmental tipping points and irreversible lock-ins that will decrease the common welfare. When taking a closer look at the macroeconomic growth prospects as measured in Gross Domestic Product (GDP) per country, a changing climate will affect countries differently, when considering different mean temperatures but also differences in the GDP sector composition per country and a differing peak temperature per GDP sector for optimal production levels. Within society, climate change has a disparate impact of sustainability on female. Female are traditionally the household caretakers who face a disproportional burden of sustainability pledges. As economic gains and losses from a warming earth are distributed unequally within society, ethical imperatives lead to the pledge to redistribute economic opportunities due to climate change to parts of society that lose from global warming in the quest for climate justice. While between countries but also over generations’ differences in climate change gains and losses lead to unique and unprecedented tax-and-bonds climate change gains and losses distribution strategies, climate justice fairness within society will require novel ways of measuring, monitoring and distributing gains and burdens’ distribution strategies, also between household members. The regular redistribution mechanisms of taxation, as used between countries or consumers, and climate bonds with diversified interest rates and maturity yield regimes, as a rebalancing between generations, needs to be extended on the gender imbalance and family or community level. The novel policy recommendation of this chapter calls for more interpersonal research on climate change burden sharing and socio-psychological mechanisms such as trust, future orientation, compassion and social responsibility – all powerful female attributes that can drive climate leadership-in-action. We will need redistribution mechanisms that are more diversified than monetary redistribution to shift and balance gender interactions that have gotten skewed due to climate change. Areas of concern are disparate impacts of Zero Waste strategies on women as household caretakers but also the long-term burden the novel Coronavirus crisis has on women, who are particularly prone to develop long-term disability as COVID-19 Long Haulers. Addressing all the mentioned areas of concern in future public policymaking will ensure to share the burden but also the benefits of climate change within the most granular micro-level of society where it seems to matter at most for the individual.

Waste services' performance assessment: The case of Tuscany, Italy

This paper assesses the performance of waste services in the region of Tuscany in Italy. It adopts non-parametric techniques for this purpose. Furthermore, it investigates the influence of the operational environment on the estimated performance by using the robust order-m technique. Meaningful levels of inefficiency were found in the Italian waste services. A specification of the ownership of the operator entrusted with waste management by municipalities and the formal adoption of the zero-waste strategy are included as environmental variables.The study concludes that the influence of the operational environment is a determinant of performance. The income per capita is negatively associated with efficiency, while population density is positively associated. Furthermore, efficiency levels are lower for municipalities with higher mixed waste per capita produced. Improving good pro-environmental behaviours is likely to improve efficiency and, thus, tariffs. The empirical results support the idea that it is necessary to make relevant organizational decisions that imply higher costs to increase the refuse collection rate. An increase in the separate collection rate beyond 50% is associated with the reduction of the efficiency level reached. Efficiency analysis does not consider the additional costs and the opportunities for municipalities to get revenues by selling them as secondary raw materials. Besides, the adoption of a zero-waste strategy is related to higher efficiency in MSW service provision. Finally, results about the ownership issue support the idea that privatization is not necessarily associated with the performance improvement of the waste services.