Upcycling food waste as a low-cost cultivation medium for Chlorella sp. microalgae.

BACKGROUND: Global food loss and waste have raised environmental concerns regarding the generation of greenhouse gases (e.g., carbon dioxide and methane gas), which directly contribute to climate change. To address these concerns, the present research aims to upcycle food waste into an alternative culture medium for the cultivation of microalgae. Various parameters including pretreatment of food waste (i.e., autoclave and non-autoclave), concentration of food waste culture medium (i.e., 10%, 30%, 50%, 70%, 90% and 100%), harvesting efficiency and biochemical compounds of Chlorella sp. microalgae were carried out. RESULTS: Based on the preliminary findings, the highest biomass concentration obtained from 10% food waste culture medium in the autoclave for Chlorella sp., including strains FSP-E, ESP-31 and CY-1, were 2.869 ± 0.022, 2.385 ± 0.018 and 0.985 ± 0.0026 g L-1, respectively. Since Chlorella vulgaris FSP-E exhibited the highest biomass concentration, this microalgal strain was selected to examine the subsequent parameters. Cultivation of C. vulgaris FSP-E in 100FW achieves a biomass concentration of 4.465 ± 0.008 g L-1 with biochemical compounds of 6.94 ± 1.396, 248.24 ± 0.976 and 406.23 ± 0.593 mg g-1 for lipids, carbohydrates and proteins, respectively. CONCLUSION: This study shows that using food waste as an alternative culture medium for C. vulgaris FSP-E can achieve substantial biomass productivity and biochemical content. This research work would contribute to the concept of net zero emission and transitioning toward a circular bioeconomy by upcycling food waste as an alternative culture medium for the cultivation of microalgae. © 2024 Society of Chemical Industry.

Technological solutions to landfill management: Towards recovery of biomethane and carbon neutrality.

Inadequate landfill management poses risks to the environment and human health, necessitating action. Poorly designed and operated landfills release harmful gases, contaminate water, and deplete resources. Aligning landfill management with the Sustainable Development Goals (SDGs) reveals its crucial role in achieving various targets. Urgent transformation of landfill practices is necessary to address challenges like climate change, carbon neutrality, food security, and resource recovery. The scientific community recognizes landfill management's impact on climate change, evidenced by in over 191 published articles (1998-2023). This article presents emerging solutions for sustainable landfill management, including physico-chemical, oxidation, and biological treatments. Each technology is evaluated for practical applications. The article emphasizes landfill management's global significance in pursuing carbon neutrality, prioritizing resource recovery over end-of-pipe treatments. It is important to note that minimizing water, chemical, and energy inputs in nutrient recovery is crucial for achieving carbon neutrality by 2050. Water reuse, energy recovery, and material selection during manufacturing are vital. The potential of water technologies for recovering macro-nutrients from landfill leachate is explored, considering feasibility factors. Integrated waste management approaches, such as recycling and composting, reduce waste and minimize environmental impact. It is conclusively evident that the water technologies not only facilitate the purification of leachate but also enable the recovery of valuable substances such as ammonium, heavy metals, nutrients, and salts. This recovery process holds economic benefits, while the conversion of CH4 and hydrogen into bioenergy and power generation through microbial fuel cells further enhances its potential. Future research should focus on sustainable and cost-effective treatment technologies for landfill leachate. Improving landfill management can mitigate the adverse environmental and health effects of inadequate waste disposal.

Municipal emission pathways and economic performance toward net-zero emissions: A case study of Nakhon Ratchasima municipality, Thailand.

The transition to net-zero emissions (NZEs) in developing countries is challenging and requires the immediate adoption of comprehensive climate policy packages, strong collaboration among all sectors and stakeholders, and timely financial and technological assistance for developing economies. This research aims to analyze and evaluate the pathways to realize an NZE scheme at the municipality level. Nakhon Ratchasima (NR) Municipality, Thailand, is selected as the case study for this research. The Global Protocol for Community-Scale GHG Emission Inventories (GPC) is applied as the robust framework to assess the city's GHG emission profile. A mathematical forecasting model and the participatory multicriteria decision-making (MCDM) approach were adopted to support evidence-based local climate action planning based on four different scenarios: the business-as-usual (BAU), nationally determined contribution (NDC), carbon neutrality (CN), and NZE scenarios. The roles of stakeholders at the local community level across all sectors in mitigation actions and investment costs were investigated, and cost-effectiveness was evaluated to understand the economic performance of the adoption and implementation of local climate policy packages. The results indicate that by employing solely conventional technologies, a residential city that is also a hub for trade and land transportation will be unable to achieve its net-zero targets. It is imperative to seek additional low-carbon businesses and decarbonizing technologies that accompany substantial investments. According to the case of NR Municipality, the implementation costs to attain the NZE target by 2050 would range between 974.40 and 4.131.96 million USD. A pivotal driver of the municipal NZE pathway is the successful mobilization private sector investments to propel the transition toward climate-friendly technologies. Cost-effectiveness analysis significantly bolsters the municipality's transitional plan preparation, holistically encompassing economic, social, and environmental considerations. By preparing these aspects together, we ensure a smooth and equitable transition to net zero, avoid conflicts and economic harm and leave no one behind. This approach ensures a harmonious balance between a net-zero future, economic growth, and environmentally friendly living for all.

Activated carbons-preparation, characterization and their application in CO2 capture: A review.

In this paper, we provide a comprehensive review of the latest research trends in terms of the preparation, and characteristics of activated carbons regarding CO2 adsorption applications, with a special focus on future investigation paths. The reported current research trends are primarily closely related to the synthesis conditions (carbonization and physical or chemical activation process), to develop the microporosity and surface area, which are the most important factors affecting the effectiveness of adsorption. Furthermore, we emphasized the importance of regeneration techniques as a factor determining the actual technological and economic suitability of a given material for CO2 capture application. Consequently, this work provides a summary and potential directions for the development of activated carbons (AC). We attempt to create a thorough theoretical foundation for activated carbons while also focusing on identifying and specific statements of the most relevant ongoing research scope that might be advantageous to progress and pursue in the coming years.

Decarbonization in waste recycling industry using digitalization to promote net-zero emissions and its implications on sustainability.

Digitalization and sustainability have been considered as critical elements in tackling a growing problem of solid waste in the framework of circular economy (CE). Although digitalization can enhance time-efficiency and/or cost-efficiency, their end-results do not always lead to sustainability. So far, the literatures still lack of a holistic view in understanding the development trends and key roles of digitalization in waste recycling industry to benefit stakeholders and to protect the environment. To bridge this knowledge gap, this work systematically investigates how leveraging digitalization in waste recycling industry could address these research questions: (1) What are the key problems of solid waste recycling? (2) How the trends of digitalization in waste management could benefit a CE? (3) How digitalization could strengthen waste recycling industry in a post-pandemic era? While digitalization boosts material flows in a CE, it is evident that utilizing digital solutions to strengthen waste recycling business could reinforce a resource-efficient, low-carbon, and a CE. In the Industry 4.0 era, digitalization can add 15% (about USD 15.7 trillion) to global economy by 2030. As digitalization grows, making the waste sector shift to a CE could save between 30% and 35% of municipalities' waste management budget. With digitalization, a cost reduction of 3.6% and a revenue increase of 4.1% are projected annually. This would contribute to USD 493 billion in an increasing revenue yearly in the next decade. As digitalization enables tasks to be completed shortly with less manpower, this could save USD 421 billion annually for the next decade. With respect to environmental impacts, digitalization in the waste sector could reduce global CO2 emissions by 15% by 2030 through technological solutions. Overall, this work suggests that digitalization in the waste sector contributes net-zero emission to a digital economy, while transitioning to a sustainable world as its social impacts.

Role of International Oil Companies in the Net-Zero Emission Energy Transition.

Scientific and engineering capabilities in hydrocarbon supply chains developed over decades in international oil and gas companies (IOCs) uniquely position these companies to drive rapid scale-up and transition to a net-zero emission economy. Flexible large-scale production of energy carriers such as hydrogen, ammonia, methanol, and other synthetic fuels produced with low- or zero-emission renewable power, nuclear energy, or hydrogen derived from natural gas with carbon capture and storage will enable long-distance transport and permanent storage options for clean energy. Use of energy carriers can overcome the inherent constraints of a fully electrified energy system by providing the energy and power densities, as well as transport and storage capacity, required to achieve energy supply and security in a net-zero emission economy, and over time allow optimization to the lowest cost for a consumer anywhere on the globe.

[Project: zero emission surgery]. / Projekt: "zero emission surgery".

BACKGROUND: Climate neutrality is the major aim of our generation. In order to be able to achieve this a net zero emission should be strived for in operating theaters. OBJECTIVE: What does zero emission implicate for the operative sector? Which structural approaches already exist? Can zero emission surgery be achieved? MATERIAL AND METHODS: Evaluation of published studies, discussion of fundamental research and expert recommendations. RESULTS: Studies in England and Germany show that by structural alterations and strict sustainability structures net zero emission surgery seems to be feasible. In Germany the attention and awareness of the topic are greatly increasing and the first projects and studies have been launched. CONCLUSION: To achieve the aim of net zero emission by 2050 we must rapidly and significantly increase our efforts.

Clustered regularly interspaced short palindromic repeats (CRISPR) technology and genetic engineering strategies for microalgae towards carbon neutrality: A critical review.

Carbon dioxide is the major greenhouse gas and regards as the critical issue of global warming and climate changes. The inconspicuous microalgae are responsible for 40% of carbon fixation among all photosynthetic plants along with a higher photosynthetic efficiency and convert the carbon into lipids, protein, pigments, and bioactive compounds. Genetic approach and metabolic engineering are applied to accelerate the growth rate and biomass of microalgae, hence achieve the mission of carbon neutrality. Meanwhile, CRISPR/Cas9 is efficiently to enhance the productivity of high-value compounds in microalgae for it is easier operation, more affordable and is able to regulate multiple genes simultaneously. The genetic engineering strategies provide the multidisciplinary concept to evolute and increase the CO2 fixation rate through Calvin-Benson-Bassham cycle. Therefore, the technologies, bioinformatics tools, systematic engineering approaches for carbon neutrality and circular economy are summarized and leading one step closer to the decarbonization society in this review.

Municipal solid waste management for reaching net-zero emissions in ASEAN tourism twin cities: A case study of Nan and Luang Prabang.

Waste generation rates have increased with rapid population and economic growth worldwide, especially in tourism cities. Nan Province and Luang Prabang (LPB) are twin cities that have been popular tourist destinations. The impact of unmanaged waste threatens the socioeconomic environment in both places. Three waste management scenarios were developed to achieve net-zero greenhouse gas (GHG) emissions from the municipal solid waste (MSW) sector in Nan and LPB by 2030. Sensitivity and benefit-cost (B/C) analyses were performed, and alternative scenarios were proposed. With the use of available waste management technology, all developed scenarios in both locations could achieve net-zero emissions within the difference contexts of the city such as waste composition. From this study, on-site waste sorting is the key for waste management to achieve net-zero emissions. Sensitivity analysis revealed that, with an average carbon price of 28.42 USD/tCO2e, all scenarios in Nan and LPB were feasible, except for scenario 2 (off-site waste sorting) in LPB. This study found that it would be challenging but achievable to reach the net-zero emissions target. The challenge includes the increased on-site waste separation rate and raising public awareness concerning municipal solid waste management as well as its importance for effective waste management. These developed scenarios show a pathway for the waste sector to achieve net-zero emissions by 2030 with available waste management technology in Nan and Luang Prabang, and the possibilities for other locations facing similar situations.

From low carbon to carbon neutrality: A bibliometric analysis of the status, evolution and development trend.

With global climate change becoming increasingly serious, carbon neutrality, a key strategy to mitigate climate change, has attracted widespread attention. However, due to the multidisciplinary and complexity of carbon neutrality studies, as well as the diversification of research content, a comprehensive review and systematic synthesis of which is quite limited. In this paper, a bibliometric analysis on the topic of carbon neutrality is conducted to reveal the research progress from a quantitative and visual perspective and describe the evolution of research hotspots. The results show that carbon neutrality research is abundant at both the macro and micro levels. Low carbon development is the premise of carbon neutrality, and emission reduction and carbon sinks are the basis of carbon neutrality. The degree of research varies significantly in different countries, with China dominating in the number of publications, followed by the USA and the UK. The realization of carbon neutrality cannot be fully achieved by one single perspective and requires a comprehensive and systematic analysis of technology, economy, and society. Carbon neutrality is a technology-driven process guided by policy. Economically, carbon taxes and carbon markets are two important market mechanisms for reducing carbon emissions. Technically, researches of negative carbon technologies and renewable energy are growing rapidly. Carbon market, carbon negative technology, circular economy, and green energy will become the focus of future research. This paper helps scholars to understand the overall state of carbon neutrality research and provides a historical reference for future research.

Update on air pollution control strategies for coal-fired power plants.

Abstract: Coal is expected to remain a significant power supply source worldwide and shifting to carbon-neutral fuels will be challenging because of growing electricity demand and booming industrialization. At the same time, coal consumption results in severe air pollution and health concerns. Improvement in emission control technologies is a key to improving air quality in coal power plants. Many scientists reported removing air pollutants individually via conventional control methods. However, controlling multiple pollutants combinedly using the latest techniques is rarely examined. Therefore, this paper overviews the current and advanced physical technologies to control multi-air pollutants synergistically, including carbon control technologies. Also, the paper aims to examine how potential air pollutants (e.g., PM2.5, SO2, NOx, CO2), including mercury from the coal-fired power plants, cause environmental impacts. The data synthesis shows that coal quality is the most significant factor for increasing air emissions, regardless of power plant capacity. It is found that selecting techniques is critical for new and retrofitted plants depending on the aging of a power plant and other socio-economic factors. Considering the future perspective, this paper discusses possible pathways to transform from linear to a circular economy in a coal power plant sector, such as utilizing energy losses through energy-efficient processes and reuse of syngas. The article provides an in-depth analysis of advanced cost-effective techniques that would help to control the air pollution level. Additionally, a life cycle assessment-based decision-making framework is proposed that would assist the stakeholders in achieving net-zero emissions and offset the financial burden for air pollution control in coal-fired power plants. Supplementary Information: The online version contains supplementary material available at 10.1007/s10098-022-02328-8.