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Activated sludge from municipal wastewater treatment processes can be used directly for the production of biodegradable polyesters from the family of polyhydroxyalkanoates (PHAs). However, municipal activated sludge typically cannot accumulate PHAs to very high levels and often low yields of polymer produced on substrate are observed. In the present work, it was found that the presence of calcium promotes selective growth and enrichment of the PHA-storing biomass fraction and significantly improved both PHA contents and yields. Calcium addition resulted in PHA contents of 0.60 ± 0.03 gPHA/gVSS and average PHA yields on substrate of 0.49 ± 0.03 gCODPHA/gCODHAc compared to 0.35 ± 0.01 gPHA/gVSS and 0.19 ± 0.01 gCODPHA/gCODHAc without calcium addition. After 48 h, three times more PHA was produced compared to control experiments without calcium addition. Higher PHA content and selective biomass production is proposed to be a consequence of calcium dependent increased levels of passive acetate uptake. Such more efficient substrate uptake could be related to a formation of calcium acetate complexes. Findings lead to bioprocess methods to stimulate a short-term selective growth of PHA-storing microorganisms and this enables improvements to the techno-economic feasibility for municipal waste activated sludge to become a generic resource for industrial scale PHA production.

AbstractClimate change, migration, and conflict have been featured prominently in academic and policy literature. While Africa remains the major reference point, studies on key conflict hotspots fail to adequately examine empirical demonstrations of how climate change forces migration, and consequently major conflicts. Drawing on semi‐structured interviews, focus group discussions, and employing the scarcity theory in a study of Agogo (Ghana), we illustrate how regional and local climate/environmental variability and scarcity trigger and sustain migration and farmer–herder conflicts. The findings offer insights into how other non‐climatic and ecological conditions reinforce the so‐called climate‐induced conflicts, exposing the limitations of the scarcity‐theory. Importantly, this study has provided an illustrative argument centered around the contextual dynamics of the nexus between climate change and farmer–herder conflict in Agogo to contribute to national, regional, and continental discussion on this critical topic.

Contexte et objectif : Les partenariats sont un mécanisme clé dans la planification, la prestation et la gestion de la foresterie urbaine (FU) et des infrastructures vertes (IG). Ils peuvent faciliter la cogestion ancrée localement et la gouvernance polycentrique. Ils peuvent également réaliser des synergies en combinant les ressources, l'engagement et l'expertise de divers groupes de parties prenantes afin de générer des résultats précieux et de construire un capital social. Néanmoins, le terme « partenariats » n'est pas utilisé de manière cohérente dans la littérature et nécessite une clarification. Les caractéristiques qui distinguent une approche de partenariat des autres modes de coopération sont identifiées et décrites. La diversité des partenariats existants axés sur la FU et les IG est décrite, en référence à leurs parties prenantes, moteurs, activités et objectifs, ainsi que les avantages potentiels de l'approche de partenariat. Les considérations à faire dans leur évaluation sont dérivées de cette analyse de fond et les facteurs de réussite possibles sont discutés. Matériels et méthodes :La diversité, les objectifs et les caractéristiques d'une approche de partenariat sont basés sur une analyse documentaire approfondie.Résultats : Les partenariats se concentrent sur divers aspects et phases de prestation de l'UF, allant de la planification, de la conception et de la création de forêts urbaines et d'IG à leur gestion et utilisation.Les avantages fournis par de tels partenariats comprennent les services environnementaux et économiques ainsi que les services sociaux et culturels tels que l'éducation environnementale, la santé, les loisirs et le tourisme.Générer des services précieux tout en entretenant des relations entre les parties prenantes contribue à développer le capital social et à renforcer les capacités.En plus des avantages environnementaux, économiques et sociaux, l'évaluation des partenariats peut également aborder des variables de processus internes telles que l'apprentissage social, la relation entre les partenaires et les résultats de motivation qui peuvent influencer la coopération future.conclusions : Les partenariats coopératifs offrent une approche prometteuse pour la prestation de l'UF.Le développement des relations entre les partenaires maximise le potentiel de développement d'une coopération efficace à long terme et de renforcement du capital social en tant qu'aide à la promotion du développement durable. Antecedentes y propósito: Las asociaciones son un mecanismo clave en la planificación, entrega y gestión de la silvicultura urbana (UF) y la infraestructura verde (GI). Pueden facilitar la cogestión arraigada localmente y la gobernanza policéntrica. También pueden lograr sinergias combinando los recursos, el compromiso y la experiencia de diversos grupos de partes interesadas para generar resultados valiosos y construir capital social. Desafortunadamente, el término "asociaciones" no se usa de manera consistente en la literatura y requiere aclaración. Se identifican y describen las características que distinguen un enfoque de asociación de otros modos de cooperación. Se describe la diversidad de las asociaciones orientadas a UF y GI existentes, con referencia a sus partes interesadas, impulsores, actividades y objetivos, junto con las posibles ventajas del enfoque de asociación. Las consideraciones que se deben hacer en su evaluación se derivan de este análisis de antecedentes y se discuten los posibles factores de éxito. Materiales y métodos:La diversidad, los objetivos y las características definitorias de un enfoque de asociación se basan en una extensa revisión de la literatura. Resultados: Las asociaciones se centran en diversos aspectos y fases de entrega de UF, que van desde la planificación, el diseño y la creación de bosques urbanos e IG hasta su gestión y uso. Los beneficios obtenidos por dichas asociaciones incluyen servicios ambientales y económicos, así como servicios sociales y culturales como la educación ambiental, la salud, el ocio y el turismo. La generación de servicios valiosos y, al mismo tiempo, el fomento de las relaciones entre las partes interesadas ayuda a desarrollar el capital social y a desarrollar la capacidad. Además de los beneficios ambientales, económicos y sociales, la evaluación de las asociaciones también puede abordar variables de procesos internos como el aprendizaje social, la relación entre los socios y los resultados motivacionales que pueden influir en la cooperación futura. Conclusiones: Las asociaciones cooperativas ofrecen un enfoque prometedor para la entrega en UF. El desarrollo de las relaciones entre los socios maximiza el potencial para desarrollar una cooperación efectiva a largo plazo y para construir capital social como una ayuda para la promoción del desarrollo sostenible. Background and Purpose: Partnerships are a key mechanism in the planning, delivery and management of urban forestry (UF) and green infrastructure (GI).They can facilitate locally rooted co-management and polycentric governance.They can also achieve synergies by combining the resources, commitment and expertise of diverse stakeholder groups in order to generate valuable outcomes and build social capital.Unfortunately, the term "partnerships" is not used consistently in literature and requires clarification.The characteristics which distinguish a partnership approach from other modes of cooperation are identified and described.The diversity of existing UF and GI oriented partnerships is outlined, with reference to their stakeholders, drivers, activities and goals, together with potential advantages of the partnership approach.Considerations to be made in their evaluation are derived from this background analysis and possible success factors are discussed. Materials and Methods:The diversity, aims and defining characteristics of a partnership approach are based on an extensive literature review.Results: Partnerships focus on diverse aspects and delivery phases of UF, ranging from the planning, design and creation of urban forests and GI to their management and use.Benefits delivered by such partnerships include environmental and economic services as well as social and cultural services such as environmental education, health, leisure and tourism.Generating valuable services whilst at the same time nurturing relationships between stakeholders helps to develop social capital and build capacity.In addition to environmental, economic and social benefits, the evaluation of partnerships may also address internal process variables such as social learning, the relationship between partners, and motivational outcomes that can influence future co-operation.conclusions: Co-operative partnerships offer a promising approach for delivery in UF.The development of relationships between partners maximises the potential for developing effective long term co-operation and for building social capital as an aid to the promotion of sustainable development. الخلفية والغرض: الشراكات هي آلية رئيسية في تخطيط وتسليم وإدارة الحراجة الحضرية (UF) والبنية التحتية الخضراء (GI). يمكن أن تسهل الإدارة المشتركة ذات الجذور المحلية والحوكمة متعددة المراكز. كما يمكنها تحقيق التآزر من خلال الجمع بين الموارد والالتزام والخبرة لمجموعات أصحاب المصلحة المتنوعة من أجل توليد نتائج قيمة وبناء رأس المال الاجتماعي. لسوء الحظ، لا يتم استخدام مصطلح "الشراكات" باستمرار في الأدبيات ويتطلب توضيحًا. يتم تحديد ووصف الخصائص التي تميز نهج الشراكة عن أساليب التعاون الأخرى. يتم تحديد تنوع الشراكات الحالية الموجهة نحو UF و GI، مع الإشارة إلى أصحاب المصلحة والدوافع والأنشطة والأهداف، جنبًا إلى جنب مع المزايا المحتملة لنهج الشراكة. يتم استخلاص الاعتبارات التي يجب مراعاتها في تقييمها من هذا التحليل الأساسي وتتم مناقشة عوامل النجاح المحتملة. المواد والأساليب:يعتمد التنوع والأهداف والخصائص المميزة لنهج الشراكة على مراجعة شاملة للأدبيات .النتائج: تركز الشراكات على جوانب متنوعة ومراحل تسليم UF، بدءًا من تخطيط وتصميم وإنشاء الغابات الحضرية و GI إلى إدارتها واستخدامها. وتشمل الفوائد التي تقدمها هذه الشراكات الخدمات البيئية والاقتصادية بالإضافة إلى الخدمات الاجتماعية والثقافية مثل التعليم البيئي والصحة والترفيه والسياحة .توليد خدمات قيمة وفي الوقت نفسه رعاية العلاقات بين أصحاب المصلحة يساعد على تطوير رأس المال الاجتماعي وبناء القدرات .بالإضافة إلى الفوائد البيئية والاقتصادية والاجتماعية، قد يعالج تقييم الشراكات أيضًا متغيرات العملية الداخلية مثل التعلم الاجتماعي، والعلاقة بين الشركاء، والنتائج التحفيزية التي يمكن أن تؤثر على التعاون في المستقبل .الاستنتاجات: تقدم الشراكات التعاونية نهجًا واعدًا للتسليم في UF .إن تطوير العلاقات بين الشركاء يزيد من إمكانات تطوير التعاون الفعال طويل الأجل وبناء رأس المال الاجتماعي كمساعدة لتعزيز التنمية المستدامة.

Global emission inventories with 1°x 1°resolution were compiled for nitrogen oxides (NO + NO2, together denoted as NO(x)), ammonia (NH3) and nitrous oxide (N2O) emissions. For NO(x) the estimated global anthropogenic emission for 1990 is about 31 million ton N year-1. The major anthropogenic sources identified include fossil fuel combustion (70%, of which the major sources are road transport and power plants) and biomass burning (20%). Natural sources contribute about 19 million ton N year-1, mainly lightning and soil processes. For NH3the estimated global emission for 1990 is about 54 million ton N year-1. The major sources identified include excreta from domestic animals and wild animals, use of synthetic N fertilisers, oceans and biomass burning. About half of the global emission comes from Asia, and about 70% is related to food production. For N2O the major sources considered include fertilised arable land, animal excreta, soils under natural vegetation, oceans, and biomass burning. The global source of N2O is about 15 million ton N2O-N year-1of which about 30% is related to food production. All three inventories are available on a sectoral basis on a 1°x 1°grid for input to global atmospheric models and on a regional/country basis for policy analysis.

The need for achieving efficient and sustainable use of water resources is pressing, however, this often requires better understanding of the potential of water conservation, taking into account the impact on return flows, and the costs in relation to sectoral benefits. Using modelling and limited observational data we explore the costs and potential water savings of 24 combinations of water conservation measures in the Rufiji basin, Tanzania. We compare these costs with estimates of the value such water savings could generate from water use in three important economic sectors; agriculture, energy and downstream ecosystems with high tourism potential. The cost of water conservation measures (median: 0.07 USD m−3) is found to be: higher than the value of most uses of water for agriculture (growing crops in expanded irrigation sites) and the median value for hydropower generation (from a new mega dam currently under construction); and lower than the ecosystem value. Nevertheless, under our modelling assumptions, the volume of additional water required to supply planned irrigation expansion in the basin could be reduced by 1.5 BCM using water conservation methods that would be financially viable, given the value of competing uses of water. Water savings of this magnitude would reduce potential trade-offs between use of water for hydropower and ecosystem services, by allowing peak environmental flow releases even in dry years, and without reducing firm energy generation. This methodology is transferable and relevant for producing realistic assessments of the financial incentives for long-term sustainable water use in agriculture, given incentives for other uses. With most reservoirs now being built for multiple purposes improved understanding of trade-offs between different sectors and functions is needed.

Transforming potential waste materials into high-value-added sustainable materials with advanced properties is one of the key targets of the emerging green circular economy. Natural mica (muscovite) is abundant in the mining industry, which is commonly regarded as a byproduct and gangue mineral flowing to waste rock and mine tailings. Similarly, chitin is the second-most abundant biomass resource on Earth after cellulose, extracted as a byproduct from the exoskeleton of crustaceans, fungal mycelia, and mushroom wastes. In this study, exfoliated mica nanosheets were individualized using a mechanochemical process and incorporated into regenerated chitin matrix through an alkali dissolution system (KOH/urea) to result in a multifunctional, hybrid hydrogel, and film design. The hydrogels displayed a hierarchical and open nanoporous structure comprising an enhanced, load-bearing double-cross-linked polymeric chitin network strengthened by mica nanosheets possessing high stiffness after high-temperature curing, while the hybrid films (HFs) exhibited favorable UV-shielding properties, optical transparency, and dielectric properties. These hybrid designs derived from industrial residues pave the way toward sustainable applications for many future purposes, such as wearable devices and tissue engineering/drug delivery.

AbstractThe shift from straw incorporation to biofuel production entails emissions from production, changes in soil organic carbon (SOC) and through the provision of (co‐)products and entailed displacement effects. This paper analyses changes in greenhouse gas (GHG) emissions arising from the shift from straw incorporation to biomethane and bioethanol production. The biomethane concept comprises comminution, anaerobic digestion and amine washing. It additionally provides an organic fertilizer. Bioethanol production comprises energetic use of lignin, steam explosion, enzymatic hydrolysis and co‐fermentation. Additionally, feed is provided. A detailed consequential GHG balance with in‐depth focus on the time dependency of emissions is conducted: (a) the change in the atmospheric load of emissions arising from the change in the temporal occurrence of emissions comparing two steady states (before the shift and once a new steady state has established); and (b) the annual change in overall emissions over time starting from the shift are assessed. The shift from straw incorporation to biomethane production results in net changes in GHG emissions of (a) −979 (−436 to −1,654) and (b) −955 (−220 to −1,623) kg CO2‐eq. per tdry matter straw converted to biomethane (minimum and maximum). The shift to bioethanol production results in net changes of (a) −409 (−107 to −610) and (b) −361 (57 to −603) kg CO2‐eq. per tdry matter straw converted to bioethanol. If the atmospheric load of emissions arising from different timing of emissions is neglected in case (a), the change in GHG emissions differs by up to 54%. Case (b) reveals carbon payback times of 0 (0–49) and 19 (1–100) years in case of biomethane and bioethanol production, respectively. These results demonstrate that the detailed inclusion of temporal aspects into GHG balances is required to get a comprehensive understanding of changes in GHG emissions induced by the introduction of advanced biofuels from agricultural residues.