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Correction: Environmental Earth Sciences (2023) 82:143 https://doi.org/10.1007/s12665-023-10806-5Sustainability for all? The challenges of predicting and managing the potential risks of end-of-life electric vehicles and their batteries in the Global South (vol 82, 143, 2023)

The transition from fossil-fuel-based internal combustion vehicles to electric vehicles plays a key role to decarbonize road transport and mitigate climate change. Even though this transition is still in its infancy, it is important to consider not only its environmental benefits but also its potential side effects. Recent projections estimate that the current electric vehicle fleet is expected to increase from 2.4 million in 2020 to over 81 million in 2050, when more than half of all new cars sold are predicted to be battery-electric vehicles (BEVs). End-of-life (EOL) BEVs and their components (particularly the batteries) are far more challenging to manage than their fossil-fueled predecessors as they contain large amounts of chemical substances that constitute potential hazards to the environment and human health and safety. The paper discusses relevant topics for understanding future risks of transition to electric mobility in the Global South countries, which include the internationally used vehicle fluxes; waste management challenges for EoL BEV and its lithium-ion batteries (LIB); environmental and human health impacts of EoL LIBs disposal and policies and regulations for the e-vehicle life cycle. Recommendations to support the development of science-based policies to close regulation gaps of the used electric vehicle international trade flow, avoid pollution-shifting and guarantee a sustainable transition to e-mobility in the Global South countries are given. As a conclusion, an integrated approach from international and national stakeholders is fundamental to guarantee strong policies and regulations as well as to support the development of a sound management of EoL EV and LIBs in the Global South countries and help pave the way to a global circular economy.

The concept of circular economy supports mitigation of climate change and other environmental pressures to the planet. Circulating materials in anthropogenic processes come with the risk of accumulating hazardous substances and compounds. In this concept, waste incineration or waste-to-energy (WtE) is a necessary technology to remove these compounds from the life cycle. In this mini-review, contaminants of major importance in the flue gas from waste incineration plants and their environmental impact are discussed. Air pollution of WtE is often seen as the most relevant environmental impact of this treatment option. The emission values parameter set for different countries is presented and compared. The most stringent legally set of emission values could be found in parts of Europe and South Korea. Japan also permits similar strict values when authorising individual incineration plants. In North America, the values are partially less strict as the best available technologies in Europe suggest being possible. Emerging economies, such as India and China, have shown efforts to improve their environmental protection standards but still have room to improve. This could be set in relation to other industrial emitting processes and therefore could be used to assess the relevance of this industry sector to the national emission inventories.

Plastic pollution is one of the significant environmental concerns due to the threefold increase in global plastic waste. Marine microplastics, including petroleum-based plastic pieces and synthetic and artificial fibers smaller than 5 mm, are not only ubiquitous in natural water but also high in wastewater streams due to the direct discharge, transfer and breakdown of plastic items. This research aims to investigate the presence and dispersion of microplastics in the downtown area and coastal suburban area of Ho-Chi-Minh City by using Raman microscopy. As a result, the most common plastics (PE, PET, PA, PP, PVC, PS and PMMA) were detected, and most of them were fibrous shorter than 500 μm. The total microplastics decreased gradually from the urban waterborne (up to 220 MPs/L) via Can Gio UNESCO Mangrove Biosphere Reserve (10 MPs/L) and to the East Sea (3 MPs/L), which reveals the potential role of the mangrove in reducing marine contaminants including microplastics. This study provides important insights into microplastic pollution in the Western Pacific Region, especially the Saigon-Dong Nai river systems, supporting useful data for natural water resources management.

Plastic pollution is one of the significant environmental concerns due to the threefold increase in global plastic waste. Marine microplastics, including petroleum-based plastic pieces, synthetic and artificial fibers smaller than 5 mm, are ubiquitous in natural water environments due to the degradation of plastic products and wastes. This research aims to investigate the microplastic presence in urban and coastal environments in the Southeast regions of Vietnam by using Raman microscopy. As a result, most common plastics (PE, PET, PA, PP, PVC, PS and PMMA) were detected, and most of them were fibrous smaller than 500 µm. The total microplastics decreased gradually from the urban waterborne (up to 220 MPs/L) via Can Gio UNESCO Mangrove Biosphere Reserve (10 MPs/L) and to the East Sea (3 MPs/L), which reveals the potential role of the mangrove in reducing marine contaminants including microplastics. This study provides important insights about microplastic pollution in the Western Pacific Region, especially Saigon-Dong Nai river systems, supporting the useful data for natural water resources management.

Biomass like poultry manure and sewage sludge have high nitrogen and chemical oxygen demand (COD) concentrations. This can cause disturbances in the anaerobic digestion process, by ammonia as well as accumulation of volatile fatty acids (VFA). Therefore, the target is to develope a high-performance methane stage for mesophilic monofermentation of these substrates. Hence a stepwise increase of the reactors, trickle bed reactor (RB), upflow anaerobic sludge bed reactor (UASB), and anaerobic filter reactor (AF) was done. To adapte the microorganizmen to nitrogen and organic loads plastic pellets have been adapted in RB and AF. The UASB enriches biomass by forming natural pellets through accumulation of the microorganism and the subsequent sedimentation. Altogether, to find out the weakness in the acetogenesis/methanogenesis the feeding process was done with a model substrate, which presents a hydrolyzate. With this one a stable process was determined for organic loads of 15.04 [kgCOD/m³*d] in RB and AF. So far, the UASB haven't reached a stable performance. Allover, there wasn't a significant linear correlation between ammonia and the biogas production detectable. The adaption of biomass through the stepwise increase of the organic loads, the immobilization of biomass as well as the reactor type influenced the process stability.

This work demonstrates the suitability of nitrogen removal during anaerobic acidification in batch configuration for a more efficient pre-treatment of chicken manure prior to anaerobic digestion. High loading rates corresponding to a total nitrogen input between 6.3 and 9.5 g L−1 allowed successful suppression of methanogenic archaea. To eliminate nitrogen, NH3-stripping and MAP (magnesium ammonium phosphate hexahydrate) precipitation were compared. In spite of decreased cell quantities detected using qPCR, removal of nitrogen caused an increase in volatile fatty acid (VFA) formation from 13 to 19%. The highest nitrogen removal during acidification (up to 29%) was achieved with three consecutives MAP precipitation steps, however, conductivity values were affected too, reaching 53.3 and 53.1 mS cm−1 after the three consecutive MAP precipitations. Additionally, MAP-precipitation reduced the concentration of important trace elements and 16S-rRNA amplicon sequencing revealed an altered taxonomic pattern, in which especially the bacterial families Marinilabiliaceae, Bacteroidales UCG-001, M2PB4-65 termite group and Idiomarinaceae were impaired. However, in spite of these inhibitory effects, nitrogen removal proved able to prevent unwanted methanogenesis and to enhance the yield of VFAs, and this strategy thus holds great potential for the optimized production of biogas in a two-phase system., We are thankful for the funding received from the German Ministry of Economic Affairs and Energy (grant no. 16KN041338, 16KN041342, 16KN041339 and 16KN041341).

Jeder EU-Staat zahlt seit diesem Jahr für jedes Kilo nicht recycelten Verpackungsabfalls aus Kunststoff eine Abgabe an die EU. Der Sachverständigenrat für Umweltfragen (SRU) hat Vorschläge, wie sich die Menge an Kunststoffabfällen deutlich senken lässt.

In our research, we have studied smallholder farmers in degraded farming systems in Northwest Tanzania and have compared them with farm households who were trained in sustainable land management by a local Farmer Field School. Both groups of farmers were affected by severe environmental degradation and poor soil fertility, but trained farmers have transformed degraded farmland into fertile, multi-functional land use systems. In this presentation, we discuss the successes and failures of both groups of farmers and draw conclusions towards restoring degraded land use systems. Farmers without training cannot restore degraded farmland with traditional agricultural management alone and fail to produce enough food, fodder, biofuel, and timber to support the whole family. The reasons for their failure are manifold and include environmental and socio-economic dimensions, e.g., poor management of soils and farm waste, lacking adaptation to climate change, traditional gender roles, and the loss of knowledge and labour in HIV/AIDS-affected households. In comparison, trained farmers change nutrient management by using advanced composting techniques. They also cultivate a greater variety of crops and trees, introduce organic pesticide management, ease manure collection, construct vegetable gardens that are watered by drip irrigation in the dry season, change gender roles and communication structures. The main differences between both groups of farmers occur in food security, health status, education level, marketing, income generation, prosperity, and gender-related responsibilities. However, the full potential of organic farm waste being used as soil fertiliser is not exhausted, as human excreta is not integrated into nutrient management. Farm households who are most vulnerable to food security, e.g., female-headed and HIV/AIDS-affected households, need to get support in strengthening their socio-economic base before transforming the farm management. In conclusion, local Farmer Field Schools significantly contribute to restoring land degradation. To transform smallholder agriculture in Tanzania, a joint partnership with local governmental organisations could help farmers to escape poverty and become food secure (SDG 1 and SDG 2). Similar approaches could support smallholder farmers in East Africa, where they contribute to three-fourth of the agricultural production.

Anaerobic digestion is a technology known for its potential in terms of methane production. During the digestion process, multiple metabolites of high value are synthesized. However, recent works have demonstrated the high robustness and resilience of the involved microbiomes; these attributes make it difficult to manipulate them in such a way that a specific metabolite is predominantly produced. Therefore, an exact understanding of the manipulability of anaerobic microbiomes may open up a treasure box for bio-based industries. In the present work, the effect of nalidixic acid, γ-aminobutyric acid (GABA), and sodium phosphate on the microbiome of digested sewage sludge from a water treatment plant fed with glucose was investigated. Despite of the induced process perturbations, high stability was observed at the phylum level. However, strong variations were observed at the genus level, especially for the genera Trichococcus, Candidatus Caldatribacterium, and Phascolarctobacterium. Ecological interactions were analyzed based on the Lotka–Volterra model for Trichococcus, Rikenellaceae DMER64, Sedimentibacter, Candidatus Cloacimonas, Smithella, Cloacimonadaceae W5 and Longilinea. These genera dynamically shifted among positive, negative or no correlation, depending on the applied stressor, which indicates a surprisingly dynamic behavior. Globally, the presented work suggests a massive resilience and stability of the methanogenic communities coupled with a surprising flexibility of the particular microbial key players involved in the process.

Solid waste composting has never been practised on a full scale in Jordan. However, the National Solid Waste Management Strategy recommended five major composting facilities to be put into operation starting from 2025. According to the Ministry of Environment, the waste sector is contributing to 10.6% of the total greenhouse gas emissions of the country. The main objective of this study was to assess the potential of solid waste composting in mitigating greenhouse gas emissions in Jordan. Applying the upstream-operating-downstream account framework and developing a model that estimates the greenhouse gas emissions, it was possible to estimate the emissions associated with composting of source-segregated bio-waste, which was compared with three other scenarios, including business as usual (dumping and landfilling), sanitary landfilling, and anaerobic digestion. The assessment revealed that composting and anaerobic digestion of the total generated source-segregated bio-waste (Scenarios 3 and 4) have the least net greenhouse gas emissions with 1.1 million Mg CO2-eq y-1, while engineered sanitary landfilling and dumping have net emissions of 2.6 and 3.75 million Mg CO2-eq y-1, respectively. The findings of this research are paving the way to make informed and responsible decisions in the Jordanian solid waste sector to adopt sustainable and integrated management options.

Trimethylbenzene (TMB) isomers (1,2,3-TMB, 1,2,4-TMB, and 1,3,5-TMB) are often used as conservative tracers in anaerobic, contaminated aquifers for assessing BTEX (benzene, toluene, ethylbenzene, xylenes) biodegradation at field sites. However, uncertainties exist about the behavior of these compounds under anaerobic conditions. For this reason, the influence of various parameters (temperature, residence time) on the biodegradability of TMB isomers was investigated under denitrifying and sulfate-reducing conditions in microcosms and 1D-column experiments. Soil and groundwater contaminated with a cocktail of aromatic hydrocarbons including the TMB isomers, both collected from an industrial site in Berlin, Germany, were used for the laboratory investigations. A continuous and complete biodegradation of 1,3,5-TMB and 1,2,4-TMB under denitrifying conditions was observed independent of realized temperature (10&ndash, 20 &deg, C) and residence time. Biodegradation of 1,2,3-TMB started after longer lag-phases and was not continuous over the whole experimental period, a strong dependence on temperature and residence time was identified. The biodegradability of all TMB isomers under sulfate-reducing conditions was continuous and complete at higher temperatures (20 &deg, C), whereas no degradation was observed for lower temperatures (10 &deg, C). First-order biodegradation rate constants ranged from 0.05 to 0.21 d&minus, 1 for 1,3,5-TMB and 1,2,4-TMB and from 0.01 to 0.11 d&minus, 1 for 1,2,3-TMB.

Nachhaltige Abfallwirtschaft als Bestandteil des Ressourcenmanagements bedarf klarer Ziele und Prioritaten. Wahrend der Umgang mit Abfallen in vielen Entwicklungs- und Schwellenlandern ein erhebliches Gesundheitsrisiko darstellt, haben Industrielander hygienische Ziele der Abfallwirtschaft gesetzlich vorgegeben und weitestgehend erreicht. Nachhaltige Abfallwirtschaft in Industrielandern wie Deutschland muss sich auf die Aufgabe konzentrieren, die richtigen Verbindungen zwischen Abfallen und Ressourcen zu schaffen. Um in Deutschland die Rohstoffversorgung langfristig sichern zu konnen, ist die Nutzung von Sekundarrohstoffen ohne Alternative. Die Nutzung von Abfallen wird politisch haufig mit der Ressourceneinsparung ohne Rucksicht auf die Wertigkeit der jeweiligen Ressourcen, auf den damit jeweils verbundenen okologischen und okonomischen Aufwand und auf die notwendige Qualitat von Sekundarrohstoffen durch pauschale Recyclingquoten gleichgesetzt. Vielmehr sollten Qualitaten im Vordergrund stehen. Dafur stellt die getrennte Sammlung von Wertstoffen aus Siedlungsabfallen neben ihrer moglichst nicht umweltbelastenden Verwertung eine entscheidende Stellschraube dar. Bis heute sind im Siedlungsabfall noch erhebliche Mengen an interessanten Wertstoffen enthalten. Die Abfallwirtschaft ist bisher vor allem ordnungsrechtlich gepragt. Okonomische Anreize zur Schliesung von Stoffkreislaufen geraten aber inzwischen immer mehr in den Fokus, da sich Moglichkeiten zu einem nachhaltigeren Ressourcenmanagement ergeben. Im Sinne nachhaltigen Denkens sollte die Abfallwirtschaft in erster Linie Materialien bzw. Produkte ruckgewinnen, die eine moglichst grose okonomische, soziale, okologische und strategische Bedeutung haben. Diese wird anhand der geostrategischen, der okologischen und der sozialen Dimension der Nachhaltigkeitsanalysen diskutiert, die strategische Dimension beinhaltet zudem die internationale Konkurrenz um Rohstoffe.

Process instability commonly encountered in anaerobic co-digestion (AcoD) of organic fractions of municipal solid wastes (OFMSWs) is addressed by utilizing hydrochar (CB-HTC) and activated hydrochar (ACB-HTC) derived from coffee ground biomass. Addition of CB-HTC or ACB-HTC shortened the lag phase resulting in high biogas yield of 68.57 Nl/kg oTS or 102.86 Nl/kg oTS, respectively within the first week. Improvement in biogas yield (~5% higher than the control) was due to unique properties which prevented washout of consortia of bacteria useful for AcoD and subsequently led to a more stable process. An increase in either OLR [1.0 kg oTS/(m3*d) to 1.5 kg oTS/(m3*d)] or temperature (36.5 °C to 42.5 °C) did not lead to increase in ammonium-nitrogen or TKN in reactors amended with hydrochars. Likewise, ratio of VFA/TA was within 0.2–0.3 after the fourth week in ACB-HTC treated reactor. Addition of ACB-HTC greatly improved nutrient retention in the digestate.

This study examines how smallholder farmers operate degraded banana-coffee-based farming systems and apply organic farm waste. We surveyed 150 farm households in two districts of the Kagera region in north-west Tanzania (Karagwe and Kyerwa districts). An expert-based typology revealed three groups of farm households that differ in biomass production (high, moderate, low). Households producing high amounts of biomass have integrated a sophisticated farm waste management system, but do not exploit the full potential of organic farm waste as a soil fertiliser and conditioner. The integration of farm waste management decreases in farm households with medium and low biomass production. None of the households is food secure, as they experience seasonality in food production and lack food storage technologies. In farm households with high and medium biomass production, the optimised use of organic farm waste could potentially lead to food security if food storage capacities were also improved. However, farm households with low biomass production will not become food secure with the introduction of organic farm waste management alone, as the land size is too small, and the socio-economic basis for it is lacking. Limited labour remains a major restriction to improving farm waste management. In the future, the safe use of human excreta needs to be fostered in engineering and research, holistic material flow analyses integrating (low-tech) agricultural solutions and concepts investigated, e.g., biochar production, safe use of mineral fertiliser and climate-smart agriculture, and the socio-economic status of female-headed households strengthened, e.g., in farmer field schools and governmental programmes.

The biogas technology is a promising approach for the recovery of energy and fertilizer from municipal organic waste (MOW). However, only scarce information on the development of initial nutrient and heavy metal loads during processing is available. Therefore, this study investigates properties of source-separated MOW during treatment in a semi-industrial scale two-stage biogas plant and subsequent digestate composting including impurities removal. Data from 15 batch experiments was investigated by material and substance flow analysis. Results of this study have shown that about 40% of nutrients contained in the MOW inflow are mineralized during anaerobic and subsequent aerobic treatment. A higher nutrient release was observed during the anaerobic treatment step. Additionally, impurities removal causes a significant reduction of final nutrient content. Heavy metal analysis confirmed a high heterogeneity of contamination levels. However, digestion and composting do not seem to significantly impact on total heavy metal loads in the substrate flow.

In the past waste management proved to reduce CO2 emissions both by reuse of recyclables and energetic utilization of substrates with high available energy load. This paper provides an overview about biomass originating from waste. Therefore the biogenic waste fractions are classified by origin. In this manner one can separate the origin of biomass in forestry, agriculture, landscape maintenance, municipal solid waste and industrial waste. Subsequent chemical and physical parameters were described to assess the applicability for thermal utilization as well as for the production of biokerosene. The focus is on calorific values, ash and water content as well as on inhibiting parameters such as sulfur, nitrogen and heavy metals. Based on this, the second part of this paper describes the energy potential of the ubiquitous occurring biomass originating from waste. Therefore the incidence of each waste fraction is related to a specific energy potential respectively calorific value. Due to this the theoretical applicability of waste as feedstock for the production of biokerosene can be assessed.

Municipal organic waste (MOW) is a promising feedstock for biogas plants and separate collection will increase available quantities. To close nutrient circles digestates shall be redistributed to arable land. However, less is known about digestate properties and how they are influenced during digestion. Therefore, changes in nutrient and heavy metal concentration in the solid digestate were investigated during anaerobic treatment of MOW in a two-stage laboratory biogas plant. Results show that the solid digestate is exposed to element accumulation, except for N, P and Mg. The loss of initial N, P and Mg load accounts up to 45%, which must be redistributed elsewhere in the digester system. K load of feedstock was completely rediscovered in the solid digestate. Heavy metal concentration in the digestate increases by factor 1.6 at average. The results emphasize that element retention in the digester system has a decisive impact on nutrient content of digestates.

The application of organic soil amendments is a common measure to prevent structural degradation of agricultural soils and to maintain and improve long-term soil fertility. Solid residues from anaerobic digestion of municipal organic waste (MOW) are rich in nutrients and organic matter and have a promising potential to be used as soil amendment. However, no study has related amendment properties of MOW digestate of one origin to different treatment procedures. We therefore investigated the impact of drying, composting and sieving on final digestate properties and specifically nutrient availability and heavy metal and carbon elution. Samples were provided by a semi-industrial two-stage biogas plant with dry fermentation of MOW. Results confirm that in comparison to drying, composting of MOW digestates leads to a significant increase of K, P, Mg, Ca, Cd and Cr in the digestates. Sieving of composted digestates showed that heavy metals are not evenly distributed and that heavy metal concentration in the digestate increases with decreasing mesh sizes (highest concentrations in the fractions1 mm). Although the element concentration is higher in composted batches, the water-extractability of nutrients, heavy metals and carbon is significantly lower from composted over dried digestates. A significant correlation was found between the dissolution of Zn, Ni, Ca and Mg and pH of eluate as well as dissolved organic carbon (DOC) release (R0.7, p0.05). Results confirm that the extent of carbon elution depends on the degradation rate of digestates. DOC may therefore be a good measure to evaluate digestate stability and to decide on treatment measures.

There is global consensus for developing a circular economy and building green societies. As the two leading countries in their regions in this field, both China and Germany want to reduce the environmental impacts of waste and avoid the programme of “NIMBY” and have accumulated much experience in waste reduction and gradient utilisation of waste. “Pay As You Throw”, “Green Dot” system and “trade in policy (the new for old policy)” have all proven to lead to higher recycling rates and the minimisation of waste in the past 30–40 years. The article shows how German waste legislation developed to achieve the actual recycling rates. Though Germany follows the European laws, above this it has set a number of even stricter requirements, which are summarised in this paper. The main strategies for implementing source separation are described, while potentials are detected for certain waste fractions like plastics and textiles.

Biogas aus erneuerbaren Rohstoffen kann entweder zur Erzeugung von Strom und Warme vor Ort genutzt oder uber eine Aufbereitungsanlage zu Biomethan weiterverarbeitet werden. Die entsprechenden Techniken stehen zur Verfugung und sind im Markt eingefuhrt. Bei allen Prozessschritten ist darauf zu achten, dass die Emissionen von Methan bzw. kritischen Nebenprodukten minimiert werden. Da der Neubau von Biogasanlagen auf Basis von Gulle und nachwachsenden Rohstoffen nach Kurzung von Subventionen im EEG kaum noch okonomisch sinnvoll zu realisieren sind, richtet sich die Aufmerksamkeit auf bisher noch in geringem Umfang genutzte Siedlungs- und Industrieabfalle. Hier muss die Qualitat von der Sammlung der Bioabfalle uber die Vergarung bis zur Biogasherstellung sichergestellt werden. Eine Erganzung der bestehenden Kompostierungsanlagen durch vorgeschaltete Vergarungsstufen, eine Ausdehnung der getrennten Sammlung von Bioabfallen und die Verringerung der Investitionskosten fur solche Anlagenkombinationen konnten zu einem neuen Schub fur die Produktion von Biogas bzw. Biomethan fuhren. Die Vermarktung auf regionaler Ebene bietet interessante Chancen fur einen „Biomassekreislauf“ und fur die dezentrale Energieerzeugung aus erneuerbaren Ressourcen.