Kerstin Kuchta

Technische Universität Hamburg | TUHH · Institute of Environmental Technology and Energy Economy

Printing inks, composed of binders, pigments, and additives, are essential components in plastic packaging but complicate recycling due to plastic contamination and degradation. While polyolefins are resistant to hydrolytic degradation, moisture generated from upstream cleaning processes, which is often ignored, can accelerate the degradation of in...

Die stoffliche Verwertung von Abfällen (Recycling) ist eines der zentralen Elemente der Circular Economy und an der dritten Stelle der Abfallhierarchie angesiedelt. Abfälle zur Verwertung können aus verschiedenen Herkunftsbereichen stammen: Produktion und Verarbeitung, getrennt erfasste Abfälle aus privaten Haushaltungen und anderen Bereichen sowie...

This review covers the decomposition mechanisms of various printing ink binder resins, with a particular focus on their behavior under extrusion conditions in the mechanical recycling process of polyolefin (PO) based plastic packaging. Thermal degradation and hydrolysis of the nitrocellulose (NC) — the most used binder for flexographic surface prin...

The increase in carbon emissions is a growing concern for the sustainability in our society, particularly as energy consumption rises, leading to annual CO2 releases into the environment. The construction sector, responsible for utilizing a significant portion of the Earth's yearly extracted raw materials, significantly contributes to this issue. A...

Background The acceptance of compostable plastic packaging in industrial composting plants is not universal despite available certification due to the persistence of plastic residues after composting. To better understand this discrepancy, this study compared the disintegration rates of two blends designed for rigid packaging (polylactic acid based...

Concrete is recognized as the second most consumed materials in the whole world. Therefore, applying circular solutions to concrete, like recycling or reusing can guarantee a considerable benefits in terms of environmental impacts. In this paper, a comparative life cycle assessment is done for different recipes of recycled concrete aggregates in co...

The aim of this study was to characterize the municipal solid waste (MSW) in Nablus city in Palestine, while focusing on the plastic waste fraction. The plastic fraction—an environmentally problematic waste stream—was further characterized into the different polymer types and formats with the aim of suggesting feasible recovery and recycling soluti...

Background: The acceptance of compostable plastic packaging in industrial composting plants is not universal despite available certification due to the persistence of plastic residues after composting. To better understand this discrepancy, this study compared the disintegration rates of two blends designed for rigid packaging (polylactic acid base...

The increased use of bioplastics in the market has led to their presence in municipal solid waste streams alongside traditional fossil-based polymers, particularly low-density polyethylene (LDPE), which bioplastics often end up mixed with. This study aimed to assess the impact of cellulose acetate plasticized with triacetin (CAT) on the mechanical...

Despite the increased demand for resource recovery from spent lithium-ion batteries (LIBs), low Mn leaching efficiencies have hindered the development of this technology. A novel process was devised to enhance the dissolution of metals by producing citric acid using a molasses medium by Penicillium citrinum. This investigation used response surface...

One of the major applications (40% in Europe) of plastic is packaging, which is often printed to display required information and to deliver an attractive aesthetic for marketing purposes. However, printing ink can cause contamination in the mechanical recycling process. To mitigate this issue, the use of surfactants in an alkaline washing process,...

We propose a novel integrated model for the recovery of tantalum from tantalum-rich waste using a combination of hydrometallurgical and bio-metallurgical processes. To this end, leaching experiments with heterotrophs (Pseudomonas putida, Bacillus subtilis and Penicillium simplicissimum) were carried out. The heterotrophic fungal strain leached mang...

The ability of full-scale industrial plants to degrade bioplastics waste must be verified to exclude any negative effects on the quality of the process outputs. This study aims to assess the degradation of two thermoplastic cellulose acetate-based bioplastics, in pure and composite forms in both Anaerobic Digestion (AD) and Composting (C) industria...

Metals recovery from spent lithium coin cells (SCCs) is enjoying great attention due to environmental problems and metal-rich contents such as Mn and Li. Fungi can generate many organic acids, and metals can be dissolved, but sucrose is not an economical medium. The main objective of this study is to find a suitable carbon substrate in place of suc...

Only few studies on the behaviour of bioplastics in anaerobic co-digestion could be found in literature and most of them are conducted in batch mode. Despite the fact that continuous experiments confirm or add new insight to the findings acquired from batch ones, there is still lack of such studies. This work aims to cover this gap, carrying out a...

In recent years, an increasing trend towards replacement of conventional fossil-based plastics with bio-based plastics was noticed, i.e., production of plastics partly or fully made from biomass is rapidly expanding. Currently, bio-based and biodegradable plastics have a very small market size, approximately only 1% of all plastics produced. Howeve...

Low-density polyethylene is the most applied packaging plastic. The recycling rate of LDPE is low, especially for the material from the post-consumer source. The quality of the LDPE post-consumer recyclates is influenced by different contaminations, either intentionally or non-intentionally. Printing ink is one of the substances that is regarded as...

The incomplete degradation of bio-plastics waste is undermining the suitability of current anaerobic digestion (AD) and composting, opening up the exploration of new treatment routes, including mixed waste. Bio-plastics are treated with mixed waste in a mechanical-biological treatment (MBT) plant with the production of a dry fraction for incinerati...

Temperature control of outdoor photobioreactors is mandatory for stable microalgal growth rates. The large necessity of water and energy, however, imposes economic and ecologic drawbacks. A novel floating tubular photobioreactor, placed horizontally on a channel outdoors is presented in this study. It is equipped with a technology allowing variable...

Background: The acceptance of compostable plastic packaging in industrial composting plants is not universal despite available certification for compostability due to the persistence of compostable plastic residues reported by some industrial plants. This study aims to better understand this discrepancy by comparing the disintegration rate of two c...

We compared chemical and microbial leaching for multi-metal extraction from printed circuit boards (PCBs) and tantalum capacitor scrap. A mixed consortium of acidophiles and heterotrophic fungal strains were used in the experiments and compared to chemical leaching using specific acids (sulfuric, citric and oxalic acids). Under optimum conditions,...

Process optimization with Lean Six Sigma (LSS) has become more popular every day for years in almost every kind of industry. This integration has brought an even wider variety of possible application areas for industries and research institutes. Recently, the use of LSS for process optimization in biological fields has become more and more common....

The aim of this work is to assess how the presence of cellulose-based bio-plastics influence the biological stabilization of mixed Municipal Solid Waste (MSW). For the scope, two cellulose acetate bio-plastics have been mixed with a synthetic mixed waste to create samples with and without bio-plastics. A self-induced bio-stabilization has been carr...

Manganese is extensively used in various advanced technologies. Due to high manganese demand and scarcity of primary manganese resources, extracting the metal from spent batteries is gaining increasing interest. The recycling of spent batteries for their critical metal content, is therefore environmentally and economically feasible. The conventiona...

Although the benefits of the Lean Six Sigma (LSS) methodology have been proven for more than 20 years, it is still underutilized in environmental science, (e.g., in anaerobic digestion and biogas production). In order to obtain a structural and data-oriented perspective for process optimization in the renewable energy sector, LSS application must b...

Despite the economic and environmental significance of recovering plastics from e-waste, the presence of contaminants (in the form of chemical substances) strongly limits the recycling of this waste stream. Some chemical substances are controlled by international or European guidelines and policies, which are continuously updated to control new sub...

ERA-MIN 2 ist das größte paneuropäische Netzwerk öffentlicher Forschungsförderorganisationen im Bereich Rohstoffe. Es handelt sich um eine öffentlich-öffentliche Partnerschaft von 21 Partnern aus 18 Ländern/Regionen aus der EU und von anderen Kontinenten (Argentinien, Brasilien, Chile und Südafrika). Im Rahmen des Projekts wurde 1) eine vollständig...

The use of bio-plastic-based packaging as an alternative to conventional plastic packaging is increasing. Among the plethora of different bio-based plastics, the most relevant ones are those that, at the end of their life, can be treated with the organic fraction of municipal solid waste. Even in these cases, their impact on the waste processing an...

Finding a sustainable approach for municipal solid waste (MSW) management is becoming paramount. However, as with many urban areas in developing countries, the approach applied to MSW management in Karachi is neither environmentally sustainable nor suitable for public health. Due to adoption of an inefficient waste management system, society is pay...

Process optimization is no longer an option for processes, but an obligation to survive in the market in any industry. This argument also applies to anaerobic digestion in biogas plants. The contribution of biogas plants to renewable energy can be increased through more productive systems with less waste, which brings the common goal of minimizing...

Open disposal is the most common technique used for municipal solid waste (MSW) manage-ment due to the absence of sanitary landfills in Pakistan. The major cities and small towns in Pa-kistan have become a showcase of negligence and mismanagement of MSW, which results in deterioration of the environmental and social-life quality. Moreover, research...

Temperature management is one of the primary considerations of biogas plant operation, and influences physical and biochemical processes. An increase in the temperature leads to an increase in the hydrolysis rate of the feedstock, while it can inhibit microorganisms taking part in different stages of anaerobic digestion. Because of the complexity o...

The use of aquatic biomass such as algae, macrophytes, or submerged macrophytes as raw material for biogas production has numerous technical and biological advantages. In addition, synergy effects can be exploited taking into account the implementation of biogas systems in urban areas, and coupling between the production of aquatic biomass, biogas...

This study has the aim of analysing the degree of contamination of recycled polyolefin purchased from the market by focusing on the content of polycyclic aromatic hydrocarbons (PAHs). Additionally, the impact of the mechanical recycling process on the polyolefin chemical quality was investigated. Results indicated that recycled polyethylene (PE) ha...

The increasing consumption of plastics and plastic products results in correspondingly substantial volumes of waste, which poses considerable environmental burdens. With the ongoing environmental actions, the application of circular economy on this waste stream is becoming inevitable. In this paper, the topics of plastics recycling, circular econom...

This work is aimed at exploring the recovery of heavy metals from the fine fraction of solid waste incineration bottom ash. For this study, wet-discharged bottom ash fine-fraction samples from full-scale treatment plants in Germany and Sweden were analyzed. The potential for the recovery of heavy metal compounds was investigated through wet density...

Polymers are employed in agriculture in several applications, the most efficient and fruitful of which is the protection of cultivations through the use of cover placed over plants while they are growing, providing protection from climatic factors, while at the same time increasing yield and/or extending the cropping season. Plastic films used for...

In 2018 municipal solid waste (MSW) incineration in Europe produced nearly 19 Mt of bottom ash (BA); only 46 %-wt. was treated, often in poorly performing plants, leaving behind 10 Mt of untreated and unrecovered BA, destined to landfill. This work was based on the inventory of BA across Europe, and on the hypothesis to achieve complete BA valorisa...

Setting up strategies for a sound management of plastic packaging waste (PPW) is becoming increasingly crucial at many levels of the value chain in Europe. After the very first implementation of an extended producer responsibility scheme in Germany in 1991, many EU Countries followed. This resulted in a complex network of schemes that differ from o...

The main obstacle to bottom ash (BA) being used as a recycling aggregate is the content of salts and potential toxic elements (PTEs), concentrated in a layer that coats BA particles. This work presents a dry treatment for the removal of salts and PTEs from BA particles. Two pilot-scale abrasion units (with/without the removal of the fine particles)...

This study aims at defining the current state-of-affairs of the German post-consumer plastic packaging (PCPP) sector. By the use of the Material Flow Analysis (MFA) tool, a comprehensive investigation of the currently available PCPP waste collection and treatment system is conducted, which enables understanding the intrinsic inefficiencies of the w...

This work aimed to estimate the annual methane production from the municipal solid waste disposal sites in Pakistan. In this study, the Intergovernmental Panel on Climate Change (IPCC) default methodology was used to estimate theoretical methane formation potential of the waste disposal sites in major cities of Pakistan. The estimates of this study...

Sustainable completion of municipal solid waste landfills requires post-closure care after a time when utilization of landfill gas produced from biodecomposition of organic waste be not possible/or economically feasible. Research proved that in-situ aeration is a promising approach employed for landfill aftercare. The application of post aeration o...

In the biogas plants, organic material is converted to biogas under anaerobic conditions through physical and biochemical processes. From supply of the raw material to the arrival of the products to customers, there are serial processes which should be sufficiently monitored for optimizing the efficiency of the whole process. In particular, the ana...

Municipal solid waste (MSW) generation rate in Asian cities is exponentially increasing with rise in urbanization and commercial activities. Beside this, the cities in developing Asia are deficient in adequate waste management and facing energy shortage as well. The ineffectual waste management practice is one of the main causative factors behind t...

Sustainable management of municipal solid waste is one of the major challenges for authorities in developing countries. Current waste disposal methods in Pakistan and other developing countries are not meeting standards of any proper waste management system opted for in the developed world. This mismanagement of waste is leading to serious environm...

Sustainable management of municipal solid waste is one of the major challenges for authorities in developing countries. Current waste disposal methods in Pakistan and other developing countries are not meeting standards of any proper waste management system opted for in the developed world. This mismanagement of waste is leading to serious environm...

In this research, the degree and source of recyclates contamination with polycyclic aromatic hydrocarbons (PAH) was studied in eight different polyolefin recyclate samples; four originating from post-consumer packaging waste and four originating from a mixed source (post-industrial, post-commercial, and post-consumer). The aim was to assess the app...

In 2018, the production of Municipal Solid Waste (MSW) in EU-28 reached 250.6 Mt, with the adoption of different management strategies, involving recycling (48 wt %), incineration and thermal valorization (29 wt %) and landfilling (23 wt %). This work was based on the analysis of the baseline situation of MSW management in EU-28 in 2018, considerin...

Rare earth elements (REEs) are commercially used in an increasing number of critical or widely popular consumer and industrial products. Neodymium (Nd) element has emerged in recent years as one of the most critical REE, due to risks associated with its security of supply at required amounts. It has been widely reported that end of life (EoL) consu...

The biogas production technology has improved over the last years for the aim of reducing the costs of the process, increasing the biogas yields, and minimizing the greenhouse gas emissions. To obtain a stable and efficient biogas production, there are several design considerations and operational parameters to be taken into account. Besides, adapt...

Due to the lack of advanced methods to clean plastic waste from organic contaminants, this study aimed at evaluating supercritical extraction as a decontamination method. Oil-adhesive high-density polyethylene (HD-PE) oil containers were subjected to supercritical extraction using supercritical carbon dioxide. The extraction was conducted at 300 ba...

Plastic waste production around the world is increasing, which leads to global plastic waste pollution. The need for an innovative solution to reduce this pollution is inevitable. Increased recycling of plastic waste alone is not a comprehensive solution. Furthermore, decreasing fossil-based plastic usage is an important aspect of sustainability. A...

The reduction of resource requirements for the outdoor cultivation of Chlorella sorokiniana using 180 L flat panel photobioreactors through medium recycling was investigated in this study. Without medium recycling, algae grew in 13.6 d from 0.92 to 5.32 gL-1with a productivity of 0.32 gL-1d-1. For the production of 748 g algae dry weight (DW), 152...

The study examines the effect of temperature fluctuations on biogas production efficiency in biogas plants with the aim of evaluating the temperature flexibility of the process. Laboratory scale batch reactors were prepared with the chosen sub- strate (Dried Distillers Grains with Soluble, DDDS) and the study was conducted in three batches. A bioga...

The aim of this study is to provide an evaluation of the recyclability of plastics derived from electrical equipment from contamination standpoint. A database was created to find trends in potentially toxic elements (PTEs) and bromine concentrations; in relation to unit's application, color, polymer type, and production date. For this study, 142 kg...

This work has two aims. Firstly, to validate the ability of experimental models derived through near infrared spectroscopy for acrylonitrile butadiene styrene (ABS), low-density polyethylene (LDPE), polyethylene ter-ephthalate (PET), and polypropylene (PP) in predicting polymers' aging; focusing on the degree of oxidation. Secondly, to assess the r...

This work has investigated the effect of stirring on the performance of two anaerobic digesters for a period of six years. In each digester, two propellers and one hydro-mixer were installed. Five different stirring scenarios were tested and adopted for this large scale biogas plant. Agricultural residuals were used as feedstock for this biogas pla...

The study examines the effect of temperature fluctuations on biogas production efficiency in biogas plants with aiming to evaluate temperature flexibility of the process. Laboratory scale batch reactors were prepared with choosen substrate (Dried Distillers Grains with Soluble) and study was conducted as three batches. Biogas formation potential te...

Municipal solid waste (MSW) production in EU concerned around 250 Mio. Mg in 2017, with the adoption of different management strategies within the member states. Waste framework directive and current Circular Economy strategy forced the acknowledgement of sustainable waste management as a main priority from the economic, social and environmental vi...

The recycling network of post-consumer plastic packaging waste (PCPPW) was studied for the Netherlands in 2017 with material flow analysis (MFA) and data reconciliation techniques. In comparison to the previous MFA of the PCPPW recycling network in 2014, the predominant change is the expansion of the collection portfolio from only plastic packages...

Agrochemical containers shall undergo decontamination before being considered for recycling. This study provides an assessment on the feasibility of the triple-rinsing decontamination procedure, while evaluating the appropriateness of the material's quality for recycling. To achieve the objectives of the study, (1) the effectiveness of the decontam...

In this study antimony concentration was analyzed in 30 plastic items (from polyethylene terephthalate (PET) bottles and e-waste) directly by X-ray fluorescence spectroscopy (XRF) spectroscopy. PET samples were digested in a microwave oven with aqua regia. The plastic components deriving from e-waste followed three parallel routes: 1. microwave dig...

The aim of this research is a preliminary assessment of antimony concentration in plastic fractions deriving from different e-waste. We considered microwave ovens, desktop computers, laptops, mobile phones, a TV case, a PC monitor and LED lamps (63 items in total). The plastic fraction ranged from 8%-wt in computers and microwave ovens, up to 40%-w...

Agriculture, one of the main economic pillars in Europe, plays a growing important role towards the environmental sustainability of the extra-urban land, in which the agricultural activities may proactively contribute to control and regulate the whole ecological conditions. Modern agriculture currently needs big quantities of agrochemicals, which a...

In view of the global environmental situation, the increasing need for energy and resources in the data centers will continue to pose new challenges for companies and politics. Despite significant efficiency gains, the energy and resource requirements of data centers in Germany are expected to increase by more than 50% by 2030. In 2018, the more th...

In biomethane potential (BMP) tests, different sources and origins of inocula might cause significant variations in the tests’ results, preventing from acquiring a harmonised and standardised evaluation of the different substrates. In this study, a method to produce standardised and storable inocula was elaborated. For the development of the differ...