Browsing by Author "Leverenz, Dominik"

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Open Access
Environmental impacts on soil and groundwater of informal e-waste recycling processes in Ghana
(2024) Owusu-Sekyere, Karoline; Aladago, David Alatule; Leverenz, Dominik; Oteng-Ababio, Martin; Kranert, Martin
This study examines the environmental impacts of informal e-waste recycling processes in Agbogbloshie, Ghana, which is one of the most notorious e-waste recycling sites in sub-Saharan Africa. Despite being unsafe and unorganized, the informal sector is still actively involved in dismantling, extracting, and disposing of e-waste in unauthorized locations on a considerably large scale. However, the academic research on the environmental consequences of informal recycling practices is limited. Soil and groundwater samples for five important and representative informal e-waste recycling processes and one related oil process were collected and analyzed to determine heavy metal-, PBDEs, PCBs, CBs, and PAHs concentrations. Contamination indices were used to assess and compare the effects of informal recycling processes, thereby providing a geochemical evaluation of soil conditions. As a result, the manual dismantling of CRT and ICT devices is the major source of heavy metal pollution. Furthermore, the burning of e-waste plastic for waste reduction purposes and the oil collection process substantially contribute to the input of organic pollutants. Regulatory measures for CRT and ICT recycling would result in an 85% reduction of heavy metals and the enforcement of a compulsory collection system for plastic and oil would eliminate 86% of the organic pollutants.
Open Access
Food waste generation in Germany in the scope of European legal requirements for monitoring and reporting
(2021) Leverenz, Dominik; Schneider, Felicitas; Schmidt, Thomas; Hafner, Gerold; Nevárez, Zuemmy; Kranert, Martin
The European Commission and the German government are committed to the United Nations SDG target 12.3 of reducing food waste along production chains and halving it at retail and consumer levels by 2030. European member states are required to monitor national food waste levels and report annual progress to the European Commission from 2020 onward. In this regard, the main objective of our study is to provide food waste quantities for Germany by applying methods meeting the legal requirements for monitoring and reporting within Europe-wide harmonized methodology. Our results refer to 2015 and are based on the best available data, using a combination of official statistics, surveys, and literature. We found that approx. 11.9 ± 2.4 million tonnes (144 ± 28 kg/(cap·year)) of food waste were generated in Germany, while the reduction potentials varied throughout the different sectors. Even though the underlying data show uncertainties, the outcome of the study represents a starting point for the upcoming monitoring activities in Germany by uncovering data and knowledge gaps. To meet the political reduction targets, a national food waste strategy was launched in 2019 by the German Federal Ministry of Food and Agriculture, which is an important step toward cooperation and exchange between actors along the entire food chain, raising awareness, and improving data quality, monitoring, and implementation of prevention measures in practice.
Open Access
Performance of micropollutant removal during wet-weather conditions in advanced treatment stages on a full-scale WWTP
(2022) Neef, Johanna; Leverenz, Dominik; Launay, Marie Alexandra
The reduction of organic micropollutants (OMP) in rivers, lakes and groundwater is an essential legal obligation of the European Water Framework Directive. Since OMP treatment in full-scale wastewater treatment plants (WWTPs) is not state of the art yet, there is little knowledge regarding removal performances, in particular during wet weather. We aimed to contribute to filling this knowledge gap by providing insights from a German case study. On-site measurements were conducted to investigate the impact of rain events on OMP removal with activated carbon processes using powdered activated carbon (PAC) and granular activated carbon (GAC). The study focused on 26 OMPs with different entry paths in the combined sewer system (CSS) and various physico-chemical properties. The monitored OMPs showed higher mass loads during wet weather at all sampling points: effluent of the secondary clarifier, effluent of the PAC treatment stage, and effluent of the GAC filter. As a result of shortened hydraulic retention time (HRT) due to rain events, the overall OMP removal was significantly lower (42% PAC and 46% GAC) than during dry weather (68% PAC and 62% GAC). In order to achieve constant removal rates during all weather conditions, the critical process control parameters are currently being investigated in ongoing studies.
Open Access
The use of self-reporting methods to identify food waste reduction potentials at consumer level - a support to achieve SDG 12.3
(Stuttgart : FEI e.V. Eigenverlag, 2021) Leverenz, Dominik; Kranert, Martin (Prof. Dr.-Ing.)
The cumulative dissertation uses a self-reporting approach to collect data on food waste at the consumer level. The main objective of this study is to contribute to filling existing knowledge gaps by performing on-site measurements of food waste at the consumer level. The collected data provide evidence-based results regarding reduction potentials and measures to prevent food waste. Measurements were first carried out in households and subsequently extended in a similar form to a gastronomic framework, namely hotels and event caterings such as conferences, business events or graduation ceremonies. For the experimental setup in gastronomic kitchens, a food waste tracking system was developed to ensure an efficient self-reporting procedure. An essential finding of the study is the evidence that self-reporting interventions contribute to raise consumer awareness, leading to behavioral changes and the autonomous implementation of reduction measures. The results demonstrate that the UN reduction targets of halving food waste (SDG 12.3) can be achieved and even exceeded.