The daily mass use of plastic products is leading to more and more pollution, as they end up in the environment as waste. However, the increased use of plastics also increases the formation of microplastics (MP), which can be formed directly or indirectly when bigger piece of plastics break down. Municipal wastewater treatment plants (WWTPs) are also a major source of MP, with most of the MP ending up in waste sludge. Each wastewater treatment process generates large quantities of waste sludge, which can be treated in several ways. Anaerobic digestion is a process that produces biogas from sludge, which can be used as an energy source. However, with high levels of MP and the desire for new energy pathways, the question arises how and to what extent MP affects biogas production. In my master thesis I will evaluate the impact of polyvinyl chloride (PVC) on biogas production. PVC is a type of plastic that is often found in sewage sludge samples. This thesis will present the influence of different PVC concentrations on biogas production and the ratio of CO2 and CH4 produced during anaerobic treatment of waste sludge. In the second part of my master thesis, I will also investigate the impact of PVC on biogas production when sludge is pretreated by ozonation. Ozonation can improve CH4 yields, depending on the ozonation time and ozone dose. In my master thesis I will therefore investigate how different ozone doses, ozonation time and or added PVC concentration affect biogas production and the CO2/CH4 ratio.
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