Carbon-based conductive materials enhance biomethane recovery from organic wastes: A review of the impacts on anaerobic treatment

Kutlar, Feride Ece
Tunca, Berivan
Yılmazel, Yasemin Dilşad
Amongst the most important sustainable waste management strategies, anaerobic biotechnology has had a central role over the past century in the management of high-pollution load sources, such as food, agricultural and municipal wastes. During anaerobic digestion (AD), valuable by-products such as digestate and biogas are produced. Biogas (mainly composed of methane) is generated through a series of reactions between bacteria and archaea. Enhancement of AD process with higher methane yield, accelerated methane production rate, and shorter start-up time is possible via tapping into a novel methanogenic pathway discovered a decade ago. This fundamentally new concept that is a substitute to interspecies hydrogen transfer is called direct interspecies electron transfer (DIET). DIET, a thermodynamically more feasible way of electron transfer, has been proven to occur between bacteria and methanogens. It is well-documented that amendment of carbon-based conductive materials (CCMs) can stimulate DIET via serving as an electrical conduit between microorganisms. Therefore, different types of CCMs such as biochar and activated carbon have been amended to a variety of AD reactors and enhancement of process performance was reported. In this review, a comparative analysis is presented for enhancement of AD performance in relation to major CCM related factors; electrical conductivity, redox properties, particle size and dosage. Additionally, the impacts of AD operational conditions such as organic loading rate and temperature on CCM amended reactors were discussed. Further, the changes in microbial communities of CCM amended reactors were reviewed and future perspectives along with challenges for CCM application in AD have been provided.


Sustainable design implications for alternative food networks: A case on Güneşköy's community supported agriculture (CSA) model
Kaplan, Ayşe; Doğan, Çağla; Department of Industrial Design (2021-6)
The global food system consists of complex processes (i.e., food production, distribution, consumption, and disposal) and contains several environmental, economic, and social sustainability challenges. As a result of the food system's problems, some producers and consumers have taken actions that have resulted in the emergence of alternative food networks. These are primarily bottom-up initiatives led by creative and innovative groups of people collaborating to develop alternative food-system solutions. Dif...
Hydrothermal carbonization processes applied to wet organic waste streams
Özçimen, Didem; İnan, Benan; Koçer, Anıl Tevfik; Bostyn, Stephane; Gökalp, İskender (2022-10-10)
Various organic waste streams are generated daily by human activities such as municipal, agricultural and industrial. The sustainable disposal of these organic wastes is a serious societal challenge. When the disposal process is not efficient, this type of wastes creates important pollution risks for air, soil, underground water and sea. Especially, wastes that have high moisture content cannot be eliminated cost effectively via thermo-chemical conversion by conventional processes such as pyrolysis, gasific...
Modelling and assessment of landfill gas generation at afyonkarahisar landfill site
Karayılan, Sevde; Aksoy, Ayşegül; Department of Environmental Engineering (2018)
Management of municipal solid wastes is one of the important environmental problems because of increasing population and developing industrialization in our country. Besides, there is a need to seek alternative energy sources due to rapid consumption of conventional energy sources. Landfilling is still the most common solid waste disposal method in the world and generated landfill gas consists of significant amount of methane that could be used for energy generation. In this study, it is aimed to model the ...
Odabaş, Yasin; Yılmazel Tokel, Yasemin Dilşad; Department of Environmental Engineering (2022-11)
In this study we investigated the impact of granular activated carbon (GAC) application on anaerobic digestion (AD) process of cattle manure. Firstly, the effect of the presence of basal medium on cattle manure digestion was evaluated. It was observed that basal medium addition decreased methane yield and increased lag time. Then, for the enhanced cattle manure digestion, a metal-based conductive material, hematite (Fe2O3), and carbon-based material, GAC, were amended into the reactors. From the comparison ...
Food Security and Eco-terrorism Impacts on Environmental Security Through Vulnerabilities
Alpas, Hami (2009-12-04)
Food security requires appropriate agricultural management and utilization of natural resources and eco-systems, as well as good governance and sustainable political systems. Food security is directly affected by climate change effects that lead to concerns in rural livelihoods. Bio-energy developments present both opportunities and challenges for socioeconomic development and the environment. In that sense, bio-energy solutions should strive to be environmentally sensitive and have a positive social impact...
Citation Formats
F. E. Kutlar, B. Tunca, and Y. D. Yılmazel, “Carbon-based conductive materials enhance biomethane recovery from organic wastes: A review of the impacts on anaerobic treatment,” CHEMOSPHERE, vol. 290, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: