Investigation of AD-MEC integrated systems for enhanced biogas production from renewable biomass
Rapidly increasing energy demands around the world cause fossil fuel resources to be depleted at an enormous rate. Therefore, researchers all over the world have been working on finding alternative energy sources with minimum impact on the environment. Biogas obtained from anaerobic digestion (AD) is a common sustainable energy source that can be produced from various types of industrial and agricultural biomass. Biogas typically contains %60-70 methane and %30-40 carbon dioxide and its high methane content makes the biogas a useful fuel that can be converted to electricity and used for heating purposes. In addition to the conventional waste to energy systems, bio electrochemical systems (BES) are newly discovered technology including different processes used for energy production from organic wastes. Methane production in BESs can be achieved by development of electroactive methanogenic biofilm on the cathode of microbial electrolysis cells (MECs) with the addition of a small amount of external voltage. In the literature, there is a limited number of studies, which investigates the integration of AD and MEC systems for enhanced biogas production from real wastes. This study aims to enhance methane production from cattle manure (CM) and wastewater biosolids (WBS) in the AD-MEC integrated reactor system by investigating the impact of external voltage addition. For this purpose, in the experimental design, three different voltages and different substrate mixing ratios of WBS and CM were used in single chamber AD-MEC reactors. The set consisted of AD-MEC reactors with different CM to WBS mixing ratios of 100:0, 30:70, 70:30 and 0:100. Reactors were operated in duplicate under mesophilic conditions (35oC) with no mixing, and current production was monitored continuously during incubation. Preliminary experimental results indicated that AD-MEC integration is more advantageous for CM digestion in comparison to WBS.
By Mert ŞANLI
Supervisor: Assist. Prof. Dr. Yasemin Dilşad YILMAZEL TOKEL
Removal of Aclonifen Pesticide from Waters by Adsorption – Activated Carbon vs Zeolite Chabazite as Adsorbents
Pesticides being one group of micropollutants, find their way into watercourses via either agricultural activities or urban wastewater discharges even after conventional wastewater treatment. Therefore, the concern is to remove them from the effluents of conventional wastewater treatment plants by means of tertiary treatment. To this purpose, several advanced treatment processes such as activated carbon adsorption, advanced oxidation processes, membrane filtration have been considered as alternative solutions. However, these systems have some advantages and disadvantages over the others in terms of several factors such as cost and mineralization efficiencies. Among these alternative methods, activated carbon adsorption is superior to the others as a relatively low-cost and flexible alternative with limited by-products. In recent years, zeolites that are crystalline aluminosilicates have attracted the attention of researchers as a lower-cost alternative to activated carbon. Indeed, the surface area of zeolites is remarkably smaller than that of activated carbon, which makes zeolites not so promising as an alternative adsorbent material. However, the zeolite Chabazite is unique, with a relatively higher surface area than the other zeolites, that is very close to the surface of activated carbon. So, it appears as a promising adsorbent alternative toward the removal of pesticides. In this thesis study, the removal of selected pesticide “Aclonifen”, from waters by adsorption onto the powdered activated carbon and onto the zeolite of Chabazite is going to be investigated comparatively.
By Cansu POLAT
Supervisor: Prof.Dr. Ülkü Yetiş
Co-supervisor: Prof.Dr. Filiz Bengü Dilek
Date & Time: June 23rd, 2021 at 15:40Zoom Link: https://zoom.us/j/92415502710?pwd=MVpPaDJ6bGxKeThVTjgrWWNmTDgwQT09