Person: ÇALLI, BARIŞ
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ÇALLI
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BARIŞ
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Publication Metadata only Influence of trace element supplementation on anaerobic digestion of chicken manure: Linking process stability to methanogenic population dynamics(ELSEVIER SCI LTD, 2018) ÇALLI, BARIŞ; Molaey, Rahim; Bayrakdar, Alper; Surmeli, Recep Onder; Calli, BarisThe effect of trace elements supplementation in anaerobic digestion of chicken manure (CM) and their influence on methanogenic population dynamics were assessed at total ammonia nitrogen (TAN) concentrations as high as 5000?mg/L for 332 days. With addition of selenium (Se), the CH4 yield increased 50% and reached to 0.27?+/-?0.01?L/g of volatile solids (VS) added. The results of metagenomic analysis showed that Se supplementation improved the digestion stability and CH4 production by increasing the activity and number of hydrogenotrophic Methanoculleus bourgensis. Due to the deficiency of trace elements other than Se, in course of time the CH4 yield decreased and dropped to 0.13?L/g of VS added. After starting to add a trace element mix containing cobalt (Co), nickel (Ni), molybdenum (Mo), tungsten (W) and Se, another hydrogenotrophic methanogen, Methanobrevibacter became dominant in the digester. Accordingly, along with the conversion of propionate to acetate and consumption of acetate via syntrophic acetate oxidation, the CH4 yield increased and reached to steady state at 0.32 +/- 0.01 L/g of VS added. (C) 2018 Elsevier Ltd. All rights reserved.Publication Metadata only Anaerobic digestion of chicken manure by a leach-bed process coupled with side-stream membrane ammonia separation(ELSEVIER SCI LTD, 2018) ÇALLI, BARIŞ; Bayrakdar, Alper; Surmeli, Recep Onder; Calli, BarisThis study pioneered the use of a single-stage methanogenic leach bed reactor (LBR) for high-solids (total solid content: 14%-16%) anaerobic mono-digestion of chicken manure. Chicken manure was loaded into the LBR in cloth sachets without adding any bulking agents. Ammonia was separated and recovered by placing a hydrophobic gas diffusion membrane in a leachate collection chamber. Methane production in the membrane-integrated LBR was 0.272 m(3)/kgVS and 2.3 times higher than that in the control LBR. The results revealed that using membrane-integrated LBR for anaerobic digestion is a simple and cost-efficient technology for the monodigestion of chicken manure and ammonia removal.Publication Metadata only Extent of bioleaching and bioavailability reduction of potentially toxic heavy metals from sewage sludge through pH-controlled fermentation(PERGAMON-ELSEVIER SCIENCE LTD, 2021) TUĞTAŞ KARNABAT, ADİLE EVREN; Yesil, Hatice; Molaey, Rahim; Calli, Baris; Tugtas, Adile EvrenUtilization of anaerobically stabilized sewage sludge on arable lands serve as a renewable alternative to chemical fertilizers as it enables recycling of valuable nutrients to food chain. However, probable pres-ence of heavy metals in sewage sludge restricts the use of stabilized sludge on lands. In this study, a novel approach based on pH-controlled fermentation and anaerobic metal bioleaching was developed to reduce ecotoxicity potential of fermented sludge prior to its land application. Sewage sludge was sub-jected to pH-controlled fermentation process at acidic, neutral, and alkaline pH levels with the aim of increasing metal solubilization and decreasing bioavailable metal fractions through anaerobic bioleaching. Alkaline reactor performed the best among all reactors and resulted in 3-fold higher hydrolysis (34%) and 6-fold higher acidification (19%) efficiencies along with 43-fold (in average) higher metal solubiliza-tion than that of neutral pH reactor. As a result of alkaline fermentation, 32-57% of the metals remained as bioavailable and 34-59% of the metals were encapsulated as non-bioavailable within solid fraction of fermented sludge (biosolid), whereas 8-12% of total metal was solubilized into fermentation liquor. Our results reveal that anaerobic bioleaching through alkaline fermentation enables biosolid production with less metal content and low bioavailability, facilitating its utilization for agricultural purposes. (c) 2021 Elsevier Ltd. All rights reserved.Publication Metadata only Synergistic Effect of Sulfide and Ammonia on Anaerobic Digestion of Chicken Manure(SPRINGER, 2019) ÇALLI, BARIŞ; Surmeli, Recep Onder; Bayrakdar, Alper; Molaey, Rahim; Calli, BarisThe effect of the sulfur load on anaerobic digestion of chicken manure (CM) was investigated in a laboratory scale anaerobic mono-digester at high total ammonia nitrogen (TAN) concentrations. The digester was operated for 268 days by increasing the organic loading rate from 0.5 to 2.5kg-VS/m(3)/day and the total Kjeldahl nitrogen up to 5050mg/l. The CH4 yield of 0.36 +/- 0.02m(3)/kg-VS was achieved at 2.5kg-VS/m(3)/day of loading rate without any inhibition. The results showed that, anaerobic mono-digestion of chicken manure was applicable with the acclimation of microbial consortium to high TAN concentrations. However, when the sulfur content of the CM fed to the digester increased suddenly by coincidence, the CH4 yield decreased about 25% from 0.36 +/- 0.02 to 0.27 +/- 0.03m(3)/kg-VS. As a result, the acetic acid concentration increased from 130 to 1700mg/l showing that the acetate consuming methanogens were detrimentally affected from TAN and total sulfide concentrations above 4000 and 100mg/l, respectively.Publication Open Access Anaerobic digestion of chicken manure: Influence of trace element supplementation(WILEY, 2018-12-07) ÇALLI, BARIŞ; Molaey, Rahim; Bayrakdar, Alper; Surmeli, Recep Onder; Calli, BarisIn this study, anaerobic digestion of nitrogen-rich chicken (egg-laying hen) manure at different trace element (TE) mix doses and different total ammonia nitrogen (TAN) concentrations was investigated in batch digestion experiments. With respect to nonsupplemented TE sets, addition of TE mixture containing 1 mg/L Ni, 1 mg/L Co, 0.2 mg/L Mo, 0.2 mg/L Se, 0.2 mg/L W, and 5 mg/L Fe at TAN concentrations of 3000 mg/L and 4000 mg/L, cumulative CH4 production and CH4 production rate improved by 7-8% and 5-6%, respectively. The results revealed that at a very high TAN concentration of 6000 mg/L, the effect of TE addition was significantly high and the cumulative CH4 production and production rate were increased by 20 and 39.5%, respectively. Therefore, it is concluded that at elevated TAN concentrations the CH4 production that was stimulated by TE supplementation was presumably occurred through syntrophic acetate oxidation.Publication Metadata only Dry anaerobic digestion of chicken manure coupled with membrane separation of ammonia(ELSEVIER SCI LTD, 2017) ÇALLI, BARIŞ; Bayrakdar, Alper; Surmeli, Recep Onder; Calli, BarisIn this study, the anaerobic digestion of egg-laying hen manure combined with membrane-based ammonia separation was investigated. Long-term continuous experiments with and without ammonia separation were performed by increasing the organic loading rate (OLR). Although the control digester was completely inhibited at an OLR and influent total Kjeldahl nitrogen (TKN) concentration of 3.85 kgVS/m(3).d and 8.2 g/l, respectively, an average methane yield of 0.30 +/- 0.02 m(3)/kgVS was achieved with a membrane-integrated digester at an OLR and influent TKN concentration of 6.0 kgVS/m(3).d and 15 g/l, respectively. When the ammonia concentration increased above 4000 mg/l, hydrogenotrophic methanogens Methanoculleus bourgensis and Methanobrevibacter sp. performed methane production via syntrophic acetate oxidation.Publication Metadata only Long-term influence of trace element deficiency on anaerobic mono-digestion of chicken manure(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2018) ÇALLI, BARIŞ; Molaey, Rahim; Bayrakdar, Alper; Calli, BarisRecent findings showed that some trace elements essential for anaerobic digestion might be deficient in chicken (laying hens) manure. In this study, the long-term influence of trace element deficiency on anaerobic mono-digestion of chicken manure was investigated. Three bench-scale anaerobic reactors were operated with or without trace element supplementation. As trace element, only Se or a mix containing Co, Mo, Ni, Se, and W was added to the reactors. The results revealed that in anaerobic digestion of thicken manure at total ammonium nitrogen concentrations over 6000 mg L-1, Se supplementation was critical but not sufficient alone for long-term stable CH4 production. Addition of a mix consisting of Co, Mo, Ni, Se and W resulted in a more stable digestion performance. Daily trace element mix supplementation promoted the hydrogenotrophic Methanoculleus bourgensis, which is an ammonia tolerant methanogen. The decrease in the relative abundance of Methanoculleus detected after termination of trace element addition and resulted in accumulation of acetate and propionate that followed by a significant decrease in CH4 production.Publication Metadata only Anaerobic digestion of chicken manure: Mitigating process inhibition at high ammonia concentrations by selenium supplementation(PERGAMON-ELSEVIER SCIENCE LTD, 2018) ÇALLI, BARIŞ; Molaey, Rahim; Bayrakdar, Alper; Surmeli, Recep Onder; Calli, BarisIn this study, the anaerobic digestion of nitrogen-rich chicken manure from egg-laying hens was investigated via long-term continuous experiments with and without the addition of different trace elements. With trace element supplementation, a CH4 yield of 0.26 +/- 0.03 m(3) kg(-1) of volatile solids (VS) added was achieved at an organic loading rate (OLR) of 3.62 kg m(-3) day(-1) based on VS and total ammonia nitrogen (TAN) content greater than 7200 g m(-3). Selenium (Se) was identified as the critical trace element for the stable anaerobic digestion of chicken manure. The dominant methanogen in the reactors was the hydrogenotrophic methanogen Methanoculleus bourgensis. Therefore, we concluded that at elevated TAN concentrations, the CH4 production stimulated by Se supplementation likely occurred through syntrophic acetate oxidation. Without trace element supplementation, severe acetic and propionic acid accumulation occurred, causing the CH4 yield to decrease below 0.12 m(3) kg(-1) of VS added.Publication Metadata only Influence of volatile fatty acids in anaerobic bioleaching of potentially toxic metals(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2021) TUĞTAŞ KARNABAT, ADİLE EVREN; Molaey, Rahim; Yesil, Hatice; Calli, Baris; Tugtas, Adile EvrenPotentially toxic metals are common contaminants associated with sewage sludge, and limited information is available on migration and transformation behavior of potentially toxic metals during anaerobic digestion (AD) process. The aim of this study was to reveal the influence of volatile fatty acids (VFAs) on the solubilization of metals through VFAs-metal complexation. Addition of readily biodegradable extra carbon source at organic loading rate (OLR) of 17.65 gVS/L.d resulted in accumulation of 67,255 mg chemical oxygen demand (COD)/L as VFAs. Low pH values due to VFAs accumulation enhanced the solubilization of Ni and more than 22% of its total concentration became soluble. Subsequent to consumption of VFAs and increase of pH to neutral levels (similar to 7.5), solubility of Ni decreased below 10% of its total concentration. Contrarily, the solubility of Cr reached to 25% of its total concentration at neutral pH values. Presumably the complexation of Cr with dissolved organic matter (DOM) have increased its concentration in the liquid fraction at neutral pH values. Fractionation analysis of metals revealed that AD process altered Cu and Zn speciation between organically-bound and residual fractions, and hence solubility of Zn and Cu remained consistently low over the entire period of the AD process.