Improved anaerobic acidification of unscreened dairy manure

Yilmaz, Vedat
Demirer, Göksel Niyazi
Even though several aspects of two-phase configuration might be very significant for efficient anaerobic digestion ( AD) of dairy manure, its application has very been limited. Two sets of experiments daily-fed continuously mixed acidogenic anaerobic reactors with no recycle were conducted to investigate the optimum conditions on anaerobic acidification of unscreened dairy manure in terms of maximum acidification and VS reduction. Effect of solids and hydraulic retention time (SRT/HRT), organic loading rate (OLR), and pH control on anaerobic acidification in terms of volatile fatty acid (VFA) formation and volatile solids (VS) reduction were investigated. Results indicated that SRT/HRT and OLR of 2 days and 15 g VS/L center dot day, respectively, yielded maximum acidification. The pH control was not effective on the acidification of dairy manure. The degree of acidification increases as HRT decreases, and also higher efficiency was determined in an uncontrolled reactor.


Anaerobic biogasification of undiluted dairy manure in leaching bed reactors
Demirer, Göksel Niyazi; Chen, S. (Elsevier BV, 2008-01-01)
Dry anaerobic digestion of high solids animal manure is of increasing importance since conventional slurry digestion is not an effective system for these manures. The investment costs for large-size reactors, costs for heating these reactors, handling, dewatering, and the disposal of the digested residue decrease the benefits of conventional slurry anaerobic digestion for high solids animal manure. Even though leaching bed reactors (LBR) constitute a promising option for dry anaerobic biogasification of ani...
Assessment of PCB contamination, the potential for in situ microbial dechlorination and natural attenuation in an urban watershed at the East Coast of the United States
Kaya, Devrim; Sowers, Kevin R.; Demirtepe, Hale; Stiell, Brian; Baker, Joel E.; İmamoğlu, İpek; Kjellerup, Birthe (Elsevier BV, 2019-09-15)
Sediment contamination is a major environmental issue in many urban watersheds and coastal areas due to the potential toxic effects of contaminants on biota and human health. Characterizing and delineating areas of sediment contamination and toxicity are important goals of coastal resource management in terms of ecological and economical perspectives. Core and surficial sediment samples were collected from an industrialized urban watershed at the East Coast of the United Stated and analyzed to evaluate the ...
Enhancing the performance of anaerobic digestion of dairy manure through phase-separation
Yilmaz, Vedat; Demirer, Göksel Niyazi (Wiley, 2008-09-01)
Anaerobic digestion (AD) is an effective way to convert animal manures into profitable by-products while simultaneously reducing, the pollution of water, air, and soil caused by these wastes. Conventional high-rate anaerobic reactors cannot effectively process animal manures with high solids-containing wastes. The two-phase configuration for AD has several advantages over conventional one-phase processes, e.g., increased stability of the process, smaller size and cost efficient process configurations. In th...
Two-Phase Thermophilic Acidification and Mesophilic Methanogenesis Anaerobic Digestion of Waste-Activated Sludge
Demirer, Göksel Niyazi; Othman, Maazuza (Mary Ann Liebert Inc, 2008-01-01)
Biological pretreatment methods of waste-activated sludge (WAS) have recently received attention because of their efficiency and relatively low investment. The application of hydrolysis/acidification step before methanization in anaerobic digestion or the two-phase anaerobic digestion process constitutes one of these methods. Two phase (thermophilic acidification and mesophilic methanogenesis) anaerobic digestion of WAS was investigated and reported to perform better in terms of chemical oxygen demand (COD)...
Kinetic modeling of enzymatic hydrolysis of pretreated kitchen wastes for enhancing bioethanol production
Çekmecelioğlu, Deniz (Elsevier BV, 2013-03-01)
It is well known that use of low cost and abundant waste materials in microbial fermentations can reduce product costs. Kitchen wastes disposed of in large amounts from cafeterias, restaurants, dining halls, food processing plants, and household kitchens contain high amounts of carbohydrate components such as glucose, starch, and cellulose. Efficient utilization of these sugars is another opportunity to reduce ethanol costs. In this study, the effect of pretreatment methods (hot water, acid solutions, and a...
Citation Formats
V. Yilmaz and G. N. Demirer, “Improved anaerobic acidification of unscreened dairy manure,” ENVIRONMENTAL ENGINEERING SCIENCE, pp. 309–317, 2008, Accessed: 00, 2020. [Online]. Available: