The Dewaterability of Disintegrated Sludge Samples Before and After Anaerobic Digestion

Apul, O. Gueven
Atalar, Ilgin
Zorba, Goezde T.
Sanin, Faika Dilek
Sludge pretreatment systems emerged during the past few decades to reduce the ever-increasing quantities of sludge. A variety of different techniques have been studied for their effectiveness in solubilizing the chemical oxygen demand (COD) and increasing the digestability and decreasing the final quantity of sludge. In this study different pretreatment techniques and their effects on dewaterability were investigated at two stages of treatment. First, dewaterability was measured as capillary suction time (CST) right after the application of pretreatment; second, the dewaterability of pretreated and subsequently digested sludge was measured at the end of the anaerobic digestion period. The pretreatment techniques applied were acid and alkali treatment, ultrasonication, microwave (MW) treatment, and a combination of MW and alkali treatment. For all the methods tested, it was found that CST value deteriorated after pretreatment compared to untreated samples. From all the methods studied, acid treatment influenced the CST the least, whereas alkali treatment influenced it the greatest. Sonication and MW had similar intermediate effects. MW treatment helped improve the high CST values caused by the alkali treatment when the two methods were combined. In the second stage of the study, the pretreated samples were anaerobically digested and the CST values were measured afterwards. This time a completely different line of results was observed; there was almost no difference in CST values following digestion regardless of the method used. This indicated that anaerobic digestion process has such a dominant impact on sludge dewaterability that the significant effects created by different pretreatment techniques prior to digestion were dampened and the CST values were brought down to a narrow range following digestion in which the control and pretreated sludge had almost equal CST values.


Operational conditions of activated sludge: Influence on flocculation and dewaterability
Sanin, Faika Dilek; Turtin, Ipek; Kara, Fadime; Durmaz, Burcu; Sesay, Mohamed L. (Informa UK Limited, 2006-01-01)
Selected operational conditions of activated sludge are investigated in relation to their effect on flocculation and dewatering. Semi-continuous reactors with 2 -L volume were operated at different mean cell residence times, C/N ratios, and three different influent cations. Results show that MCRT, C/N ratio, and the cation type affect the bioflocculation capacity of activated sludge measured by the quantity of extracellular polymeric substances. As the MCRT value operated in the reactors and the C/N ratio o...
Effects of hydraulic residence time on metal uptake by activated sludge
Ozbelge, TA; Özbelge, Hilmi Önder; Tursun, M (Elsevier BV, 2005-01-01)
The combined uptake Of Cu2+ and Zn2+ by activated sludge (biomass) was investigated at steady state in an activated sludge process (ASP) without recycle (namely, once-thro ASP), for different values of influent metal concentrations and hydraulic residence time in the range of 2.5-40 h. The experiments were performed at a constant pH of 7 and temperature of 25 degreesC. The results showed that the percentage removal of both copper and zinc by activated sludge increased with the increasing residence time; mor...
Enhancement of bio-gas production and xenobiotics degradation during anaerobic sludge digestion by ozone treated feed sludge
Ak, M. S.; Muz, M.; KOMESLİ, Okan Tarık; Gökçay, Celal Ferdi (Elsevier BV, 2013-08-15)
Elimination of large amounts of sludge produced during biological treatment is a pressing environmental issue both in this country and elsewhere. For example EU Landfill Directive 99/31/EC [41] prohibits landfilling of both liquid and untreated wastes with a target to reduce the current amount of bio-degradable wastes, including sewage sludge, 50% and 65% by the years 2013 and 2020, respectively. Anaerobic digestion has now proven to be the most energy efficient way of destroying and stabilizing waste activ...
Cytochrome P4501A and associated mixed-function oxidase induction in fish as a biomarker for toxic carcinogenic pollutants in the aquatic environment
Arinc, E; Sen, A; Bozcaarmutlu, A (Walter de Gruyter GmbH, 2000-06-01)
Polycyclic aromatic hydrocarbons (PAHs), dioxins, dibenzofurans, and polychlorinated biphenyls (PCBs) present in polluted environment induce cytochrome P4501A (CYP1A) isozyme in fish, which in turn results in a marked increased production of carcinogenic metabolites from PAHs. The induction of hepatic CYP1A in fish by certain classes of chemicals has been suggested as an early warning system, a "most sensitive biological response" for assessing environmental contamination conditions. This has implications f...
Optimization of supercritical carbon dioxide extraction of antioxidants from roasted wheat germ based on yield, total phenolic and tocopherol contents, and antioxidant activities of the extracts
Gelmez, Niluefer; Kincal, N. Suzan; Yener, Meryem Esra (Elsevier BV, 2009-04-01)
Effects of pressure (148-602 bar), temperature (40-60 degrees C) and time (10-60 min) on antioxidant (phenolics and tocopherols) contents and antioxiclant activities of supercritical carbon dioxide (SC-CO2) extracts of roasted wheat germ were determined, using central composite rotatable design. The dependent variables were yield (%), total phenolic contents (TPC, mg gallic acid equivalent (GAE)/g extract), total tocopherol contents (TTC, mg tocopherol/g extract) and antioxidant activities (AA, mg scavenged...
Citation Formats
O. G. Apul, I. Atalar, G. T. Zorba, and F. D. Sanin, “The Dewaterability of Disintegrated Sludge Samples Before and After Anaerobic Digestion,” DRYING TECHNOLOGY, pp. 901–909, 2010, Accessed: 00, 2020. [Online]. Available: