Bioflocculation of mesophilic and thermophilic activated sludge
العنوان: | Bioflocculation of mesophilic and thermophilic activated sludge |
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المؤلفون: | A. de Keizer, J.C.T. Vogelaar, Gatze Lettinga, S. Spijker |
المصدر: | Water Research 39 (2005) 1 Water Research, 39(1), 37-46 |
بيانات النشر: | Elsevier BV, 2005. |
سنة النشر: | 2005 |
مصطلحات موضوعية: | Polymers, Laboratorium voor Fysische chemie en Kolloïdkunde, Waste Disposal, Fluid, Bioreactors, activated sludge, biological treatment, Physical Chemistry and Colloid Science, Waste Management and Disposal, Water Science and Technology, Sewage, afvalwaterbehandeling, Chemistry, Ecological Modeling, Pollution, Aerobiosis, Bacteria, Aerobic, Wastewater, temperatures, biologische behandeling, Milieutechnologie, Sewage treatment, Shear Strength, Mesophile, Paper, hydrofobiciteit, Flocculation, Environmental Engineering, water, Industrial Waste, flocs, flocculation, temperatuur, Bioreactor, Particle Size, hydrophobicity, paper-mill, Civil and Structural Engineering, WIMEK, adsorptie, geactiveerd slib, reactors, Environmental engineering, temperature, uitvlokking, Oxygen, Activated sludge, waste water treatment, Chemical engineering, adsorption, Environmental Technology, DLVO theory, whitewater, effluent, Waste disposal |
الوصف: | Thermophilic activated sludge treatment is often hampered by a turbid effluent. Reasons for this phenomenon are so far unknown. Here, the hypothesis of the temperature dependency of the hydrophobic interaction as a possible cause for diminished thermophilic activated sludge bioflocculation was tested. Adsorption of wastewater colloidal particles was monitored on different flat surfaces as a function of temperature. Adsorption on a hydrophobic surface varied with temperature between 20 and 60 degrees C and no upward or downward trend could be observed. This makes the hydrophobic interaction hypothesis unlikely in explaining the differences in mesophilic and thermophilic activated sludge bioflocculation. Both mesophilic and thermophilic biomass did not flocculate with wastewater colloidal particles under anaerobic conditions. Only in the presence of oxygen, with biologically active bacteria, the differences in bioflocculation behavior became evident. Bioflocculation was shown only to occur with the combination of wastewater and viable mesophilic biomass at 30 degrees C, in the presence of oxygen. Bioflocculation did not occur in case the biomass was inactivated or when oxygen was absent. Thermophilic activated sludge hardly showed any bioflocculation, also under mesophilic conditions. Despite the differences in bioflocculation behavior, sludge hydrophobicity and sludge zetapotentials were almost similar. Theoretical calculations using the DLVO (Derjaguin, Landau, Verweij and Overbeek) theory showed that flocculation is unlikely in all cases due to long-range electrostatic forces. These calculations, combined with the fact that bioflocculation actually did occur at 30 degrees C and the unlikelyness of the hydrophobic interaction, point in the direction of bacterial exo-polymers governing bridging flocculation. Polymer interactions are not included in the DLVO theory and may vary as a function of temperature. |
وصف الملف: | application/pdf; application/octet-stream |
تدمد: | 0043-1354 |
URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::658089add0cb46e85c120e9748ac38ae https://doi.org/10.1016/j.watres.2004.07.027 |
حقوق: | RESTRICTED |
رقم الأكسشن: | edsair.doi.dedup.....658089add0cb46e85c120e9748ac38ae |
قاعدة البيانات: | OpenAIRE |
تدمد: | 00431354 |
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