This study investigates the effect of aeration basin temperature, pH and dissolved oxygen (DO) concentration on filterability and compressibility characteristics of activated sludge. Laboratory-scale semi-continuous reactors, fed with synthetic wastewater were used. Effects of temperatures of 15, 20, 25, 30, 35°C; pH values of 5.7, 7.2, 8.2, 9.0 and DO concentrations of 0.5, 1.0, 1.5, 2.0, 5.0 ml/l were studied by keeping all the other parameters constant in each case. Results indicated that as the operating temperatures of reactors were increased, specific resistances to filtration also increased. Up to 25°C a decrease in compressibility of the sludges was observed and above 25°C the sludges became more compressible. Similarly, as the operating pH of the reactors were increased, sludge filterabilities decreased. Increases in the pH of the reactors caused the sludges to become more compressible. On the other hand, low aeration basin DO concentrations reduced the filterability of sludges; and caused the formation of low compressible sludges, and poor effluent qualities. At higher DO concentrations higher filterabilities, better effluent qualities and more compressible sludges are resulted.


Effects of nickel, chromium and initial feed concentration on the batch growth of a microbial consortium developed from sewage
Gökçay, CELAL FERDİ; Dilek, Filiz Bengü (Informa UK Limited, 1991-01-01)
Effects of nickel, chromium and substrate concentration on the microbial growth of acclimatized and unacclimatized microbes of sewage origin were studied in batch cultures at a constant temperature of 25 °C, at pH 7.0. A synthetic medium supplemented with Ni(II) (5 and 10 mgl‐1) or Cr(VI) (1 and 50 mgl‐1) or with their combinations and at various feed concentrations (650, 975, 1300 mgl‐1) was employed to investigate the effects on the specific growth rate (μm) of the microbial culture. The experimental resu...
GOKCAY, CF; Yetiş, Ülkü (Elsevier BV, 1991-01-01)
Hexavalent chromium, which is frequently encountered in the tannery effluents and in the electroplating wastes, is normally considered toxic to the activated sludge culture. Often a physico-chemical pretreatment prior to biological treatment is considered necessary. However, in this study it has been shown that an acclimatized activated sludge culture is fully capable of coping with the Cr(VI)-containing wastes and moreover the culture was significantly stimulated by up to 25 mg l-1 Cr(VI). None of the t...
Toxicity of 2,4-D acid to phytoplankton
Okay, OS; Gaines, A (Elsevier BV, 1996-03-01)
The toxic effects of 2,4-D on Phaedoactylum tricornutum (Bohlin) and Dunaliella tertiolecta (Butcher), two species of phytoplankton well suited to bioassay studies and responsive to pollutants, were studied by monitoring changes in growth in terms of cell populations, chlorophyll fluorescence and the rate of (CO2)-C-14 assimilation. Short term bioassays, batch and continuous cultures were studied. Pure 2,4-D acid appeared more toxic than the commercial amine form of the herbicide but this may have been due ...
Effect of Anaerobic Azo Dye Reduction on Continuous Sludge Digestion
Ozkan-Yucel, Umay Gokce; Gökçay, Celal Ferdi (Wiley, 2014-10-01)
Effect of continuous feeding of a reactive azo dye, reactive orange 107, and its hydrolyzed form (HRO107), on a conventional anaerobic digester was investigated in this study together with observation of change in microbial community. Laboratory-scale digesters were fed with waste activated sludge and azo dye for 575 days continuously. The influent concentrations of reactive azo dye were between 200 and 3200 mg/L. The digester performance was not adversely affected by azo dye and its reduction metabolites t...
Effect of acclimatization of microorganisms to heavy metals on the performance of activated sludge process
Ozbelge, Tulay A.; Özbelge, Hilmi Önder; Altinten, Pinar (Elsevier BV, 2007-04-02)
Although selected heavy metals (HMs) stimulate biological reactions at low concentrations, all HMs are toxic to microorganisms (MOs) at moderate concentrations and can cause inhibitory effects on the biological processes. Therefore, MOs must be acclimated to HMs or other toxic substances present in wastewaters (WWs) before they are used in an activated sludge process (ASP). In this study, combined effect of Cu2+ and Zn2+ ions in a synthetic WW on the efficiency of a laboratory- scale ASP without recycle was...
Citation Formats
G. SURUCU and F. D. Sanin, “EFFECT OF TEMPERATURE, PH AND DO CONCENTRATION ON FILTERABILITY AND COMPRESSIBILITY OF ACTIVATED-SLUDGE,” WATER RESEARCH, pp. 1389–1395, 1989, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34764.