Biokinetic behavior and settling characteristics in an activated sludge under the effect of toxic Ni(II) influentes

Toxicity of Organotin Compounds to Activated Sludge

“…1 and Table 1 reveal that an increase in sludge age ( ) leads to reduction of inhibition of respiration rate. This behavior has already been established in the literature for other toxic compounds such as heavy metals (Bagby and Sherrard, 1981;Lombrana et al, 1993) and permits the use of sludge age as a control operating variable for the mitigation of the inhibitory e!ect of organotin compounds. The decreasing toxicity with increasing sludge age could be attributed to the larger amount of extracellular polymers with sludge age, providing many functional groups that may act as binding sites for inhibitors (Neufeld and Herman, 1975;Battistoni et al, 1993).…”

“…The #ask was hermetically sealed by the probe of a membrane oxygen meter. The O concentration was recorded as a function of time up to concentrations of about 2 ppm, while the activated sludge was continuously mixed by means of a magnetic stirrer (APHA, 1989;Lombrana et al, 1993).…”

“…The impact of toxic compounds on activated sludge is in#uenced by several factors such as the acclimation of biomass to these substances (Chang et al, 1986), the sludge age of biomass (Lombrana et al, 1993), the concentration of biomass (Lamp and Tollefson, 1973), the length of exposure of biomass to the toxic compound (Madoni et al, 1999), the species of microorganisms present in activated sludge (Shuttleworth and Unz, 1991), and the pH (Villaescusa et al, 1997). Therefore, the e!ects of these factors on the determined toxicity should be investigated.…”

Elimination of Cu(II) toxicity by powdered waste sludge (PWS) addition to an activated sludge unit treating Cu(II) containing synthetic wastewater

“…Most of the literature studies are on the adverse effects of metal ions on activated sludge performance [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] or biosorption of metal ions on different biosorbents including PWS in batch systems with no biological treatment [22][23][24][25][26][27][28][29]. Since the toxic effects of metal ions on activated sludge bacteria are well documented in literature, this study provides a good option to eliminate metal ion toxicity in activated sludge systems.…”

“…Toxicity of heavy metal ions on activated sludge bacteria vary depending on the type and concentrations of heavy metal ions and the organisms as well as the environmental conditions such as pH, temperature, dissolved oxygen (DO), presence of other metal ions, ionic strength and also the operating parameters such as, sludge age (SRT) and hydraulic residence time [5]. A number of studies were reported in literature on toxic effects of heavy metal ions on activated sludge organisms [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”