Surplus Activated Sludge Modified And Applied Research In Wastewater Treatment

The paper studied that physical method and chemical method were used to denature activated sludge. The denatured effect of the activated sludge was investigated by decreasing the organic matter (COD) in the wastewater. The influence of different methods, the reagent amount and time, pH value on the denatured activated sludge were studied, which provided the theoretical basis for activated-sludge recycle.The results showed that the denatured effect was not obvious by cell's pulverizer and high shear emulsification machine. The denatured effect of the activated sludge was best at about pH 7.0. Low pH caused the amidogen of microorganism in the activated sludge protonized and high pH caused make the hydroxyl salinized, and increased the hydrolyzation of microorganism which would have side effect on the denatured effect.The amount and reaction time of ClO₂ and NaClO would affect the denatured effect of the activated sludge. When the addition amount of ClO₂ was higher 8.0mg/100ml or NaClO higher than 10mg/100ml, the activity of the sludge would drop. The reaction time was 8min, the denatured effect was best. Under the condition of acid, the effect of pH and ClO₂ or NaClO had some influence on the activated sludge and in the basic range ,the effect was not obvious because ClO₂ converted into ClO^- and ClO₃^- in the short time and NaClO decomposed to Cl^- and ClO₃^-.The test showed that the denatured effect of the activated sludge was not evident by the way of physical method and reagent.