Study on Improvement of Settleability and Dewatering Characteristics of Activated Sludge by Humus Soil
Chuanyin Wei · China Water & Wastewater · 2009
The improvement effect of the settleability and dewatering characteristics of activated sludge by adding humus soil was investigated.The results show that adding the humus soil can improve the settleability and dewatering characteristics of the activated sludge significantly.With the dosage increase of humus soil,the initial settling velocity,thickening ratio and cake solid content of activated sludge are increased,and sludge volume index(SVI),specific resistance to filtration(SRF) and capillary suction time(CST) are decreased significantly.When the sludge concentration is 2 300 mg/L and the dosage of humus soil is 5.0 g/L,the initial settling velocity of sludge is increased from 1.72 m/h to 3.01 m/h,the thickening ratio of the sludge is increased from 2.86 to 7.14,and SVI is decreased from 152 mL/g to 61 mL/g.When the sludge concentration is 7 300 mg/L and the dosage of humus soil is 5.0 g/L,the SRF is decreased from 1.33×1012 m/kg to 5.7×1011 m/kg,the CST is decreased from 20.3 s to 15.7 s,and the cake solid content is increased from 13.4% to 33.0%.