The Research On Sewage Sludge In Conditioning And Optimization Of Dewatering Performance

Sludge is the byproduct of waste water biological treatment which has a large amount.The other feature of sludge is high moisture. High moisture directly affects the transportation,treatment and recycling of sludge. Therefore, in th paper, chemistry conditioning and advanced oxidation methods were used to dewater.Chemistry conditioning is one of the most important methods for sludge hydration.Dosing conditioner can improve the dewatering performance. By experiments, confirming the flocculant was CPAM, coagulant was PFC and PAFC, aid was G and Z. After dosing conditioners, settlement lasting 2.0 h, the volume of water occupied 2/5. After filtration, for100 g sludge, the volume of water was about 90 %. For mechanical dewatering, when the dosing amount of CPAM was 0.25 %, PFC was 1 %, PAFC was 9 %, G was 15 % and Z was5 %, the moisture of sludge was coming down from 96.90 % to 85.24 %.Advanced oxidation is one of the emerging methods for sludge dewatering. Advanced oxidation is used to damage the membrane, release internal water and then dewater. By experiments, the oxidizer was O3 and the catalyst was C.For 10 kg sludge,moisture of99.19 %, used advanced oxidation. The flow of O3 was 50 L/h, and the time was 20 min. The amount of C was 1 %. Then dose the conditioner, whichCPAM was 0.25 %, PFC was 1 %,PAFC was 9 %, G was 15 % and Z was 5 %,.After mechanical dewatering, the moisture of sludge dropped to 79.07 %.After concentrated and initially dewatered, the moisture of sludge drops about 90 %.However, it needs to be dewatered again for transportation, landfill, disposal and recycle.Therefore, used sludge of moisture of 90 % to dewater again. The conditioner used for dewatering again was PFC and Z. When the amount of PFC was 7.5 %, Z was 20 %, using mechanical dewatering, the moisture of sludge cake was below 80 %. As the amount of Z recreasing to 25 %, the moisture of sludge cake dropped to 73.47 %. Known from the research, the waste fly ash in the power plant could also be used as aid in the sludge dewatering. When the amount of PFC was 12.5 %, and the fly ash was 20 %, via mechanicaldewatering, the moisture of sludge cake could be below 70 %, dropped to 69.72 %. It was a good effect, but need more PFC as the same condition.