The use of fly ash as conditioner for dewatering of biological sludges in drying beds

Guitonas, A.; Hatzinikolaou, N.; Riziotis, C.

doi:10.1080/02772249109357735

Cited by 1 publication

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“…During the early 1960s, Moehle reported the use of fly ash as a sludge conditioner. Recently, Guitonas et al examined the conditioning of sludge by fly ash for dewatering in pilot‐scale drying beds. Smollen and Kafaar prepared a mixture of charcoal powder and organic flocculants to achieve better sludge dewatering results with less consumption of organic flocculants.…”

Section: Introductionmentioning

confidence: 99%

Improving Sludge Dewaterability by Adding the Semi‐Dry Flue Gas Desulfurization Residue under Microwave Radiation

Liang

Shi

Guo-you

2014

CLEAN Soil Air Water

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Because of the high moisture content within sludge, it is difficult to obtain a sludge dewatering rate of >60% within municipal sludge treatment. In this study, the semi-dry flue gas desulfurization residue was added as a sludge conditioner to concentrated sludge under microwave radiation. The results showed that with a gradually increased dosage of the residue to the sludge, the settling velocity of the sludge increased considerably and moisture content in the filtered cake and the specific resistance to filtration value decreased considerably. After treatment by the residue conditioning combined with microwave radiation, the sludge settling performance and filtration dewaterability were further improved. The optimal operation conditions were summarized as a mass ratio of the residue and sludge by a dry weight basis of about 1:1 w/w, and 50 s microwave radiation. The addition of the residue can also speed up the filter cake drying process, effectively kill harmful microorganisms, and promote toxic metal passivation. These improvements may be attributed to the alkalinity of the residue and microwave radiation damaging the stability of biological cells within the sludge, while the CaSO 4 · 2 H 2 O and CaSO 3 · 0.5 H 2 O acts as skeleton formers, thereby facilitating the sludge dewatering process.

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Section: Introductionmentioning

confidence: 99%