Evaluation of volatile fatty acids production and dewaterability of waste activated sludge with different thermo-chemical pretreatments                            

Lei Yu；Wenduo Zhang;  He Liu;  Ganghui Wang;  Hongbo Liu;          全文下载

Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan

University,Wuxi 214122,PR China

Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,Suzhou 215011,PR China

ABSTRACT:The effects of three kinds of waste activated sludge (WAS) thermo-chemical pretreatments, including thermo-NaOH, thermo-mixed alkali and thermo-CaO₂ pretreatments, on volatile fatty acids (VFAs) production and sludge dewaterability were investigated in a large-scale WAS anaerobic fermentation project. Performances of VFAs production of sludge pretreated with thermo-NaOH (7.48 ± 0.64 g VFAs/L) and thermo-CaO₂ (7.91 ± 0.56 g VFAs/L) were proved to be better than that with thermo-mixed alkali (6.93 ± 0.63 g VFAs/L). Sludge pretreated with thermo-CaO₂ presented the best dewaterability and the moisture content of the sludge cake could be reduced to as low as 63.4 ± 4.4% after dewatering by plate-and-frame filter press. Conversely, the dewaterability of sludge pretreated with thermo-NaOH was significantly deteriorated and the VFAs were hard to be recovered. Furthermore, the economic feasibility comparison of thermo-NaOH, thermo-mixed alkali and thermo-CaO₂ pretreatments for WAS anaerobic fermentation showed that the net profits were 1.55, 34.44 and 38.69 USD/ton dewatered sludge, respectively. Thermo-mixed alkali and thermo-CaO₂ pretreatments are promising pretreatment methods for the wide application of WAS anaerobic fermentation.

KEYWORDS:Waste activated sludge; Pretreatment; Fermentation; Volatile fatty acids; Dewaterability; Large-scale project;

JOURNAL:International Biodeterioration & Biodegradation

SOURCE:Elsevierjournal

DOI:10.1016/j.ibiod.2018.02.008

YEAR:2018

PAGES:170-178

PUBLISHER:Elsevier Ltd