Role of oxidants in enhancing dewaterability of anaerobically digested sludge through Fe (II) activated oxidation processes: hydrogen peroxide versus persulfate.
Improving dewaterability of sludge is important for the disposal of sludge in wastewater treatment plants (WWTPs). This study, for the first time, investigated the Fe(II) activated oxidization processes in improving anaerobically digested sludge (ADS) dewaterability. The combination of Fe(II) (0-100 mg/g total solids (TS)) and persulfate (0-1,000 mg/g TS) under neutral pH as well as the combination of Fe(II) (0-100 mg/g TS) and hydrogen peroxide (HP) (0-1,000 mg/g TS) under pH 3.0 were used to examine and compare their effect on the ADS dewaterability enhancement. The highest ADS dewaterability enhancement was attained at 25 mg Fe(II)/g TS and 50 mg HP/g TS, when the CST (CST: the capillary suction time, a sludge dewaterability indicator) was reduced by 95%. In contrast, the highest CST reduction in Fe(II)-persulfate conditioning was 90%, which was obtained at 50 mg Fe(II)/g TS and 250 mg persulfate/g TS. The results showed that Fe(II)-HP conditioning was comparable with Fe(II)-persulfate conditioning in terms of highest CST reduction. Economic analysis suggested that the Fe(II)-HP conditioning was more promising for improving ADS dewaterability compared with Fe(II)-persulfate conditioning, with the saving being up to $65,000 per year in a WWTP with a population equivalent of 100,000.
Advanced Water Management Centre, The University of Queensland, St Lucia, Queensland 4072, Australia.|Institute of Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan.
Kang
K
Song
Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China.
Xu
X
Zhou
School of Automation Science &Engineering, South China University of Technology, Guangdong 510640, China.
Yiqi
Y
Liu
Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Yanyan
Y
Gong
Institute of Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan.
Beibei
B
Zhou
Advanced Water Management Centre, The University of Queensland, St Lucia, Queensland 4072, Australia.
Dongbo
D
Wang
Advanced Water Management Centre, The University of Queensland, St Lucia, Queensland 4072, Australia.
Qilin
Q
Wang
D000693:Anaerobiosis; D001421:Bacteria, Anaerobic / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D016877:Oxidants / Q000378:metabolism*; D010084:Oxidation-Reduction; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology*; D014867:Water / Q000378:metabolism*; D014881:Water Supply
D006861:Hydrogen Peroxide; D007501:Iron; D016877:Oxidants; D012722:Sewage; D062065:Wastewater; D014867:Water