title: Enhanced dewaterability of anaerobically digested sewage sludge using Acidithiobacillus ferrooxidans culture as sludge conditioner.
abstract: Role of Acidithiobacillus ferrooxidans culture in bioacidification and dewaterability of anaerobically digested sewage sludge (ADS) was investigated. A. ferrooxidans culture grown in 9K medium along with Fe(2+) produced iron flocculant containing, secondary iron minerals and biopolymeric substances as confirmed by FT-IR, XRD, and SEM-EDX. Bioacidification of ADS was performed using 10% (v/v) A. ferrooxidans culture, isolated cells and cell-free culture filtrate; and dewaterability was assessed using the capillary suction time (CST) and specific resistance to filtration (SRF). Isolated bacterial cells significantly (P<0.05) reduced the sludge dewaterability when supplemented with Fe(2+) while the whole culture and cell-free filtrate rapidly acidified the sludge without Fe(2+) and showed significant reduction of CST (71.3-73.5%) and SRF (84-88%). Results clearly indicated that the culture and filtrate of the A. ferrooxidans facilitated rapid sludge dewaterability while the cells supplemented with Fe(2+) also enhanced dewaterability but required 2-4 days.
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong.
authors: Kumarasamy
authors: K
authors: Murugesan
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong.
authors: Balasubramani
authors: B
authors: Ravindran
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong.
authors: Ammaiyappan
authors: A
authors: Selvam
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong.
authors: Mayur B
authors: MB
authors: Kurade
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong.
authors: Shuk-Man
authors: SM
authors: Yu
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong.
authors: Jonathan W C
authors: JWC
authors: Wong
mesh_terms: D042763:Acidithiobacillus / Q000302:isolation & purification / Q000378:metabolism*; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005374:Filtration; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D012722:Sewage / Q000382:microbiology*; D012995:Solubility; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D012722:Sewage; D014867:Water; D007501:Iron; D010100:Oxygen
keywords: Acidithiobacillus ferrooxidans; Anaerobically digested sewage sludge; Sludge conditioning; Sludge dewaterability