『Abstract
Sewage sludge contains large amount of water-soluble phosphorus,
which is prone to runoff loss when sewage sludge is land applied.
Phosphorus export from sewage sludge is land applied. Phosphorus
export from sewage sludge is an important cause for water eutrophication.
Immobilization of phosphorus before sewage sludge land application
seems necessary. In this study, three amendments including red
mud (RM), lime and mixture of RM and lime were employed to immobilize
phosphorus in fresh sewage sludge. It was found that phosphorus
was effectively controlled by RM, lime and mixture of RM and lime.
Sequential chemical extraction results indicate that the RM amendment
transformed H2O-P in the sewage sludge into
the NaOH-P, while the lime amendment transformed H2O-P
in the sewage sludge into the HCl-P. Such transformations in phosphorus
fractions would have little influence on phosphorus availability
but would retard and reduce potential phosphorus loss following
sewage sludge was land applied.
Keywords: Sewage sludge; Red mud; Lime; Phosphorus』
Introduction
Materials and methods
Materials
Analytical methods
Immobilization experiments
Batch leaching experiments
Sequential leaching experiments
Column leaching experiments
Sequential chemical extraction experiments
Results and discussion
Sewage sludge characteristics
Batch leaching experiments
Sequential leaching experiments
Column leaching experiments
Sequential chemical extraction experiments
Conclusion
Acknowledgments
References