|
International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 10, No. 6, 2013, pp. 1157-1166
|
Bioline Code: st13114
Full paper language: English
Document type: Research Article
Document available free of charge
|
|
International Journal of Environment Science and Technology, Vol. 10, No. 6, 2013, pp. 1157-1166
en |
Application of waterworks sludge in wastewater treatment plants
Sharma, A. K.; Thornberg, D. & Andersen, H. R.
Abstract
The potential for reuse of iron-rich sludge from
waterworks as a replacement for commercial iron salts in
wastewater treatment was investigated using acidic and
anaerobic dissolution. The acidic dissolution of waterworks
sludge both in sulphuric acid and acidic products such as
flue gas washing water and commercial iron solution was
successful in dissolving the iron from waterworks sludge.
The anaerobic dissolution of waterworks sludge due to co-
digestion with biological sludge (primary and biological
activated sludge) resulted in reduction of iron, increase in
dissolved iron(II), increase in pH due to the produced
alkalinity from dissolution of iron(III)hydroxides from
waterworks sludge, lower internal recirculation of phos-
phate concentration in the reject water and reduced sul-
phide in the digested liquid. However, recirculation of the
produced soluble iron(II) as an iron source for removal of
phosphate in the wastewater treatment was limited, because
the dissolved iron in the digester liquid was limited by
siderite (FeCO
3
) precipitation. It is concluded that both
acidic and anaerobic dissolution of iron-rich waterworks sludge can be achieved at the wastewater treatment plant,
and are economically and environmentally more favour-
able compared to deposition of the waterworks sludge in
controlled landfills.
Keywords
Water works; Sludge; Wastewater; Iron; Phosphate
|
|
© 2013 - Center for Environment and Energy Research and Studies (CEERS) Alternative site location: http://www.ijest.org
|
|