Author(s): V. Nenov; B. Bonev
Linked Author(s):
Keywords: Phosphorous removal; Sludge; Sludge treatment; Municipal wastewater; Struvite; Struvite precipitation
Abstract: The work is focused on evaluation of struvite precipitation from the sidestream of sludge treatment facilities of a conventional Municipal Wastewater Treatment Plant by addition of seawater concentrate containing predominately Mg 2+ ions. The seawater concentrate is naturally available through the solar salt production from Black Sea water. The experiments carried at two different pH (pH=8.5 and pH=9.0) show that the differences in equilibrium phosphorous, in absolute values, are not significant regarding the experiments performed at high Mg: o-PO4 3-ratio. It is found that at magnesium concentration higher than 4.0 m M the phosphorous is removed solely as struvite. The relationships derived between magnesium dose and phosphorous removal indicate that at high dosages of magnesium, the extent of phosphorus removal increases. This assumption is proved by X-ray diffraction analysis. The results obtained reveal that 94% of the soluble phosphorous can be removed from the centrifuge supernatant as struvite at magnesium to phosphorous molar ratio of 16.7: 1 using a seawater concentrate as magnesium containing additive.
Year: 2003