The mechanism of metals precipitation by biologically generated alkalinity in biofilm reactors

Bio-Precipitation of Zn (II) from Municipal Wastewater Spiked with Zinc

“…The increase in pH proved that the precipitation process has occurred in non sterilized samples. This is consistent with the report published by Remoudaki et al, (2003), which stated that an increase in the pH of samples favour for metal precipitation.…”

“…removed from waste stream by using chemical precipitation (Remoudaki et al, 2003;Reis et al, 2013). Zinc will react with precipitants such as carbonates, hydroxides or sulphides to form zinc precipitates (Kaksonen et Cibati et al, 2013).…”

Characterization, morphology and composition of biofilm and precipitates from a sulphate-reducing fixed-bed reactor

“…Metal sulphides are generally less soluble than their corresponding metal hydroxides; allowing quantitative metal precipitation [15,16]. Metal sulphides are also more compact, have faster settling velocities and exhibit better thickening and dewatering characteristics than the corresponding hydroxide sludge [17].…”

Investigations of nickel(II) removal from aqueous solutions using tea factory waste

“…These are ion exchange [9], solvent extraction [10], reverse osmosis, electrodialysis [3], precipitation [11], flocculation [12], sorption [13], activated carbon adsorption and membrane separation processes [14]. However, these techniques have certain disadvantages, such as high capital and operational costs or the treatment and disposal of the residual metal sludge.…”