The revised potential – pH diagram for Pb – H₂O system

Abstract

Thermodynamic properties of lead species in aqueous solution are collected. The chemical equilibria between various forms of Pb(II) are considered. The speciation diagrams for the equilibria 4[PbOH]+(aq) ⇄ [Pb4(OH)4]4+(aq) and 2[Pb3(OH)4]2+(aq) ⇄ [Pb6(OH)8]4+(aq), and the thermodynamic activity - pH diagram of Pb(II) species are plotted. Basic chemical and electrochemical equilibria for lead are calculated. The potential - pH diagram for Pb - H2O system is revised.

Impact of physical and chemical parameters on square wave anodic stripping voltammetry for trace Pb2+ detection in water

“…From pH 6.0 to 8.0, the peak potential shifted by approximately −63 mV. The half-reaction of Pb 2+ reduction does not involve hydroxide ions or protons and is not affected by pH, but the half-reaction potential of PbOH + (eqn (2) 64 is pH dependent.…”

“…Lead in acidic water is stable in its soluble divalent ion (Pb 2+ ) form, whereas in alkaline water with no other inorganic and organic contaminants, the lead hydroxo cation PbOH + is formed. As the pH increases, the response to Pb 2+ ions are decreased by the resulting shift from a corrosive zone to a passivation zone, where Pb 2+ ions become less favorable in the equilibrium from Pb 2+ to PbOH + ions following eqn (1): 64 …”

Dispersion and rheology for direct writing lead‐based piezoelectric ceramic pastes with anisotropic template particles

“…Significant cross‐linking is not expected at pH 12.5 due to the relatively low concentration of M 2+ cations. Based on Pourbaix diagrams the divalent cations exist predominantly as simple metal hydroxides at pH 12.5 56‐59 . Despite the extreme pH of the suspension, acrylic polymer hydrolysis is not considered in this analysis because PAA does not hydrolyze within the short mixing times of this study at room temperature 60,61 …”

“…Based on Pourbaix diagrams the divalent cations exist predominantly as simple metal hydroxides at pH 12.5. [56][57][58][59] Despite the extreme pH of the suspension, acrylic polymer hydrolysis is not considered in this analysis because PAA does not hydrolyze within the short mixing times of this study at room temperature. 60,61 F I G U R E 3 Zeta potential as a function of pH for 0.08 vol% PIN-PMN-PT suspensions with and without the acrylic binder system exhibiting the surface charge modification enacted by acrylic binding to the particle surface [Color figure can be viewed at wileyonlinelibrary.com]…”

Using Sewage Sludge Ash as an Efficient Adsorbent for Pb (II) and Cu (II) in Single and Binary Systems

“…At pH higher than 7, the lead ions are efficiently removed from solution, but in this case were not removed due to an adsorption process but were removed due to precipitation process according to the potential-pH diagram for Pb ions in water systems [23][24][25][26]. Dissolved ionic species present at pH values higher than 7 are Pb(OH) + (aq), Pb 4 (OH) 4 4+ (aq) and Pb(OH) 2 .…”