The behaviour of zinc and zinc-silver alloys in the presence of some inhibitors

Effects of Solution Chemistry on the Dechlorination of 1,2,3-Trichloropropane by Zero-Valent Zinc

“…12,15,19À24 These studies show that ZVZ corrosion This incorporation likely occurs through adsorption of silicate anions 15,21,22 and/or the formation of zinc silicate films. 15,20 In the first case, silicate anions outcompete hydroxide for active sites on the ZVZ (due to stronger adsorption). 15 In the second case, the zinc silicate film presumably passivates the ZVZ surface by forming a physical barrier limiting metal-solvent interactions.…”

“…Despite the insights into the structure of the oxide film gained from the TEMs of ZVZ exposed to DI water and groundwater, these data did not reveal precisely what caused the type II film to form in groundwater. The formation of this film is likely to be due to interactions of ZVZ with anions present in groundwater such as carbonate, phosphate, or silicate, all of which are known to inhibit ZVZ corrosion when their concentrations are sufficient. ,,− To isolate any effects of anions present in our groundwater samples, we performed batch reactor experiments in solutions containing the corrosion inhibitors listed above, and other anions, at or above their concentrations in Site Water P (SWP). We believe SWP to be a representative sample, as most of the constituents were present at concentrations within the ranges that are typical of groundwater. − The constituents with higher concentrations were Na + , Cl – , and SO 4 2– , which were included in our tests.…”

“…In these studies, SiO 2 was seen to inhibit the reduction of a number or organohalides − and nitroaromatic compounds by adsorption to the ZVI surface. While the reactivity of ZVZ with contaminants in silicate solutions has not, to our knowledge, been previously investigated, many studies have addressed the effect of silicate anions on ZVZ corrosion. ,,− These studies show that ZVZ corrosion (or reactivity) is decreased in the presence of silicate, and they attribute the inhibitory effect of silicate to incorporation of Si into or onto the surface of the ZVZ in a Zn-rich conversion layer. This incorporation likely occurs through adsorption of silicate anions ,, and/or the formation of zinc silicate films. , In the first case, silicate anions outcompete hydroxide for active sites on the ZVZ (due to stronger adsorption) .…”