Acidified water surfaces

Electron Spectroscopy Studies of Acidified Water Surfaces... 

FAIRBROTHER ET AL. Electron Spectroscopy Acidified Water Surfaces 107... 

Acidified water surfaces degree of surface sensitivity, 111 experimental description, 107-109 stratospheric significance, 107 sulfuric acid, 109-111 surface composition, 111-113 surface vs. bulk composition, 113-114 Adsorption... 

Atomic layer epitaxy, 117 Atomic level studies of CdTe(lOO), electrochemical digital etching, 115-123 Auger electron spectrometers, 106 Auger electron spectroscopy bisulfate anion adsorption on Au(l 11), Pt(l 11), and Rh(l 11) surfaces, 126-138 to monitor composition of acidified water surfaces, 106-114 underpotential deposition of lead on Cu(lOO) and Cu(lll), 142-154 use for bisulfate anion adsorption, 127... 

W. Schopp, Recovery of Acidified European Surface Waters, Environ. Sci. Technoi. 2005, 39,64A.]... 

Water and Suspended Solids. Water and suspended solids were collected simply by immersing a 1-L plastic bottle (wide mouth) under the water surface several times at different depths. Collected water was transferred to a 5-gal plastic container until the latter was filled. Samples were shipped to the laboratory and filtered immediately through a 0.45-pm membrane filter. The filtrate was acidified to pH 2 with HC1. 

Many factors control whether a given water body will become acidified as a result of a given deposition regime. In addition to the deposition rate and the lake residence or turnover time, these include the ratio of water surface area to watershed area, the composition of the lake bottom, the residence time of incident precipitation en route through the watershed, and the buffering capacity of the watershed. The presence of organic material can also be important. 

All standards were prepared by dilution of Alfa Inorganics Ventron primary standard solutions using acidified filtered surface Gulf Stream seawater (salinity ca. 36% ) or distilled water. Sample injections were made with Eppendorf microliter pipets with disposable plastic tips. 

HBr, and HI) ultimately come down as acid rains and acidify surface waters. I26l Acidified water is by itself toxic to marine life. Its effect is amplified, however, by the solubilization of metals and hydrolysis of other chemical compounds. 

Fig. 8.19 Surface pressure against area isotherms for pentadecanoic acid monolayers on acidified water (pH = 2). (From reference Gl, with permission.)...

High quality HMS was repeatedly and reproducibly prepared by a novel extraction procedure to remove the primary amine template using acidified water. This very efficient extraction (100%) does not affect the physical properties of the resulting mesostructure. Compared to the ethanol-extracted HMS, no subsequent calcination step is required to remove the surface ethoxy groups produced during the ethanol extraction. Moreover, the recovered surfactant can be easily re-used in a fresh synthesis. Furthermore, an improved hydrothermal stability was observed after using the acidified water extraction procedure. 

Figure 2 Typical surface pressure/area isotherm of stearic acid on an acidified water subphase.

R.F. Wright et al. (2005) Environmental Science <6 Technology, vol. 39, p. 64A - Recovery of acidified European surface waters . 

Welch et al. (1996) also demonstrated the effect of acidifying water samples from Lake Hoare in Taylor Valley prior to analysis. Their results in Fig. 19.38 indicate that the measured Ca + concentrations of acidified water samples from Lake Hoare are higher than those of unacidified samples by a factor of two. The reason is that the hydrogen ions in the aeidified water samples displace calcium ions that are sorbed to negatively charged sites on the surfaces of colloidal particles. 

Aqueous samples such as drinking water, surface water, and waste water but also beverages and urine samples, should always be acidified with mineral acids for stabilization purposes immediately after collection. This is especially true for the prevention of desorption processes during sampling and storage of samples in the course of trace metal analysis. Acidification reduces the tendency for ions to be adsorbed onto active sites at the surface of the containment vessel, and it also inhibits bacterial growth [9]). Glacial acetic acid and... 

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