Water potential daily changes

Figure 9-22. Schematic representation of daily changes in the water potentials in the soil, a root, and a leaf of a plant in an initially wet soil that dries over a 1-week period for a rapidly draining sandy soil. TS011 is the water potential in the bulk soil, proot is that in the root xylem, and 4/leaf is the value in a mesophyll cell. Shaded regions indicate night. [Adapted by permission from Slatyer (1967).].

Systems that are exposed to excessive turbulence of anaerobic wastewater and a potential increased release of hydrogen sulfide. Systems with a risk for increased turbulence are inlet structures, drops, cascades, sharp bends and inverted siphons. As an example, changes in the flow regime from a pressure pipe into a gravity sewer may give rise to the release of hydrogen sulfide. Corrosion of the sewer pipe wall is often pronounced near the daily water... 

The response of the Cu ion-selective electrode (ISE) (Orion) was found to be Nernstian to at least pCu 13 in pCu buffers. The electrode was polished and calibrated daily. Before each titration the ISE was conditioned with pCu 10 buffer, and then with 1 x 10 M Cu in buffered ground water. The lowest total Cu concentration used in the ISE titrations was 1 x 10 M. The response of the electrode was unreliable below that concentration. The titration was stopped when successive Cu additions resulted in a potential change of less than 28 mV (log Cu). It was assumed that Cu(OH)2 began to precipitate at that point. 

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