Evaluating Aeration‐Stripping Media on the Pilot Scale

Abstract

A pilot-scale air-stripping study evaluated the performance of numerous full-size packing materials in the removal of 11 contaminants in up to 10 flow conditions within the range encountered in practice. The overall liquid phase mass transfer coefficients (K L a) were calculated based on the concentrations within the packing (i.e., excluding end effects). For the operating conditions tested, K L a was greatly affected by the liquid loading. The volumetric air-to-water (A:W) ratio and the stripping factor (R) had very limited effect on K L a, primarily because the stripping factors were significantly > 1. At the various A:W ratios, the authors found distinct relationships between K L a and pressure drop, which indicated that A:W = 25 was more effective than A:W = 50 and A:W = 100. Because the various packing materials performed quite differently, the optimal designs for the various packings will consist of air-strippers of somewhat different dimensions operating under different operating conditions. However, the packing materials' low contribution toward the overall cost and the similarity of the various designs reduce the effect of using different materials. Space and height restrictions, tendency to foul, and ease of cleaning may be more critical design factors in the selection of packing.

The regulatory context for cVOCs

“…Although both PTA and GAC can be used for compliance with the current VOC standards, this initial treatment analysis focuses on PTA. During the past few decades, PTA has become one of the most common methods of removing VOCs from drinking water (Narbaitz et al, 2002). Therefore, to assess the effectiveness of PTA in removing the spectrum of VOCs, a paper study was conducted as an exercise to evaluate removal efficiencies of the 23 regulated and 17 unregulated VOCs in "typical" PTA designs.…”

On Thermal Performance of Seawater Cooling Towers

“…This equation is a modified form of Onda's correlation (Onda et al, [27]) and has an average error of ±26% relative to experimental data. A comparison between the packing characteristic (Merkel number) calculated using the Djebbar and Narbaitz's correlation and the experimental given by Narbaitz et al [28] is shown in Fig. 7a.…”