From these studies, it can be concluded that cocurrent contacting of vapor and liquid streams is a very satisfactory method to utilize for the design of a multistage vapor-liquid equilibrium unit.A contactor, six in. in length, with an annular space of %or %-in., packed with Metex screen, will be 100% efficient at throughputs up to 1000 grams per hr per cm2, which corresponds, respectively, to 6 and 28 liters of liquid per hr.

There has been a great deal of recent interest in evaluating the potential for vapor transport from subsurface contamination into nearby buildings. There does not exist, however, any method for calculating whether buildings that are not directly over the source of contamination may be impacted. For simplicity, typical modeling approaches for estimating vapor migration through soil into buildings assume that the contaminated plume or soil lies directly underneath the building. The models do not take into account the lateral distance, if any, between the source of VOC emissions and the indoor space. This paper presents an approach to calculate diffusion-limited emission fluxes as a function of lateral distance and evaluates the significance of these emissions over relatively short lateral distances from the source. A theoretical, mathematical approach was used. The results show that soilgas concentration and emission flux are both a decreasing exponential function of the lateral distance from the edge of the contaminant plume. Based on our calculations, the emission flux and the soil-gas concentration are insignificant within a relatively short lateral distance from the source (e.g., 30 m).

Extensive difficulty has been encountered in the use of the Dusseldorf Method for oxidizable organic materials in the assessment of incinerator performance. Many of the problems can be attributed to difficulties in standardization arising from the wide interpretation which can be put on the original description of the analytical procedure.If, however, a rigorous procedure is adopted, good correlation is obtained between this and the two new procedures described (Methods 3 and 4). The determinations carried out using the total organic carbon analyzer (Method 4) are undoubtedly the most rigorous, but as this technique is available to only a limited number of laboratories, the procedure recommended for general use is the modified chemical oxygen demand test (Method 3), which offers many advantages over the Dusseldorf procedure.

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