Determination of Henry's law constant for methyl tert-butyl ether (MTBE) at groundwater temperatures

The dimensionless Henry's law constant was determined for methyl tert-butyl ether (MTBE) at six temperatures (3, 5, 10, 15, 20 and 25 degrees C) by using a thermostatted flask (430 ml) containing an aqueous MTBE solution. The ratio between the gas phase and the water phase in the flask was approximately 1.7:1. The aim of this study was to acquire data needed to model the behaviour of MTBE at groundwater conditions. The dimensionless Henry's law constant at 10 degrees C is approximately 0.01 but is 0.03 at 25 degrees C. This is important for modelling MTBE because the variation of vaporization cannot be disregarded at groundwater temperatures. In a second experiment the water solubility of MTBE was determined to be 62.1 g/l at 5 degrees C and 35.5 g/l at 20 degrees C). The high solubility at low temperatures could cause MTBE plumes from spills (fuel accidents etc.) to spread rapidly.     

Direct observation of phototransients in natural waters

Nanosecond laser spectroscopic measurements were made on a variety of natural waters containing humic substances. Both short-lived (nanosecond) and long-lived (microsecond) transient absorptions were observed. The long-lived transients exhibited maxima at 475 and 720 nm. The former is tentatively assigned to a triplet state transition while the latter is due to solvated electrons formed on laser excitation. Water samples from widely diverse sources showed similar transient absorption properties as well as fluorescence properties. All transients were shown to depend linearly on laser intensity, indicating that the photoproducts observed are likely to be formed in water sources illuminated by solar radiation having much lower intensities than used here.     

Some Remarks About the Effect of Smoke from Charcoal Kilns on Soil Degradation

The charcoal kilns under study were situated in the Polish Western Carpathiens (Bieszczady). Aromatic hydrocarbon products of wood burning in the kilns were identified. The rate of decomposition of beech leaves was relatively high as environmental conditions enhanced decomposition. The intensity of soil metabolism is increasing during a long-term exposure to smoke, which is one of the indicators of anthropogenic disturbance resulting from organic factors.