Volatilisation processes in wastewater treatment plants as a source of potential exposure to vocs

Abstract

The results of a survey estimating volatilisation rates (as gas exchange constants and flux rates) of a range of hazardous alkane, aromatic, organohalogen, organosulphide, ketone and alcohol volatile organic compounds (VOCs) from a water bay are presented. More than 73 experimental test runs were earned out over a year under varying seasonal conditions to measure the simultaneous concentrations of VOCs in air and water phases. The data were processed employing new advances in 'surface renewal' volatilisation models. Based on the experimental data, estimates of theoretical equilibrium constants, gas exchange constants and flux rates for each VOC were made. Within the ranges of concentration which may reasonably be encountered by process workers, the fluxes for a broad range of VOCs ranged from approximately 0.04x 10~8 to 9.0x10"' g cm" 2 h~'. The results were used to make predictions about the relationship between volatilisation processes and their implications for occupational hygiene nsk assessment.

Influence of Physical Factors on Trichloroethylene Evaporation from Surface Water

“…6, the experimental evaporation trend very closely followed the extrapolated trend at 1.58 m/s wind velocity. According to Bianchi and Varney (1997), a flux transfer rate for the VOCs is a function of wind speed and VOC concentration differences between air and water phases. In case of our experiments at the low-wind condition, the velocity of wind (0.54 m/s) might not have been efficient in the removal of TCE molecules, resulting in TCE concentrations above the water surface.…”

Determination of volatile organic compounds in industrial wastewater plant air emissions by multi-sorbent adsorption and thermal desorption-gas chromatography-mass spectrometry

“…Although several papers have focused on the monitoring of VOC emissions in industrial facilities [10][11][12][13][14][15], the emissions of VOCs from wastewaters in industrial-sewage treatment plants are often overlooked as sources of hazardous substances. Previous papers have shown the influence of urban WWTP emissions on air quality [16][17][18][19][20][21]. However, there are only a few studies on the composition of industrial WWTP emissions [22,23] and their relative importance as a potential source of specific hazardous air pollutants must be further investigated.…”

“…Most of the methods that have been developed for determining VOC emissions from urban and industrial WWTPs are either canister-based [11,22] or sorbent-based [16,18,19,21,23]. New trends in VOC determination focus on the development of versatile, portable, low-cost and environmentally-friendly techniques without compromising the limit of detection.…”

Electronic noses for the continuous monitoring of odours from a wastewater treatment plant at specific receptors: Focus on training methods

“…However, we observed that, when very complex mixtures are analyzed (gaseous emissions from wastewater treatment plants contain hundreds of different compounds [15,16]), the sensor responses are strongly correlated, and their temperature dependence is not clearly definable.…”