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Physical and Chemical Properties of Pesticides and Other Contaminants: Volatilization, Adsorption, Environmental Distribution, and Reactivity
Published in James N. Seiber, Thomas M. Cahill, Pesticides, Organic Contaminants, and Pathogens in Air, 2022
James N. Seiber, Thomas M. Cahill
This applies only to liquid surfaces that are unaffected by the underlying solid substrate, as occurs in the standard ASTM evaporation rate test and to quiescent liquid pools. The inclusion of M increased the slope of previous Ln flux vs. Ln VP regressions to a value close to 1.0. This correlation can be used for screening level assessment and ranking of liquid chemicals for evaporation rate, such as pesticides, fumigants, and hydrocarbon carrier fluids used in pesticide formulations, liquid consumer products used indoors, and accidental spills of liquids. In addition to vapor pressure, other factors that influence volatilization include movement of air over chemical deposits exposed to the open environment and the thickness of the deposit. The direct effect of wind flow rate on the volatilization of weed oil mixtures (e.g., Beacon oil, Chevron oil) was demonstrated in an earlier study (Woodrow et al., 1986). This study also showed that the weed oils (mixtures of hydrocarbons of varying molecular weight and vapor pressure) volatilized differentially from deposits on inert Teflon and glass surfaces (Figure 3.2). That is, components with higher vapor pressures and lower molecular weights volatilized early on, eventually leaving the original deposit enriched in the components of higher molecular weight and lower vapor pressure. This phenomenon was demonstrated both in the laboratory and in the field. In the field, weed oils applied to seed alfalfa led to significant volatilization, which is thought to have contributed to photochemical smog formation (see Table 2.2).
Risk Assessment Techniques and Methods of Approach
Published in D. Kofi Asante-Duah, Hazardous Waste Risk Assessment, 2021
Volatilization — Volatilization is the process by which a chemical compound evaporates into the vapor phase from another environmental compartment. The volatilization of chemicals is an important mass transfer pathway. Knowledge of volatilization rates is necessary to determine the amount of chemical that enters the atmosphere and the change of pollutant concentrations in the source media. The transfer process from the source (e.g., water body, sediments, soil) to the atmosphere is dependent on the physical and chemical properties of the chemical compound in question, the presence of other pollutants, and the physical properties of the source media and the atmosphere. Lyman et al. (1990), among others, elaborate several estimation methods for evaluating this parameter.
Environmental Fate and Transport of Solvent-Stabilizer Compounds
Published in Thomas K.G. Mohr, William H. DiGuiseppi, Janet K. Anderson, James W. Hatton, Jeremy Bishop, Barrie Selcoe, William B. Kappleman, Environmental Investigation and Remediation, 2020
Thomas K.G. Mohr, James Hatton
The vapor pressure of a liquid or solid is the pressure of the gas in equilibrium with the liquid or solid at a given temperature. Volatilization, the evaporative loss of a chemical from the liquid to the vapor phase, depends on the vapor pressure of the chemical and on environmental conditions that influence diffusion from the evaporative surface. Chemicals with relatively low vapor pressures, high sorption onto solids, or high solubility in water are less likely to vaporize and become airborne than are chemicals with high vapor pressures or less affinity for solution in water or adsorption to solids and sediments. Because most solvent-stabilizer compounds are highly soluble and have relatively low vapor pressures, they are generally unlikely to partition into the soil-vapor phase and migrate through the soil as vapors.
Human urine-based fertilizers: A review
Published in Critical Reviews in Environmental Science and Technology, 2022
Tristan M. P. Martin, Fabien Esculier, Florent Levavasseur, Sabine Houot
Ammonia volatilization causes air pollution (e.g., acidification and particulate matter). Volatilization depends highly on the product characteristics (e.g., pH and NH3 concentration), application techniques and pedo-climatic conditions (Huijsmans, 2003). For stored urine, using trailing hoses followed by harrowing 4 hours later, ammonia emissions from open soil range from 2% to 10% of the nitrogen applied and only from 0.3% to 1.1% with trailing shoes. Volatilization is very low for both techniques when urine is applied on growing crops (0.2%–0.4% of nitrogen applied) (Rodhe et al., 2004). Ammonia emissions from other products were not studied, and great diversity is expected due to the various characteristics of the products. NH3 volatilization is expected to be lower for nitrified and acidified urine than for other products due to the lower ammonia concentration and low pH. Alkalinized urine may have a volatilization rate as high as that of granular urea since increasing pH near the granule (due to urea hydrolysis) can promote volatilization (Fenn & Hossner, 1985). The other volatile organic compounds (VOCs) were barely studied but may imply some environmental impacts. For example, VOCs from slurry may contribute to the formation of tropospheric ozone (Liu et al., 2018).