Dry Removal of Gaseous Fluorine Pollutants

The conservation equations governing buoyant plume rise are solved for the case of non-uniform wind conditions. A power law is selected to represent the actual wind profile. Analytical solutions are presented both for uniformly stable and neutral atmospheric conditions. These solutions are shown to be of the same form as those obtained in the simpler uniform case but with the plume rise now depending explicitly on the wind speed shear. A sensitivity analysis of the effects on plume rise of typical variation in wind shear and entrainment reveals that the two quantities have an almost equal effect therefore justifying the use of the present model. To simplify computations a “uniform wind” is introduced such that when used in conjunction with Briggs' equations the results become consistent with those of the present theory.     

Assessment of the abiotic transformation of 17β-estradiol in the presence of vegetable matter

A study using 17β-¹⁴C₄-estradiol (¹⁴C-E2) was performed to confirm and characterize the catalytic transformation of estrogens in the presence of a model vegetable matter (namely rabbit food) as a surrogate material for vegetable wastes found in sewage. Results corroborated the occurrence of an abiotic transformation. Unknown transformation byproduct(s) accounted, respectively, for 38% and 9% of the initial radioactivity in liquid and extractable solid phases after 72 h; on the other hand, only 15% and 7% of this radioactivity corresponded to ¹⁴C-E2 in those same matrices. Mass balance was closed including the radioactivity irreversibly bounded to the solid phase. Formation of ¹⁴C₄-estrone was monitored by Liquid Chromatography with tandem Mass Spectrometry detection; negative results were found in all sampling events. This process could be harnessed to optimize sustainable technologies for the removal of phenolic microcontaminants from wastewater.     

Pesticide distribution in an agricultural environment in Argentina

An assessment of the off-site migration of pesticides from agricultural activity into the environment in the Neuquen River Valley was performed. The aim of this study was to evaluate the distribution of pesticides in several compartments of a small agricultural sub-catchment. Soil, surface water, shallow groundwater and drift deposition were analyzed for pesticide residues. Results showed the presence of some pesticide residues in soil, surface water and shallow groundwater compartments. The highest detection frequencies in water (surface and subsurface) were found for azinphos-methyl and chlorpyrifos (>70%). In terms of concentration, the highest levels were observed in shallow groundwater for azinphos methyl (22.5 μg/L) and carbaryl (45.7 μg/L). In the soil, even before the application period had started, accumulation of residues was present. These residues increased during the period studied. Spray drift during pesticide application was found to be a significant pathway for the migration of pesticide residues in surface water, while leaching and preferential flows were the main transport routes contributing to subsurface contamination.     

Health and social impacts of a flood disaster: responding to needs and implications for practice

Carlisle in northwest England suffered its worse floods for more than 180 years in 2005. A study, reported here, was undertaken to assess the health and social impacts of these floods via in‐depth, taped individual and focus‐group interviews with people whose homes had been flooded and with agency workers who helped them. Respondents spoke of physical health ailments, psychological stress, water health‐and‐safety issues related to the floods, and disputes with insurance and construction companies, which they felt had caused and exacerbated psychological health problems. Support workers also suffered from psychological stress. Furthermore, it was found that people had low expectations of a flood and were not prepared. The findings are presented in five sections covering flood risk awareness, water contamination issues, physical health, mental health, and impact on frontline support workers. The discussion focuses on the implications of the findings for policy and practice vis‐à‐vis psychological health provision, contamination issues, training and support for frontline support workers, matters relating to restoration, and preparation for flooding.     

Modeling non-point source pollution from rice farming in the Thachin River Basin

With the worldwide intensification of agriculture, non-point source pollution of surface waters has become a pressing issue. Conventional river water quality models consider non-point sources as accumulated entries into the rivers and do not investigate into the processes generating the pollution at its source, thus preventing the determination of effective mitigation measures. The models require extensive data inputs, which is a deficiency in many developing and emerging countries with limited data availability. The current study applies a Material Flow Model as a complementary approach to quantify non-point source pollution from agricultural areas. Rice farming in the Thachin River Basin is presented as a case study, with a focus on nutrients. The total nitrogen and phosphorus flows from rice farming to the river system are quantified, the key parameters influencing these flows are determined and potential mitigation measures are discussed. The results show that rice contributes considerable nutrient loads to the Thachin River Basin. Scenario simulations demonstrate that a significant nutrient load reduction could be achieved by following the official recommendations for fertilizer application, thus confirming the local efforts to introduce best management practice. Our results underline the importance of non-point source pollution control in intensive agricultural areas, particularly of tropical lowland delta areas such as the Central Plains of Thailand. The specific benefit of applying a Material Flow Model in this context is that with limited data availability, one can reach an understanding of the system and gain a first overview over its key pollution problems. This can serve as supportive basis for determining consecutive in-depth research requirements.