Atrazine transport through packed 10 cm soil columns representative of the 0-10 cm soil horizon was observed by measuring the atrazine recovery in the total leachate volume, and upper and lower soil layers following infiltration of 7.5 cm water using a mechanical vacuum extractor (MVE). Measured recoveries were analyzed to understand the influence of infiltration rate and delay time on atrazine...

Bacteria transport in soils primarily occurs through soil mesopores and macropores (e.g., biopores and cracks). Field research has demonstrated that biopores and subsurface drains can be hydraulically connected. This research was conducted to investigate the importance of surface connected and disconnected (buried) biopores on Escherichia coli (E. coli) transport when biopores are located near ...

An analytical method has been developed for the quantification of two herbicides (ethidimuron and methabenzthiazuron) and their two main soil derivatives. This method involves fluidized-bed extraction (FBE) prior to cleanup and analysis by reverse-phase liquid chromatography with UV detection at 282 nm. FBE conditions were established to provide efficient extraction without degradation of the f...

A column of alumina modified with sodium dodecyl sulfate (SDS) and dimethylglyoxime (DMG) was prepared for the preconcentration of trace nickel from water samples for flame atomic absorption spectrometry (FAAS) determinations. Under optimized conditions (pH=7.0; flow rate: 20 mlmin-1) nickel was retained on the column. The nickel collected on the column was eluted with 5 mL of 1 M nitric ac...

Time domain reflectometry (TDR) is rapidly becoming a popular method for measuring solute concentrations in the laboratory as well as in the field. Success or failure of TDR to represent solute resident concentrations depends on the accuracy of the invoked calibration. In this study, we compared three commonly used calibration methods that relate the impedance, Z+ as measured with TDR, to the s...

contaminated groundwater by gasoline spill is a worldwide environmental problem. gasoline contains methyl tert-butyl ether (mtbe) and benzene, which are the chemicals of concerns (cocs) among the gasoline components. mtbe is highly water soluble and has a low henry’s law constant and low soil adsorption co-efficient. therefore, mtbe can easily move through the soil and then accumulate, distribu...

Summertime weeds as Digitaria sanguinalis in many agro-ecosystems exist. In several cases, a welldefined weed control could be able to predict the seed emergence, to know the physiological status of the seeds in the soil bank, as well as, the factors that control and involving their germination. The goal of this work is to establish a relationship between the thermal properties and the process ...