Wastewater Flow and Pathogen Transport from At-Grade Line Sources to Shallow Groundwater.

On-site wastewater treatment systems are commonly used in sparsely populated areas where capital-intensive centralized wastewater treatment facilities are not feasible. The primary objective of this work was to investigate vadose zone and groundwater transport of a bromide (Br) tracer and naturally occurring applied to the soil surface in secondarily treated wastewater at a public rest stop in central Alberta, Canada, with seasonally fluctuating water table (between 0.2 and 1.

Arsenic Metabolites, Including N-Acetyl-4-hydroxy-m-arsanilic Acid, in Chicken Litter from a Roxarsone-Feeding Study Involving 1600 Chickens.

The poultry industry has used organoarsenicals, such as 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, ROX), to prevent disease and to promote growth. Although previous studies have analyzed arsenic species in chicken litter after composting or after application to agricultural lands, it is not clear what arsenic species were excreted by chickens before biotransformation of arsenic species during composting. We describe here the identification and quantitation of arsenic species in chicken litter repeatedly collected on days 14, 24, 28, 30, and 35 of a Roxarsone-feeding study involving 1600 chickens of two strains.

A modified sequential extraction method for arsenic fractionation in sediments.

A modified sequential extraction method was developed to characterize arsenic (As) associated with different solid constituents in surficial deposits (sediments), which are unconsolidated glacial deposits overlying bedrock. Current sequential extraction methods produce a significant amount of unresolved As in the residual fraction, but our proposed scheme can fractionate >90% of the As present in sediments. Sediment samples containing different As concentrations (3-35 μg g(-1)) were used to assess the developed method.