We present a set of new, semi-analytical solutions to simulate three-dimensional contaminant transport subject to first-order chain-decay reactions. The aquifer is assumed to be areally semi-infinite, but finite in thickness. The analytical solution can treat the transformation of contaminants into daughter products, leading to decay chains consisting of multiple contaminant species and various...

OBJECTIVES To determine nutrient and contaminant concentrations, document concentration changes related to common preparation methods and provide a basic risk-benefit analysis for select subsistence foods consumed by residents of Kotzebue, Alaska. STUDY DESIGN Eleven organic nutrients and 156 persistent organic pollutants (POPs) were measured in foods derived from spotted seals and sheefish. ...

Previous studies indicated that the coupling of multizone and CFD (Computational Fluid Dynamics) models can provide a good compromise between the accuracy and required computation time. The results show that the coupled model predicts contaminant distribution more accurately than multizone model alone for the zones close to the contaminant source location. For all other zones, the multizone mod...

In the industrial production of penicillin V, the phenoxyacetate precursor is added to the fermentor to direct biosynthesis. When used for producing semisynthetic penicillins, the penicillin V is often hydrolyzed to 6-aminopenicillanic acid with the regeneration of the phenoxyacetate precursor. To reduce raw-material as well as waste-disposal costs, it is desirable to recycle the phenoxyacetate...

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is not an appropriate measure for its availability; bioavailability rather depends on the dynamic interplay of potential mass transfer (flux) of a compound to a microbial cell and the capacity of the latter to degrade the compound. In water-unsa...

In order to better understand the robustness of our protocols and to identify failure modes for Sanger Sequencing in the UMGC we carried out a series of experiments testing the effects of DNA template concentration, primer concentration, and sample purity on Sanger sequencing data quality. We determined that the UMGC’s Sanger sequencing processes are robust for a wide range of template and prim...

Traditional and new relationships of polychlorinated biphenyl (PCB) distribution among the solid phases, the free aqueous phase, and biolipids are comprehensively reviewed using seven well-characterized freshwater and marine sediments polluted with PCBs. The traditional relationship relating free aqueous concentration and biolipid concentration to sediment total organic carbon, compound octanol...

Abstract The hydrogen peroxide role in photocatalytic degradation of an anionic azo dye, Acid Orange 7 (AO7), was investigated a slurry reactor. Commercial ZnO nanoparticles with average size between 10 to 30 nm were used as catalysts. Optimum conditions for different parameters, including dye concentration (10–100 mg/L), catalyst (0.1–0.5 g/L), and pH (5–10), determined first the absence H2O2....

This study examined the use of zoned ventilation systems using a coupled CONTAM/EnergyPlus model for new California dwellings. Several smart control strategies were developed with target halving ventilation-related energy use, largely through reducing dwelling rates based on zone occupancy. The controls evaluated annual consumption relative to continuously operating non-zoned, code-compliant me...

Biomass and contaminant accumulation and partitioning in plants determine the harvest stage for optimum contaminant uptake during phytoremediation of municipal biosolids. This wetland microcosm bioassay characterized accumulation and partitioning of biomass, nutrients (N and P), and trace elements (Zn, Cu, Cr, and Cd) in cattail (Typha latifolia L.) in a growth room. Four cattail seedlings were...