Tetrazolium reduction assays, phospholipid analysis, and 16S rRNA (rDNA) sequence analysis were applied to assess the distribution, composition and activity of microbial communities developing in biofilters treating non-ozonated and ozonated drinking water. The response of media-attached biomass to both operating temperature (38C vs. >128C) and ozone application point was assessed. As judged by...

-Edible garden plants (carrots, spinach, and tomatoes) were grown to maturity inside continuous air-flow bioreactors, and were regularly irrigated with synthetic groundwater containing a mixture of '4C-labeled and unlabeled TCE. Two dose levels were tested (about 560 Fg/L and 140 Fg/L). Following TCE exposure for 31 to 106 days, different plant tissues and bioreactor compartments were analyzed ...

ÐA protocol was developed to rapidly assess the eciency of chemical washing for the removal of excess biomass from biotrickling ®lters for waste air treatment. Although the experiment was performed on a small scale, conditions were chosen to simulate application in full-scale biotrickling ®lters. From 18 treatments with di€erent combinations and concentrations of chemicals, only washing with 0...

Rigorous techniques for consistent initialization of differential–algebraic systems (DAEs) are in general difficult to apply. Even worse, since initialization algorithms generally require the solution of a set of non-linear algebraic equations, they may not even converge. Hence, simpler approaches for initialization are of considerable interest in the numerical implementation of DAE models. In ...

It is well known that the permeability and density of an aggregate decreases with its size, affecting its settling velocity and coagulation rate (rate of particle capture) with other particles. This change in aggregate density with size can be described by fractal scaling relationships. Two distinctly different fractal scaling approaches, however, have been used to describe aggregate permeabili...

ÐMicrobial pathogens are one of the major health risks associated with water and wastewaters. Current methods for the detection of pathogenic viruses, bacteria, protozoa and helminths tend to be inaccurate, time consuming and expensive. As a result, indicator bacteria are commonly used to determine the relative risk of faecal contamination and the possible presence of pathogens in water and was...

Sorption of P to the bed sand medium is a major removal mechanism for P in subsurface flow constructed reed beds. Selecting a sand medium with a high P-sorption capacity is therefore important to obtain a sustained P-removal. The objective of this study was to evaluate the P-removal capacities of 13 Danish sands and to relate the removal to their physico-chemical characteristics. The P-removal ...

Ethanol-blended gasoline has been used in Brazil for 20 years and, probably, is going to be more widely used in North America due to the MtBE environmental effects on groundwater. The potential impacts caused by the presence of ethanol in UST spills are related to the co-solvency effect and the preferential degradation of ethanol over the BTEX compounds. These interactions may increase the leng...