Making the most of Information from Environmental Monitoring Systems

2010 S.C. Water Resources Conferences - Science and Policy Challenges for a Sustainable Futur

Integration of Environmental Information Systems

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio

The Carolinas Coastal Ocean Observing and Prediction System: An Infrastructure for Communications and Data Management for Real-Time Environmental Monitoring

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio

Activity and Distribution of Attached Bacteria in Chesapeake Bay

The purpose of this study was to further our understanding of the role of particle-associated bacteria in phytoplankton degradation in the Chesapeake Bay, USA, and to identify environmental parameters that control production by free and particle-associated bacteria. Surface and bottom waters at 10 stations along the length of the Bay were sampled over a 2 yr period. Samples were analyzed for temperature, salinity, chlorophyll, phaeophytin, particulate protein, thymidine incorporation (an estimate of bacterial growth rate), and bacterial total direct counts. Results demonstrated that freeliving bacteria were responsible for most of the total bacterial production, which was correlated with temperature and particulate protein, but not with chlorophyll. In contrast, attached bacteria were much more active than free-living bacteria on a per-cell basis. Cell-specific thymidine incorporation by freeliving bacteria correlated with temperature and particulate protein quantity, whereas that by attached bacteria correlated with temperature, particulate protein quantity and particulate organic quality, as indicated by extent of phytoplankton degradation

Dynamics of Coupled Microbial and Contaminant Transport.

Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. This project's objective is to develop the understanding of the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases. In particular this interdisciplinary research project provides fundamental information on the attachment/detachment dynamics of anaerobic bacteria in heterogeneous porous media under growth and growth-limiting conditions. This is a critical requirement for designing and evaluating in situ bioremediation efforts

Relationship between the adhesive properties of bacteria and their transport and colonization in the subsurface environment. Final report for period September 15, 1996 - September 30, 1999

This research has focused on the attachment of bacteria to solid surfaces and the significance of their adhesion properties in their transport through porous media. Our work has focused on strains of Pseudomonas and a related species Burkholderia cepacia. Most of our experimental strains were isolated from subsurface environments at USDOE experimental field sites. The first portion of this project was conducted at the University of Maryland during 1994-1996, during which two graduates and one graduate student were supported by the award. The project was then continued under contract number DE-FG02-96ER62302 at the University of South Carolina, where one postdoctoral associate has been supported by the award

Dynamics of Coupled Contaminant and Microbial Transport in Heterogeneous Porous Media: Purdue Component

Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. Understanding the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases is a critical requirement for designing and evaluating in situ bioremediation efforts. This interdisciplinary research project, of which we report only the Purdue contribution, provides fundamental information on the attachment/detachment dynamics of bacteria in heterogeneous porous media. Fundamental results from the Purdue collaboration are: (a) development of a matched-index method for obtaining 3-D Lagrangian trajectories of microbial sized particles transporting within porous media or microflow cells, (b) application of advanced numerical methods to optimally design a microflow cell for studying anaerobic bacterial attachment/detachment phenomena, (c) development of two types of models for simulating bacterial movement and attachment/detachment in microflow cells and natural porous media, (d) application of stochastic analysis to upscale pore scale microbial attachment/detachment models to natural heterogeneous porous media, and (e) evaluation of the role nonlocality plays in microbial dynamics in heterogeneous porous medi

The effect of surface free energy and medium surface tension on bacterial attachment to solid surfaces

The process of bacterial attachment to solid surfaces comprises three components, i.e., the bacterial surface, the substratum, and the liquid medium, all of which have been shown to affect the thermodynamics of adhesion. Different bacterial strains and phenotypes can differ considerably with respect to cell surface composition, and thus surface free energy. Accordingly, attachment ability ranges from bacteria which attach readily to surfaces to those which have little adhesive ability. Influence of substratum properties was shown by the relationship between numbers of attached bacteria and substratum work of adhesion for water (WA). Maximum attachment occurred within a substratum WA range of 75 to 105 mJ m−2, but the WA at peak attachment was not the same for all bacteria tested. The liquid medium influences attachment because of the (i) interaction between water and the substratum and bacterial surfaces and the presence of (ii) dissolved macromolecules, which tend to adsorb on surfaces, and (iii) surface active agents which influence surface tension and thus the thermodynamics of adhesion. Dimethyl sulfoxide and a series of low-molecular-weight alcohols were shown to affect numbers of attached cells by affecting liquid surface tension