Correlative Field and Laboratory Microcosm Approaches in Ascertaining Xenobiotic Effect and Fate in Diverse Aquatic Microenvironments.

The impact of a multitude of toxic chemicals, or xenobiotics, on diverse aquatic environments and the need to consider such factors in adjacent land use and disposal situations has necessitated the development of usable analytical predictive approaches. A microbial and enzymatic assessment protocol for determining the environmental effect and fate of these manufactured chemicals in coastal wetlands was devised. The protocol combined in situ analyses of interrelated soil/sediment microenvironments with statistical and analytical laboratory microcosm approaches in presenting valid predictive models of xenobiotic fate and effect. The general objective of this combined field/laboratory analysis was to provide a better understanding of biotic and abiotic factors that influence toxic chemical breakdown over a range of salinity conditions. An overview of research in the area of microcosm development and design was first outlined followed by a technical description of two aquatic microcosm systems developed in this study. Variations in microbial diversity, enzyme activity, microbial ATP, and substrate uptake in ecologically-diverse, interrelated coastal soil/sediment microenvironments were examined to develop baseline protocols for combined in situ/microcosm fate and effect analyses. Strong correlative linkages were established between control microcosm and in situ measurements. Environmental impact was assessed using these correlative field approaches in a toxicant runoff incident in a freshwater swamp forest habitat. A testing protocol for examining microcosm features and operating parameters was also presented. Sequential and differential introduction of a toxicant into microcosm systems assessed the importance of pre-exposure and adaptation responses in environmental fate and effect estimates. Several industrial source phenols were used in a test case to evaluate overall microcosm performance. Relative biotransformation and biodegradation was dependent upon ecological factors such as salinity, temperature, pH/Eh and water-sediment ratio. In addition, the chemical structure of the phenolic compound itself was a key factor in compound disappearance and in its effect on important food web substrate rates, i.e., chitin degradation, in wetland systems. Biotransformation and biodegradation kinetics of several toxicant classes were examined with microcosm mathematical model estimates comparing closely to chromatography residue data and in situ results. A ranking criteria of relative toxicity for potentially hazardous chemical classes in coastal wetlands was achieved

Activated Sludge and Other Aerobic Suspended Culture Processes

© 2011 by the authors. A review of the literature published in 2008, 2009 and 2010 relating to activated sludge treatment of wastewater is presented. The review considers information on the topics of modeling and kinetics; process microbiology; nitrogen and phosphorus removal; treatment and effects of xenobiotics; oxygen transfer; and solids separation

Crude Oil

Petroleum crude oil is the main energy source worldwide. However, global fossil fuel resources and reservoirs are rapidly and disturbingly being depleted. Thus, it is particularly important to shed light on new techniques developed for economic production and better utilization of crude oil. In addition, the processes involved in the production, refining, and transportation of crude oil are environmentally hazardous. It is essential to develop cleaner technologies and to find innovative solutions to overcome these problems. Over four sections, this book discusses materials used in cracking crude oil and improving its specifications, methods for reducing or eliminating the hazardous effects of petroleum pollution, and the environmental effects of crude oil, as well as presents case studies from different countries

Phytoforensics on energetics: novel plant tissue measure approach and modeling

Explosives and energetics are common soil and groundwater pollutions. This research was to develop novel phytoforensics approaches on energetics. Four different plants species, including woody perennial trees and monocot grasses, were planted both in soil and sand reactors with continuous exposure to a mixture of explosives in the greenhouse. Time dependent assessments were carried out to determine kinetic mechanisms of uptake, transport and accumulation. Plant concentrations were analyzed by both traditional solvent extraction and novel sap analysis methods. A dynamic soil-plant system model was developed to quantify the relationship between tissue concentration and soil pore water concentration for non-volatile organic chemicals with root pathway only. The model included processes of diffusion exchange between root and soil, mass flow in xylem, metabolism and chemical equilibrium in soil and plant interior. The novel plant analysis method with sap extracted by freeze-centrifuge treatments was validated by solvent extract method on the range of plant species and tissues. The novel approach is rapid, cost effective and labor saving and does not require any soil or water sampling, thereby can access vast field samples not practical previously. The Stella® soil-plant system model was effective in estimating the concentrations in soil pore water, plant sap and tissue from dosing concentration input in the experimental settings of this work. The model can be applied for non-volatile compounds and different conditions with only minor adaptions and might be the base of improvement of soil-plant system models for phytoforensics. The phytoforensic approach was validated on RDX and HMX by both experimental results and simulated results as strong correlation were achieved between plant concentration and exposure concentration --Abstract, page iii

Microbial degradation of plastics: Biofilms and degradation pathways

Plastics are recalcitrant polymers released in the environment through unpredicted use leading to accumulation and increased water and soil pollution. Transportation of these recalcitrant polymers in agricultural soil, sediment, and water has been causing concerns for environmentalists. Biofilm community adhered on plastic polymers have a significant contribution in their degradation as they warrant bioavailability of substrates, sharing of metabolites and increased cell viability thereby accelerating biodegradation. Metabolic enzymes of the microbes can be exploited as a potent tool for polymer degradation. However very little or no reports are available about the influence of biofilm and plastic degradation and vice versa. The present chapter reports the impact of biofilm microbes in the degradation of commonly used plastics. Furthermore, potent microorganisms and their interactions with the plastic surface has been deciphered, which would serve as a better understanding of the utilization of biofilm-based methods in the development of plastic waste management

Evaluering av nedbrytningsegenskaper for utvalgte offshorekjemikalier

Project manager Aina C. Wennberg and Karina PetersenA review of biodegradation data for specific oil field chemicals and chemical groups were performed in order to evaluate if the current categorisation of these were appropriate based on the biodegradation properties. Data were compiled from databases like ECHA and MITI and from the literature. For compounds with limited or inconclusive test data, biodegradation was also estimated by the BIOWIN models, and the EAWAG-BBD pathway prediction system was used to predict plausible biodegradation pathways. A weight of evidence approach was used to assess the compiled information and a conclusion regarding categorisation of the single chemicals and/or chemical groups were performed whenever possible. For most compounds, no clear conclusion on the biodegradability could be drawn. Only two of the investigated compounds, benzotriazole and N-methyldiethanolamine, were assessed to very likely and likely have a biodegradability of less than 20% in seawater.Norwegian Environment Agenc