The extent of agricultural drainage has created concern for its potential undesirable effects on surface water quality. Land applications of liquid manure on tile drain fields have the potential to transport solutes and bacteria to the drains following precipitation or irrigation events and many times are directly sent to a surface water body, and have been documented as a source of contamination of surface waters. This study determined the potential for and magnitude of E. coli and solute migration to tile drains through the soil profile. Water from subsurface drains was analyzed for chemical and bacterial composition following tracer applications. Two sites were selected for the study to determine transport at large (field) and small (plot) scales. At the large-scale site, both tracers, bacteria (E. coli and Total Coliform) and Amino-G (a conservative tracer), were used to monitor the speed of transport from the surface to the tile drain following liquid manure applications, tracer applications and additionally precipitation events. The concentrations of E. coli were monitored every hour for 76 days during the spring. Both tracers, bacteria and Amino-G, were detected in the tile drainage shortly after precipitation events. The peak concentration of E. coli was observed to be 1.2 x 10⁶ CFU/l00mL. These elevated concentrations of E. coli might be attributed to the characteristics of the soil, high organic matter and well-structured clay soils. Both the rapid breakthrough of tracer to the tile drain and the peaks of tile water temperature during precipitation events provided evidence of macropore flow. Antecedent soil moisture and warmer temperatures appeared to provide ideal conditions for bacteria growth. The small-scale study site was selected for a more focused study. The purpose of this site was to quantify more accurately the percent mass of surface applied tracer that was transported to the tile drain, allowing mass balance calculations. Experiments were conducted during the summer to control the rate and total amount of irrigation. Amino-G readings were taken every 10 seconds for 125 hours of continuous irrigation. Tracer applications were conducted at runoff and non-runoff conditions. Both types of tracer applications had Amino-G breakthrough in less than 10 minutes after initiation of irrigation. Tracer applied at runoff rates resulted in 4 to 17 times more total tracer mass migrating to the tile drain than when applied at non-runoff rates. The total mass of Amino-G migrating to the tile drain during non-runoff conditions depended on the total volume of applied tracer, regardless of the tracer concentration. For an application of 5.6 mm at 12 mg/L, 5.7% of the total applied tracer migrated to the tile drain, whereas for an application of 1.9 mm at 27.7 mg/L only 2.8% of the total applied tracer migrated to the tile drain. Tile flow response to irrigation experiments appeared to be governed by soil moisture. Lysimeter samples were taken continuously every 4-8 hours until the 94th hour after tracer application. Tile water concentrations were consistently greater than concentrations found in the deeper suction lysimeters at corresponding times, providing further evidence of preferential flow. E. coli transported through the soil and into the drains were demonstrated to be event-driven by precipitation events and irrigation events. In addition, the characteristics of this type of soil - the high clay content, the well-defined structure, the high level of organic matter and rich biological activity has been known to enhance the preferential pathways and transport processes in the soil profile, resulting in rapid transport of surface applied solutes and effluents to tile drains. / Graduation date: 2003

The purpose of this work was to determine if environmentally-relevant concentrations of chlorpyrifos and copper, two commonly detected chemicals in Western surface waters, can negatively impact the biological health of salmonids. Both compounds are highly neurotoxic to fish, but each with distinct biological target sites and mechanisms of action. We used common biochemical and physiological indicators of toxicity, and correlated these effects with potentially significant behavioral alterations. For chlorpyrifos, the mechanism of toxic action is the inhibition of acetylcholinesterase (AChE) throughout the peripheral and central nervous system. Here, we conducted biochemical assays of AChE activity in brain and muscle tissues after exposing steelhead trout (Oncorhynchus mykiss) and coho salmon (0. kisutch) to chlorpyrifos for 96 hours. We then correlated the AChE inhibition with behavioral impairment in swimming and feeding activities. In juvenile steelhead and coho exposed to 0.6-2.5 ��g/L chlorpyrifos, AChE activity was inhibited between ~10-65%. This biochemical indicator was significantly correlated with changes in behavioral patterns. Spontaneous swimming rates were reduced ~30-80% in the exposed fish, and strikes at food items (brine shrimp) were reduced ~10-70%. For copper and some other neurotoxicants, the olfactory nervous system is a sensitive target site in fish. The highly-developed olfactory system in salmonids is particularly susceptible to toxic insult by dissolved chemicals since receptor neurons are in direct contact with the aquatic environment. Here, we used electrophysiological techniques to record odor-evoked responses from the sensory epithelium and the olfactory bulb as direct measures of olfactory function in juvenile coho salmon. In fish exposed to copper, chlorpyrifos, or esfenvalerate for 7 days, field potentials recorded from the sensory epithelium and the olfactory bulb showed reduced or obscured olfactory responses to two classes of odorants, which activate non-overlapping populations of receptor neurons. To determine if this reduced sensory input can subsequently alter or diminish olfactory-mediated predator avoidance behaviors, paired physiological and behavioral tests were conducted on juvenile coho exposed to copper. In fish exposed to 2-20 ��g/L copper for 3 hours, olfactory sensitivity was reduced by ~50-9O%. When these fish were presented with a predatory alarm cue (conspecific skin extract), fish with reduced olfactory function increasingly failed to exhibit antipredator behavior. In the following experiments, we show that chlorpyrifos and copper can impair the biochemical and physiological biology of salmonids at environmentally-relevant concentrations, and that these sublethal effects can alter potentially important behavioral patterns. / Graduation date: 2004

The agricultural production of peppermint has been shown to contribute significant quantities of nitrate-nitrogen to groundwater recharge. In an effort to provide new tools for increasing nitrogen efficiency within peppermint production, three research questions were proposed: i) How should plant tissue samples be collected to achieve the greatest precision when using the mint stem nitrate test for nitrogen management?; ii) What is the consumptive use of water by peppermint in the post-harvest period?; and iii) How does irrigation uniformity affect nitrate loading to groundwater when N is supplied through chemigation? In the first investigation, structured field experiments were designed and conducted on commercial peppermint fields to isolate potential environmental, management, and sampling influences on stem nitrate test results. The most significant effects observed were those of the type of stem material collected (a 441% effect at p<0.001) and the number of stems collected to estimate the field mean concentration. It was found that the variance of the sample population and the number of stems required for a given sampling error could be greatly reduced by only collecting stems from within the plant canopy. Less pronounced but statistically significant differences in stem nitrate concentrations were produced by variations in solar radiation on hourly (a 17% effect at p<0.05) and daily (a 29% effect at p<0.01) scales. In an analysis of stem nitrate spatial variability, a purely random distribution of stem nitrate concentrations was observed on the 1-150 m scale. For the second investigation, a field study was conducted to measure the consumptive use of peppermint in the post-harvest period and to develop crop coefficients (Kc) used to predict evapotranspiration rates. The soil water balance was measured on two fields with a neutron moisture probe over an 80 day period. Over the 49 days following harvest, a cumulative consumptive use of 96 mm was observed. Basal crop coefficients increased from near zero to approximately 0.40 within 40 days post-harvest. The third, and final, investigation developed a simple heuristic statistical model to explore the effective adequacy of chemical application as influenced by the uniformity of irrigation. To perform this analysis, an expression was presented whereby irrigation distribution parameters for the normal, or Gaussian, model could be derived from common irrigation design terms. The results of this model indicate that the effective chemical adequacy is greatly compromised when the irrigation uniformity coefficient is low and/or the design irrigation adequacy is high. / Graduation date: 1998

It is the responsibility of humans, as environmental stewards, to monitor our impact on the environment so that efforts can be made to remediate the effects of our actions and change behaviors. To better understand our environmental footprint, sensitive and simple analytical methods are needed to quantify the contaminants that we discharge into our natural surroundings. Emerging environmental contaminants are of particular concern because there is limited or no information available on their occurrence, fate, and toxicity. As a result, the implications of using these chemicals are not well understood. Therefore, accurate environmental data are needed to help scientists and government policy-makers make informed decisions on research directions and chemical regulation. However, challenges exist for the analysis of emerging contaminants, including a lack of suitable analytical standards and internal standards, their broad range of chemical properties, and that they are frequently present at trace levels and in complex environmental matrices. The work presented within this dissertation focuses on the development, validation, and comparison of analytical methodologies based on large-volume injection high-performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS) for the analysis of emerging environmental contaminants in aqueous environmental matrices. Large-volume injection (e.g. 900 μL to 4,500 μL) is an analytical technique that eliminates sample preparation associated with pre-concentration by injecting larger-than-traditional volumes of sample directly onto a HPLC column. In Chapter 2, a direct aqueous large-volume injection method was developed and validated for the quantification of natural and synthetic androgenic steroids in wastewater influent, wastewater effluent, and river water. This method was then applied to hourly composite samples of wastewater influent that were taken over the course of a single day. This work expands on the research of the endocrine-disrupting chemicals that occur in wastewater and provides an estimate of the community use/abuse of synthetic androgenic steroids. Environmental analytical methods should be as environmentally friendly as possible and efforts should be made to reduce the waste generated during analysis while maintaining analytical performance. In Chapter 3, a method based on large-volume injection was compared to two methods based on solid-phase extraction. The purpose of this comparison was to demonstrate that the same method performance could be achieved by large-volume injection as that by solid-phase extraction while reducing waste, labor, and costs. Estrogens and perfluorinated chemicals were used as model analytes and wastewater influent was used as a model matrix. The results of this study provide convincing reasons for analysts to adopt large-volume injection as an alternative to solid-phase extraction. In Chapter 4, a novel analytical method was developed and validated to quantify newly-identified and legacy fluorinated chemicals in groundwater. The final method combined micro liquid-liquid extraction, non-aqueous large-volume injection, and orthogonal chromatographic separations. Ground water samples collected from six different U.S. military bases was used to demonstrate the method. This is the first report on the occurrence of these newly-identified fluorinated chemicals in any environmental media and serves as a rational for conducting future research on their environmental fate and toxicity. The breadth of the research presented in this dissertation advances the field of environmental analytical chemistry in several areas. First, classes of environmental contaminants for which there is limited (synthetic androgenic steroids) or no (newly-identified fluorochemicals) environmental data were studied. Second, novel methods based on direct-aqueous and non-aqueous large-volume injection were developed and validated to identify and quantify those contaminants. Third, it was demonstrated that solid-phase extraction is not a "necessary evil" needed to develop methods for emerging environmental contaminants in aqueous matrices. Finally, this work is a platform on which other environmental chemists can use to develop large-volume injection methods in the future. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from Aug. 2, 2012 - Feb. 2, 2013

No description available.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Biological Sciences / Master / Master of Philosophy

Extended producer responsibility (EPR) as a holistic approach to product stewardship has been increasingly incorporated into environmental policy agenda in the last two decades. One major expectation of EPR is to prevent environmental problems at source by providing appropriate incentives for product eco-design changes. However, available studies empirically examining the actual influence of EPR on eco-design are limited. This research therefore aims to fill the research gap by evaluating the effectiveness of existing EPR programmes in driving eco-design changes from the perspective of China’s electrical and electronic (EE) industry, and shed some light on the prospects of EPR development in China. Based on the analytical framework developed from reconstructed intervention theory, three intensive empirical studies have been carried out. The first study examines the perception and responses of 50 China’s EE manufacturers regarding the EU EPR programmes (i.e. the WEEE and RoHS Directives). The second study investigates the responses of 36 China’s EE manufacturers to the Chinese EPR programmes (i.e. China WEEE and China RoHS legislation) and identifies possible factors that exert causal impact on the occurrence of eco-design. In order to gain a deeper insight into the practical manifestations of effective EPR implementation in the private sector, three company case studies have been conducted in the third stage of the research, serving as an important supplement to the first two studies. The three studies show that EPR programmes in a stringent regulatory approach focusing on products’ environmental properties such as substance bans can exert strong influence on design changes. However, mandated recycling legislation seems to have little driving effect for companies to change product design. The research points to the weakness of collective producer responsibility that is currently adopted in many EU Member States for WEEE implementation in achieving continuous eco-design improvements. It highlights the significance of realising the principle of individual producer responsibility in EPR programmes for achieving this goal. Based on an attributability assessment, the research further shows that there are a number of factors that influence the adoption of eco-design in China, and the link between legislative EPR programmes and eco-design is complex and evolving. Not only may the EPR programmes have different existing, anticipating and potential effect on the incorporation of eco-design, but they may have very different driving influence on environmental laggards and leaders. In this regard, this research suggests that there is no one-stop solution for EPR in China. A mixed mechanism that integrates various policy instruments such as administrative, economic and informative instruments, in conjunction with cooperation and infrastructure facilities, would be the most effective means to implement EPR in the context of China, thereby achieving the goal of sustainable production and consumption. / published_or_final_version / Kadoorie Institute / Doctoral / Doctor of Philosophy

In the area of indoor built environment modelling, the main focus was usually put on the accuracy of the modelled equipment within the given environment. There was not enough attention placed on the modelling of occupants inside the building, who represent the ultimate end?users and should be the most important element of an indoor built environment model. This deficiency was mainly due to the difficulties of modelling human behaviour with the traditional mathematical modelling methods usually adopted in the field. Therefore, in order to model the occupants more effectively, a more appropriate alternative approach is needed. This thesis examined the suitability of agent?based modelling and simulation (ABMS) for the indoor built environment. Philosophies of ABMS for the built environment were discussed, with the natural flow of progression stages in indoor built environment models outlined and explored, showing the need for switching a problem of simplicity to one in which a complex organised system was defined. Scenarios of single active agent case in ABMS for indoor built environment were used to demonstrate the effectiveness of this approach, with the finding that ABMS was versatile in modelling different types of occupants. It provided an illustration of the difference between people with different sensation time, and estimated energy savings between occupants with varied understanding of the environment. A classification scheme for different types of indoor built environment models with different levels of complexities was proposed and discussed. Based on the classification scheme, models with different levels of complexities were applied to the same building to explore the feasibility and practicality of the scheme. It was found that the simulation results provided insightful figures on probable energy consumption for different types of occupants and their crowd behaviour when interactions between occupants were considered. Findings included the amount of energy saved (around 10%) by a knowledgeable occupant over a less informed one, and the tendency for the majority (?66%) of occupants trying to save energy by assessing the environment themselves under different conditions. To further assist building management and the implementation of ABMS approach in built environment for simulations, the concepts of geographic information system (GIS) were modified for applications in the indoor environment, based on its similarity with ABMS for a grid?based environment. A prototype program was developed to test the applicability of the proposed concepts, with OPC connectivity for connections to real?world equipment. It was found that the idea of indoor GIS helps to solve problems such as the facility layout problem or the difficulties of information storage/retrieval in facility management, and this concept also integrated well with ABMS. With the successful modelling of different types of occupants and simulation results consistent with real data, it can be concluded from the work that ABMS is a promising approach for future generations of indoor built environment models. Also, with the inspiring framework of indoor GIS, the combination of ABMS and GIS in an integrated platform will certainly bring a powerful tool to the field. / published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

Since globalization have promoted the ornamental trade and accelerated the movement of freshwater fishes around the world, non-native species pose a high potential to be released into local freshwater habitats, and to spread and establish as invasive and nuisance species with adverse ecological, economic and social impacts. This study aimed to investigate the potential of the ornamental freshwater fish trade as an invasion pathway in Hong Kong, assess the ecological risk of common aquarium freshwater fish species being traded in the local market, identify species of concern and recommend ways for their management with a view to minimizing biological invasion risk associated with the aquarium trade. Based on a series of systematic market surveys through visiting 46 major aquarium shops in Hong Kong, about 167 freshwater fish species were found in the local aquarium trade between summer 2012 and spring 2013. Twenty-five species were randomly selected to go through two standard ecological risk assessment protocols (i.e., FISK & IFRA). The assessment results indicated that the goldfish (Carassius auratus), common carp (Cyprinus carpio carpio) and Wel’s catfish (Silurus glanis) have a high invasive risk in Hong Kong. The ornamental trade is one of the significant sources of freshwater fish invasions in Hong Kong. An integrated invasive species management plan is recommended to apply and implement in Hong Kong. The key elements of this management plan include (1) development of law and regulation on invasive species, (2) establishment of an early detection programme (like the current study), (3) implementation of control and eradication measures, (4) setting up invasive species handling guidelines and (5) fostering public education programs on biological invasion prevention. The plan should involve the participation of all stakeholders, such as government, industry, social community organization and public in order to engage them to jointly effectively tackle and manage invasive species and thereby conserve Hong Kong’s aquatic biodiversity. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management