Eutrophication is a nutrient enrichment of dams and lakes. Increased eutrophication in dams results in blooms of cyanobacteria. Cyanobacteria are troublesome as they form massive surface scums, impart taste and odour to the water. Some strains of cyanobacteria such as Microcystis aeruginosa are dangerous to humans and animals. They produce toxins that can kill animals drinking the contaminated water and have also been implicated in human illnesses. The study investigated the effectiveness of techniques deployed in controlling cyanobacterial growth in Rietvlei, Roodeplaat and Hartbeespoort Dams. This was done by interpreting data from April 2010 to March 2012. The conditions in the three dams show that Microcystis produced toxins in the summer season and all the variables analysed were favourable for the production of toxins. The methods deployed to rehabilitate the dams do not completely solve the problems of toxins experienced by the dams. / Environmental Sciences / M. Sc. (Environmental Management)

Eutrophication is a nutrient enrichment of dams and lakes. Increased eutrophication in dams results in blooms of cyanobacteria. Cyanobacteria are troublesome as they form massive surface scums, impart taste and odour to the water. Some strains of cyanobacteria such as Microcystis aeruginosa are dangerous to humans and animals. They produce toxins that can kill animals drinking the contaminated water and have also been implicated in human illnesses. The study investigated the effectiveness of techniques deployed in controlling cyanobacterial growth in Rietvlei, Roodeplaat and Hartbeespoort Dams. This was done by interpreting data from April 2010 to March 2012. The conditions in the three dams show that Microcystis produced toxins in the summer season and all the variables analysed were favourable for the production of toxins. The methods deployed to rehabilitate the dams do not completely solve the problems of toxins experienced by the dams. / Environmental Sciences / M. Sc. (Environmental Management)

Effluent from on-site sewage treatment and disposal systems (OSTDS) is generally known to impact groundwaters and surface waters with nitrogen (N) and phosphorus (P) and other contaminants. Little research has quantified this problem along the Indian River Lagoon (IRL), especially in Indian River County (IRC) where there are 26,660 active systems. This study assessed the effects of OSTDS on contamination of surface and groundwaters along three urbanized canals and the St. Sebastian River in IRC, all of which flow into the Central IRL. Multiple lines of evidence were used to define the source of the nutrient loadings including the novel approach of using the artificial sweetener, sucralose, as an indicator of human sewage impact. Results indicate that areas with high densities of OSTDS are contributing N to surface waters and elevating N:P ratios through submarine groundwater discharge and promoting eutrophication in the Central IRL. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

[Truncated abstract] The use of constructed wetlands for tertiary purification of municipal wastewater has received increasing attention around the world because direct discharge of secondary-treated municipal wastewater to water bodies has caused eutrophication. Plant species selection and vegetation management may enhance nutrient removal efficiency in constructed wetlands. However, there is a lack of knowledge on the relations between plant growth and nutrient removal efficiency in constructed wetlands. The objective of this study is to better understand how plant growth and resource allocation are influenced by nutrients in wastewater and how nutrient removal efficiencies are affected by plant species and vegetation management. The preliminary experiment was conducted to select macrophytes, especially ornamental species, to grow in the wastewater in the wetland microcosms. Ten plant species, comprising six ornamental species: Alocasia macrorrhiza, Canna indica, Iris louisiana, Lythrum sp., Zantedeschia aethiopica, Zantedeschia sp., and four sedge species: Baumea articulate, Baumea juncea, Carex tereticaulis and Schoenoplectus validus, were planted in the wetland microcosms and fed a simulated wastewater solution in the concentrations similar to the secondary-treated municipal wastewater. C. indica has shown vigorous and healthy growth, and a relatively high potential of rooting-zone aeration and nutrient removal efficiency. B. articulata and S. validus also showed relatively high nutrient removal efficiency. ... The high nutrient availability and optimum N/P ratio were required for stimulating plant growth, resulting in allocation of more resources to above-ground tissues compared to below-ground parts, and enhancing nutrient removal efficiency. Nutrient removal efficiencies were significantly influenced by growth of C. indica and S. validus, nutrient loading rates and N/P ratios in the wastewater. The nutrient uptake kinetics of C. indica and S. validus were investigated to elucidate the differences in nutrient uptake between species. Wetland plant species have shown differential nutrient uptake efficiency and different preferences for inorganic N source, with C. indica preferring NO3-N and S. validus preferring NH4-N. C. indica had greater capacity than S. validus to take up PO4-P when the concentration of PO4-P in the solution was relatively low, whereas S. validus was more capable than C. indica to take up NO3-N when the concentration of NO3-N in the solution was relatively low. The PO4-P uptake capacity was higher in younger than older plants. Overall, the study has suggested that different plant species have differential capacity to take up nutrients. In addition to nutrient uptake, plants have significant other roles in terms of nutrient removal from the wastewater (such as leaking oxygen into the rhizosphere in which oxidation of substances like ammonia can occur). The properly high nutrient availability and optimum N/P ratio are required to stimulate the plant growth, resulting in enhancing the treatment performance in the wetlands. These findings have important implications for improving our ability to engineer ecological solutions to the problems associated with nutrient-rich wastewater.

NCRP report No.160 states that medical exposure increased to nearly half of the total radiation exposure of the U.S. population from all sources in 2006 (NCRP 2009). Part of this increase in exposure is due to the rise in nuclear medicine procedures. With this observed growth in medical radionuclide usage, there is an increase in the radionuclide being released into wastewater after the medical procedures. The question then arises: what is the behavior of medical radionuclides and their impurities in the wastewater process? It is important to note that, often, medical radionuclides are not exactly 100% radionuclide pure, but they meet a certain standard of purity. Of particular interest are the longer lived impurities associated with these medical radionuclides. The longer lived impurities have a higher chance of reaching the environment. The goal of this study is to identify the behavior of medical radionuclides and their impurities associated with some of the more common radiopharmaceuticals, including Tc-99m and I-131, and locate and quantify levels of these impurities in municipal wastewater and develop a model that can be used to estimate potential dose and risk to the public. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from May 24, 2012 - May 24, 2014

Historical environmental changes in two shallow, unstratified, estuaries in Buzzards Bay, Massachusetts are compared, using three diatom paleo-production indicators: sedimentary biogenic silica (BSi), BSi flux and ratio of Centric to Penate diatoms. Both estuaries were exposed to pollution. New Bedford Harbor (NBH) has a history of intensive nutrient loading and industrial pollution, while the control site, Apponagansett Bay, has lower levels of nutrient loading. Consideration of local precipitation history and diatom parameters suggests that salinity-driven changes in diatom production are negligible. Over the past ∼350 yrs, BSi concentrations and fluxes are higher in NBH. Thus, overall diatom production is sensitive to nutrient enrichment and less responsive to industrial pollutants. The relationship between the C/P ratio and environmental conditions is not as clear, possibly due to its dependence on eelgrass abundance. The uniqueness of this study lies in its use of the parameters combined, as well as its geographic setting.

Water quality parameters including ammonia, nitrate+nitrite, phosphate, total suspended solids, Escherichia coli, and dissolved oxygen were statistically evaluated from sampling data collected by the Bureau of Water Quality (City of Muncie, Indiana) at five sampling locations in Delaware County over a five-year period (2002-2006). These data were also compared with water quality standards/guidelines to determine how sample values compared to acceptable levels of these parameters. Friedman's non-parametric test was used to study the differences between sites and seasons. Spearman's Rank Correlation was used to study the correlations between water quality parameters at each sampling site. Significant differences were observed for individual parameters when evaluated relative to sampling location based on pooled monthly collected data as well as data evaluated on a seasonal basis. These differences indicated the fact that different sources were responsible for observed concentrations at a particular location and that seasonal phenomenon such as precipitation, discharge and temperature also affected sample concentrations at individual sampling locations. Most notable were differences in geometric mean concentrations of ammonia, nitrate+nitrite, phosphate and E. coli upstream and downstream of the wastewater treatment plant (WWTP), with highest concentrations downstream, indicating the significant impact of the WWTP on water quality in the White River. Significant correlations observed among some study parameters suggested that sample concentrations may have been affected by similar sources. In comparison to water quality standards, concentrations of ammonia, nitrate+nitrite, phosphate, and E. coli were at unacceptable levels at most sampling locations. / Department of Natural Resources and Environmental Management

Stream samples were tested at 18 sites in three subwatersheds of the Upper White River for ammonia, nitrate, orthophosphate, atrazine, and diazinon. Nutrient results were tested with a general linear model and in linear regressions with selected landuse characteristics. A critical areas index for surface runoff of pollutants was created using a geographic information system. Comparisons were made between results obtained by Ball State University and by the Muncie Bureau of Water Quality and other outside laboratories. Most mean concentrations of nutrients were likely related to combinations of agricultural and residential landuse factors. Only concentrations of ammonia and orthophosphate were significantly related (a = 0.05) to any landuse characteristics. Atrazine levels were high in the spring, but decreased in the fall. Results suggest that improved or increased best management practices should be implemented in these subwatersheds to control non-point source pollution of the streams. / Department of Natural Resources and Environmental Management

Norovirus (NoV) is a significant cause of gastroenteritis globally, and the consumption of oysters is frequently linked to outbreaks. Depuration is the principle means employed to reduce levels of potentially harmful agents or toxins in shellfish. The aim of this thesis is to construct mathematical models which can describe the depuration dynamics of water-borne pathogens, and specifically examine the dynamics of NoV during depuration for a population shellfish. Legislation is currently under consideration within the EU by the Directorate-General for Health and Consumers (DG SANCO) to limit the maximum level of NoV that consumers are exposed to via this route. Therefore it is important to the utility of the thesis that any models constructed should incorporate control measures which could be used to implement minimum NoV levels. Doing so allowed calculation of minimum depuration times that would be required to adhere to the control measures incorporated into the models. In addition to modelling the impact on pathogens during the depuration, we wished to gain some insight into how the variability, and not just the mean levels, of water-borne pathogens can be as important with respect to the length of depuration required to minimise any food safety risks to the consumer. This proved difficult in the absence of any data sets that can be used to calculate variability measures, as little data is currently available to inform these values for NoV. However, our modelling techniques were able to calculate an upper limit on the variability of water-borne pathogens that can be well approximated by lognormal distributions. Finally we construct a model which provided linkage between the depuration process and the accretion of pathogens by shellfish while still within farming waters. This model proposed that the pulses of untreated waste waters released by sewage treatment works due to high levels of rainfall would be transmitted into shellfish whilst filter-feeding.

Thesis submitted in fulfilment of the requirements for the degree Doctor of Technology: Biomedical Technology in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology 2008 / The quality of South Africa’s water sources is fast deteriorating due to an influx of pollutants from industrial and agricultural areas. In addition, urbanisation has led to the establishment of informal settlements along river systems. This study focuses on the importance of maintaining water quality and the management of water resources in order to ensure its sustainability in South Africa. The primary aim of this study was to determine the extent of bacterial contamination in three rivers namely the Berg-, Plankenburg- and Diep Rivers in the Western Cape, South Africa and to investigate the application of a bioremediation system as a possible treatment technology. Several aspects contributing to the contamination were addressed and different approaches were studied and reviewed. In all three rivers, four sampling sites were identified, which were sampled over a period of 9 to 12 months. Contamination levels for the three rivers were evaluated by applying various enumeration techniques, which could provide an accurate indication of the planktonic bacterial pollution load in the river systems. The Most Probable Number (MPN) technique was used to determine the level of faecal coliforms and E. coli. The highest MPN, faecal coliform and E. coli counts of 3.5 x 107 micro-organisms/100 m , 3.5 x 107 micro-organisms/100 m and 1.7 x 107 micro-organisms/100 m , respectively, were recorded at Site B2 in week 37 in the Berg River. Results showed that in all the river water sampled and evaluated, the total MPN count mostly exceeded the maximum limit of 2000 micro-organisms/100 m (SABS, 1984) stipulated for river water throughout the study period. The heterotrophic plate count (HPC) method was used to determine the number of culturable micro-organisms in planktonic samples, while the flow cytometry (FCM) and epifluorescence microscopy (EM) with different fluorochromes (Acridine orange and BacLight™ Live/Dead stain) were employed to evaluate total bacterial counts in planktonic (water) samples. The highest HPC at the various sites sampled was 1.04 x 106 micro-organisms/m (Berg River, Site B2), 7.9 x 104 micro-organisms/m (Plankenbrug River, Site A) and 1.7 x 105 micro-organisms/m (Diep River, Site B). Total cell counts as high as 3.7 x 107 micro-organism/m (Berg River, Site B2), 5.5 x 108 micro-organism/m (Plankenburg River, Site D) and 2.5 x 109 micro-organisms/m (Diep River, Site B) were obtained by the FCM technique, which were significantly (p < 0.05) higher than the total counts obtained by epifluorescence microscopy. The results thus show that the FCM technique was the most reliable method for determining the total cell count in river water samples. This technique makes use of computer software whereas epifluorescence microscopy involves manual counting which may lead to human error. In addition, the impact of residential, agricultural and industrial areas situated along these rivers was also investigated. Even though exact point sources of pollution could not be determined, it was found that all the sources, such as the storm water drainage pipes, the industrial as well as the agricultural areas, could contribute to increased MPN, heterotrophic and total bacterial counts. This study also aimed at investigating and comparing the microbial contamination levels at various sites in the Plankenburg and Diep Rivers in the Western Cape, South Africa. Sampling of sites along the Plankenburg River started in June 2004 and continued for a period of one year until June 2005. Sampling of the Diep River sites started in March 2005 and continued for a period of nine months until November 2005. Faecal coliform (FC) and E. coli (EC) counts were determined by means of the Most Probable Number technique, the number of culturable cells were determined using the heterotrophic plate count (HPC) technique and total microbial counts were evaluated by Flow cytometric analysis (FCM). The highest microbial counts for the Plankenburg River were observed at site B where the highest MPN, FC, E. coli and total FCM counts of 9.2 x 106 (week 14), 3.5 x 106 (week 39) and 3.5 x 106 micro-organisms/100 m (week 39) and 2.1 x 108 micro-organisms/m (weeks 1 and 39) respectively, were recorded. The highest HPC recorded for the Plankenburg River was 7.9 x 106 micro-organisms/100 m (week 44, site A). Site B is situated close to an informal settlement where waste effluents from storm water drainage pipes enter the river system. In addition, other possible contamination sources included agricultural (site A) and industrial (site C) areas bordering the Plankenburg River. The highest total MPN, FC and E. coli counts in the Diep River were 5.4 x 106 (week 23) and 1.6 x 106 micro-organisms/100 m [FC and E. coli, respectively (both in week 23)], recorded at site B. The highest HPC and total FCM counts of 1.7 x 107 micro-organisms/100 m (week 14) and 2.5 x 109 microorganisms/ m (week 23), respectively, were also recorded at site B. This site was identified as the most contaminated site along the Diep River and served as an accumulation point for waste effluents from the residential and industrial areas, which included paint and machine manufacturers. Other sources situated along the Diep River included storage and maintenance facilities for steel containers, a waste water treatment plant and an oil-refinery. Most of the bacterial counts obtained for the Plankenburg and Diep Rivers exceeded the accepted maximum limit for river water for most of the sampling period. Bacterial species from the Berg- and Plankenburg Rivers were isolated and identified. The presence of various Enterobacteriaceae species isolated at all the sites in both rivers confirmed faecal contamination of these water sources over the entire sampling period. Opportunistic pathogens such as Klebsiella sp., Serratia sp., Enterobacter sp., Shewanella sp., Aeromonas sp., Pseudomonas sp., Acinetobacter sp. and Citrobacter freundii as well as pathogens such as Bacillus cereus and B. anthracis were also identified in both river systems. All the respective articles are presented in the required format of the journal in which the article has been published or submitted to.