An increase in anthropogenic activity has led to the heightened levels of pollution entering aquatic systems. These excessive concentrations of heavy metals, nitrogen (N), and phosphorus (P) in water bodies can lead to several adverse impacts, such as eutrophication and human health risks. Therefore, the removal of pollutants from wastewaters, prior to their discharge into the natural environment, is of paramount importance. However, conventional wastewater treatment (WWT) technologies have their limitations; for instance, large capital/operational costs, and incomplete removal of contaminants. Therefore, innovative and more effective treatment technologies are required. Macro-algae typically have high growth and solar energy conversion rates, and are able to sequester nutrients, utilise CO2, and adsorb metals from aquatic environments. Therefore, algae may have potential applications in WWT. Furthermore, costs could be negated by the production of renewable algal biomass which may have a variety of commercially exploitable applications. However, issues such as poor selection of species or cultivation systems, and a lack of understanding of the influence of biological, chemical and physical factors, particularly in a highly dynamic wastewater environments, has led to varied results and prevented algal WWT becoming a widespread reality. In this thesis the algae Cladophora coelothrix and Cladophora parriaudii were studied as potential organisms for implementation into WWT. In addition to the features mentioned above, Cladophora was selected due to its ubiquity, filamentous morphology, which minimises harvesting costs, as well as their natural dominance and bloom forming behaviour in nutrient-rich environments. The influence of dewatering techniques, environmental factors, and nutrient regime upon the growth, nutrient/metal removal, and biochemical composition of the biomass were assessed. The first aspect of the thesis was an abiotic screening process, in order to investigate the robustness of Cladophora and its suitability for WWT applications on a fundamental level. Good rates of growth (4-13.3% d-1) and nutrient removal (45.2-99.9%) were observed throughout the screening process, except under the most extreme of conditions, e.g. pH 3. This indicated that Cladophora are potentially suitable for treating a broad range of wastewaters and merit further research to improve its potential applicability for WWT applications and commercial realisation. For instance, developing a reliable and accurate method for fresh weight (FW) assessment and hence productivity estimation. The determination of growth rate via FW measurement is one of the most basic aspects of algal biology, yet no standardised method exists for filamentous macro-algae. A variety of FW methods were systematically assessed in terms of accuracy and physiological impact. Methods involving mechanical pressing to dewater the biomass resulted in >25% reduction in the final biomass yield, compared to control cultures. The best method for FW determination employed a reticulated spinner, which was rapid, reliable, and easily standardised. Furthermore, this approach ensured accurate growth estimation with minimal physiological impact, measured as growth, maintenance of structural integrity and nutrient removal. This indicates that the method developed has the potential for widespread application in macro-algal cultivation, as such the method was employed throughout this thesis. The influence of nutrient regime on growth, biochemical composition, and bioremediation capacity was studied for both species of Cladophora. The nutrient regimes tested, representative of a broad variety of wastewaters, included four different N/P ratios, four N sources (ammonium, nitrate, nitrite and urea), and six different equimolar N source combinations provided at two N/P ratios. There were clear differences in performance between the two species, with higher rates of growth observed in all instances by C. parriaudii (4.75-11.2% d-1 vs. 3.98-7.37% d-1). Furthermore, ammonium was removed preferentially, whereas urea was removed secondarily. However, the presence of urea in the medium enhanced growth and uptake of the other co-existing N-forms, and yielded a carbohydrate-rich biomass (37.6-54% DW). These findings demonstrate that algal strain selection is important for treating wastewaters with specific nutrient profiles. In addition, results from this study suggest that nutrient regimes can be tailored to produce biomass with certain properties or characteristics, which make it suitable for further, potentially commercially viable, applications, such as metal biosorption. Since the biochemical characteristics of algal biomass were shown to be affected by nutrient regime, the final chapter describes research investigating the influence of nutritional history on metal biosorption. C. parriaudii was cultivated under different nutrient regimes to produce biomass of varying biochemical composition. This biomass was then used for metal removal, with maximum removal rates ranging from 1.08-2.35 mmol g1, 0.3-0.62 mmol g-1, 0.22-0.48 mmol g-1, and 0.43-0.61 mmol g-1 for Al2+, Cu2+, Mn2+, and Pb2+, respectively. Observations from this work indicate that metal removal is achieved by various mechanisms including adsorption, ion exchange, complexation and micro-precipitation, and that the biosorption efficacy is dependent upon the number and type of functional groups present, which are in turn influenced by the cultures nutrient regime. Overall, this study demonstrates the inter-relatedness of biological, chemical, and physical factors on algal growth, nutrient removal, biochemical composition, and metal biosorption. Results from this work have highlighted the need for standardisation in protocols, increased understanding of the influence of algal selection and nutrient characteristics in bioremediation, and highlighted the importance of considering biological aspects, specifically nutritional history, in biosorption studies.

No description available.

This project addressed if decaying macroalgae and leaf detritus play a major role in the detrital pool of a 7th-order karst riverine system. Decay rates, macroinvertebrates colonization patterns, and change in δ13C values of Cladophora, Platanus occidentalis, and a mix of Acer negundo and A. saccharinum were tracked during summer and autumn months for portions of multiple years. Packs of air-dried Cladophora, Acer, and P. occidentalis were placed in mesh bags and put in groups (n=4) in wire baskets. Seven baskets were submerged in riffle (0.5 m) and deeper run (2 m) habitats. Benthic organic matter was collected with each pack to see if there was a correlation with δ13C signatures of decaying macroproducers to help understand what is entering the detrital food web. Summer 2014 Cladophora and Acer were significantly faster to breakdown than Platanus in both habitats. In autumn‒spring 2014‒2015, Cladophora was significantly faster to breakdown than leaves. Isotopic values of Cladophora were not significantly different than leaves in summer 2014 but were significantly more δ13Cdepleted in the autumn‒spring 2014‒2015. There were no significant differences in macroinvertebrate abundance between the macroproducers for either season. Cladophora had significantly lower macroinvertebrate richness in both seasons, lower shredder abundance, but a significantly higher abundance of clingers. The mean δ13C values of benthic detritus were significantly different than all three macroproducers in the summer and significantly different than Cladophora in the run treatment for autumn‒spring. Seasonality had a strong influence on breakdown rates, leading to greater mass loss of all three species in the warm summer months compared to the cooler autumn‒spring months. The low macroinvertebrate richness and shredder abundance on the decaying macroalga suggests Cladophora may not be consumed by macroinvertebrates but used strictly as habitat. The implication of rapid Cladophora decay during warm seasons, plus few colonizing macroinvertebrate taxa, is that the decaying macroalgae may not pass through a decomposer food web before being remineralized as CO2.

<p>Cladophora cellulose polypyrrole composites are recognized as potential biomaterials with future applications in hemodialysis. In this project conductive Cladophora cellulose-polypyrrole (clad-ppy) composites were prepared using two different oxidizing agents: iron (III) chloride and phosphomolybdic acid (PMo). Cyclic voltammetry, conductivity and Specific surface area measurements were done to characterize the synthesized composites. Furthermore in vitro blood compatibility studies were performed. Whole blood was incubated with clad-ppy membranes and then blood was analyzed for platelet number reduction and complement activation products (C3a and sC5b-9). Clad-ppy with Iron (III) chloride membranes were found to be superior in terms of conductivity and surface area while Clad-ppy with PMo membranes were found to provoke less blood activation. The results indicated that each oxidizing agent gave distinct properties to the composite material.</p>

Cladophora cellulose polypyrrole composites are recognized as potential biomaterials with future applications in hemodialysis. In this project conductive Cladophora cellulose-polypyrrole (clad-ppy) composites were prepared using two different oxidizing agents: iron (III) chloride and phosphomolybdic acid (PMo). Cyclic voltammetry, conductivity and Specific surface area measurements were done to characterize the synthesized composites. Furthermore in vitro blood compatibility studies were performed. Whole blood was incubated with clad-ppy membranes and then blood was analyzed for platelet number reduction and complement activation products (C3a and sC5b-9). Clad-ppy with Iron (III) chloride membranes were found to be superior in terms of conductivity and surface area while Clad-ppy with PMo membranes were found to provoke less blood activation. The results indicated that each oxidizing agent gave distinct properties to the composite material.

The goal of this study was to assess the epiphytic diatom community structure of two host species along a karst gradient in the upper Green River, Kentucky to a gain a better understanding of the role of diatoms in the food web. The host species studied were Podostemum ceratophyllum and Cladophora. Percent cover of P. ceratophyllum and Cladophora were quantified in the four study reaches. The host species were sampled near-shore and mid-channel in each reach in September and October of 2013. After diatoms were extracted from the host and enumerated the density and diversity were quantified. Twelve genera were identified with > 91% of the community in each reach being Cocconeis. The second most abundant genus was Achnanthes or Navicula depending on the reach. The density and diversity of diatoms increased longitudinally going downstream. Exceptions to this trend occurred when high flow events disturbed the community. Within reaches there were no differences in diatom diversity in near-shore and mid-channel habitats. Diatom density in near-shore and mid-channel habitats was only different in the most downstream reach. Cladophora had a community twice as dense as P. ceratophyllum, but less diverse. The results of this study indicate that there are longitudinal differences in diatom communities in the upper Green River and host species are an important factor in determining the community composition. The importance of epiphytic diatoms in the food web, however, remains unclear.

No description available.

<em>Cladophora glomerata</em> is a filamentous green alga that currently forms extensive blooms in nearshore areas of Lake Ontario, eastern Lake Erie, Lake Michigan, and isolated locations in Lake Huron. The biomass, areal coverage, algal bed characteristics, and tissue phosphorus concentrations of <em>Cladophora glomerata</em> were measured at 24 nearshore rocky sites along the northern shoreline of Lake Erie?s eastern basin between 1995-2002. Midsummer areal coverage at shallow depths (&le;5m) ranged from 4-100 %, with a median value of 96%. Peak seasonal biomass ranged from <1 to 940 g m^-2 dry mass (DM), with a median value of 171 g m^-2 DM. Tissue phosphorus varied seasonally, with initial high values in early May (0. 15 to 0. 27 % DM; median 0. 23 % DM) to midsummer seasonal low values during peak biomass (0. 03 to 0. 23 % DM; median 0. 06 % DM). A numerical <em>Cladophora</em> growth model (CGM) was revised and field-tested at 5 sites in eastern Lake Erie during 2002. The CGM is useful for: 1) Predicting <em>Cladophora</em> growth, biomass, and tissue phosphorus concentrations under non-point source P loading with no depth restrictions; 2) providing estimates of the timing and magnitude of the midsummer sloughing phenomenon; 3) determining the contribution of <em>Dreissena</em> invasion to the resurgence of <em>Cladophora</em> in eastern Lake Erie; and 4) developing management strategies for <em>Cladophora</em> abatement. The CGM was applied to investigate how the spatial and temporal patterns of <em>Cladophora</em> growth were influenced by the natural variability in environmental parameters in eastern Lake Erie. Seasonal patterns in <em>Cladophora</em> growth were strongly influenced by temperature, and peak depth-integrated biomass was strongly influenced by both available light and phosphorus. The photosynthetic capacity of field collected <em>Cladophora</em> was a poor predictor of the mid-summer sloughing phenomenon. The CGM, however, predicted that self-shading within the dense <em>Cladophora</em> mats would have caused negative growth rates at the base of the dense mats for 14 days prior to the sloughing event. The metabolic imbalances at the base of the <em>Cladophora</em> mats were driven primarily by the availability of light and were exacerbated by intermediate water temperatures (~23??C). The excellent agreement between model simulations and field data illustrates the ability of the CGM to predict tissue P and growth over a range of sites and depths in eastern Lake Erie and suggests potential for the model to be successfully applied in other systems.

The Baltic Sea is a brackish water that is severely affected by eutrophication. Anthropogenic (human) nitrogen emissions is a contributing factor leading to algal blooms and hypoxic and anoxic seabeds. Municipal wastewater treatment plants account for 27 percent of the nitrogen emissions into the Baltic Proper. According to an article published by Karlsson-Ottosson in the magazine Ny Teknik and the HAVET 2015/2016 report, the increased meat consumption causes difficulties for the sewage treatment plants to purify the nitrogen in the wastewater. This, according to the article and report mentioned, correlates with increased nitrogen emissions from the municipal wastewater treatment plants. The purpose of this study was to investigate if this observed correlation could be confirmed. This study has measured the nitrogen content of urine from participants (n=36) categorized by diet. The diet categories that was included in this study were meat (K), lacto-ovo vegetarian (LOV) and vegan (V). The daily protein intake from the participants in the categories mentioned above was analyzed in this study. Furthermore, the growth of green algae (Cladophora glomerata) and presence of phytoplankton was investigated by fertilizing the collected samples with urine. The results show that there is no difference in nitrogen content in urine, neither in the protein intake between the three diet categories, nor in the case of presence of phytoplankton. Regarding the growth of the green algae, there was a significant difference between the diet groups of meat (K) and control (KON), and also between meat (K) and people on a vegan diet (V). The green algae therefore grew better in brackish water with urine from people who had a meat (K) diet than it did in brackish water with urine from people who had a vegan (V) diet. Though the growth results showed a significant difference between these diet groups (K and V), the alleged correlation between increasing meat consumption and increasing nitrogen emissions from municipal wastewater treatment plants needs to be further studied. / Östersjön är ett brackvattenhav som är svårt drabbat av eutrofiering. Antropogena (mänskliga) kväveutsläpp är en bidragande orsak som leder till algblomning samt hypoxiska och anoxiska bottnar. Kommunala avloppsreningsverk står för 27 procent av kvävetillförseln till Egentliga Östersjön. I en artikel som publicerats av Karlsson-Ottosson samt i rapporten HAVET 2015/2016, orsakar den ökade köttkonsumtionen svårigheter för avloppsreningsverken att rena avloppsvattnet från kväve. Detta korrelerar, enligt artikeln och rapporten, med de ökade kväveutsläppen från avloppsreningsverken. Syftet med studien var att undersöka om korrelationen kunde fastställas. Denna studie har mätt kvävehalten i urin från deltagare kategoriserade efter kosthållning. Dessa kategorier är kött (K), lakto-ovo vegetarian (LOV) samt vegan (V). Proteinintaget hos deltagarna undersöktes, kategoriserat efter ovan nämnda kategorier. Vidare har tillväxten av grönslick (Cladophora glomerata) samt förekomsten av fytoplankton med tillsatt urin från de insamlade proverna undersökts. Resultaten visade ingen skillnad gällande kvävehalten i urin mellan de tre kategorierna. Det var inte heller någon skillnad gällande proteinintaget mellan dessa. Förekomsten av fytoplankton påvisade inte någon skillnad. Angående tillväxten av grönslick påvisades en signifikant skillnad mellan grupperna kött (K) och kontroll (KON) samt mellan kött (K) och vegan (V). Grönslick tillväxer därför mer i brackvatten med urin från människor som äter kött än den gör i brackvatten med urin från människor med vegansk kost. Då resultaten gällande tillväxt på grönslick visade en signifikant skillnad mellan kosthållningarna (K och V) behöver den påstådda korrelationen mellan ökad köttkonsumtion och ökade kväveutsläpp från kommunala avloppsreningsverk studeras vidare.

<em>Cladophora</em> is a widespread freshwater filamentous cholorophyte genus and is frequently observed in eutrophic waters where it can produce large nuisance blooms. These blooms can have direct impacts on water intake for power generation, irrigation canals and can be aesthetically unpleasant. Much of the ecological and physiological studies on <em>Cladophora</em> have assumed that the populations of this genus in North America belong to the species <em>Cladophora glomerata</em>. However, this has never been tested despite that it is well documented that identifying freshwater <em>Cladophora</em> to the species level is difficult due morphological variability under different ecological conditions. In addition, the species epithets for freshwater <em>Cladophora</em> are based on European collections and it is not clear if these should be applied to North America. This study examines approximately 40 collections of <em>Cladophora</em> from the Laurentian Great Lakes and 43 from various locations in North America ranging from the Northwest Territories to Puerto Rico. Initially we determined the nucleotide sequences of the internal transcribed spacer (ITS) region of the nuclear ribosomal cistron and observed sequence divergence to be low (0-3%), demonstrating an inability for this marker to resolve species delineation as divergence of this region was low. Amplification of the inter-simple sequence repeat (ISSR) regions were used to analyze microsatellite motif frequency throughout the genome to evaluate the biogeography relationships, including diversity, of freshwater <em>Cladophora</em> sp. five different primers were used on 70 individuals. UPGMA analyses of the presence/absence of bands demonstrate that each of the Great Lake populations separate into groups according to the Lake they were initially sampled from. However, collections from North America are highly variable and do not form well supported biogeographic clades. In addition, these collections appear to be distinct from type cultures of freshwater <em>Cladophora</em> from Europe. Supplementary morphological analysis using suggested taxonomically valid criterion (length and diameter of main axis, ultimate branch, and apical cell) none were able to differentiate Great Lake populations.