Dissertations / Theses: 'Algal metabolites in water'

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Provan, Anne. "Systematic chemical screening of mircroalgae." Thesis, University of Strathclyde, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366955.

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Mann, Maryssa Gudrun Ailsa. "An investigation of the antimicrobial and antifouling properties of marine algal metabolites." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1007465.

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Prevention of the accumulation of undesirable biological material i.e. biofouling upon a solid surface requires the use of antifouling systems. The solid surface may be a contact lens, an off shore oil rig or a living organism. When chemicals are employed as a mechanism of defense against biofouling, the agents involved are known as antifouling agents. Marine algae must protect themselves from fouling organisms and it is thought that one of the mechanisms used by these organisms is the production of secondary metabolites with an array of biological activities. In vitro studies have shown numerous compounds isolated from marine algae to possess antibacterial, antifungal and antimacrofouling activity. The aim of this study was to evaluate the secondary metabolite extracts of selected Southern African marine macro-algae as a potential source of compounds that inhibit biofilm formation and that could be used as antifouling agents. In this project, marine macro-algae were collected from various sites along the South African coastline. Their extracts were screened for antimicrobial activity against four ubiquitous microorganisms, Staphylococcus aureus, Klebsiella pneumoniae, Mycobacterium aurm and Candida albicans. Results of screening assays guided the fractionation of two Rhodophyta, Plocamium corallorhiza and Laurencia flexuosa. The algae were fractionated using silica gel column chromatography and compounds were isolated by semi-preparative normal phase HPLC. Compound characterization was performed using UV, IR and advanced one- and two-dimensional NMR (¹H, ¹³C NMR, COSY, HSQC, HMBC and NOESY) spectroscopy and mass spectrometry. Ten halogenated monoterpenes including four members of the small class of halogenated monoterpene aldehydes were isolated from extracts of P. corallorhiza. The compounds isolated included the known compounds 3,4,6,7-tetrachloro-3,7-dimethyl-1-octene; 4,6-dibromo-1, 1-dichloro-3,7 -dimethyl-2E,7 octadiene; 4,8-d ibromo-1,1,7 -trichloro-3, 7-dimethyl-2,5Eoctadiene;1 ,4,8-tribromo-3, 7 -dichloro-3,7-dimethyl-1 E,5E-octadiene; 8-bremo-6, 7-dichloro-3,7-dimethyl-octa-2E,4E-dienal; 4-Bromo-8-chloro-3,7-dimethyl-octa-2E,6E-dienal; 4,6- Dibromo-3,7-dimethyl-octa-2E,7-dienal; 2,4-dichloro-1-(2-chlorovinyl)-1-methyl-5-methylidene-cyclohexane and two new metabolites 4,8-chloro-3,7-dimethyl-2Z,4,6Z-octatrien-1-al and Compound 3.47. Methodology was developed for the chemical derivatization and mass spectrometric analysis of the aldehydic compounds, The aldehyde trapping reagent 0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride was used to derivatize the molecules, stabilizing them and allowing for their complete characterization. From Laurencia flexuosa a new cuparene sesquiterpene 4-bremo-2-(5-hydroxy-1,2,2- trimethylcyclopent-3-enyl)-5-methylphenol was isolated along with two geometric isomers of the vinyl acetylene bromofucin , An halogenated monoterpene 3S*,4R*-1-bromo-3,4,8-trichloro-9-dichloromethyl-1-E,5-E,7-Z-octatriene was also isolated but was suspected to be a contaminant and an investigation into its biological source revealed that it originated from Plocamium suhrii. A third alga, Martensia elegans was extracted based on published reports of antimicrobial compounds in related species. A new a-alkyl malate derivative was isolated and characterized. Selected compounds isolated during the course of the study were employed in preliminary assays that tested their ability to inhibit biofilm formation by Pseudomonas aeruginosa. The halogenated monoterpenes isolated from the Plocamium species were the only active compounds. 3S*,4R*-1-bromo-3,4,S-trichloro-g-dichloromethyl-1-E,5-E,7-octatriene from P. suhrii inhibited biofilm formation through antibacterial activity on planktonic cells but could not prevent biofilm formation when employed as a film on the surface of microtitre plate wells. 1,4,8-tribromo-3,7-dichloro-3,7-dimethyl-1E,5E-octadiene and 4,6-dibromo-1,1-dichloro-3,7-dimethyl-2E,7-octadiene inhibited biofilm formation when applied as a film to the microtitre plate wells but had no significant antibacterial activity. No potential antifouling agents were identified in this project but the antimicrobial activity exhibited by the crude algal extracts was highly encouraging and a number of new research areas have been identified.
KMBT_363
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Gordon, Richard. "The Role of Water Motion in Algal Reproduction." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/GordonR2001.pdf.

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Wissinger, Joshua Clinton. "Hydrothermal Treatment of Algal Feedstocks." University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1370954774.

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Nylund, Göran M. "Epibiosis of red algae and algal metabolites as settlement inhibitors of the barnacle Balanus improvisus Darwin." Göteborg [Sweden] : Dept. of Marine Botany, Göteborg University, 1999. http://bibpurl.oclc.org/web/20311.

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Thesis (master's)--Göteborg University, 1999.
Title from PDF t.p. (viewed on Sept. 25, 2007). At head of title: Tjärno Marine Biological Laboratory. Includes bibliographical references (p. 13-14).

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Woodruff, Sarah Louise. "Biomineralisation reactions of algal biofilms at the sediment-water interface." Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368647.

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Wells, Charles Digby. "Tertiary treatment in integrated algal ponding systems." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1006162.

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Inadequate sanitation is one of the leading causes of water pollution and consequently illness in many underdeveloped countries, including South Africa and, specifically, the Eastern Cape Province, where cholera has become endemic. As modern wastewater treatment processes are often energy intensive and expensive, they are not suitable for use in these areas. There is thus a need to develop more sustainable wastewater treatment technologies for application in smaller communities. The integrated algal ponding system (IAPS) was identified as a possible solution to this wastewater management problem and was investigated for adaptation to local conditions, at the Rhodes University Environmental Experimental Field Station in Grahamstown, South Africa. The system was monitored over a period of nine years, with various configuration adjustments of the high rate algal pond (HRAP) unit operation investigated. Under standard operating conditions, the system was able to achieve levels of nutrient and organic removal comparable with conventional wastewater treatment works. The mean nitrate level achieved in the effluent was below the 15mg.l-1 South African discharge standard, however, nitrate removal in the IAPS was found to be inconsistent. Although the system was unable to sustain chemical oxygen demand (COD) removal to below the 75mg.l-1 South African discharge standard, a removal rate of 87% was recorded, with the residual COD remaining in the form of algal biomass. Previous studies in the Eastern Cape Province have shown that few small wastewater treatment works produce effluent that meets the microbial count specification. Therefore, in addition to the collation of IAPS data from the entire nine year monitoring period, this study also investigated the use of the HRAP as an independent unit operation for disinfection of effluent from small sewage plants. It was demonstrated that the independent high rate algal pond (IHRAP) as a free standing unit operation could consistently produce water with Escherichia coli counts of 0cfu.100ml-1. The observed effect was related to a number of possible conditions prevailing in the system, including elevated pH, sunlight and dissolved oxygen. It was also found that the IHRAP greatly enhanced the nutrient removal capabilities of the conventional IAPS, making it possible to reliably and consistently maintain phosphate and ammonium levels in the final effluent to below 5mg.l-1 and 2mg.l-1 respectively (South African discharge standards are 10mg.l-1 and 3mg.l-1 in each case). The quality of the final effluent produced by the optimisation of the IAPS would allow it to be used for irrigation, thereby providing an alternative water source in water stressed areas. The system also proved to be exceptionally robust and data collected during periods of intensive and low management regimes were broadly comparable. Results of the 9 year study have demonstrated reliable performance of the IAPS and its use an appropriate, sustainable wastewater treatment option for small communities.

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Lu, Songhui. "Ecological studies of phytoplankton and harmful algal blooms in Junk Bay, Hong Kong." Click to view the E-thesis via HKUTO, 2001. http://sunzi.lib.hku.hk/hkuto/record/B42576209.

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Williams, David Ellis. "Novel secondary metabolites from selected cold water marine invertebrates." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/29175.

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A study of the secondary metabolism of two nudibranchs and one soft coral has led to the isolation of eighteen new and two known secondary metabolites. The structures of all compounds were determined by a combination of the interpretation of spectral data, chemical degradations and interconversions, and single crystal x-ray diffraction analysis. The British Columbian dorid nudibranch Diaulula sandiegensis yielded two new steroidal metabolites, diaulusterols A (41) and B (42). The 25-(3-hydroxybutanoate) residue of diaulusterol A (41) and the 2α,3α-diol array of both 41 and 42 are not commonly encountered in naturally occurring steroids. Both metabolites exhibited considerable antibacterial and antifungal activity. Steroid 41 exhibited fish antifeedant activity. The relative concentration of 4.1 and 42 in the skin extracts of D. sandiegensis appears to be related to the animals' seasonal abundance. Extracts of the British Columbian soft coral Gersemia rubiformis yielded a series of ten diterpenes possessing cembrane (170-175), pseudopterane (167-169) and gersolane (176) carbon skeletons. The structure of an eleventh diterpene remains unresolved. In addition, the structure of a degraded diterpene possessing a 13-membered ring (177) is tentatively proposed. G. rubiformis represents the first example of a soft coral to yield pseudopterane diterpenes. The organism is the first to contain cembrane, pseudopterane and gersolane metabolites, a fact which has biogenetic implications. Two new sesquiterpenes were also isolated. Tochuinyl acetate (165) and dihydrotochuinyl acetate (166) represent the first examples of cuparane sesquiterpenes to be isolated from a soft coral. A biogenesis is proposed. Metabolite 166 exhibited fish antifeedant activity. Investigations of Gersemia rubiformis collected in Newfoundland waters revealed that the secondary metabolism differed from west coast specimens. The isolation of the new unstable sesquiterpene (+)-β-cubebene-3-acetate (178) resulted. Skin extracts of the dendronotoid nudibranch Toquina tetraquetra were examined in an attempt to correlate its feeding dependency and lack of predation to the presence of allomones. Metabolites 165, 166, 170, 179 and the new butanoate diterpene 180 could be traced to the coelenterates which make up the animal's diet. Tochuinyl acetate (165), dihydrotochuinyl acetate (166) and rubifolide (170) were previously found in extracts of Gersemia rubiformis. Ptilosarcenone (179) has been reported as one of the major metabolites of the sea pen Ptilosarcus gurneyi²¹³. The exact origin of a sixth metabolite, pukalide (63), remains unknown. It is proposed that Tochuina tetraquetra selectively sequesters dietary metabolites for defensive purposes.
Science, Faculty of
Chemistry, Department of
Graduate

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Westensee, Dirk Karl. "Post-treatment technologies for integrated algal pond systems." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018180.

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Integrated Algae Pond Systems (IAPS) are a derivation of the Oswald designed Algal Integrated Wastewater Pond Systems (AIWPS®) and combine the use of anaerobic and aerobic bioprocesses to effect wastewater treatment. IAPS technology was introduced to South Africa in 1996 and a pilot plant designed and commissioned at the Belmont Valley WWTW in Grahamstown. The system has been in continual use since implementation and affords a secondarily treated water for reclamation according to its design specifications which most closely resemble those of the AIWPS® Advanced Secondary Process developed by Oswald. As a consequence, and as might be expected, while the technology performed well and delivered a final effluent superior to most pond systems deployed in South Africa it was unable to meet The Department of Water Affairs General Standard for nutrient removal and effluent discharge. The work described in this thesis involved the design, construction, and evaluation of several tertiary treatment units (TTU') for incorporation into the IAPS process design. Included were; Maturation Ponds (MP), Slow Sand Filter (SSF) and Rock Filters (RF). Three MP's were constructed in series with a 12 day retention time and operated in parallel with a two-layered SSF and a three-stage RF. Water quality of the effluent emerging from each of these TTU's was monitored over a 10 month period. Significant decreases in the chemical oxygen demand (COD), ammonium-N, phosphate-P, nitrate-N, faecal coliforms (FC) and total coliforms (TC) were achieved by these TTU's. On average, throughout the testing period, water quality was within the statutory limit for discharge to a water course that is not a listed water course, with the exception of the total suspended solids (TSS). The RF was determined as the most suitable TTU for commercial use due to production of a better quality water, smaller footprint, lower construction costs and less maintenance required. From the results of this investigation it is concluded that commercial deployment of IAPS for the treatment of municipal sewage requires the inclusion of a suitable TTU. Furthermore, and based on the findings presented, RF appears most appropriate to ensure that quality of the final effluent meets the standard for discharge.

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West, Charles Edward. "The photodegradation of diazepam and its human metabolites in water." Thesis, University of Plymouth, 2007. http://hdl.handle.net/10026.1/2254.

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In recent years, the environmental occurrence, fate and effects of pharmaceuticals or pharmaceutically active compounds (PhACs) and their metabolites have received increased attention. PhACs have been detected in wastewater, river water, marine waters and even sewage sludge and soil. Since PhACs are developed with the intention of stimulating or inhibiting physiological responses, these findings have prompted concern over their environmental fate and potential adverse effects on nontarget ecological species. The major source of discharge of PhACs to the environment is through sewage treatment works (STWs) effluents and sludges. Although used in quantities similar to many agrochemicals and other organic micropollutants, PhACs are not required by legislation to undergo the same level of testing for possible environmental effects. Therefore, PhACs and their metabolites have been subject to many years of unrestricted emission to the environment. Typically, concentrations measured in municipal sewage treatment plant effluents are mg L'', whilst those in the surface waters range from ng L' to μg L"1. The fate of PhACs in the aquatic environment is determined by both abiotic and biotic processes. Abiotic transformations in surface waters may occur via hydrolysis and photolysis, with photolysis thought to be a significant factor in determining their environmental fate. In the present study, the anti-anxiety drug, diazepam (Valium®) along with its known human metabolites, nordiazepam, temazepam and oxazepam were selected for photodegradation studies. The photodegradability of each drug in distilled and natural waters was evaluated using a Suntest CPS Xenon are lamp, selected to reproduce the spectral distribution of solar irradiation, with emphasis on the determination of degradation rate constants and half-lives under realistic environmental conditions. Solid phase extraction (SPE) methods were developed for extraction of these compounds from natural water samples and analysis was performed using high performance liquid chromatography (I-IPLC) separation with electrospray ionisation multistage mass spectrometry (ESI-MS") detection. Results demonstrated that whilst the compounds were hydrolytically stable in aqueous solutions, photolysis significantly reduced the concentration of diazepam and its metabolites in aqueouss olutions. The measuredh alf-lives (t112o) f diazepam, nordiazepam, temazepam and oxazepam in distilled water were 100,193,36 and 32 hours respectively. Novel photoproducts including 5-chloro-2-methylaminobenzophenone (m/z 246, [M+11]+) and 2-arnino-5-chlorobenzophenone (#/z 232, [M+II]+) were detected and characterised by electrospray ionisation multistage mass spectrometry (EST-MS") and comparison with reference compounds. The identities of a range of further photoproducts observed in aqueous solutions of photodegraded PhACs were proposed based on ESI-MS" data analysis, The presence of natural organic matter (NOM), specifically humic acids at environmental levels (1 mg L'') were found to approximately double the rate of photodegradation for diazepam and nordiazepam (t1n 28 and 48 hours respectively). In contrast, results for the metabolites temazepam and oxazepam suggest that the presence of humic acids led to a reduction in the rateo f photodegradatio(nti n 72 and6 6 hoursr espectively). The direct and indirect photodegradation kinetics determined in the present study for diazepam and its human metabolites were applied to UK river catchment models using a computer model, GREAT-ER. Maximum predicted environmental concentrations (PECs) were determined for each compound and the impact of phototransformation on the removal of each compound was evaluated in two river catchments representing an urban/industrial catchment (river Aire) and a rural catchment (river Exe) respectively, under low flow (summer) and mean flow (winter) river conditions. The modelling predictions suggest that phototransformation may be an important process for removing diazepam and excreted human metabolites of diazepam from natural riverine and lacustrine environments. The overall results demonstrated that with photolysis half-lives ranging from 193-32 hours, diazepam and its human metabolites are unlikely to be persistent in natural waters.

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Nielsen, Eric J. "Algal suscession and nutrient dynamics in Elephant Butte Reservoir /." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd741.pdf.

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Sirunda, Johannes Jaime. "The effects of water transfer from Swakoppoort and Omatako Dams on the water quality of Von Bach Dam, Namibia." University of the Western Cape, 2011. http://hdl.handle.net/11394/5413.

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>Magister Scientiae - MSc
In the Otjozondjupa Region, Namibia, water is transferred from Swakoppoort and Omatako Dams into Von Bach Dam to limit evaporation losses and bring water closer to the purification plant. There is a gap in the knowledge about the effects on water quality in Von Bach Dam due to water transfer from Swakoppoort and Omatako Dams, as previous studies on such aspects in the area do not exist. The study objective was to; (a) characterise water quality of the three dams, (b) determine whether water transfers affect the water quality of Von Bach Dam, (c) determine if the treatment of water abstracted from Von Bach Dam for potable water supply has been influenced by water quality changes arising from water transfers. Four sampling locations were established in Von Bach Dam, one in Swakoppoort Dam, and one in Omatako Dam. Water samples were collected in these three dams weekly. Two senior officers responsible for water treatment were interviewed about possible water treatment problems arising from the water transfer. Descriptive statistics, ANOVA and correlation were carried out to analyse the data. The results showed that, secchi disk depths, total phosphorus, orthophosphate, ammonia, dissolved organic carbon, chlorophyll a and microcystis were statistically different in the three dams at a 5% significance level. Upstream land uses, geology of the catchment and water stratification are likely to influence the water quality in the three dams. During water transfers into Von Bach Dam, secchi disk depths, turbidity, dissolved oxygen, iron, total phosphorus, ammonia (NH₄-N) and chlorophyll a were statistically different at a 5% significance level at all the four sampling locations within this dam. These differences are due to the influence of water transfers. The influence of water transfers on water quality was localised at the discharge points SL4 (at the inflow of Von Bach Dam) and SL1 (at the outflow of Von Bach Dam). Water treatment problems due to high ammonia, dissolved organic carbon, and turbidity in the water abstracted from Von Bach Dam occurred during water transfers and runoff from the catchment. This view was supported by the study findings.

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Gerlach, Kyle T. "Assessment of Ferrate for Pre-Oxidation Treatment of Harmful Algal Blooms in Drinking Water Treatment." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-theses/1332.

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Harmful algal blooms in surface water supply systems pose a threat to public health and are increasing in both frequency and geographical distribution. Cyanobacteria can contribute to taste and odor issues and potentially release harmful cyanotoxins into the water. Several treatment methods are currently employed to control these blooms, including physical separation and chemical pre-oxidation. However, existing oxidation options can be costly; increase the release of intracellular material causing the formation of disinfection byproducts; or disrupt coagulation and filtration processes. This study investigated ferrate (Fe(VI)) as an alternative to other oxidants by measuring its effect on algae cells. Fe(VI) has several advantages as an oxidant, including a high oxidation potential, a low potential for harmful disinfection byproduct production, and formation of Fe(III) - which can potentially be beneficial for downstream treatment processes. Bench scale studies were conducted with laboratory prepared waters containing the common cyanobacteria Microcystis aeruginosa to examine the interactions between Fe(VI) and algae. The effects of ferrate oxidation on algae were characterized by particle counts, UV254 absorbance, total organic carbon (TOC) and dissolved organic carbon (DOC), and total nitrogen. Ferrate decomposition was also monitored. Results showed that Fe(VI) lysed algal cells under some conditions, but further oxidation of released organic matter is possible at some doses. Additionally, some coagulation benefits were observed through an overall decrease in total particle counts and an increase in particle sizes. In general, the results indicate that Fe(VI) could be a possible alternative to other oxidants for water utilities during harmful algal blooms; however, the final fate of resulting organic matter and the potential for disinfection byproduct formation should be further studied.

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Mailhot, Hélène. "The use of some physico-chemical properties to predict algal uptake of ogranic compounds /." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65504.

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Conroy, Joseph David. "Testing the algal loading hypothesis the importance of Sandusky River phytoplankton inputs to offshore Lake Erie processes /." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1186592400.

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Johansen, Richard A. "A holistic approach to monitoring water quality and harmful algal blooms in fresh water using satellite remote sensing." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1553251246641376.

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Wolf, David M. "Beyond Marginal Valuation: The Economic Impacts of Harmful Algal Blooms." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1529492086337544.

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Boggess, Chadwick D. "Optimization of Growth Parameters for Algal Regrowth Potential Experiments." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1234.

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Water cost is one of the key deterrents in making algal biofuels a feasible alternative to traditional petroleum fuels. Research into recycling of algal media was conducted in a laboratory setting at the California Polytechnic State University in San Luis Obispo. A growth assay was created to allow for algal cultures, specifically Ward’s Chlorella sp., to proliferate in sealed culture vessels. Bold’s Basal Medium (BBM) was selected as the media due to its extensive use with freshwater algal strains. However, this medium can limit algal growth through nutrient limitation and it became necessary to augment the original recipe. 50mM of sodium bicarbonate was added to the media in order to buffer the purging of 100% CO2 into the culture vessel. The resultant pH of the CO2 saturated media was 6.25. The elemental? composition of Chlorella vulgaris was compared with the nutrient content of BBM to estimate possible nutrient limitations which could occur throughout growth (Oh Hama, 1988). From this analysis, the nitrogen and phosphorus concentration in BBM was augmented by a factor of three (BBM3N3P). Further, vitamins, specifically cyanocobalamin, thiamine HCL, and biotin, were incorporated after conducting a comparison growth study with BBM 3N3P. The average maximum specific growth rates for the normal BBM and for the vitamin-enhanced BBM were 0.689 +/- 0.0818 and 0.887 +/- 0.1901 (mean +/- std. deviation) per day, respectively. This difference was proved significant by a t-test with a p-value equal to 0.041. A standardized methodology for conducting a regrowth potential experiment was outlined by the research. One phase of this methodology included reintroduction of nutrients consumed during the first round of growth. Prior to continuing with this methodology the effect of supplementing trace metals and micronutrients into the culture was investigated. At a p-value of 0.0956, there was no significant difference between BBM 3N3P + vitamins and the same media with eight times the trace metal and micronutrient concentration. This allowed for up to seven rounds of regrowth with no inhibition caused from the restoration of these nutrients. A final regrowth was conducted on BBM 3N3P + vitamins + 50 mM bicarbonate. A significant difference existed between both the Round 1 and Round 2 cultures, as well as between the Round 2 cultures and their respective controls. This signified the possible release of allelochemicals by the Chlorella sp.. A preliminary investigation into the possible use of anaerobic digester effluent as a primary source of nutrients for algal cultures was also conducted. The digestate (diluted 50% v/v with a saline make-up) grew significantly faster than the controls (p-value<0.001). Further, after the introduction of trace metals and micronutrients the digestate columns outlived the control columns increasing the feasibility of using digestate to supplemental algal cultures.

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Hesterlee, Craig D. "Dynamic modeling of West Point Reservoir hydrothermal and algal growth forcing mechanisms." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/20732.

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Nielsen, Eric J. "Algal Succession and Nutrient Dynamics in Elephant Butte Reservoir." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/280.

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A water quality model was created for Elephant Butte Reservoir, New Mexico to understand nutrient dynamics and algal response during a three year period. The model chosen for this study was CE-QUAL-W2 because of its proven ability to represent hydrodynamics and the ability to represent multiple algal groups. Elephant Butte has been subject to large algal blooms. This study examined the phosphorus loading into the reservoir to see if it could sustain the observed algal growth. Data showed that the amount of bioavailable phosphorus was more than enough to support large blooms. This study also was an initial attempt to model multiple groups of algae that will later be used in other water quality models built and maintained by the US Bureau of Reclamation. Four algal species were modeled; diatoms, dinoflagellates, cyanobacteria and greens. Research into literary values of kinetic parameters for multiple algal species was conducted and the results were compiled in this paper to assist future modeling efforts. Because Elephant Butte was often nitrogen-limited the calibration of algal growth was difficult. Algal growth was very sensitive to the adjustment of kinetic parameters for nitrogen half-saturation, light requirements, growth rates and temperature rate multipliers.

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Wilson, Hugh Edward Campbell. "Short term forecasting of algal blooms in drinking water reservoirs using artificial neural networks /." Title page, abstract and table of contents only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phw7462.pdf.

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Razzano, Mandy L. "Monitoring Algal Production in Akron Water Supply Reserviors in Northeast Ohio Using Satellite Imagery." Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1310178613.

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Crafton, Elizabeth Ann. "Investigation and Management of Cyanobacteria-dominated Harmful Algal Blooms in a Drinking Water Source." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1539688257233302.

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Welk, Amber Lee. "A contribution towards real-time forecasting of algal blooms in drinking water reservoirs by means of artificial neural networks and evolutionary algorithms." Click here to access, 2007. http://digital.library.adelaide.edu.au/dspace/handle/2440/48542.

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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, Discipline of Ecology and Evolutionary Biology, 2008.
"December 2007" Bibliography: pages 172-185. Also available in print form.

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Dufresne, Laura C. "Destruction of algae-produced taste-and-odor compounds by chlorine, potassium permanganate, and chlorine dioxide." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-11242009-020302/.

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Sibali, LL, JO Okonkwo, and C. Zvinowanda. "Determination of DDT and Metabolites in Surface Water and Sediment Using LLE, SPE, ACE and SE." Springer Science, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001502.

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Abstract Surface water and sediment samples collected from Jukskei River in South Africa, were subjected to different extraction techniques, liquid–liquid (LLE), solidphase extraction (SPE), activated carbon extraction (ACE) and soxhlet extraction (SE) for sediment. The samples were extracted with dichloromethane, cleaned in a silica gel column and the extracts quantified using a Varian 3800 GC-ECD. The percentage recovery test for 2,40DDT, DDE and DDD and 4,40DDT, DDE and DDD in water ranged from 80%–96% and 76%–95% (LLE); 56%–76% and 56%–70% (SPE) and 75%–84% (ACE), respectively; while that recoveries for sediment samples varied from 65%– 95% for 2,40DDT, DDE and DDD and 80%–91% for 4,40DDT, DDE and DDD. The high recoveries exhibited by ACE compared very well with LLE and SE. This was not the case with SPE which exhibited the lowest value of recoveries for both 2,4 and 4,40DDD, DDE and DDT standard samples. The mean concentrations of DDT and metabolites ranged from nd-1.10 lg/L, nd-0.80 lg/L, nd- 1.21 lg/L and 1.92 lg/L for LLE, SPE, ACE and SE, respectively. The total DDT (2,40 and 4,40-DDT) in water and sediment samples ranged from 1.20–3.25 lg/L and 1.82–5.24 lg/L, respectively. The low concentrations of the DDT metabolites obtained in the present study may suggest a recent contamination of the river by DDT.

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Gigante, Bethany Marie. "SALINE ADAPTATION OF THE MICROALGA Scenedesmus dimorphus FROM FRESH WATER TO BRACKISH WATER." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1382355969.

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Graham, Philip Mark. "Modelling the water quality in dams within the Umgeni Water operational area with emphasis on algal relations / Philip Mark Graham." Thesis, North-West University, 2007. http://hdl.handle.net/10394/1022.

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Based on many years of water quality (including algal) and water treatment cost data, available at Umgeni Water, a study was undertaken to better understand the water quality relationships in man made lakes within the company's operational area, and to investigate how water quality affected the cost of treating water from these lakes. The broad aims to the study were to: identify the key environmental variables that were affecting algal populations in lakes; and if these were significant to establish predictive models relating algae to the water quality; and to develop models relating the water quality in lakes to the cost of treating water from the lakes. Semi-quantitative models were developed relating algal abundances with important environmental variables. In most cases, the models developed were related to algal populations that were known to adversely affect water treatment. Direct algal impact on water treatment processes was through the production of either taste and odour forming compounds (requiring advanced water treatment, such as use of activated carbon), or their ability to clog sand filters and so reduce filter run times (requiring more frequent backwashing of filters). Thereafter lake water quality parameters (which included water physico-chemistry and algae) were investigated to determine which factors were most significantly impacting on water treatment and hence treatment costs at selected water works (WW) within the Umgeni Water operational area. Models were developed relating raw water quality entering respective water works with costs incurred in treating that water. The models allowed simulations to be developed illustrating how changes in water quality might impact on water treatment costs. The impact of eutrophication and contamination of rivers and lakes, and its subsequent impact on surface water resources, was quantified.
Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2004.

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Athayde, Salena Tatiana Silva. "Algal and bacterial dynamics in waste stabilization ponds and wastewater storage and treatment reservoirs." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343989.

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Nilsson, Emmelie. "Algal blooms and water quality in coastal waters of Öland : Possible effect on local tourism?" Thesis, University of Kalmar, School of Pure and Applied Natural Sciences, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hik:diva-1468.

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Utvecklingen av algblomningar i Östersjön har blivit mer diskuterat i media under senare år. Eftersom algblomningar ofta infaller samtidigt som turistsäsongen så har områden som är beroende av turistnäringen drabbats hårt. Under sommaren 2005 inträffade massiva giftiga algblomningar i Östersjön, och detta påverkade turismen på Öland negativt ur ekonomisk synpunkt. Mänsklig påverkan är ansedd vara huvudorsaken bakom den ökade förekomsten av algblomningar i Östersjön. Målet med detta projekt är att undersöka hur förekomsten av algblomningar påverkar turismen på Öland. Genom att ha samlat in vattenprover vid tre olika platser på Öland under sommaren 2007, har parametrar så som näringsstatus, temperatur, salthalt, phytoplankton sammansättning och klorofyll-a undersökts. Mängden nederbörd har observerats via data från SMHI. Detta har gjorts för att kunna studera eventuella samband mellan näringsstatus vid kusterna och möjlig avrinning från land. Två enkäter har skickats ut till samtliga camping ägare på Öland, i ett försök att se hur algblomningar har påverkat turismen under åren 2005, 2006 samt 2007. En enkät utdelades också under sommaren 2006, men denna var riktad till turisterna som besökte campingar på Öland. Ett av de slutliga målen var att undersöka hur förekomsten av algblomningar och miljöfaktorer, så som temperatur, salthalt, nederbörd och näringsämnen är sammankopplade. Provtagningsplatserna skiljde sig åt när det gällde till vilken grad de påverkats av algblomningar. Den nordvästra kusten, Köpingsvik, har nästan aldrig exponerats för algblomningar, medan den östra kusten, Gärdslösa, oftast har det. Den sydvästra kusten , Mörbylånga, har varit drabbad under vissa år. Detta material har sedan jämförts med material insamlat från 2006. Resultatet från 2007 visar på högre koncentrationer av näringsämnen och klorofyll-a jämfört med data från 2006. Resultatet från 2007 visar på högre koncentrationer av näringsämnen och klorofyll-a jämfört med data från 2006. Turismen under 2006 och 2007 visade inte ha varit negativt påverkat av algblomningar. Turismen under 2005 visade sig däremot ha varit negativt påverkat av algblomningar. Cyanobakterier förekom i lågt antal under 2006 och 2007, men andra alggrupper blommade under våren och sommaren, speciellt en grupp av sötvatten dinoflagellat kallad Peridiniopsis polonicum. Denna art förekomi höga antal i både Gärdslösa och Mörbylånga, under slutet av juli och i augusti.

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Jeon, Youchul. "Understanding the Impacts of Harmful Algal Blooms on Biologically-Active Filtration for Drinking Water Treatment." University of Toledo / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1596730692085583.

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Rahman, FM Arifur. "USING SATELLITE OBSERVATIONS TO ASSESS SUSPENDED SEDIMENT, ALGAL AND CYANOBACTERIA COMPOSITION IN LAKE ONTARIO." Kent State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=kent1626455092080768.

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Pruyn, Marley. "Qualitative Detection of Selected Designer Drugs and Relevant Metabolites in Environmental Water Samples." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2571.

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Designer drugs are compounds which have been synthetically derived from illicit drugs. After consumption, drugs and their metabolites are introduced into the sewage water which is treated and disposed into the environment. A combined target, suspect and non-target workflow was created to detect designer drugs in environmental water samples. Multiple water samples were spiked with an unknown mixture of drugs and metabolites to assess the efficiency of the method. Samples were collected from sewage influent and effluent pipes, downstream from a sewage outfall and reclaimed water. Analysis was conducted with high resolution MS using the QExactive Orbitrap. Screening was performed using a database compiled in-house using TraceFinder EFS. Structure confirmation was achieved using MassFrontier. Target drugs and their metabolites were detected in sewage influent but not in sewage effluent, downstream of the effluent pipe, or in reclaimed water. The workflow was adequate to detect designer drugs in multiple water matrices at concentrations as low as 20ppt.

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Zeckoski, Rebecca. "Water quality modeling for the Kennet and Avon Canal, a navigational canal in an inland catchment." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/226858.

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The Kennet and Avon Canal in southern England is experiencing severe water quality problems caused by inorganic sediment and algae. These water quality problems are affecting the angling sport of fishermen downstream of the confluence of the canal with the River Kennet. The Environment Agency has been called upon to remedy these issues, but before proceeding they desire a computer model capable of predicting the water quality impacts of various scenarios under consideration. No such model was available to them. This project identified the key solids generation and transport processes to be included in a water quality model for inland navigational canals. Where available, equations from the literature describing relevant processes were used or modified for inclusion in a canal modeling algorithm. Where literature was not available, water quality samples were taken to characterize needed relationships. The final algorithm was coded and tested using a simplified dataset that allowed clear evaluation of the simulated processes. After successful testing, the canal model was applied to the Kennet and Avon Canal. The time series predicted by the model were compared to observed hydrological, solids, and chlorophyll-a (representing algae) data at multiple points in the canal. The model adequately predicted all of these constituents at the monitored locations. The final task in the project required evaluation of six management scenarios proposed by the Environment Agency to address the water quality problem. The model suggests that filtration or other treatment of water in the canal near the confluence with the river is the best management option, as it will address both the elevated inorganic sediment and algae concentrations at the most critical point in the canal. Less desirable options include efforts that only target inorganic sediment, which could increase algal concentrations by increasing light availability; and diversion of surface flows from the canal, which could possibly damage the hydrologic balance of the canal while encouraging undesirable algal growth.

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Carrim, Ayesha Hamid. "The effect of pre-ozonation on the physical characteristics of raw water and natural organic matter (NOM) in raw water from different South African water resources / Ayesha Hamid Carrim." Thesis, North-West University, 2006. http://hdl.handle.net/10394/21.

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Research in the use of ozone in water treatment conducted by many authors support the idea that the nature and characteristics of natural organic matter (NOM) present in raw water determines the efficiency of ozonation in water purification. An ozone contact chamber was designed and made to allow pre-ozonation of water to take place. The concentration of ozone in the chamber was determined using the Indigo method. For the duration of one year, water samples were collected from four different sampling sites and analyzed to determine their overall ecological status with regard to several variables such as pH, chlorophyll-a, SAC254, turbidity, DOC, algal species composition and sum of NOM. Two dams sites and two riverine sites were chosen, Hartbeespoort Dam (a hyper-eutrophic impoundment), Boskop Dam (a mesotrophic impoundment), Midvaal Water Company at Orkney and Sedibeng Water at Bothaville. The samples were treated in Jar Tests with FeCI3 and the same variables were measured. Preozonation followed by Jar Tests was performed on each sample at twoconcentrations of ozone and the variables were measured to examine the efficiency of ozonation. In general, the ph was high and stayed the same for all the samples and for all the treatments. DOC was variable and showed no relationship to any other variable or to the treatments. Hartbeespoort Dam was found to be a eutrophic impoundment characterized by high algal bloom of the cyanobacteria Microcystis sp., Turbidity, SAC254, and the sum of NOM were lower than for the riverine sites but higher than for Boskop Dam. The NOM constituted more intermediate molecular weight(1MW)and low molecular weight (LMW) fractions than the riverine sites. Ozone was effective in reducing chlorophyll-a, turbidity and SAC254 from Hartbeespoort Dam, but the presence of large numbers of algal cells interferes with its efficiency. Release of cell-bound organics after ozonation can lead to increases instead of decreases in these variables. Jar Test results demonstrate that ozonation improves water quality when compared to conventional treatment although the interference of algal cells can alter results. Boskop Dam is a mesotrophic impoundment characterised by low productivity, low SAC254, tow turbidity and low sum of NOM. However, it has a large portion of the LMW fraction of NOM present. This LMW fraction affects the treatment process as this fraction is not acted upon by ozone. Therefore it was found that ozonation did not improve the quality of the water when compared to conventional treatment. The two riverine sites, Midvaal and Sedibeng were similar to each other. Both sites had high algal productivity with high chlorophyll-a values indicative of algal blooms observed at certain times. These blooms consisted either of members of Bacillariophyceae or Chlorophyceae. High turbidity and SAC254 was observed during the rainy season and was related to the high percentage HMW and IMW fractions of NOM present. There was correlation between the turbidity and SAC254 of these sites leading to the assumption that the turbidity of the river is due to the presence of HMW humic fractions of NOM. Ozonation was effective in improving water quality with respect to turbidity, SAC254 and chlorophyll-a removal, both on its own and after conventional treatment when combined with a coagulant. However, the species of algae present affects ozonation as members of Bacillariophyceae are not affected by the actions of ozone because of the presence of a silica frustule whereas members of Chlorophyceae are easily removed by ozone. In general, ozone acts upon the HMW and LMW fractions of NOM causing them to breakdown into smaller fractions. Ozone has no effect on samples that have a high percentage of the LMW fraction of NOM. This LMW fraction is more readily removed by conventional treatment than by ozonation. The presence of large numbers of algal cells as well as the species of cells can negatively affect the treatment process with regard to ozone.
Thesis (M. Environmental Science (Water Science))--North-West University, Potchefstroom Campus, 2007.

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Scott, Robert Nigel. "Algal and related biological studies of reservoirs in South Wales with reference to management of water treatment systems." Thesis, Cardiff University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238187.

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Öfverman, Charlotte. "Progesterone metabolites : learning, tolerance, antagonism & metabolism." Doctoral thesis, Umeå universitet, Obstetrik och gynekologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-27064.

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Progesterone metabolites as allopregnanolone, isoallopregnanolone and tetrahydrodeoxy-corticosterone (THDOC) are increased in the luteal phase of the menstrual cycle, throughout pregnancy and during stress. Allopregnanolone and THDOC are neurosteroids with 3α-hydroxy, 5α-configurations and positive modulating effect on the GABAA receptor. They have similar properties and effect, and share the same binding sites on the GABAA receptor. Isoallopregnanolone has a 3β-hydroxy, 5α-configuration and a diverse effect as a proposed antagonist to both allopregnanolone and THDOC. Neurosteroids are thought to exert their effect predominantly at extrasynaptic GABAA receptors, containing for example α4- or α5-subunits. Such receptors are involved in the tonic response. Different subunits have diverse distribution pattern in the brain and are involved in different functions. The α5-subunit, mainly expressed in the hippocampus, is involved in learning, while α4 is more widespread and involved in e.g. anxiety and anaesthesia. The aim of the present thesis was to contribute to the knowledge about selected progesterone metabolites and their effects on learning and tolerance development, as well as their metabolism. Also basic characteristics between different α-subunits of the GABAA receptor were evaluated. The thesis shows that the effect of bicuculline and pentobarbital is not dependent on the α-subunit isoform of the GABAA receptor expressed in oocytes. Acute tolerance developed after allopregnanolone-induced anaesthesia with a decrease at both mRNA and protein levels of the GABAA receptor α4-subunit in the thalamus VPM nucleus. A negative correlation between the α4 mRNA and the increased dose of allopregnanolone needed to maintain the anaesthesia level was also shown. In addition, allopregnanolone induces a learning impairment in the Morris water maze test, when high concentrations of allopregnanolone are present in the brain. This impairment is not possible to reverse by isoallopregnanolone. In α5β3γ2L-transfected HEK-293 cells THDOC induces a baseline shift of its own and also potentiate the GABA-current. Neither of those THDOC effects can be inhibited by isoallopregnanolone. Instead isoallopregnanolone shows an agonistic effect on the THDOC-potentiation of the GABA-response. The main allopregnanolone metabolites identified, 5α-DHP and isoallopregnanolone, as well as allopregnanolone itself are mainly localized to the brain after an i.v. injection. After an isoallopregnanolone injection there is a more even distribution of the given steroid and the metabolites between plasma and brain. There is an epimerisation between isoallopregnanolone and allopregnanolone and vice versa. In conclusion, the present thesis shows that the α4-subunit in the thalamus VPM nucleus is likely to be involved in the acute tolerance development against allopregnanolone and that allopregnanolone-induced learning impairment is likely to be hippocampus dependent. The lack of antagonistic effect of isoallopregnanolone on the THDOC-induced α5β3γ2L-GABAA response, together with epimerisation of isoallopregnanolone to allopregnanolone, could explain why isoallopregnanolone does not work as an antagonist to the allopregnanolone-induced learning impairment in a hippocampus dependent learning task.

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Vogiazi, Vasileia. "Developing Electrochemical Aptamer-based Biosensors for Quantitative Determination of Cyanotoxins in Water." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613751183300163.

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Wood, Joseph. "Causes and Consequences of Algal Blooms in the Tidal Fresh James River." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3429.

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This dissertation includes 3 chapters which focus on algal bloom of the tidal fresh James River. The first chapter describes nutrient and light limitation assays performed on algal cultures and draw conclusions about long-term patterns in nutrient limitation by comparing results with a previous study . This chapter also describes the influence of riverine discharge upon nutrient limitation in a point-source dominated estuary. This chapter was published in Estuaries and Coasts (Wood and Bukaveckas 2014). The second chapter presents the first comprehensive assessment of the occurrence of the cyanotoxin Microcystin in water and biota of the James River. Data presented in this chapter show that bivalve grazing declines in the presence of Microcystin in the water. The chapter also describes feeding habits in fish as a predictor for inter-specific differences in Microcystin accumulation in their tissues. The work presented in this chapter was published in Environmental Science & Technology (Wood et al. 2014). The third chapter describes the fate of algal carbon in the James River Estuary and the importance of autochthonous and allochthonous sources of organic matter in supporting production of higher trophic levels. Here I draw upon ecosystem metabolism data (NPP and R), abundance and grazing estimates for primary consumers and estimates of advective losses of chlorophyll and external inputs of nitrogen to place ‘top-down’ effects in the broader context of factors influencing chlorophyll and nitrogen fluxes in the James. . This chapter also describes results from mesocosm experiments used to assess the influences of grazers on chlorophyll, nutrients and Microcystis. This work will be submitted in the summer of 2014 to the journal Ecosystems.

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Cilliers, Anneke. "The treatment of brewery effluent using an integrated high rate algal ponding system." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1005177.

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The application of high rate algal ponds (HRAP) in the treatment of brewery effluent that met the South African Department of Water Affairs and Forestry's (DWAF) general limits for discharge into a natural water resource of 1998 were tested during a lO-month baseline phase, followed by an 11-month optimization phase. The objective of the baseline phase was to monitor the seasonal performance of HRAPs. The hydraulic retention time (HRT) fluctuated between 11.16 d and 12.00 d in HRAPs. The chemical oxygen demand (COD) increased from 130.12 ± 6.94 mg/L (post-AD), to 171.21 ± 7.99 mg/L (post-HRAP) . The presence of algal cells and evaporation contributed towards an increase in post-HRAP COD. The ammonia (NH₄-N) concentration decreased from 46.59 ± 2.47 mg/L (post-AD), to 1.08 ± 0.12 mg/L (post-HRAP). The nitrite (NO₂- N) concentration remained below 1.00 mg/L in post-pilot plant AD, post-PFP and post-HRAP effluent. The phosphate (PO₄-P) concentration decreased from 29.81 ± 1.39 mg/L (post-AD) to 17.30 ± 1.16 mg/L PO₄-P. The objective of the optimization phase was to manipulate the HRT to achieve the maximum treatment rate that met the DWAF general limits for discharge into a natural water resource of 1998. Nitrogen (as NH₄-N, NO₃-N, NO₂-N) removal efficiency was used as an indicator of nutrient removal success. HRT was influenced by season. The optimal HRT for autumn was 4.30 d at a temperature of 20.53ºC in HRAP A2 (heated) and 18.96ºC in HRAP B2 (ambient). The optimal HRT for summer was 2.74 d at 29.90ºC in HRAP A2 (heated) and 26.36ºC in HRAP B2 (ambient). The COD decreased from 152.33 ± 4.85 mg/L (post-AD) to 95 .00 ± 3.75 mg/L (post-HRAP A2), and to 100.82 ± 5.93 mg/L (post-HRAP B2). The incoming NH₄-N concentration decreased from 42.53 ± 1.38 mg/ L (post-AD), to 1.70 ± 0.81 mg/ L (post-HRAP) . The nitrate (NO₃-N) concentration post-HRAP was 12 - 14 mg/L. The main methods for NH₄-N removal were probably NH₄-N volatilization through algal uptake. HRAPs were able to lower nitrogen and phosphorous concentrations to within the DWAF limits under normal operating conditions. It is recommended that HRAP treated brewery wastewater be used for irrigation after salt removal, or alternatively, for groundwater recharge . Regulatory exemptions would be required for higher than permitted COD and EC concentrations to enable these actions.

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Roberts, Joanne B. "Determination and identification of drug and chemical metabolites in waste water by LCMS/MS." Thesis, Glasgow Caledonian University, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.726806.

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Schock, Kevin A. "An analysis of a persistent isotherm tilt during early-spring and its effect on the diatom bloom : Lake Washington, Seattle, WA /." Thesis, Connect to this title online; UW restricted, 2008. http://hdl.handle.net/1773/10177.

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Lu, Songhui, and 呂頌輝. "Ecological studies of phytoplankton and harmful algal blooms in Junk Bay, Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B42576209.

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Ewerts, Hendrik. "Effectiveness of purification processes in removing algae from Vaal Dam water at the Rand Water Zuikerbosch treatment plant in Vereeniging / H. Ewerts." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4572.

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The aim of this study was to investigate the efficacy of purification processes at the Rand Water Zuikerbosch treatment plant near Vereeniging. Raw water is abstracted via a canal and gravity pipeline from the Vaal Dam (in the upper Vaal River) and purified to ensure it meets the stringent standards set for drinkable water. The first step was to determine the ecological status of the raw water and it was done by measuring chemical, physical and biological variables as well as to identify and enumerate the different algal groups that occur in the raw water. The turbidity of the raw water was low but the phosphorous and ortho–phosphate levels were high. The Cyanophyceae (blue–green bacteria) especially Anabaena species were dominant in the raw water for the duration of the study. Potential problems such as relatively high alkalinity, chemical oxygen demand (COD) and total dissolved solids (TDS) as well as potentially hazardous chemicals such as cadmium and lead were observed in the raw water. The Zuikerbosch Water Treatment Plant (ZWTP) is a conventional water treatment plant which involves the following stages: coagulation, flocculation, sedimentation, sand filtration and chlorination. The use of pre–treatment chemicals ensures better water quality and effective removal of particles from the water. Only five of the variables (methylisoborneol (MIB); geosmin; chlorophyll–a; chlorophyll–665 and total organic carbon (TOC) were measured before filtration, after filtration and in the final water. Samples from the raw water, before and after filtration, as well as final water were collected weekly for a period of two years to measure the environmental variables as well as to do algal identification and enumeration. The purification processes at ZWTP were not able to remove MIB, geosmin, chlorophyll–a and TOC from the final water. Algal concentration was reduced but not totally removed by the purification processes. Although some variables were not totally removed by the purification processes, ZWTP produce potable water that complies with the Rand Water guidelines.
Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2011.

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Fretwell, Elizabeth A. "The Temporal and Spatial Relationship between Phosphorus and Nitrogen Concentrations, Algal Growth, and Nutrient Sources in the Meduxnekeag River Watershed." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/FretwellEA2006.pdf.

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Coogan, Melinda Ann La Point Thomas W. "Bioaccumulation of triclocarban, triclosan, and methyl-triclosan in a North Texas wastewater treatment plant receiving stream and effects of triclosan on algal lipid synthesis." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3986.

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Roblin, Rachel. "Water Quality Modeling of Freshwater Diversions in the Pontchartrain Estuary." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/693.

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A 1-D tidal, salinity and water quality model that analyzes the general effects freshwater diversions have on the water quality of the Pontchartrain Estuary over a 17-year period is presented here. Using the modeled live algae concentrations in conjunction with the algal bloom probability model results produces an accurate prediction of algal bloom occurrences between 1990 and 2006. The model predicts that the addition of freshwater diversions into Maurepas swamp and increases to flow in the Bonnet Carré Spillway may cause more intense and frequent algal blooms to occur around the Pontchartrain Estuary. The model also predicts that high nutrient input events that occur earlier in the year (January/February) will not likely have algal blooms associated with them. When nutrient input events (even small events) occur in the late spring or early summer, algal blooms have a high probability of occurring when the salinity, temperature and light levels are sufficient.

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Oosthuizen, Marthinus Gerrit Johannes. "Changes in density and composition of algal assemblages over time in two water purification plants / Oosthuizen M.G.J." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8173.

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In recent years, due to a change in the water situation in South–Africa and the effect of eutrophication in our water systems, there has been a significant increase in algal abundance and changes in species composition. The aim of this study was to investigate algal assemblages at two water purification plants with the main focus on dominant species that may pose a problem in the water purification process. Both water purification plants, especially the one at Virginia, experience problems with blue–green bacteria that are toxic and detrimental to water purification. There was also a need to determine the time of year that blooms of problematic algae occur in the system, in order to develop sufficient measures to remediate the situation. Chemical data helped with the explanation of algal tendencies. To achieve the principal aims of the study, algal species were identified and the concentrations were determined. It was possible to relate algal assemblages, dominance and succession to the prevailing environmental variables. Sixty three phytoplankton species, belonging to seven major algal groups, were identified. Aside from these, thirty four species were only identified up to genus level. The blue–green bacteria, diatoms and green algae were the main phytoplankton groups and constantly succeeded each other. Blooms of blue–green bacteria occurred in the raw water due to high temperatures and dissolved inorganic nitrogen concentrations in the late summer periods. These organisms did not penetrate far into the purification process, indicating that the purification procedures were sufficient for effective removal of blue–green bacteria.
Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

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King, Leighton R. "The Response of Utah Lake's Plant and Algal Community Structure to Cultural Eutrophication." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7631.

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Human activities have long had a negative impact on the water quality of freshwater lakes around the world. Utah Lake, located in north-central Utah, has been a subject of such impacts, as the lake experiences recurrent harmful algal blooms during the summer months. Lake warnings and closures have made the public increasingly aware of the ecological and economic impact of these blooms. The objectives of this study were to: 1) compare historical and present-day water quality and ecosystem conditions using environmental data contained in sediment cores, 2) identify whether, and when, Utah Lake transitioned from clearwater to turbid conditions, and 3) incorporate historically-validated lake plant community structure models into establishing forward-thinking lake management targets. The first two objectives will guide lake remediation efforts by providing insight into where lake managers should set our water quality goals and help identify the main driver(s) of eutrophication in Utah Lake. Environmental data from sediment cores indicate a transition in the lake’s recent history, marking a shift to greater phytoplankton dominance, which I attribute to the introduction of invasive common carp around 1881. The third objective provides management and restoration efforts with the water clarity requirements for returning the lake to its historical ecological state.

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Dissertations / Theses on the topic 'Algal metabolites in water'

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