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Industrial water pollution in a surface water system in Colombo, Sri LankaMohamed Ali, Sithy Kadija January 1991 (has links)
Surface waters are increasingly polluted by the industries in Colombo, Sri Lanka. Among these the food and drink industries are prominent in urban Colombo. To understand the extent of pollution of the inland surface waters a project was undertaken in the San Sebastian canal, which runs through the heart of Colombo, and the connecting waterways. It entailed the chemical and physical monitoring of the surface waters and the waste water discharges of the industries. The results indicated that the San Sebastian canal was a highly polluted canal with a very low dissolved oxygen level. The oxygen sag was very marked at the industrial discharges. Most of the industries, by nature of the highly organic waste waters in addition to being untreated failed to meet the specified standards of discharges into inland surface waters. The rainfall-pollutant and the rainfall-lag analysis indicated the poor dilution of these strong waste waters, and the low assimilative capacity of the highly polluted canal system. Hence, the San Sebastian canal polluted the receiving river Kelani, into which it discharges in the east, and the Beira lake in the west, where the polluted waters are pumped from the canal to maintain the level of the lake.
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Life-cycle parameters of Tisbe battagliai (Copepoda: Harpacticoida) as indicators of chronic toxicityWilliams, Timothy Dorian January 1997 (has links)
There is growing concern about the fate and biological effects of chemical contaminants in the marine environment. In the United Kingdom, the present ability to detect the potential longterm effects of contaminants is limited by the lack of suitable laboratory methods for measuring chronic toxicity. The harpacticoid copepod Tisbe battagliai was selected as a candidate test organism and a suite of chronic toxicity test methods was developed for measuring the effect of chemical contaminants on individual copepods (postembryonic development, reproduction and life-table analysis) and populations of T battagliai. The development of chronic test methods proceeded alongside investigations of the influence of key environmental variables (temperature and food availability) on the biology of this species. These investigations provided a valuable insight into the potential importance of these environmental factors for influencing the development of populations of T battagliai in the field, and helped to define the optimum conditions for the culture and chronic toxicity testing of this species in the laboratory. The methods were further evaluated using pentachlorophenol (PCP) as a reference toxicant and the aim was to investigate the potential interaction between toxicant (PCP), environmental factors (temperature and food availability), and their effects on the population dynamics of T battagliai. In summary, results showed that temperature, and food quantity and quality, were important determinants of population dynamics. There were significant interactions between the chosen environmental variables (e. g. temperature), PCP, and subsequent biological effects on Tisbe battagliai, and results highlighted some important differences in toxicity testing approaches based on the measurement of individuals and populations of copepods. Established laboratory toxicity test procedures do not take account of the degree of complexity in the natural environment and this underlines the Miculty in extrapolating from laboratory. results to the field situation. In conclusion, the project was successful in its primary objective of developing a suite of techniques that can be used to measure the potential chronic toxicity of chemical contaminants in the marine environment. The methods using Tisbe battagliai are relatively simple to perform, are amenable to standardisation and provide relatively cost-effective measurements of chronic toxicity. The test methods can be used to provide chronic toxicity data but, more importantly, they can be used to address some of the current limitations associated with single species laboratory tests. For example, used in conjunction with key environmental variables, the methods provide a greater understanding of the potential interaction between contaminants and abiotic variables, thereby, improving the extrapolation of laboratory results to the field situation. The ability to carry out measurements on individual and populations of T. bauagliai provides a valuable insight into the predictive links between effects at different levels of biological organisation.
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The sub-surface distribution of some heavy metals following sewage sludge injection into grassland soilsBrown, Rachel January 1994 (has links)
The use of suitable sewage sludge in agriculture is currently its cheapest disposal option, both in terms of monetary cost, resource utilisation and environmental impact Monitoring of die heavy metal content of the soil after sludge application is required by European Council Du-ective 86/278/EEC, and whilst the behaviour of metals from surface-applied sludge is well documented, the behaviour following other methods of application has received litde attention. The most important alternative land application method cturentiy in use is the subsurface injection of sludge. In this project, field- and laboratory-based experiments were set up to describe the postinjection disttibution of Cd, Cu, Ni, Pb and Zn and the effect on this of: tine design (using die straight tine, side-inclined tine and winged tine), rate of injection (225 m^ ha'-^ and 300 m3 ha"-^), and soil factors ^ H , cation exchange capacity, organic carbon, percentage clay,. Fe and Mn concentration, and redox potential). An assessment of the variability of die injection operation was also important, as account needs to be made of metal distribution and variability in order to delimit an appropriate sampling regime. The results of these experiments indicated that Cu, Pb and Zn are basically immobile, remaining widiin 120 mm of die centte of die original slot location. Tine design was seen to have a significant influence on the pattern of subsurface metal distribution, but neither this,' rate of injection nor soil factors adequately predicted die extent of diis distiibution. Instead, metal identity and concentration widiin the sludge were identified as the most influential factors, in that appreciable quantities of Cd and Ni are leached out of the profile to distances exceeding 300 mm from die sludge, and greater metal concentirations (of the remaining metals) in the injected sludge create distinct gradients in the soil and saturates exchange sites, thus promoting mobility via diffusion, over-riding normal metal chemistry. Of those measured variables that had a secondary effect on distribution, pH, Fe oxide concentration and percentage clay were identified as the most important soil factors.The winged tine was seen to promote soil disturbance and hence metal distribution, and the paraplow to restrict both. In practical terms, these conclusions indicate that the current sampling protocol is inadequate. An alternative regime is suggested.
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Determination of selected acidic pharmaceutical compounds in wastewater treatment plantsMadikizela, Lawrence Mzukisi January 2017 (has links)
A thesis submitted to the Faculty of Science, University of the
Witwatersrand in fulfilment of the requirements for the degree of
Doctor of Philosophy. November 2016. / This research was directed towards the environmental monitoring and assessment of the most used non-steroidal anti-inflammatory drugs (NSAIDs) which are naproxen, ibuprofen and diclofenac. The work involved the development and application of sensitive techniques for the quantification of naproxen, ibuprofen and diclofenac in the South African aquatic environment. Based on this information, a multi-templates molecularly imprinted polymer (MIP) was synthesized and applied alongside the commercial available sorbent (Oasis MAX) in the solid-phase extraction (SPE) of target compounds from water samples. The extracted compounds were then quantified using high performance liquid chromatography (HPLC).
MIP was synthesized by applying a bulk polymerization approach at 70 ͦ C where all target compounds were used as multi-templates. Other reagents used in synthesis were 2-vinyl pyridine, 1,1’-azobis-(cyclohexanecarbonitrile), ethylene glycol dimethacrylate and toluene as functional monomer, initiator, cross-linker and porogenic solvent, respectively. Synthesis of a non-imprinted polymer (NIP) under similar reaction conditions as MIP was carried out with the omission of templates.
Techniques employed in characterization of MIP and NIP were Fourier transform infrared spectroscopy (FTIR), Brunauer, Emmett and Teller (BET) method, CHNS analyzer, zeta potential, cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy, thermogravimetric analysis, differential scanning calorimetry and x-ray diffraction. Monomer-template interactions were investigated using molecular dynamics.
The performance of the MIP was evaluated based on its ability to selectively extract target compounds in organic (acetonitrile, acetone, chloroform and toluene) and aqueous media. The extraction capacity of the MIP in organic solvents for naproxen, ibuprofen and diclofenac increased from high polarity to low polarity solvents. In a low polarity solvent (toluene), the extraction capacity achieved for naproxen, ibuprofen and diclofenac were 14.4, 11.0 and 14.0 mg/g, respectively. In this case, the selectivity of the MIP where gemfibrozil was employed as the
competing species was evident. Selectivity of the MIP collapsed during the adsorption of naproxen, ibuprofen and diclofenac from water using gemfibrozil and fenoprofen as competitors. This resulted in high extraction efficiencies for target compounds and competitors, however, both gemfibrozil and fenoprofen were easily desorbed from the MIP using weak organic solvent due to lack of molecular recognition.
During the binding sites characterization, the best fit of pseudo-second-order implied a chemisorption of all target compounds onto MIP sorbent. The data also fitted well in Langmuir isotherm which meant that the adsorption of target pharmaceuticals occurred on the homogeneous binding sites of the MIP.
Optimized adsorption conditions in water such as MIP amount of 50 mg, extraction time of 10 min, sample pH of 2.5 and sample volume of 10 mL were applied for the selective adsorption of naproxen, ibuprofen and diclofenac in contaminated wastewater and river water. In WWTP influent, naproxen recovery was 38%, whereas ibuprofen and diclofenac were 69% and 87%, respectively.
MIP was further used as a selective adsorbent in solid-phase extraction (SPE) of three drugs from environmental samples. The selectivity of the MIP in environmental samples was compared to that of the commercially available Oasis MAX sorbent. The application of molecularly imprinted solid-phase extraction (MISPE) reduced matrix effects and improved the sensitivity of the analytical method. In this case, the detection limits for naproxen, ibuprofen and diclofenac were 0.2, 1 and 0.6 μg/L, respectively. When deionized water was spiked with 5 and 50 μg/L of target compounds, recoveries greater than 80% were obtained.
Thereafter, the developed MISPE was applied for selected acidic drugs from environmental samples. Environmental samples were collected from urban (Durban) and semi-urban/rural areas (Ladysmith) of KwaZulu-Natal Province in South Africa. The most abundant compound in the environment was ibuprofen. In river water samples from Durban, the maximum concentrations found for naproxen, ibuprofen and diclofenac were 6.8, 19 and 9.7 μg/L, respectively. The maximum amounts found for the same drugs in Ladysmith river samples were generally lower
with naproxen, ibuprofen and diclofenac detected at 2.8, 6.7 and 2.6 μg/L, respectively. The same trend was observed in wastewater.
Further work on the monitoring of acidic compounds in wastewater was conducted using Oasis MAX as the SPE sorbent prior to HPLC analysis. All target compounds were detected in Kingsburg and Umbilo WWTPs located in Durban surroundings. The influent and effluent concentrations detected were in the ranges of 6.4 to 69 μg/L and 0.6 to 4.2 μg/L, respectively. Further to this, the removal efficiency of the target compounds during the WWTP process in Kingsburg and Umbilo was in the range of 69 to 97%.
The extent of pollution in the environment was further assessed by the monitoring of ketoprofen and triclosan in wastewater and river water using SPE with Oasis HLB sorbent and HPLC. Traces of both compounds ranging from 1.2 to 9.0 μg/L were detected in wastewater. The maximum concentrations found in river water were 2.0 and 0.9 μg/L for ketprofen and triclosan, respectively.
Overall, the analytical methods implemented in this work were highly accurate, precise and sensitive. The synthesized MIP was highly selective and its application in environmental studies led to the development of a less expensive analytical method. This work also gives the overview of the extent of water pollution caused by acidic pharmaceuticals in various water matrices. / MT2017
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The movement of cohesive sediment in a large combined sewerWotherspoon, David January 1994 (has links)
The presence of sediment deposits within sewerage systems may lead to operational (premature surcharging and surface flooding) and potential environmental problems (sediments act as a store of pollutants which can be released during erosion events). The consequences of allowing these problems to persist have been recognised internationally. In the U.K., the water industry has promoted fundamental and applied research to develop the necessary operational and analytical tools to manage these problems. Under the Urban Pollution Management Research Programme the major aspects of sediments in sewers have been studied and their effects included in new methodologies and tools. Most studies in the U.K. and elsewhere have concentrated on the movement of non - cohesive sediments, whilst it has been recognised that combined sewer sediment deposits possess cohesive characteristics (although this cohesion primarily arises from agglutination and biological processes in the combined sewer rather than classical concepts of cohesion). New computer based models, e.g Mosqito (Moys 1987) and MOUSETRAP (WRc 1993) , are based on sediment transport capacity theories with the limited availability of sediment within the system recognised through storage layers which become available only when certain threshold levels of shear stress are exceeded. Studies in the U.K. to estimate the release of pollutants stored within sewer sediment beds also require a knowledge of the hydraulic shear stress conditions at which the sediment beds will erode and become entrained into the flow. The reported study examines the apparent cohesive nature of a sediment bed in a large diameter sewer concurrently with flow hydraulics, sediment bed deposit depth and suspended solids flux for a number of dry and wet weather periods. Instrumentation was developed and assessed for hydraulic measurements within the study sewer system and in particular, a novel system was devised to improve flow measurement accuracy in large diameter sewers. Development work was also undertaken on an ultrasonic device to monitor the temporal variation in sediment deposit depth at a point. The constituent materials of the sediment bed were examined and rheological techniques were employed to assess the structural strength of the sediment bed present in the study sewer. The results confirmed the apparent cohesive nature of the sediment bed, with the structural strength of the bed far exceeding the normal hydraulic shear stress ranges encountered in the sewerage system. A relationship between apparent yield strength and liquid content of the sediment bed was obtained from the rheological tests. The bed structural strength was then compared with temporal changes in the flow - induced shear forces. An empirical model was developed to predict the availability for erosion of the cohesive deposits in the combined sewer studied. This model was tested against further temporally varying data sets from the sewer and was found to predict the erosion of the sediment bed under varying levels of applied shear stress together with changes in the sediment transport flux. It was concluded that when Dry Weather Flows induce bed shear stresses in excess of 1-2 N/m erosion of the sediment bed structure can be caused, with storm flows which induce shear stresses in excess of 4-6 N/m eroding the bed to a greater depth. The sediment bed was observed to be rapidly re-established following an erosion event. The investigation and model developed contribute significantly to knowledge about the behaviour of sediments in sewers and provide for the first time a model to simulate erosion of a sediment bed with apparently cohesive properties and consequent increase in sediment and pollutant transport rates.
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Construction nonpoint source pollution : a proposed control programPendowski, James Joseph January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
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Assessment of the health of the Swan-Canning river system using biochemical markers of exposure of fishWebb, Diane January 2005 (has links)
Most environmental studies concerning the environmental health of the Swan- Canning River system have focussed on nutrient inputs from both rural and urban catchments that are the cause of algal blooms. On occasions these algal blooms have resulted in fish deaths attributed to oxygen starvation. Relatively few studies have examined whether non-nutrient contamination is affecting the health of the riverine environment. Those studies that have, have concentrated on measuring the levels of heavy metals, organochlorines, organophosphates, and hydrocarbons in the sediments and water of the river system, and in the flesh of the biota. However, chemical analysis often fails to detect chemicals of concern due to high laboratory detection limits. In addition, analysis of the body burden of contaminants within biota does not necessarily convey if exposure is inducing adverse effects at the individual or ecosystem levels. The use of biochemical markers as a tool for the assessment of the health of the Swan-Canning River system was examined under a collaborative research project with the Waters and Rivers Commission, established in response to the recognition of the paucity of information from chemical analyses. The present study focussed on the estuarine portion of the Swan-Canning River system, using the black bream (Acanthopagrus butcheri), an estuarine dependent fish species, as a biomonitoring tool. Prior to the commencement of this study it had been determined that the black bream was a suitable fish species for use as a biomonitoring tool when using mixed function oxygenase (MFO) activity induction under laboratory conditions. / Biopsies taken from feral black bream collected from eight sites during the period 2000 to 2002 from the estuary confirmed that the use of MFO induction in this fish species as a biomarker of exposure to organic contaminants is a reliable biomarker. Fish gender was a confounding factor in the interpretation of MFO induction when using the enzyme ethoxyresorufin-O-deethylase (EROD) as EROD activity was suppressed in both pre- and post-spawning female black bream. No such suppression was identified when using the MFO enzyme ethoxycoumarin-O-deethylase (ECOD). However, due to differences in the pattern and intensity of the induction of EROD and ECOD activities it was concluded that ECOD activity was not a substitute for EROD activity to detect certain chemical as ECOD activity represents a different cytochrome P450 pattern to EROD activity. No spatial, seasonal or interannual differences in the level of the enzyme sorbitol dehydrogenase (SDH) in the blood of the black bream were measured indicating that the interpretation of MFO activity induction was not compromised by hepatocellular damage. This study has shown that the black bream in the Swan-Canning Estuary are exposed to, and are metabolising polycyclic aromatic hydrocarbons (PAHs), notwithstanding that the chemical analysis of the contaminant load of these substances in the estuarine waters is consistently below laboratory detection limits. In addition, biomarker responses such as ECOD activity indicate that various other organic pollutants are present and are being metabolised by the black bream. / The measurement of biliary metabolites clearly show that, under winter conditions, the comprehensive drainage system of the Swan Coastal Plain contributes PAHs from pyrogenic sources such as burnt fuels into the estuary although the onset and intensity of rainfall events notably impacts on the volume of stormwater inflow. During the summer months, when freshwater flow is minimal, petrogenic sources of PAHs are dominant. Metabolic enzyme analysis points to the black bream being challenged in their aerobic capacities during summer, and that gill tissue was the most suitable tissue to evaluate the aerobic and anaerobic capacity of this fish species. Furthermore, there was a significant negative correlation between stress protein (hsp70) expression and DNA integrity in field-collected fish suggesting that the black bream within the estuary are highly stressed. No gradient of response in biomarker levels was identified in the Swan-Canning Estuary under either winter or summer conditions indicating there are multiple sources of inputs of potential pollutants along the length of the estuary. Stormwater and road runoff are the primary source of pollutant input into the estuary in the winter months, while summer biomarker levels, particularly PAH, appear to reflect the high usage of the estuary for recreational purposes and runoff from poorly irrigated parks and gardens. Significant rainfall events at any time of the year have the potential to adversely impact the biota of the estuary, particularly when these events result in a flush of water from the drains following long dry periods. / The study shows that the black bream is a suitable fish species to use under field conditions to detect the presence of bioavailable non-nutrient contamination within the Swan-Canning Estuary. A suite of biomarkers in black bream have been tested seasonally and annually but only a small number of biomarkers have proven suitable for routine monitoring of the health of the Swan-Canning Estuary. This treatise concludes with several recommendations for further investigations into biomarkers of fish health for the purpose of increasing our understanding on the sources and type of contamination entering the estuary, and potential effects on the aquatic biota of the Swan-Canning River system. These recommendations include, but are not limited to: (1) the need to determine baseline levels for the different biomarkers investigated in this study, (2) the examination of the Moore River or the Warren River estuaries as potential reference sites for biomarker studies in the Swan- Canning Estuary, (3) the advantage of identifying a second estuarine-dependent indigenous fish as a biomonitoring tool, (4) the requirement for a targeted study aimed at clarifying the relationship between major drain discharges, biomarker levels and impacts on river biota, and (5) a study of estuarine waters utilising SPMDs be undertaken in tandem with biomarker analysis of field captured fish would be beneficial.
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Identification, transport and treatment of adhered deleterious substances of stormwater in an urban catchmentNg, Warren Heng Wan Unknown Date (has links)
This thesis develops and presents a practical, rapid and cost effective method of assessing the most efficient strategy to limit sediment and associated contaminants from entering and impacting on Auckland's waterways. Although sediment removal objectives have been defined by Auckland Regional Council's stormwater quality guidelines, the deployment of treatment systems based upon current best management practice does not ensure that these objectives will be achieved. Due to the lack of established methods for the collection and analysis of stormwater related contaminants, an elaborate sampling and analytical protocol was established to validate the results obtained. The research has been undertaken as a series of studies with specific sampling methodology described in detail at the beginning of each study. Current issues and practices relating to the local stormwater industry are also reviewed.The accumulation of metal contaminants in estuarine studies is typically considered in terms of the preferential accumulation of heavy metals in the sediment fine fraction and the accumulation of these contaminants in the bulk sediment. For these data to be considered in the context of stormwater treatment, a third factor, looking at the total mass load distribution of these contaminants within the particle ranges of sediment is introduced. This thesis proposes that a substantial amount of coarser particles are making their way into our receiving environment and that attached to them are a significant proportion of the total contaminant load. Although the contaminants on coarse particles may not be bioavailable in their original state, they undergo physical changes while in transport and once deposited the chemical and biological effects on the receiving environment will ultimately be just as detrimental.A contaminant yield assessment method is developed in which the removal efficiency of every stormwater contaminant can be accessed based on a target sediment removal range. From a cost-benefit perspective, the marginal benefit of higher contaminant removal is also discussed. Finally the framework of a contaminant-based stormwater model, incorporating provenance, nature and transport is developed to access the true nature of stormwater contamination discharged to the receiving environment. The model will generate generic particle and contaminant distributions, which may be used by policy makers to predict treatment efficiencies based on target sediment removal objectives.
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noneCheng, Shih-Yin 25 July 2003 (has links)
none
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The determination of trace metals in sea water using ICP-MSBloxham, Martin John January 1994 (has links)
Inductively coupled plasma-mass spectrometry (ICP-MS) offers exceptional sensitivity and multi-element capability for trace metal analysis but the formation of polyatomic ions (particularly below m/z = 80) can cause, serious interferences. Such species can be introduced via precursor atoms in atmospheric gases, the sample matrix or impurities in the argon support gas. This thesis describes the development of a portfolio of analytical methods coupled with ICP-MS detection for the determination of trace metals such as manganese, cobalt, copper, nickel, zinc, mercury and lead in complex matrices such as sea water. A literature review of coupled techniques is given in Chapter one. Chapter two discusses the effect of sea water on the analytical performance of ICP-MS. Initial studies were carried out using a single channel flow injection (FI) manifold and included an investigation of the addition of nitrogen to the nebulizer gas flow of the ICPMS for the reduction of the ArNa* polyatomic ion interference at m/z = 63 on the Cu signal. This was followed by a multivariate simplex optimisation for the suppression of the ArNa* polyatomic ion interference at m/z = 63 and non-spectroscopic interferences affecting other masses in sea water, for the determination of Cu, Cr, Mn, Ni, Co, Zn and Pb. In Chapter three an on-line FI-ICP-MS matrix elimination method for the determination of trace metals such as Mn, Co, Cu, Zn and Pb in sea water is discussed. The method involved chelation of the analytes onto Chelex-100 or MetPac CC-1 iminodiacetate (IDA) .resin, with the simultaneous removal of indirectly interfering matrix species, particularly Na and CI ions. Results showing how the effects of the interferences were overcome, together with validation of the method by the analysis of open ocean, coastal and estuarine certified reference materials are reported. s Chapter four compares FI approaches coupled with AFS, ICP-AES and ICP-MS detectors for the determination of total mercury. Initial studies compared figures of merit for FI (conventional pneumatic nebulization) and Fl-cold vapour generation (CVG) coupled with ICP-AES and ICP-MS. Detection limits for total Hg were improved by developing simple on- and off-line preconcentration procedures using a MetPac CC-1 micro-column incorporated in a FI manifold vAth conventional pneumatic nebulization. An AFS detector was then used in the development of a method for the determination of total mercury with an on-line bromide/bromate oxidation step. In chapter five an LC-ICP-MS method for the speciation of Hg in sea water samples is described. The method involved the separation of mercury(II) chloride, methylmercury chloride and ethylmercury chloride on a Cig ODS stationary phase with an ammonium acetate/acetonitriIe/2-mercaptoethanol mobile phase. In order to achieve the necessary detection limits required for the determination of mercury in real sea water samples (< 50 ng r^), an off-line preconcentration method using a dithiocarbamate resin was used.
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