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dc.contributor.advisorSteyl, Gideon
dc.contributor.advisorVan Tonder, Gerrit
dc.contributor.authorBijengsi, Famah Fortunata Immaculata
dc.date.accessioned2015-10-14T10:00:48Z
dc.date.available2015-10-14T10:00:48Z
dc.date.issued2012-12
dc.identifier.urihttp://hdl.handle.net/11660/1373
dc.description.abstractEnglish: This thesis aims at geohydrologically assess arsenic in the Jagersfontein area and hence proposing remediation option. The field procedure carried out involved hydrocensus and sampling where samples were collected and analysed for micro and macro parameters with emphasis on arsenic. Isotopic (18O, D (deuterium) and Tritium 3H) analysis was also carried out to characterise the water in terms of its origin, fate and age. A total of 20 boreholes were sampled. Historical data from Bloemwater was also incorporated in the study. According to the chemical analysis, the most abundant cation is magnesium followed by calcium, and the most abundant anion is sulphate. Three different water types were classified; sodium/potassium sulphate, magnesium sulphate and calcium/magnesium bicarbonate. Hence they are from different sources. Sample collected from the mineshaft showed highest arsenic concentration which is higher than the South African National Standards (SANS 241, 2006) guideline for acceptable arsenic concentration in drinking water while all other individual boreholes in the main town of Jagersfontein showed low arsenic concentration (<0.006 mg/l); hence concluding that arsenic contamination comes from the mine. Mine water that has been treated in package plant (JFinal) still shows high arsenic concentration. Water from Kalkfontein dam is being treated in a bigger treatment plant (went operational in July 2012) and mixed with treated mine water. This reduces the arsenic concentration of water to an acceptable level before it is finally supplied to the community. Spearman’s correlation coefficient calculated show a weak correlation between arsenic and other chemical parameters and so it is concluded that arsenic and these elements are not of same source implying the source of arsenic is not geogenic. Isotopic analysis shows the water samples plot very close to the global meteoric water line (GMWL) implying the groundwater is meteoric and is derived from the atmosphere. Clustering of the samples around the GMWL hints they might be of the same age. However one sample (surface water sample) plotted away from GMWL and it is attributed to effects of evaporation. The hardness of the water samples is generally high. To solve this problem, individual owners of boreholes add water softeners (chlorine, crystals) to soften the water. There are several techniques available for removal of arsenic from water in large conventional treatment plants. The basic principles of these technologies are based on physical-chemical processes such as oxidation, coprecipitation and adsorption on coagulated flocs, adsorption onto sorptive media, ion exchange, and membrane filtration. Most treatment options need the oxidation of As(III) to As(V) for efficient removal of arsenic. For the case of Jagersfontein, coagulation and filtration technology (FeCl3 as coagulant) will be the best option because it is very efficient in removing arsenic (V) which happens to be the dominant specie in the water. It is the cheapest technique compared to the others and it is also less sophisticated. However what is currently done in Jagersfontein to reduce the concentration of arsenic in water is dilution/mixing. Mine water treated in a package is mixed with treated water from Kalkfontein dam. Water (not arsenic contaminated) from Kalkfontein dam is treated in a bigger treatment plant which went operational in July 2012.en_ZA
dc.description.abstractAfrikaans: Die doel van hierdie tesis is om arseen in die Jagersfontein-gebied te assesseer om sodoende remediërende oplossings te vind. Die veld prosedures wat uitgevoer was, is hidrosensus en monsters wat geneem is vir analisering. Monsters is ontleed vir mikro- en makro- parameters met die klem op arseen. Isotoop- (18O, D (deuterium) en Tritium 3H) analise is ook uitgevoer om die water te karakteriseer in terme van oorsprong, toekoms en ouderdom. 'n Totaal van 20 boorgate is geëvalueer. Historiese data van Bloemwater is ook ingesluit in die studie. Volgens die chemiese analise is magnesium die volopste katioon gevolg deur kalsium, en sulfaat is die volopste anion. Drie verskillende water tipes is geklassifiseer, naamlik natrium-/kaliumsulfaat, magnesiumsulfaat en kalsium-/magnesium bikarbonaat. Die water tipes het dus verskillende oorspronge. Monsters wat uit die mynskag geneem is, het die hoogste arseen konsentrasies getoon. Die konsentrasies is hoër as die riglyne van die Suid-Afrikaanse Nasionale Standaarde (SANS 241, 2006) vir aanvaarbare arseenkonsentrasie in drinkwater, terwyl al die ander individuele boorgate in Jagersfontein lae arseen konsentrasie (<0,006mg/l) getoon het. Daar is dus tot die slotsom gekom dat arseen besmetting nie van die myn afkomstig is nie. Myn water wat in die pakket-plant (JFinaal) behandel is, toon steeds hoë arseen konsentrasies. Water van die Kalkfonteindam word behandel in 'n groter behandelings plant (wat vanaf Julie 2012 in werking is) en word dan gemeng met behandelde myn water. Dit verminder die arseen konsentrasie in die water tot 'n aanvaarbare vlak voordat dit finaal aan die gemeenskap verskaf word. Spearman se korrelasiekoëffisiënt toon 'n swak korrelasie tussen arseen en ander chemiese parameters en vandaar is tot die gevolgtrekking gekom dat arseen en hierdie elemente nie van dieselfde bron is nie. Dit impliseer ook dat die bron van arseen nie geogenies is nie. Isotoop analise toon dat die water monsters baie naby aan die globale meteoriese waterlyn (GMWL) plot, wat impliseer dat die grondwater meteories is en ‘n atmosferiese afkoms het. Groepering van die monsters om die GMWL toon dat hulle miskien dieselfde ouderdom kan hê. Daar is wel een monster (oppervlakwater monster) wat weg plot van GMWL en dit word toegeskryf aan die effek van verdamping. Die hardheid van die water monsters is oor die algemeen hoog. Om hierdie probleem op te los, voeg individuale eienaars van boorgate, waterversagters (chloor, kristalle) by om die water te versag. Daar is verskeie tegnieke beskikbaar vir die verwydering van arseen in water by groot konvensionele behandelings plante. Die basiese beginsels van hierdie tegnologie is gebaseer op die fisies-chemiese prosesse soos oksidasie, ko-presipitasie en adsorpsie op gekoaguleerde vlokkies, adsorpsie op absorbeerbare media, ioonuitruiling en membraanfiltrasie. Vir die doeltreffendste verwydering van arseen word oksidasie van As (III) na As (V) gebruik. In die geval van Jagersfontein, sal koagulasie en filter tegnologie (FeCl3 as stollingsmiddel) die beste opsies wees, want dit is baie effektief in die verwydering van arseen (V), wat in dié geval die dominante spesie in die water is. Dit is die goedkoopste tegniek in vergelyking met die ander en dit is ook minder gesofistikeerd. Wat tans in Jagersfontein gedoen word om die konsentrasie van arseen in water te verminder, is verdunning/menging met ander water. Mynwater wat behandel is in ‘n packet word gemeng met behandelde water uit die Kalkfonteindam. Water (nie arseen besmette) van die Kalkfonteindam word in 'n groter behandelingsplant behandel wat in Julie 2012 in werking getree het.af
dc.description.sponsorshipIGS (Institute for Groundwater Studies)en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectDissertation (M.Sc. (Institute for Groundwater Studies))--University of the Free State, 2012en_ZA
dc.subjectGroundwater -- Arsenic content -- South Africa -- Free State -- Jagersfonteinen_ZA
dc.subjectGroundwater -- Quality -- South Africa -- Free State -- Jagersfonteinen_ZA
dc.subjectDrinking water -- Contamination -- South Africa -- Free State -- Jagersfonteinen_ZA
dc.subjectArsenicen_ZA
dc.subjectGroundwateren_ZA
dc.subjectAssessment,en_ZA
dc.subjectRemediationen_ZA
dc.titleA geohydrological assessment of arsenic as a contaminant in the Jagersfontein area and remediation optionsen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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