<p>Osnovni cilj teze bio je doprinos poznavanju prisustva pesticida u površinskim i podzemnim vodama u Srbiji, kao i mehanizama rasprostiranja podzemnom vodom. Korišćeni su rezultati sedmogodišnje kampanje analize kvaliteta površinske vode i korespodentnih punktova za zahvatanje podzemne vode za četiri velike reke u Srbiji: Dunav, Savu, Tisu i Veliku Moravu. Pored sistematizacije i analize podataka o izvršenim analizama na pesticide voda reka i podzemnih voda, urađena su usmerena istraživanja koja se odnose na mehanizme i intenzitet sorbiranja, laboratorijska ispitivanja i terenski ogled. Rezultati ispitivanja i analiza su obrađeni numeričkim modelima.</p> / <p>The main aim of the thesis was to contribute to the knowledge of the presence<br />of pesticides in surface and groundwaters in Serbia, as well as transport<br />mechanisms in groundwater. The results of a seven-year analysis of the<br />quality of surface waters and correspondent points for groundwater<br />abstraction for the four major rivers in Serbia were used: Danube, Sava, Tisa<br />and Velika Morava. In addition to systematization and analysis of data from<br />campaigns carried out for the presence of pesticides in river water and<br />groundwater, targeted research related to the mechanisms and intensity of<br />sorption was implemented that consisted of laboratory and field experiment.<br />The results of experiments and analyzes were processed by numerical<br />models.</p>

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A research report submitted to the Faculty of Science, in partial fulfilment of the requirements for the degree of Master of Science in Hydrogeology, School of Geosciences, University of the Witwatersrand. Johannesburg, June 2017. / Groundwater is a principal source of water for many semi-arid countries, including Botswana and South Africa. This is especially true for the rural communities within these regions that lie on the periphery of local water scheme pipelines and make direct use of groundwater. The Ramotswa transboundary aquifer, which supplies local communities and nearby cities with fresh groundwater, is a highly productive and unique karst sequence shared by South Africa and Botswana. The objective of the study was to contribute to the available hydrogeological data by means of evaluating groundwater flow, nitrate pollution and the median recession index and master recession curve for the aquifer. The interpreted airborne geophysical data revealed the presence of collapsed features in the northeastern area corresponding to the karst morphology. A piezometric map of the area shows the groundwater flow is towards the north-northeast, which is supported by salinity increase across the study area. Increased nitrate concentrations were identified in areas with increased rainfall, shallow groundwater and a mature karst system. Only 3% of the 36 sample sites had nitrate concentrations exceeding the WHO guideline limit of 50 mg/l. This was attributed to the legacy of unlined pit latrines in karstified areas. Pollution is entirely anthropogenic and generally from non-point sources. A median recession index computed by RECESS program from the Dinokana spring discharge data was 295.7 days per log cycle and the generated master recession curve’s gentle slope alludes to massive storage potential within the karst compartment. The results of the study can alert stakeholders alike of the health risk of direct consumption of the groundwater without pretreatment. Establishing an understanding of the nitrate pollution sources and groundwater flow direction, and estimating the recession index provides informed groundwater pollution and vulnerability management options. This can improve the aquifer resource assessment and the livelihoods of local communities in the face of increasing climate change. / XL2017

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The purpose of the research was to determine if pesticides were being transported from the place of application by the shallow groundwater and discharged into the Chesapeake Bay and Atlantic Ocean, and quantify the pesticides if they were transported. One reference (undeveloped) and four agricultural sites were tested over a 11 month period from April 1992 to February 1993. Over 500 groundwater samples were analyzed from both shallow wells and seepage meters placed in the Chesapeake Bay and Magothy Bay. The samples were analyzed in accordance to EPA Method 525.1 by solid phase extraction with octadecyl bonded disks followed by gas chromatography. The samples were examined for 5 of the most commonly used pesticides: atrazine, alachlor, carbofuran, cyanazine, and metolachlor. Pesticides were detected in only 16 samples. All the detections were at low concentrations, with only one being over 1 μg/L. The study concluded that if pesticides were being transported by the groundwater, they were below a μg/L (ppb). / Master of Science

The most important thermal, chemical, physical, and biological methods for treating hazardous wastes and the fate of their land-disposed residues are reviewed and evaluated. Technologies are described as major, minor, and emerging according to their stage of development or application to hazardous waste; major ones include rotary kiln, liquid injection, and cement kiln incineration; neutralization, chemical oxidation-reduction, and ion exchange; filtration, distillation and settling techniques; and activated sludge, aerated lagoon, and landfarming treatment. Emerging technologies include molten salt and fluidized- bed combustion, liquid-ion extraction and other processes, none of which are considered to be outside the realm of current or future economic feasibility. In addition, waste reduction strategies and the land burial of stabilized/solidified wastes are discussed. Residues from these technologies vary widely according to waste type and composition, but a common component in many of them is heavy metals, which, as elements, cannot be further degraded to other products. The results of the available literature suggests that these metals will be retained in clay liners beneath a landfill through the mechanism of cation exchange, with the adsorption of metals favored by their smaller hydrated size, lower heat of hydration, and in some cases, higher valences than the naturally occurring alkali earth metals. Other important factors include ionic activity, the pH and ionic strength of the solution, the presence of complexing agents, and the possible surface heterogeneity of the clay. In soils, metal binding through cation exchange with clay is augmented by adsorption onto iron and manganese oxides and complexing with organic matter such as humic acids. Many field studies with landfarmed metal-bearing wastes show that these mechanisms are usually sufficient to retain metals to within several inches of their zone of application. / M.S.

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Deep injection wells (DIW) in Florida are regulated by the U.S. Environmental Protection Agency (USEPA) and the state of Florida through the Underground Injection Control regulations contained within the Safe Drinking Water Act. Underground injection is defined as the injection of hazardous waste, nonhazardous waste, or municipal waste below the lowermost formation containing an underground source of drinking water within one-quarter mile of the wellbore. Municipalities in Florida have been using underground injection as an alternative to surface disposal of treated domestic wastewater for nearly 40 years. The research involved collecting data as of September, 2007 on all the Class I DIWs in the state of Florida and evaluating the differences between them. The analysis found regional differences in deep well practice and canonical correlation analyses concluded that depth below the USDW is the most significant factor to prevent upward migration of the injected fluid. / by Jie Gao. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Providing clean water remains a challenge in many African countries. Ethiopia, with the second largest population in Africa is also faced with this predicament. Efforts to improve supply have focused on abstracting groundwater. Although relatively cheaper to utilize, groundwater is prone to contamination, from improperly disposed of waste, particularly urban areas with no appropriate sanitation services. The city of Addis Ababa is faced with this difficult situation. Currently about 75 % of the population of Addis Ababa has access to sanitation in the form of pit latrines, while 0.6 % has access to sewerage services. The rest of the population is considered to have no access. This proliferation of pit latrines in the city has enhanced the risk of groundwater contamination. This research was initiated with the objective of assessing the temporal and spatial extent of contamination of groundwater due to human waste. It attempted to review the quality of water in deep wells and springs. The data analyzed indicates that the temporal and spatial extent of contamination has increased over the past few decades. Over abstraction of groundwater has also been observed. Whilst contaminant levels such as nitrates and chlorides in many wells are below maximum permissible values, few wells in the centre of the city have exhibited higher values. This steady temporal increase may soon make some wells unsuitable for human consumption. Efforts to reduce this risk will need to focus on sewerage services provision, review of existing environmental policy, public awareness drive and sustainable groundwater management. / D.Phil. (Environmental Science)