Ultraviolet advanced oxidation processes were compared using sodium perborate (UV/NaBO3 AOP) or hydrogen peroxide (UV/H2O2 AOP) for 1,4-dioxane removal from tertiary wastewater effluent. Both UV/H2O2 and UV/NaBO3 AOPs were also tested with the addition of acetic acid. Results revealed that sodium perborate performed similarly to hydrogen peroxide – the UV/NaBO3 AOP with 6 milligrams per liter (mg/L) as H2O2 resulted in 43.9 percent 1,4-dioxane removal, while an equivalent UV/H2O2 AOP showed 42.8 percent removal. Although the oxidants performed similarly, NaBO3 is an average of 3.3 times more expensive than H2O2. However, the solid form of NaBO3 can provide a major benefit to remote and mobile operations. Unlike H2O2 solution, which degrades over time and requires repeated costly shipments, NaBO3 is a convenient source of H2O2, and a long-term supply can be shipped at once and mixed into solution as needed. Additionally, acetic acid addition increased 1,4-dioxane removal by 5.7 percent in an UV/H2O2 AOP. It is proposed that the UV irradiation of acetic acid produced the acetoxyl radical, which cohesively works with the hydroxyl radical, produced via H2O2 irradiation, to enhance 1,4-dioxane degradation in a combined, novel UV/H2O2/acetic acid AOP. Other UV-AOP observations relate to a decrease of up to 29 percent in total dissolved solids (TDS), an inverse relationship between TDS and turbidity removals, and degradation of organic matter. Despite organic matter changes, the UV/NaBO3 AOP did not reduce trihalomethane formation due to the increased chlorine demand from hydrogen peroxide residual. Additionally, new insights into limitations of H2O2 residual test methods are included.

<p> Lake Atitlan in Guatemala is a vital source of drinking water. The deteriorating conditions of water quality in this lake threaten human and ecological health as well as the local and national economy. Given the sporadic and limited measurements available, it is impossible to determine the changing conditions of water quality. The goal of this thesis is to use Hyperion satellite images to measure water quality parameters in Lake Atitlan. For this purpose <i> in situ</i> measurements and satellite-derived reflectance data were analyzed to generate an algorithm that estimated Chlorophyll concentrations. This research provides for the first time a quantitative application of hyperspectral satellite remote sensing for water quality monitoring in Guatemala. This approach is readily transferable to other countries in Central America that face similar issues in the management of their water resources.</p>

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. 01 December 2016. / Pressure on water as a resource is increasingly becoming inherent and unavoidable as economies continue to expand globally. The challenges experienced in water resource management inspired the need to understand institutional frameworks holistically. This lead to the primary purpose of this study: to explore perspectives of governance in sustainable policy development. The study intended to increase understandings of the strengths and weaknesses within governance structures in relation to contextual institutional operations and mandates. A comparative analysis of various governmental tiers in South Africa, with particular interest in Gauteng, was examined. Within Gauteng, the study focussed on district and local municipalities. Respondents comprised of participants operating at national, provincial and local level; and included institutions associated with water resource management. The participants were selected using a purposive sampling technique: snowball sampling. In assessing the identified institutions, data was gathered through the use of a questionnaire and interview questions. Together with content analysis, data was used to supplement the Institutional Analysis and Development framework; which provided a platform to incorporate actors into the research enhancing the researchers understanding of actors involved in the policy arena, including their features and functions. Areas contributing to institutional fragmentation and poor institutional linkages were indicated as management functionality in terms of the top-down management approach. This includes management styles, lack of funds, capacity and skills relevant to the implementation of IWRM. Emphasis on the development of the NWRS2 was noted to be a major driver of sustainable water resource management, rather than the IWRM. Control and coordination of cooperative governance is strongly emphatic of management functionality. Overall, key findings highlight the importance placed toward economic development, moreover than social and environmental development. Integration of institutional structures is highly recommended for successful policy implementation. / MT2017

Wetland mitigation has become a 2.4 billion dollar per year industry in the U.S. and in Virginia it leads to the replacement of 77 ha of palustrine forested wetlands (PFWs) per year with mitigation wetlands, including created forested wetlands (CFWs). Mitigation hinges on the idea that compensation wetlands lead to “no net loss of wetland function” when compared to impacted wetlands. We assessed the functions of provision of habitat and biogeochemical functions associated with production of biomass, the retention and removal of nutrients and the accumulation of soil C over 8 years in seven CFWs of approximately 11 and 20 years and compared them to natural reference wetlands (NRWs). CFW plant communities were similar to NRWs in all measured parameters in the herbaceous and shrub/sapling strata and in all strata combined. However, non-native dominance showed a significant positive linear relationship with CFW age. In the tree strata, 11 year old (yo) CFWs had lower richness than NRWs and both age classes of CFWs had lower FQI than NRWs. NRWs held 10 to 20 times more carbon in woody biomass than CFWs. Tree species composition was significantly different between CFWs and NRWs, however NRW trees were similar to CFW saplings. 11 yo CFWs held lower percentages of C, N and P and had higher Db than NRWs in both the 0-10 and 10-20 cm depth. 20 yo CFWs developed similar levels of %C, %P, bulk density (Db), and nutrient ratios in the surface and displayed rapid increases in %C and %N over 8 years. However, CFWs offered 45% lower soil total soil C storage and 50% lower %N. Furthermore, all CFWs stored lower nutrient levels than NRWs in the 10-20 cm soil depth. We found that FQI correlated positively with total C accumulation rates in woody biomass and soil C, indicating that biogeochemical function and the provision of habitat can be complimentary in CFWs. Finally, 11 and 20 yo CFWs adhered to the regulatory performance standards established for Virginia in terms of stems per ha and wetland indicator status, but all wetlands (including NRWs) failed to achieve <5% non-native species cover.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.