After several decades of rapid urbanisation, population growth and industrialisation, most developing countries have now become home to the rapidly increasing informal sector’s polluting activities. With marked failures in their use of traditional Command and Control (CAC) legislation, limited technical and fiscal environmental protection resources coupled with weak environmental protection, complimentary judicial and legislative institutions, it has become necessary for these countries to look somewhere else for environment regulation policy. This study evaluates potential contributions of public-led voluntary agreements programs in the control of informal sector pollution in Lusaka’s Soweto and City markets in Zambia. The study employs Binary Logistic Models to establish factors critical to the successful implementation of environmental management voluntary agreements in the two markets. It also uses the Contingent Valuation Method (CVM) to assess and estimate traders’ Willingness to pay (WTP) for proposed improvements to cleanliness in the markets. The main empirical data for the study was collected by means of a questionnaire survey of 93 traders in the two markets and supplemented by semi-structured interviews. The study finds that indeed voluntary agreements have a potential to control informal sector pollution in developing countries like Zambia. The study also finds that while the informal sector significantly contributes to urban pollution, they are hamstrung by lack of capacity to control their own pollution. The absence of adequate regulatory enforcement and appropriate incentives in terms of waste bins and cleaners in these markets seriously militate against the sector’s limited efforts in implementing positive environmental management in these markets. The traders’ mean willingness to pay (WTP) for the proposed improvement to cleanliness in the two market is K483,384 per trader per year while the total WTP of all the traders in the two markets is K1,208,460,000 or K1.2 billion per year. As a proportion of the traders’ average annual income, the mean WTP amounts to 0.8%. The study concludes that deliberate interventions with the aim of enhancing their capacity are necessary. In this regard specific recommendations have been made for policy intervention in specific key areas, namely; the provision of appropriate incentives in form of increasing the number of waste bins and cleaners in the markets together with supporting organisational structure and efficient services in terms of frequent removal of waste from the markets by the local authority; the expansion and strengthening of the physical presence of regulatory and enforcement agents in these markets and finally; the building of a shared understanding among the traders of the need for maintaining a clean and environmentally conducive market area through continued sensitisation programs in these markets Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2012. / Agricultural Economics, Extension and Rural Development / unrestricted

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2012. / Polychlorinated biphenyls (PCBs) are known harmful chemicals which require urgent remediation, monitoring and assessment in the environment. The predominant current methods used to analyze PCBs involve expertise and are cost intensive. Most of these methods are chromatographic based techniques which are difficult to sustain in Africa due to the expensive nature of the instrument, costly running expenses and skilled labour required. These limitations face Africans, who are the most affected by the presence of PCBs in their environment as a result of improper disposal and usage of these compounds.

Sewage pollution of surface waters is a pressing issue of global concern, even in regions with extensive wastewater and sewage treatment infrastructure. Contaminants, like harmful bacteria that can cause gastrointestinal disease and hinder economic growth and development, enter natural waters through a variety of point and non-point source discharges that range from treated to untreated. With increasing urbanization, aging infrastructure, and changing precipitation patterns due to climate change, it is increasingly important to understand and predict the persistence and transport of sewage-derived bacterial pollution in surface waters. To effectively monitor and predict these contaminants, it is critical to understand sewage-derived bacteria’s extra-enteric ecology, or the ecological dynamics they experience after transitioning from a primary habitat (like the human gastrointestinal system) to a secondary habitat (like natural waters). Dynamics of fecal bacteria are assumed to be driven by loss, as commonly observed for the fecal indicator bacteria (FIB), Enterococcus sp., with sunlight exposure as the dominant driver (i.e., greatest impact on population dynamics). However, particle association of FIB may alter their persistence and transport in natural waters, though this aspect of extra-enteric ecology is rarely included in predictive models. Models predicting persistence and transport of fecal bacteria and pathogens could be improved by incorporating information on the impacts of particle association on dominant loss rates of FIB and the population dynamics of various indicated pathogenic groups. Further, it is important to understand the variation in and drivers of surface water optical properties, like water transparency, due to the likely importance of light penetration to fecal bacteria environmental persistence. This dissertation aims to address the critical knowledge gaps of how particle association influences the extra-enteric ecology of various sewage-derived bacteria and how optical properties relevant to the light-dependent mortality of FIB vary spatially and temporally in an urban-influenced water body. To do so, I employ a combination of empirical, modeling, and observational techniques. The Hudson River Estuary (HRE) is an ideal field site for this research because of its consistent problems with sewage pollution, especially following precipitation events, despite significant improvements following the Clean Water Act in 1972. Managing human health risks associated with sewage pollution is especially important for this water body that runs through the NY/NJ metropolitan area with its 19 million stakeholders. Further, previous research quantifying FIB dynamics has predominantly been conducted in clear, low turbidity water columns. Experiments constraining the dynamics of FIB in water with low clarity, like in the HRE, would fill this important knowledge gap in the field of sewage pollution monitoring and modeling. Chapter 1 assesses the impact of particle association on dominant growth rates and persistence of the brackish fecal indicator bacteria, Enterococcus sp. (also called enterococci). In this chapter, I conducted a series of natural water microcosm laboratory experiments to quantify dominant growth rates of enterococci. I then used these growth rates to parameterize a 1-dimensional advection-diffusion-decay model to simulate enterococci persistence in waters ranging from clear, quiescent lakes to turbid, turbulent waters. This combined empirical and mathematical modeling approach led to four major conclusions related to the persistence and transport of enterococci in natural waters: 1) particle association increases dominant growth rates (light-induced and dark, temperature-dependent growth) and induces sinking of enterococci, 2) particle association increases simulated enterococci persistence, 3) simulated enterococci persist longer in more turbid and/or more turbulent waters, and 4) discharge timing later in a diel cycle increases simulated Enterococcus sp. persistence. Results from this chapter demonstrate the importance of distinguishing free-living and particle-associated Enterococcus sp. in models of their persistence and transport and provide empirical data for independently constraining their population dynamics. Further, the simulated persistence indicates that sewage-derived fecal bacteria discharged into water bodies like the HRE will last longer than discharges in clear, calm waters (e.g. Lake Tahoe) and even clear, turbulent waters (e.g. coastal ocean in California). This information is broadly applicable to water quality management and indicates how variability in turbidity or turbulence within a water body could alter sewage discharge persistence and exposure risk for the public. Model sensitivity testing confirmed the consistent impact of particle association on enterococci persistence and reaffirms the need for FIB models to include particle association. An adapted version of Chapter 1 was published in Water Research (Myers and Juhl 2020). Because particle association increases enterococci persistence and growth rates, it is important to determine if particle association similarly affects co-occurring pathogenic bacteria and if particle association prevalence is similar. Chapter 2 is a valuable complement to Chapter 1 and addresses key knowledge gaps related to ambient pathogen abundance, particle association, and correlation with FIB in surface waters, in addition to the effect of particle association on dominant pathogen growth rates. In this chapter, I report multi-year observations of abundance and particle association proportions in the HRE for four bacterial genera: the fecal indicator Enterococcus sp., two enteric pathogens (Salmonella sp. and Shigella sp.) and a naturally-occurring, marine pathogen (Vibrio sp.). I found that mean particle association ranged from 34% to 49% and that overall abundances were significantly positively correlated across all genera. The second major goal of this chapter was to determine if particle association impacted dominant growth rates of pathogens similarly to the effect observed for enterococci (Chapter 1). In experiments similar to those in Chapter 1, I quantified the fraction-specific (free-living, particle-associated, and total) temperature and light-dependent growth of the three pathogenic genera. Overall, particle association consistently increased temperature- and light-dependent growth rates across genera, similarly to Chapter 1, though particle association did not benefit Vibrio sp. as much as the enteric genera. I found that Salmonella sp. had similar temperature- and light-dependent growth rates to enterococci. By contrast, Shigella sp. growth rates were greater than those of enterococci. As expected due to its different origin, Vibrio sp. also had dissimilar growth rates to enterococci. Interestingly, Shigella sp. behaved more similarly to Vibrio sp., with increasing dark period growth with temperature, which is opposite of the trend observed for the other two enteric organisms (Salmonella sp. and enterococci). The disparities and similarities of dominant growth rates between enterococci and 2 co-occurring fecal pathogens, together with the finding that abundances were positively correlated across all genera, suggests that enterococci are good indicators of recent sewage pollution, but have limitations in their use for assessing extended water column persistence of some co-occurring pathogenic bacteria. Information in this chapter is important for our understanding of FIB use to monitor sewage pollution persistence and for water quality management to minimize human exposure risk, especially in water bodies where environmental persistence is likely longer, like in turbid and turbulent waters (as shown in Chapter 1). Persistence simulations in Chapter 1 demonstrated that water transparency (modeled as diffuse attenuation of light, 3), was critical for determining the persistence of enterococci. It is then important to understand how water transparency varies throughout a water body to eventually predict how sewage bacteria persistence timescales vary. Chapter 3 examines the spatial and temporal variability of water transparency and its primary drivers (suspended particulate matter (SPM), chlorophyll, and colored dissolved organic matter (CDOM)) throughout the terrestrially- and marine-influenced HRE using observational and laboratory techniques. Data in this chapter indicate that water transparency in the HRE is predominantly controlled by SPM (measured as turbidity) and, to a lesser degree, chlorophyll. Despite some dramatic changes in inputs affecting the primary drivers (e.g. decreased sewage pollution - NYCDEP 2012, decreased chlorophyll concentrations - Caraco et al. 1997; Smith et al. 1998, and increased dissolved organic carbon transport - Findlay 2005) in the HRE, the dominance of turbidity in determining water transparency found in this study was consistent with work in the 1980s (Stross and Sokol 1989). Together, the findings by Stross and Sokol 1989 and in this chapter suggest that future work on understanding water transparency variability and its impact on sewage bacteria persistence in the HRE should focus on quantifying the variability in SPM. In contrast to other estuarine systems, CDOM absorption in this chapter minimally impacted water transparency (measured here via KdPAR). This chapter also documents spatial and temporal variability of water transparency and its primary drivers in the HRE. Turbidity and chlorophyll fluorescence varied seasonally, generally consistent with trends in other estuarine systems. Turbidity, chlorophyll, and CDOM absorption were all elevated after increased river flow from Tropical Storm Isaias. All three primary drivers of water transparency were also commonly higher for nearshore and tributary sites, as opposed to mid-channel sites, possibly due to increased shallow bed resuspension and terrestrial runoff. In the upper, freshwater portions of the estuary, CDOM absorption was highest, indicating a greater relative importance of CDOM on water transparency in this region. Data in this chapter also demonstrated that Wastewater Treatment Plant (WTP) outfalls commonly had elevated optical brighteners and (Sl(275-295), a CDOM slope ratio that indicates excess smaller CDOM molecules at a treated discharge, and a contrasting influence on CDOM absorption. This information could then allow CDOM absorption and optical brightener fluorescence to be used as indicators of treated or untreated discharges that could be measured on a faster timescale than current bacteria monitoring via culture-based techniques. Appended to this dissertation are results from experiments examining bacterial community composition for free-living and total populations in the HRE, which provide additional context for the research presented in this dissertation. The free-living and and total bacteria communities were not found to be significantly different, which indicates that there are not distinct communities in free-living and particle-associated fractions. Together with results from Chapters 1 and 2, this indicates that particle association may increase growth rates for bacteria that become particle-associated, instead of particles supporting the development of a unique and more resistant bacteria community. Four of the five fecal core families (bacteria commonly found in human fecal samples) were also identified in samples for these experiments, though relative abundance of these groups for free-living and total fractions were largely uncorrelated with each other over time. This finding demonstrates a notable influence of sewage inputs on the bacterial community in the HRE. Finally, these observations demonstrate that bacteria community composition varied seasonally, as noted by the significant influence of temperature and salinity on bacterial community composition. A wide variety of genera were strongly associated with colder (<12°C) water temperatures and samples from colder water generally exhibited higher alpha diversity. The findings from this dissertation have significantly contributed to our understanding of the extra-enteric ecology of the fecal indicator bacteria Enterococcus sp. and multiple co-occurring potential pathogens. This dissertation demonstrates that particle association must be considered in models of sewage-derived bacteria persistence. This dissertation also deepens our current understanding of water transparency drivers and their spatial and temporal heterogeneity in the turbid and turbulent system of the HRE. The results from this dissertation are useful for improving predictions of sewage pollution persistence and, by extension, minimizing human exposure risk to potentially harmful bacteria. These findings are broadly applicable beyond the HRE, to water bodies of varying turbidity and turbulence conditions.

京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第18486号 / 地環博第120号 / 新制||地環||25(附属図書館) / 31364 / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 宇佐美 誠, 教授 ショウ ラジブ, 准教授 森 晶寿 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

Population growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research is to expand the available research data on green roofs with cisterns by investigating the water quality and hydrology effects of different green roof designs including depth of media, an additional pollution control layer beneath the growth media, and different drainage layer materials. Furthermore, a comparison study is performed on the cistern water quality, direct filtrate water quality, and control roof filtrate water quality. Results show that phosphorus concentrations are lower when using a pollution control layer beneath the growing media, and that evapotransporation and filtrate factor values from the 4-inch media and the 8-inch media are approximately equal for one year. However, hydrograph results show that the 8-inch media design has a lower peak flow and longer attenuation when compared to the 4-inch media design for a single storm event. Furthermore, the drainage layer material has no significant effect on the water quality or hydrology of the green roof discharge. The data also emphasizes the importance and effectiveness of the incorporation of a cistern into a green roof system.

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Recent approval of emission standards for small utility engines by the California Air Resources Board suggested that substantial reductions in emissions from small utility engines will soon be required. Although the 1994 standards can be met by simple engine modifications, the 1999 standards may require the use of emission control technologies such as catalytic converters because they are more stringent. In this research catalytic control of individual hydrocarbons such as methane, ethylene, benzene, and toluene were evaluated. A platinum coated catalyst treated emissions from a 107cc, four-cycle gasoline engine loaded with a 1.4KW portable generator. Determination of emissions was performed at three different load levels: 0%, 50% and 92% of the engine rated load. Among the four hydrocarbons, toluene was oxidized as much as 60%, and benzene 40%, whereas ethylene remained unaffected by the catalyst. Also, a 5% to 10% methane oxidation occurred in one trial. / Master of Science