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Onsite wastewater treatment systems (OWTSs) are a commonly used means of wastewater treatment in the Dickinson Bayou watershed which is located between Houston and Galveston. The Dickinson Bayou is classified as "impaired" by the Texas Commission on Environmental Quality due to high levels of bacteria, specifically E. coli. Failing OWTSs within the bayou's watershed are possible sources for the impairment of the bayou. Conventional OWTSs, comprised of a septic tank and a soil absorption field, rely heavily on soil treatment of effluent. The type of soils is a significant factor in treatment capabilities. In the Dickinson Bayou watershed, soils are primarily composed of clays, which are known to be problematic for conventional systems as they restrict water flow and create perched water tables. These perched water tables may contribute to surface runoff during rainfall events. The HYDRUS modeling software for water and solute flow through variably saturated media was used to simulate OWTSs in the Dickinson Bayou watershed. HYDRUS was used to simulate conventional septic systems with soil absorption fields, aerobic treatment units (ATUs) with spray dispersal systems, and mound systems. Results found that the simulated conventional systems fail due to high water tables and clay soils. However, system failure in the watershed remains uncertain due to lack of field data for validation. The alternative systems mitigate these issues, but ATUs can lead to higher contamination levels without proper maintenance. Therefore, mound systems are the suggested alternative for OWTSs in the watershed.

The sustainability of water resources is an international and national concern. With increased human activity, water distribution on a global, regional, and local scale has been negatively impacted. Managing water resources also includes managing wastewater. A promising solution to the issues of water scarcity and distribution in the environment is the reuse of wastewater. Wastewater is produced from various sources (domestic, industrial, and commercial); however, if this water is able to be reused closer to the source of generation it could positively impact water distribution. In the United States, approximately 25% of domestic wastewater is treated in onsite wastewater treatment systems OWTS (mainly septic tanks and drainfields). However, septic systems are not efficient at removing nitrogen and pathogens, making them a risk to public health and the environment. In recent years, advanced onsite wastewater treatment systems have been developed to reduce contaminants into the environment. These systems are effective at removing contaminants but often require many mechanical parts and have high energy requirements. These additional components require homeowners to perform more maintenance on advanced OWTS than conventional systems or pay for maintenance to be performed. Passive Nitrogen Reduction Systems (PNRS) are being developed that provide high levels of nutrient removal while keeping maintenance requirements and costs low for the homeowner. (PNRS) use two-stage packed bed bioreactors to remove nitrogen from wastewater via nitrification (Stage I) and denitrification (Stage II). Our laboratory has developed a two-stage bench scale PNRS that uses ion exchange (IX) materials, clinoptilolite and scrap tire chips, to enhance the removal of nitrogen from wastewater by buffering transient loads to the biological processes. Pathogens can be present in domestic wastewater and if untreated can be released to groundwater and open water bodies endangering the health of the public. PNRS have the potential to reduce pathogenic microorganism released into the environment, however; the reduction of pathogens in PNRS that include IX media had not previously been studied. In this research, E. coli was used as a fecal indicator bacteria (FIB) because of its simplicity and national and worldwide acceptance. In our study, the performance of a PNRS with and without IX media was evaluated. Hourly studies were performed to determine the removal efficiency of E. coli from the system under varying hydraulic loading rates. Biofilm detachment experiments were conducted to measure E. coli adsorption and growth patterns within the column reactors. Batch adsorption experiments were completed to determine the effect of different types of media with and without IX material on E. coli growth over extended time periods. E. coli enumeration data from the hourly experiments demonstrated that there was a 0.84 log reduction of E. coli throughout the PNRS from the septic tank effluent to the final effluent released from the system. The evening and afternoon periods showed a higher reduction of E. coli compared with the morning period. Removal efficiencies were greater in the first stage of treatment (nitrification) as compared to the second stage treatment (denitrification). However, these variances did not result in significant differences in overall E. coli removal efficiency. Adsorbed E. coli were evenly distributed in the column containing IX media, while a decrease in adsorbed E. coli with depth was observed in the column without IX media. Batch adsorption studies revealed that when E. coli are present in wastewater solution with media, E. coli are initially adsorbed but can grow in the system after 6-12 hours. This growth indicates that other FIB should also be used to determine the fate of pathogens in PNRS. Based on all E. coli enumeration experiments, the PNRS developed reduce E. coli by almost 85%; however, this reduction is not adequate to meet onsite water reclamation regulations. Further studies are needed to develop tertiary treatment for pathogen reduction and wastewater reuse.

Three wastewater treatment systems (WWTS) situated on Cayes in the Belize Barrier Reef System were assessed in terms of the unique public health and environmental circumstances of being a tourist destination surrounded by fragile coral reef. Laughing Bird Caye, Silk Caye, and Little Water Caye are three small cayes that are the staging points for local diving, fishing, and other recreational tourism. All three systems are based upon pour-flush toilets, semi-anaerobic biodigesters and drainage fields. Limitations in cost, available resources, useable area, high infiltration rates of the sand, and salinity of the water have played a major factor in the construction and performance of the WWTS on the Cayes. This thesis aims to form an understanding of treatment efficiency of the WWTS, investigate the effectiveness of decentralized saltwater-based WWTS in comparison to freshwater-based WWTS, and provide recommendations to improve the performance and resource recovery in a manner appropriate for the context in which the systems are deployed. A mathematical model was developed to predict the performance of the WWTS based on available operational and water-quality input data. The model is based on the mass balances of six species: inert solids, fecal solids, bacterial biomass, soluble substrate (i.e. dissolved organic carbon), ammonium and nitrate. Effects of salinity were estimated for the two saltwater-based WWTS. The model predicted the effluent concentrations of fecal solids, soluble biological oxygen demand (BOD), ammonium, and nitrate. A sensitivity analysis was also performed on the predicted effluent treatment efficiency based upon influent load, oxygen concentration and system salinity. Results from Silk Caye and Laughing Bird Caye indicate that varying the number of visitors from seasonal lows to highs has a moderate impact on the effluent fecal solids and soluble BOD in the effluent. Due to the relatively large volume of the WWTS at Little Water Caye, and thus high HRT, varying the number of visitors did not have a significant effect. The model predicted a reduction of nitrogen from the effluent due to settled solids and the assimilation of the nitrogen into bacteria. However the model consistently projected an effluent nitrate concentration (as mg/L as N) between 60 and 63 across the three WWTS. The oxygen concentration within the WWTS had the greatest effect on effluent BOD of the three parameters tested in the sensitivity analysis. Results from the sensitivity analysis indicate that a minimum concentration of 0.95 mg/L of oxygen is required before the model can accurately predict the effluent BOD concentration. The concentration of effluent fecal solids did not significantly change with changes in oxygen concentration. Salinity had a significant effect on the predicted fecal solids and soluble BOD in the effluent. Predicted fecal solids in the effluent wastewater increased approximately 60 percent from freshwater conditions to 4 percent salinity. Similarly, effluent BOD concentration increased strongly with increasing salinity. The increase in concentration is due to the major reduction of substrate-consuming bacteria by cell-die-off. The model predicts that a significant increase in cell die-off begins to occur at 2.4 percent salinity. The predicted effluent of the freshwater-based WWTS on Little Water Caye was compared to 166 wastewater treatment plants operating in Brazil. Comparison between the WWTS on the Caye and the decentralized WWTS in Brazil indicate that the predicted removal efficiencies of total suspended solids and soluble BOD are higher than the measured efficiencies of the WWTS. However, the total nitrogen removal efficiency for the WWTS on the Caye was the least effective; most-likely because the model does not account for denitrification within the biodigester. The comparison between the WWTS illustrates that the predicted removal efficiency of BOD and TSS solids is most likely less in the actual measurement than predicted value from the model. The WWTS on the Cayes were constructed to mitigate the impacts of the wastewater produced by visitors on the general health of the pubic and the environment. Considering the reports of the eutrophication affecting the coral reefs surrounding the Cayes, the WWTS have largely failed in at least one aspect of their purpose. The effluent water quality predicted by the model also suggests that significant concentrations of nitrogen are entering the surrounding ocean habitat as ammonia and nitrate. Recommendations to improve the effluent wastewater quality were separated into three categories based upon the required level of input to realize the recommendation. The input includes the capital cost and labor of the change, the level of buy-in from the users of the system, and the resulting maintenance requirements. The implementation of a urine separation toilet system was proposed as a method to reduce effluent nitrogen entering the environment and to create a resource recovery system (RR) from the already constructed WWTS.

Eutrophication of the Baltic Sea has been an issue for decades and the pollution constantly continues with oxygen deficient bottoms and a damaged marine life as a result. One of the main causes of eutrophication are elevated levels of the nutrient phosphorus. Phosphorus leaks to the sea from various human activities such as agriculture, animal farming and sewage. In Sweden, the onsite wastewater treatment systems are a big problem since they load the Baltic Sea with nearly as much phosphorus as all Swedish municipal wastewater treatment plants. The need for a reduced impact on the Baltic Sea is major and the individual wastewater treatment systems must therefore be looked over. While phosphorus is a contributing factor to eutrophication, it is one of the most important nutrients for all life. Phosphorus builds up our DNA, helps transport of various substances in and out of our cells and provides energy to the cell's processes. We would simply not be able to survive without phosphorus. We ingest phosphorus through the food we eat, which in turn is dependent on fertilizers containing phosphorus. Phosphorus is mined from phosphate ore and the majority of it is used to produce fertilizers. Unfortunately, phosphate ore is not a finite resource and in the last few years it has been realized that the economically extractable phosphorus is a dwindling resource. To be able to produce food for the world's growing population, we need to find ways to recycle phosphorus. In individual drainage systems there is a large potential to catch up phosphorus and then reuse it on agricultural land. This thesis deals with the problems of onsite wastewater treatment systems and suggests measures to improve their status. Ways to recycle phosphorus in combination with having a well-functioning drainage is being investigated and difficulties about the regulations are being discussed. To recover phosphorus and at the same time reduce the burden on the environment should be seen as an incredibly important action, since our sea’s health is acute but lack of the nutrient could have devastating consequences.

The development of society calls for a new approach to traditional building systems, which no longer meet the demands of today's society. This is mainly manifested in the following points: 1. Traditional buildings, when decayed, generate a large amount of construction waste, which occupies more land and resources in the form of landfills. New buildings should aim to minimize or eliminate construction waste generation, thus reducing environmental damage. The transformation of buildings from "Cradle to Grave" to "Cradle to Cradle." 2. Different ages, social roles, and professions require varying building functionalities and sizes. Buildings should be adaptable to meet these diverse needs. 3. Buildings should not be permanently fixed to a single location but should be in a continuous process of change, even to the extent of being movable. 4. Buildings should have a growth and transformation process, where components can be recycled and reused, similar to how chemical elements can cycle naturally in the environment. 5. Buildings should be designed for rapid transport, assembly, and disassembly. They should not require specialized construction workers for installation. This is in contrast to traditional buildings with long construction periods, poor construction quality, and high levels of complexity. 6. Building design should be simplified and modular, allowing for quick achievement of aesthetic, functional, safety, and livability requirements. Owners should be able to participate in the design process, enabling them to meet their own usage and living needs. This approach differs from traditional building design, which requires extensive involvement from trained architects and engineers, resulting in higher construction costs and resource consumption. 7. New recycling houses should be adaptable for various functions and building types, such as houses, apartments, townhouses, offices, affordable housing, single-story or multi-story buildings, and even high-rise structures. 8. In summary, the concept of recycling houses aligns with the need for sustainable and adaptable buildings that minimize waste, accommodate diverse needs, promote ease of construction, and allow for resource conservation. / Master of Architecture / The development of society calls for a new approach to traditional building systems, which no longer meet the demands of today's society. This is mainly manifested in the following points: 1. Traditional buildings, when decayed, generate a large amount of construction waste, which occupies more land and resources in the form of landfills. New buildings should aim to minimize or eliminate construction waste generation, thus reducing environmental damage. The transformation of buildings from "Cradle to Grave" to "Cradle to Cradle." 2. Different ages, social roles, and professions require varying building functionalities and sizes. Buildings should be adaptable to meet these diverse needs. 3. Buildings should not be permanently fixed to a single location but should be in a continuous process of change, even to the extent of being movable. 4. Buildings should have a growth and transformation process, where components can be recycled and reused, similar to how chemical elements can cycle naturally in the environment. 5. Buildings should be designed for rapid transport, assembly, and disassembly. They should not require specialized construction workers for installation. This is in contrast to traditional buildings with long construction periods, poor construction quality, and high levels of complexity. 6. Building design should be simplified and modular, allowing for quick achievement of aesthetic, functional, safety, and livability requirements. Owners should be able to participate in the design process, enabling them to meet their own usage and living needs. This approach differs from traditional building design, which requires extensive involvement from trained architects and engineers, resulting in higher construction costs and resource consumption. 7. New recycling houses should be adaptable for various functions and building types, such as houses, apartments, townhouses, offices, affordable housing, single-story or multi-story buildings, and even high-rise structures. 8. In summary, the concept of recycling houses aligns with the need for sustainable and adaptable buildings that minimize waste, accommodate diverse needs, promote ease of construction, and allow for resource conservation.

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Investment managers are entrusted with clients assets and should act with due care and diligence when dealing with it. The regulation of investment managers does not preclude the possibility that they can defraud their clients. The question posed by this research is whether the regulator can as part of its risk-based supervision methodology apply a fraud auditing approach to identify possible investment fraud schemes. The regulatory mandate and powers to pro-actively detect fraud is considered as well as the changes required to the regulator’s methodologies. / Dissertation (MPhil)--University of Pretoria, 2011. / Accounting / unrestricted

Phosphorous and nitrogen are vital elements for the well-being of biological life. Industrial discharges, waste water infiltration systems, conventional waste water collection and treatment systems, agricultural runoffs and landfill leachates had been emitting significant quantity of these nutrients into water bodies. These induced negative consequences to the environment including eutrophication of aquatic water bodies, toxicity to marine life and depletion of phosphate resources. Reactive filter technology is developed based on the need to remove and retain nutrients from waste water while improving the quality of effluents from emission sources. Reactive filter materials are used to build filter bed systems that treats domestic waste water, storm water, landfill leachates and contaminated subsurface water to the desired quality. In the past natural minerals such as zeolites and industrially produced polonite had been subject to laboratory study for the sorption of ammonium, heavy metals and phosphorous. The following paper is based on the results of experiment consisting of two columns packed with mordenite and polonite reactive materials filtering in series to reduce NH4 and PO4 content of a waste water. Septic tank effluent pre filtered using 0.45 μm filter is used as influent waste water into the dual columns. The dual column filtered a total of 24.07l s (372PV) and 23.42 ls (496PV) of the waste water. Sampling of the feed water and filtrates of both columns were done every second day with measurement of pH, conductivity and temperature. Analyzed samples confirmed that the dual column filtration resulted in re-moval efficiency of 84.39 % (PO4), 67.98 % (NH4) and -37.762.8 % (NOx). Filtration in the first (mordenite) column resulted in relatively larger proportion of the influent ammonium ion exchange than sorption of phosphate while the filtration in the second (polonite) column sorbed quite high amount of phosphorous than ammonium from effluent of the first column. Saturation of mordenite occurred faster even though there was sorption potential for few more of influent ammonium. All PO4 removal in mordenite column occurred above breakthrough condition. Polonite packed column was in a condition of a third of it’s saturation potential for PO4 removal at the end of the experiment. pH of samples was the parameter which is correlated significantly with filtration in polonite column than temperature and electrical conductivity. The performance of polonite was higher at higher pH than at lower pH. The mean concentrations of the dual column effluent were 0.77 mg-PO4/l and 11.13 mg-NH4/l. This is acceptable by the standards of environmental laws. The result of the experiment is valuable in prediction of performance and designing of real time filter bed.

Pharmaceuticals, personal care products (PPCPs) and other trace organic contaminants (TOrCs) encompass a diverse group of chemicals that are not currently monitored or regulated in US drinking water or wastewater. Researchers have found low levels of TOrCs in aquatic and terrestrial environments all over the globe, and observed negative effects on impacted biota. The primary source of TOrCs in the environment is domestic wastewater discharges. Centralized wastewater treatment plants present greater risks on a global scale, but on a local scale, onsite treatment systems may have more potent impacts on resources that are invaluable to residents, including groundwater, surface waters, and soils. The objective of this thesis is to identify and characterize promising treatment technologies for onsite TOrC remediation. Receptors who could be impacted by TOrC discharges are assessed, and applications that may require alternative treatment are identified. The best treatment technologies are recognized as those that protect sensitive environmental receptors, provide permanent removal pathways for as many TOrCs as possible, and are not prohibitively expensive to install or maintain. Findings from a pilot study show increased removal of conventional pollutants and TOrCs in an aerobic treatment unit (ATU), two types of biofilter, and a hybrid constructed wetland, all relative to septic tank effluent. The constructed wetland achieved the highest nutrient removals with TN concentrations below 10 mg/L throughout the study. A system with an ATU and peat biofilters achieved the highest removals of persistent pharmaceuticals carbamazepine and lamotrigine (>85% and >95%, respectively). / Master of Science