No description available.

The purpose of this study was to treat soils contaminated by pyrene through phytoremediation. The plant species selected were Phragmites communis Trin., Typha orientalis Presl, Vetiveria zizanioides, Rohdea japonica (Thunb.) Roth et Kunth, Cyperus malaccensis. Lam. subsp. monophyllus (Vahl) T. Koyama, Bolboschoenus planiculmis (F. Schmidt) T. Koyama and Bidens pilosa respectively. The degradation efficiencies of pyrene in soils and concentration of pyrene in the plant tissues were evaluated in this study. In addition, the change of microbial biota in soils was investigated in the tests of this study. The experimental results indicated that after twenty-two weeks, soils planted with V. zizanioides, R. japonica and T. orientalis have better pyrene degradation efficiencies. Especially, after fourteen weeks the pyrene degradation efficiencies were 86%, 84% and 77% respectively, which showed that the efficiencies 10% to 20% higher than those unplanted control experiments, which was 66%. In addition, the pyrene degradation efficiencies in summer were found to be higher than those in winter. The degradation efficiencies of pyrene in sterilized soil with and without T. orientalis were found equal to 59% and 55%, respectively. These values were found lower than those in the experiment without sterilization, in which the pyrene degradation efficiencies with and without T. orientalis were 77% and 66%, respectively, after the fourteen weeks experiment. Hence the rhizospheric microorganisms had a significant effect on the degradation of pyrene in soils. The pyrene degradation efficiencies were improved with application of fertilizer (HYPONeX No.2, HYPONeX Co., USA). After fourteen weeks, it was found that the experiment with fertilizer and with or without T. orientalis planted were 7% higher, which were 84% and 73% respectively, compared to 77% and 66% with no application of fertilizer. Proper surfactants have positive effect on phytoremediation. In this study, we found that addition of the surfactant Triton X-100 or combined surfactants (Triton X-100, Tween 20 and sodium dodecylbenzene sulfonate) both presented better pyrene degradation efficiencies than the system without adding surfactant. After ten weeks, soils planted with V. zizanioides and added with surfactants showed the pyrene degradation efficiencies equal to 85% and 87% (combined) respectively, which showed that 4% and 6% higher rate than the system without adding surfactants (81% ). After twenty two weeks, soils planted with V. zizanioides and added with surfactants showed that the pyrene degradation efficiencies were 96% and 96% (combined) respectively. They were all higher than the system without adding surfactants (94%). Soils planted with R. japonica also showed the same results. In this study, it was also found that the degradation efficiencies were higher at the surface layer of the soil than subsurface layer due to better oxygen content there. Hence the activities of microorganisms in the surface layer were higher than those in the subsurface layer of soils. After twenty two weeks, soils planted with V. zizanioides showed the residual concentration of pyrene were 5.7mg/Kg (surface layer) and 10.8 mg/Kg (subsurface layer). The difference between them was about 50%. Soils planted with R. japonica, T. orientalis or unvegetation also showed the same results. The pyrene concentrations of the roots, stems and leaves were analyzed and the results showed that pyrene did not exist in the plant stems or its leaves. Since pyrene could not be absorbed into plant¡¦s tissues by plants, the phytoextraction and phytovolatilization did not occur in this study. It was concluded that the degradation of pyrene in soils was mainly in rhizoremediation. The soils planted with V. zizanioides showed that the inhibition of Lactobacillus sp, while the soils planted with R. japonica and T. orientalis showed unfavorable conditions to Rhibopus sp.. Four weeks after this experiment, both Lactobacillus sp. and Rhibopus sp. were not existent. The soils planted with V. zizanioides, R. japonica and T. orientalis showed an increase of the number of bacteria (CFU), and thus the pyrene degradation efficiency was increased.

This thesis is focused around improving soil moisture estimates of spatial variability and mean at the field scale, which are useful for many different applications. The objectives were: (1) examine soil moisture spatial patterns and variability within field scale, and (2) compare field-scale soil moisture determination methods. An observational study was conducted, in which soil moisture was monitored over a 500 m by 500 m area during two and a half growing seasons at a prairie pasture in central Saskatchewan. Analysis of the spatial patterns of root-zone soil moisture revealed two distinct spatial patterns representing wet (spring) and dry (fall) periods. The relationship between spatial variability and mean soil moisture was found to follow an unusual concave trend, where variability was smallest at mid-range moisture contents. These spatial variability characteristics are a result of differences in participation level. Some locations were non-participating having only small moisture changes over the growing season, while others were dynamic having large changes. At the pasture site, these participation differences are a result of high soil heterogeneity, which may be characteristic of Solonetzic soils. In the second part of this thesis, methods to determine mean field-scale root-zone soil moisture were evaluated. The cosmic-ray neutron probe has the most potential for providing field-scale measurements. However, these measurements are only representative of moisture in the top 20 cm of soil, and need to be scaled up in order to represent the entire root-zone (0–110 cm). The three scaling methods applied to obtain lower root-zone soil moisture were: (1) a single time stable location, (2) representative landscape unit, where a single monitoring profile for each vegetation type was used, and (3) modeling by exponential filter. The representative landscape unit approach estimated soil moisture changes well, but not volumetric water content. The time stability method performed the best, followed by the exponential filter. However, the exponential filter has more potential, as the time stability method is difficult to apply to other field sites; particularly those without existing soil moisture instrumentation, due to its calibration requirements. The findings of this thesis make a contribution to the large body of existing literature on soil moisture variability and scaling. Suggestions for future research are provided.

No description available.

Current irrigation scheduling technologies are limited to refilling the root zone based on measured or predicted amount of water stored within the root zone. This needs measurement of soil-water status and specifying soil field capacity that make this approach expensive and challenging. The FullStopTM wetting front detector (FS) was specifically developed to be a simple and affordable technology to help farmers manage water, nutrients and salts in the root zone. This device responds to a strong wetting front, but research has shown it is less sensitive to weak redistributing wetting fronts, and this may compromise its efficacy in certain situations. The objectives of this study were to recommend a modified version of the FS that responds to weak redistributing wetting fronts and to develop guidelines for the deployment of these detectors to schedule irrigation. The research described herein comprises of two phases: the first phase focused on literature review, field evaluation of wetting front detector of varying sensitivities (WFD) and laboratory measurements of hydraulic properties of soil and wick materials. The second phase validates the HYDRUS-2D/3D for the development of guidelines on how to use WFD to schedule irrigation. The first phase includes: i) a literature review on passive lysimetry that relates design features to the sensitivity of WFD and how prototypes of WFD operate; ii) hydraulic characterization of soil and wick materials to describe the functioning of the different WFD designs; iii) an empirical investigation to determine whether the wick characteristics limits the attainment of equilibrium between the opening of the outer tube and the water table in the inner tube; iv) field evaluations of five types of WFD under sprinkler and natural rainfall to examine the accuracy and sensitivity of the different WFD designs; and v) analysis of the equilibrium between the WFD and the surrounding soil, and recommendations for the best design options based on the sensitivity requirement for different situations. The second phase of the study used observed data sets to validate the Hydrus-2D/3D model. After validation, the model was used to simulate different irrigation scenarios to develop guidelines for the deployment of WFD to schedule irrigation. Field evaluations of various WFD designs showed that length has significant effect on the sensitivity of WFD (P ≤ 0.05). The 90-cm-long Tube wetting front detector (90TD) was significantly more sensitive than the original FS design. The hydraulic conductivity function of two wick materials (Diatomaceous Earth and Fine sand) were not limiting for the attainment of the equilibrium between the Tube Detector and the surrounding soil, and the opening of the Tube Detector and the water level in the inner tube. The Hydrus-2D/3D model performed well in simulating the measured responses of FS or 90TD and the experimental sensitivity thresholds of these detectors. This model was deployed to link WFD responses to different simulated irrigation scenarios to generate monitoring protocol such as detector placement depth, irrigation amount or interval. The model simulations showed that FS can be used to schedule irrigation objectively for sprinkler or drip irrigations, i.e. adjusting irrigation amount or interval based on the response of a detector. Though further study is warranted, model simulation has indicated that 90TD can be used to improving furrow irrigation management. It is envisaged that WFD technology can guide farmers to make informed irrigation decisions and alerting farmers to percolation losses below the root zone. / Thesis (PhD)--University of Pretoria, 2014 / gm2015 / Plant Production and Soil Science / PhD / Unrestricted

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Dale J. Bremer / Heat stress is an important problem in potted nursery plants, but container color may moderate effects of solar radiation on container soil temperatures. Field studies were conducted near Manhattan, Kansas, USA during summer to evaluate effects of container color on growth of roots and aboveground biomass in: bush beans (Phaseolus vulgaris); red maple (Acer rubrum); and eastern redbud (Cercis canadensis). In the tree studies, effects of shaded soil-surfaces on plant growth were also evaluated. Four treatments among studies included containers colored black (control), flat white, gloss white, and silver, with two additional treatments in the tree studies of green and black containers with shaded soil surfaces (black shaded); treatments were arranged in a completely randomized design. Plants were grown in a bark-based soil-less media, and temperatures were measured at 5 cm depths in the sun-facing sides and centers in five containers per treatment. After four months (June-October), plant variables were measured. Roots were separated into three sections: core (10.2 cm diam.), north, and south, rinsed of all media, dried and weighed. In the bean study, media temperatures at the sun-facing side averaged lowest in gloss and flat white (~36 oC) and greatest in the black control (50.3 oC). Accordingly, total root biomass at the sun-facing side was reduced by 63 to 71% in black compared to flat and gloss white containers. In heat-sensitive maples, media temperatures at the sun-facing side averaged up to 7.7 oC greater in black, black shade and green than in other treatments; temperatures in black shade may have been lower if shade cloth had covered the sun-facing sides of containers in addition to only the media surface. Media temperatures in the core averaged 3.5 to 3.8 oC greater in black than in flat and gloss white, resulting in up to 2.5 times greater belowground biomass and up to 2.3 times greater aboveground biomass in flat and gloss white than in black pots. In heat-tolerant redbuds, the effects of container color on whole-plant growth were less evident. Data suggests that heat-sensitive plants benefit from using white pots or painting outer surfaces of green and black pots white.

Commercial energy use in Arizona is different from the rest of the United States because of their high demand for air conditioning. Nearly half of the energy used in commercial buildings goes to heating, cooling, and ventilation. In an attempt to reduce overall every use in buildings, looking at these categories led to an examination of ventilation in buildings, which is the main cause for high heating and cooling costs. Ventilation of fresh air is required in order to provide a safe, healthy environment, with acceptable indoor air quality. Indoor air quality and pollution has continuously come to light as a major health concern for building occupants. Chemicals used in manufacturing allow consumers to buy and expose themselves to toxic substances such as volatile organic compounds on a daily basis. With minimal regulations on indoor air, it is important to find ways to better filter and clean it. The traditional solution is ventilation, but more fresh air ventilation means more heating and cooling. This paper explores the research that has been done on plants and phytoremediation and the applicability to indoor air quality. With the proof that certain combinations and amounts of plants can filter the air of volatile organic compounds, systems are explored for indoor air filtration instead of mechanical ventilation. This type of system can greatly reduce heating and cooling costs in buildings due to the reduction of outdoor air being brought in and requiring conditioning. A system of this type is a feasible solution to indoor air quality and can lead to a significant reduction in energy use. The proposed AIRMAPS is a system that in certain quantities can reduce the need for fresh air ventilation by 25%, which in turn has shown through the validation by eQUEST, that the energy used for heating, cooling, and ventilation fans can also be reduced by approximately the same amount. The plants used are spider plant, dumb cane, English ivy, and golden pothos. The average formaldehyde removal by each of these plants is a low approximation of 75% per cubic meter. This paper also considers the growing materials used for the plants; activated carbon, potting soil mix, and grow-stones, as well as their formaldehyde removal capabilities.

As wetlands construídas estão entre as tecnologias eficientes recentemente comprovadas para tratamento e polimento de águas residuárias. Comparando com os sistemas convencionais de tratamento, são de baixo custo, fácil operação e manutenção. Esta pesquisa objetivou avaliar estudos de caso nacionais de utilização de wetlands para tratamento de efluentes em nível terciário com a finalidade de efetuar a remoção de nutrientes, buscando estabelecer parâmetros técnicos, operacionais e de manutenção. Foram avaliados sistemas que utilizaram como macrófita: Typha, Vetiver zizanioides L.Nash, Colocasia esculenta, Hedychium coronarium, Heliconia psittacorum, and Cyperus alternifolius; através de fluxos superficial e subsuperficial; o material filtrante foi brita e areia e o tempo de detenção hidráulica variou de 1,1 a 5 dias. Os resultados encontrados variaram de 5,6 por cento a 93,9 por cento para remoção de nitrogênio amoniacal e de 5 a 90,5 por cento para remoção de fósforo total. Constatou-se que a discrepância entre os resultados está associada ao tempo de detenção hidráulico utilizado, tipo de fluxo escolhido, material filtrante e manejo das macrófitas. Concluiu-se que a wetland construída pode ser usada como tratamento de efluentes em nível terciário para remoção de nutrientes, podendo-se afirmar que: a escolha da combinação de macrófita, material filtrante e fluxo deve ser feita de acordo com o efluente a ser tratado; não há um definição quanto ao tempo de detenção hidráulica ideal para cada sistema o que indica a necessidade de instalar pilotos para avaliação antes de implementar as estações em escala real; a poda deve ser feita respeitando o ciclo de desenvolvimento de cada espécie; é necessário realizar pesquisas que monitorem o sistema a longo prazo para avaliar o seu comportamento. / The constructed wetlands are among of the recently proven efficient technologies for treating and polishing of wastewater. Compared to conventional treatment systems, they are low cost, easily operated and maintained. This study aimed to evaluate national case studies of use of wetlands as a tertiary stage of wastewater treatment in order to make the removing of nutrients and establish technical, operational and maintenance parameters. The evaluated systems used as macrophyte: Typha, Vetiver zizanioides L.Nash, Colocasia esculenta, Hedychium coronarium, Heliconia psittacorum, and Cyperus alternifolius; through surface and subsurface flows; the filter material was gravel and sand and the hydraulic retention time ranged from 1.1 to 5 days. The results ranged from 5.6 per cent to 93.9 per cent for ammonia removal and from 5 to 90.5 per cent for total phosphorus removal. It was found that the discrepancy between the results is associated to the use of hydraulic detention time, to the type of flow, filter material and management of macrophytes. It was concluded that the constructed wetland can be used as tertiary stage of wastewater treatment for nutrients removal, it´s possible to say that: the combination between macrophyte, flow and filter material should be made in accordance with the effluent to be treated ; there is no definition as to the optimal hydraulic retention time for each system indicating the need to install a pilot treatment for evaluation before implementing the seasons full-scale; pruning should be done respecting the development cycle of each species; studies should be conducted to monitor the long-term system to evaluate their behavior.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-08-26T18:27:33Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tratamento dos resíduos de fossas e tanques sépticos em um sistema de alagado construído.pdf: 3758497 bytes, checksum: 51e75f00b9f942fa3c8bcb520f75bbea (MD5) / Made available in DSpace on 2014-08-26T18:27:33Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tratamento dos resíduos de fossas e tanques sépticos em um sistema de alagado construído.pdf: 3758497 bytes, checksum: 51e75f00b9f942fa3c8bcb520f75bbea (MD5) Previous issue date: 2014-03-31 / Due to the lack of public sewer service in the country, Individual and Household Sewage Disposal Treatment Systems (SITDE) are still widely used in Brazil. The SITDE require cleaning maintenance and at the time of execution of this cleaning occurs the generation of the called Pit and Septic Tanks Waste (RFTS). This material has high load of pollutants and presence of pathogenic organisms and must be properly designed to ensure the quality of the environment and safeguard public health. In this context, low cost and potential for deployment in small settlements technologies emerge as an alternative of treatment. This study aimed to evaluate the efficiency of the Constructed Wetlands System (SAC) with the Vetiver plant species (Chrysopogon zizanioides) in the treatment of the liquid fraction of the RFTS. An experimental system was built with the deployment of two identical tanks. One tank received the vegetation and the other operated as a control treatment. The tanks were filled with a substrate consisting of gravel # 0, gravel # 1 and medium sand. The constructed wetland system (SAC) acted under a descending vertical subsurface flow and RFTS was applied on the system under batch, remaining in the tanks for a period of six (6) days. The RFTS influent to the treatment system was characterized according to the parameters of pH, total oil and grease, ammonia nitrogen, settleable solids, total coliforms, Escherichia coli, surface, solid fixed solids, volatile solids, Biochemical Oxygen Demand (BOD) and total phosphorus. The RFTS treated by SAC was analyzed according to the same parameters and the results were compared with the stipulations for disposition in water bodies of class 2, according to Resolution 430/2011 of Conama and Goiás State Decree 1.745/1979. The attributes removal efficiency was calculated considering the phenomenon of evapotranspiration, which showed an average rate of 38.11% in the SAC. The tributary RFTS system showed a great variability in the concentrations of the attributes. The results were subjected to F test (5% probability). Statistically, the only differed treatments between the tank vegetated and the tank control was removal of BOD which was more effective WS with the average removal of 86.80 %, while the tank control showed an average increase of 65.94 %. The average concentrations output WS met the requirements under federal and state law , except for E. coli showed an average outlet concentration can change the class of the receptor. Statistically, the treatments (vegetated tank and control tank) differed only for the BOD removal, which was more effective for the SAC, with the average removal of 86.80%, while the tank control showed an average increase of 65.94%. The average concentrations of SAC output attended the provided by the federal and state laws or release in Class 2 water. / Devido à carência do serviço público de esgotamento sanitário no país, os Sistemas Individuais de Tratamento e Disposição de Esgoto Doméstico (SITDE) ainda são muito utilizados. Os SITDE necessitam de manutenção com realização de limpeza e, no momento da execução desta limpeza ocorre a geração do chamado Resíduo de Fossas e Tanques Sépticos (RFTS). Este material possui elevada carga de poluentes e presença de organismos patogênicos devendo ser destinado corretamente de forma a garantir a qualidade do meio ambiente e preservar a saúde pública. Neste contexto, tecnologias de baixo custo e com potencial para implantação em pequenos núcleos populacionais surgem como uma alternativa de tratamento. Este trabalho objetivou avaliar a eficiência do Sistema de Alagado Construído (SAC) com a espécie vegetal capim Vetiver (Chrysopogon zizanioides) no tratamento da fração líquida dos RFTS. Foi construído um sistema experimental com a implantação de dois tanques idênticos. Um tanque recebeu a vegetação e o outro operou como controle (testemunha). Os tanques foram preenchidos com substrato formado por brita #0, brita #1 e areia média. O sistema de alagado construído (SAC) atuou em regime de fluxo vertical subsuperficial descendente e o RFTS foi aplicado no sistema em regime de batelada permanecendo nos tanques por um período de 6 (seis) dias. O RFTS afluente ao sistema de tratamento foi caracterizado segundo os parâmetros pH, óleos e graxas totais, nitrogênio amoniacal, sólidos sedimentáveis, coliformes totais, Escherichia coli, sólidos totais, sólidos fixos, sólidos voláteis, Demanda Bioquímica de Oxigênio (DBO) e fósforo total. O RFTS tratado pelo SAC foi analisado conforme os mesmos parâmetros e os resultados foram comparados com o estipulado para a disposição em corpos hídricos de classe 2, conforme a Resolução 430/2011 do Conama e o Decreto estadual 1.745/1979, do Estado de Goiás. A eficiência na remoção dos atributos foi calculada considerando o fenômeno da evapotranspiração, que apresentou taxa média de 38,11% no SAC. O RFTS afluente ao sistema experimental apresentou grande variabilidade nas concentrações dos atributos. Os resultados foram submetidos ao teste F (5% de probabilidade). Estatisticamente os tratamentos (tanque vegetado e tanque controle) diferiram apenas para a remoção da DBO onde o SAC foi mais eficaz com a remoção média de 86,80%, enquanto o tanque controle apresentou incremento médio de 65,94%. As concentrações médias de saída do SAC atenderam ao disposto pelas legislações federal e estadual para lançamento em corpos hídricos de classe 2.

Revised; Originally Published: 2000 / 8 pp. / Whether you are beginning a new landscape or renovating an existing one, planning ahead can prevent many problems. The majority of maintenance requirements and plant problems result from either selecting the wrong kind of plant for a location or planting an inferior specimen of the selected plant type. In other words, there are two decisions to be made: ▪ What species, or kind, of tree are you going to buy — an oak, pine, mesquite, or acacia? ▪ Assuming you decide on an oak, which one in the row of oaks at the nursery are you going to buy? The first decision is called Plant Selection and the second is Selecting Plants. Our goal is to install the right plant in the right place. This publication will cover the factors involved in making good decisions to achieve this goal.