Orientador: José Teixeira Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-22T23:02:36Z (GMT). No. of bitstreams: 1 Poli_DelciMagalhaes._M.pdf: 7037560 bytes, checksum: a3c49fdccdd6e0ddac9ecf51ba79b687 (MD5) Previous issue date: 2012 / Resumo: O trabalho foi desenvolvido no campo experimental da Faculdade de Engenharia Agrícola da Universidade Estadual de Campinas, Campinas, SP, posição geográfica definida pelas coordenadas 22° 53' 22" LS e 47° 044' 39" LW. O estudo procurou verificar se a utilização de crostas de eletrofusão da bauxita como substrato, em leitos cultivados construídos ou "Constructeds Wetlands" com os vegetais aquáticos emergentes Typha sp, Canna limbata e Cyperus prolifer, interfere na dinâmica do pH, fósforo e nitrogênio presentes em águas residuárias domésticas. Foram utilizados 6 tanques artificiais, sendo constituído por 3 séries de duas unidades, com fluxo vertical e saídas subsuperficiais, nominados por série Typha, leitos 3.1 e 3.2; série Canna, leitos 2.1 e 2.2; série Cyperus 1.1 e 1.2 e preenchidos com crostas de eletrofusão da Bauxita. A dimensão de cada tanque é de 4 metros de comprimento por 3 metros de largura por 1 metro de altura, totalizando 12 m³. Em cada uma das séries foram plantados os vegetais Typha sp, Canna limbata e Cyperus prolifer respectivamente. O período de monitoramento foi de setembro de 2009 a fevereiro de 2010. O desempenho do foi avaliado considerando o desenvolvimento dos vegetais, quantidades e qualidades químicas das águas residuárias. As águas foram coletadas semanalmente, em dias aleatórios, nas entradas e saídas dos tanques durante o período monitorado; os vegetais foram colhidos, somente uma vez, no final do período. As vazões médias diárias e os pH médios ocorridos no período monitorado, observados no afluente e nas saídas da série Typha foram 962 l/dia, 864 l/dia e 804 l/dia; os pH foram 6,9; 8,6 e 9,0. Na série Canna as vazões foram 954 l/dia, 797 l/dia e 735 l/dia; os pH foram 6,9; 9,2 e 9,3. Na série Cyperus as vazões foram 792 l/dia, 723 l/dia e 664 l/dia; os pH foram 6,9; 9,0 e 9,1. Os tempos de detenções hidráulicas, considerando os leitos nas séries citadas foram: 4,2 dias e 4,6 dias; 4,0 dias e 4,6 dias e 4,3 dias e 4,4 dias. As porcentagens médias de retenções de nitrogênio total nos leitos, considerando as massas que entraram, por intermédio dos afluentes, durante o período monitorado foram: a) Série Typha 27% e 19%; b) Série Canna 35% e 19%; c) Série Cyperus 32% e 21%. As remoções realizadas pelos vegetais foram: a) Série Typha 26% e 9%; b) Série Canna 42% e 11%; Série Cyperus 22% e 15%. Em relação ao fósforo, as porcentagens médias de retenções, considerando as massas que entraram nos leitos por meio dos afluentes, foram: a) Série Typha 70% e 31%; b) Série Canna 73 e 19%; Série Cyperus 74% e 27%. As remoções realizadas pelos vegetais foram: a) Série Typha 11% e 4%; b) Série Canna 17% e 4%; c) Série Cyperus 7% e 11%. As massas vegetais totais secas produzidas foram: a) Série Typha 39,9 Kg e 11.2 Kg; b) Série Canna 50,5 Kg e 26,4 Kg; Série c) Cyperus 24 Kg e 15 Kg. O estudo mostrou que o substrato promoveu alterações na eficiência e eficácia da retenção e remoção de nutriente, crescimentos dos vegetais, produção de matéria seca e qualidades da água efluente / Abstract: The study was conducted in the experimental field of the Faculty of Agricultural Engineering, State University of Campinas, Campinas, SP, geographical position defined by coordinates 22° 53' 22" LS and 47° 04' 39" LW. The study examined whether the use of bauxite electrofusion crusts, as a substrate in constructed wetlands with emergent vegetables Typha sp, Canna limbata and Cyperus prolifer, interferes on the dynamics of pH, phosphorus and nitrogen present in domestic wastewater. It was used 6 artificial beds, consisting of 3 sets of two units with vertical flow and subsurface outflows, nominated by Typha series, 3.1 and 3.2 beds; series Canna, 2.1 and 2.2 beds, series Cyperus, 1.1 and 1.2 and filled with Bauxite electrofusion crusts. The size of each bed was 4 meters long by 3 meters wide by 1 meter high, totaling 12 m³. In each series the vegetables Typha sp, Canna limbata and Cyperus prolifer were planted respectively. The monitoring period was from September 2009 to February 2010. The performance was evaluated considering the development of plants, the chemical quantities and qualities of wastewater. The waters were collected weekly, on random days, at the entrances and exits of the beds during the monitoring period; the plants were harvested only once, at the end of each period. The average daily flow rates and average pH occurred during this period, observed in the tributary and the outflow of the series Typha were 962 l/day, 864 l/day and 804 l/day, the pH were 6.9, 8.6 and 9.0. In the series Canna flow rates were 954 l/day, 797 l/day and 735 l/day, the pH were 6.9, 9.2 and 9.3. In the series Cyperus flow rates were 792 l/day, 723 l/day and 664 l/day, the pH were 6.9, 9.0 and 9.1. The hydraulic detention time, considering the beds in the series cited were 4.2 days and 4.6 days, 4.0 days and 4.6 days and 4.3 days and 4.4 days. The average percentage of total nitrogen retention in the beds, considering the masses that came through the tributaries during the monitoring period was: a) Series Typha 27% e19% b) Series Canna 35% and 19%, c) Series Cyperus 32% and 21%. The removals conducted by the plants were : a) Series Typha 26% and 9%, b) Series Canna 42% and 11%; Series Cyperus 22% and 15%. Regarding the phosphorus, the average percentage of retention, considering the masses that entered the bed through the tributaries was: a) Series Typha 70% and 31%, b) Canna Series 73 and 19%; Series Cyperus 74% and 27 %. The removals conducted by the plant were: a) Series Typha 11% and 4%, b) Series Canna 17% and 4%, c) Cyperus Series 7% and 11%. The total dry plant mass produced were: a) Series Typha 39.9 Kg is 11.2 Kg b) Series Canna 50.5 kg is 26.4 kg; Series c) Cyperus 24 Kg is 15 Kg. The study has shown that the substrate promoted changes in the efficiency and effectiveness of nutrient removal and retention, growth of vegetables, dry material production and quality of effluent water / Mestrado / Análise Ambiental e Dinâmica Territorial / Mestre em Geografia

Orientadores: Meuris Gurgel Carlos da Silva, Sirlei Jaiana Kleinübing / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-21T03:51:16Z (GMT). No. of bitstreams: 1 Santana_HarrsonSilva_M.pdf: 3086288 bytes, checksum: df57d56b5e16a94632301ad2849fb91b (MD5) Previous issue date: 2012 / Resumo: Este trabalho teve como objetivo avaliar a bioadsorção dos íons Cd2+, Cu2+, Pb2+, Ni2+ e Zn2+ pela macrófita aquática Limnobium spongia em sistema estático. Diagramas de especiação em função do pH, foram simulados usando o software HYDRA, de modo a se conhecer as diferentes espécies em meio aquoso, nas condições estudadas. Observa-se que em pH<5,0 não ocorre precipitação para todos os íons estudados. A técnica de Espectroscopia na Região do Infravermelho (FTIR) foi utilizada para identificação dos grupos funcionais presentes no bioadsorvente, que poderiam estar envolvidos no processo de bioadsorção. Observou-se que os grupos aminos, amidas e ácidos carboxílicos participam do processo de bioadsorção dos íons metálicos estudados. Para análise da superfície do bioadsorvente nas diferentes condições estudadas foi utilizada a Microscopia Eletrônica de Varredura (MEV). A técnica de EDX (Espectroscopia de Raios X por Energia Dispersiva) acoplada a MEV foi utilizada para caracterizar as espécies naturalmente presentes na macrófita e fazer um mapeamento da distribuição das diferentes espécies metálicas bioadsorvidas. Verificou-se grande quantidade de íons Mg2+, Na2+, Al3+, e Ca2+, naturalmente presentes na macrófita e redução destes íons após a bioadsorção dos íons metálicos estudados, indicando que o mecanismo de troca iônica pode estar ocorrendo. Modificações químicas da biomassa foram efetuadas a fim de aumentar a sua capacidade de bioadsorção. O tratamento com NaOH (0,1M) provocou uma elevação na capacidade de remoção de 35, 20, 10, 11 e 15% para os íons Cd2+, Cu2+, Pb2+, Ni2+ e Zn2+, respectivamente. Foi realizado um estudo estático (cinético e de equilíbrio) da bioadsorção das diferentes espécies metálicas pela macrófita L. spongia nas temperaturas de 20, 30 e 40 ºC. Pelo estudo cinético observa-se que nos primeiros 90 minutos o sistema macrófita/íon metálico entra em equilíbrio para todas as espécies estudadas. As quantidades máximas adsorvidas, de acordo com o modelo de Langmuir foram de 0,65; 1,29; 0,69 e 0,83 mmol g-1, para os íons Cd2+, Pb2+, Ni2+ e Zn2+, respectivamente, na temperatura de 40 °C e 0,83 mmol g-1 para o Cu2+ na temperatura de 20 °C. Diferentes soluções eluentes foram testadas na dessorção dos diferentes íons metálicos. Foram estudados, ainda, três ciclos de bioadsorção/dessorção, sendo verificado que a macrófita manteve suas características de bioadsorção / Abstract: This study had the objective of evaluating the bioadsorption of Cd2+, Cu2+, Pb2+, Ni2+ and Zn2+ by macrophyte Limnobium spongia in static system. Speciation diagrams as a function of pH were simulated using the software HYDRA, in order to know the various species in the aqueous solutions under the conditions studied. It is observed that at pH <5.0, precipitation does not occur for all ions studied. The Fourier transform infrared spectroscopy (FTIR) technique was used to identify the functional groups presented in biosorbent, which could be involved in the bioadsorption process. In order to analyze the biosorbent surface in different conditions, the Scanning Electron Microscopy (SEM) was used. The EDX (Energy Dispersive Spectroscopy X ray) technique coupled with SEM was used to characterize the own species of macrophytes and to map the distribution of the various metal species on the bioadsorbent surface. There was a large amount of Mg2+, Na2+, Al3+, and Ca2+ ions naturally presented in the macrophyte and the reduction of these ions after bioadsorption, indicating that the ion exchange mechanism may be occurring. Biomass chemical modifications were performed in order to increase by bioadsorption capacity. The treatment with NaOH (0.1 M) caused an increase in the removal capacity of 35, 20, 10, 11 and 15% for Cd2+, Cu2+, Pb2+, Ni2+ and Zn2+, respectively. A bioadsorption static study was conducted (kinetic and equilibrium) of different metal species by macrophyte at temperatures of 20, 30 and 40 ºC. The kinetic study shows that in 90 minutes the system macrophyte / metal ion comes into equilibrium for all species. The maximum bioadsorbed amounts, according to the Langmuir model, were 0.65, 1.29, 0.69 and 0.83 mmol g-1 for Cd2+, Pb2+, Ni2+ and Zn2+, respectively, at a temperature of 40 ºC and 0.83 mmol g-1 for Cu2+ at 20ºC. Different eluents were tested in solutions of different metal ions desorption. Furthermore, the study of three biosorption/desorption cycles were made and it was verified that the macrophyte kept their biosorption characteristics / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

This study investigated the response of macrophytes to physico-chemical factors in seven South African estuaries and showed that dominant salt marsh species that occur in different estuaries respond to the same environmental factors. The most important variables influencing distribution were elevation, water level, sediment- and groundwater electrical conductivity and depth to the water table. In permanently open estuaries (Kromme and Olifants) transect surveys identified three distinct vegetation zones i.e. submerged macrophytes, intertidal salt marsh and supratidal salt marsh. In the Kromme Estuary intertidal salt marsh (81.2 ha) covered extensive areas, whereas supratidal (143 ha) and floodplain (797.1 ha) salt marsh were dominant in the Olifants Estuary. Transect surveys identified four distinct vegetation zones (submerged macrophytes, intertidal salt marsh, supratidal salt marsh and reeds and sedges) in the temporarily open/closed estuaries (Mngazi, Great Brak, East Kleinemonde and Seekoei estuaries), although all zones did not occur in all of the estuaries sampled. In the Mngazi Estuary reeds and sedges (1.09 ha) covered extensive areas (no submerged or salt marsh vegetation was present), whereas salt marsh (Great Brak 24.45 ha, East Kleinemonde 17.44 ha and Seekoei 12.9 ha) vegetation was dominant in the other estuaries. Despite the geographic differences, environmental factors influencing macrophyte distribution were similar in all estuaries. Canonical Correspondence Analysis showed that vegetation distribution was significantly affected by elevation, groundwater and sediment electrical conductivity and depth to groundwater. Supratidal species were associated with a greater depth to groundwater (1.2 ± 0.04 m; n = 153) compared to intertidal species (0.5 ± 0.01 m; n = 361). Correlation analysis showed that water level and rainfall were correlated with groundwater electrical conductivity in the lower and upper intertidal zones for all the estuaries sampled. These data indicate the influence of the estuary channel on the physico-chemical conditions of the salt marsh. Low rainfall (16 ± 3.3 mm per annum) in the Olifants Estuary (30-100 mS cm-1) and lack of freshwater flooding in the Kromme Estuary (42-115 mS cm-1) have resulted in high sediment electrical conductivity by comparison with the other estuaries sampled. In the Orange River Estuary approximately 70 ha of salt marsh have been lost through the building of a causeway and flood control levees. Even though salt marsh vegetation can tolerate hypersaline sediments by using the less saline water table, the groundwater at the Orange River Estuary was too saline (avg. of 90.3 ± 6.55 mS cm-1, n = 38) to be of use to the dominant floodplain species, Sarcocornia pillansii. Freshwater inflow to estuaries is important in maintaining longitudinal salinity gradients and reducing hypersaline conditions. In the Olifants Estuary and the Orange River Estuary where supratidal salt marsh is dominant, freshwater inflow is important in raising the water level and maintaining the depth to groundwater and salinity. Lack of freshwater inflow to the Kromme Estuary has highlighted the importance of rainfall in maintaining sediment salinity within acceptable ranges for the salt marsh. Macrophytes are relatively good indicators of physico-chemical factors in estuaries. From an understanding of the response of specific species to environmental variables, ecological water requirements can be set and sensitive areas can be rehabilitated.

Studies on morphological variation are important as it can depict the relationship with environmental factors clearly and convey an understanding of the manner, mechanism and factors influencing plant adaptation and evolution. Although many studies have been conducted on South African salt marsh plant physiology and phytosociology there are at present very few morphological studies on estuarine plants. The aim of this study was to compare the morphological variation of estuarine macrophytes in three different estuary types in the warm temperate biogeographic zone of South Africa and to compare characters used in the taxonomic descriptions of species with those measured in the field. Permanently open estuaries investigated were Ngqusi (WC), Kowie (KW) and Swartkops (SW) estuaries. The Knysna Estuary (KN) was the estuarine bay investigated and the temporarily open/ closed estuaries (TOCEs) were the East Kleinemonde (EK) and Great Brak (GB) estuaries. Macrophytes were morphologically different across different estuary types. This suggests that there were different factors operating between these estuary types that would directly influence the morphology of species. The variation of plant height with different estuary types can be attributed to the fact that smaller salt marshes also have smaller habitat ranges compared to larger ones. The variation in morphological characteristics such as plant height can also be attributed to biogeographical range. Most morphological characteristics measured in the field fall within previously published ranges, and so these characters are useful in delimiting species. There were significant relationships between phenotypic variables and multivariate environmental variables. The most important of these variables were soil electrical conductivity, soil organic content and soil water content. Specifically, plant height increased with water content and decreased with salinity, flower stalk length had strong significant positive correlations with moisture content, organic content and pH while there were strong significant correlations with redox potential and electrical conductivity. Salt marshes are considered ideal for studying variation of species due to the explicit environmental gradients and plants occurring in salt marshes are halophytes that exhibit a range of morphological traits that allows for growth and reproduction under the stressful and extreme conditions. Considering recent climate change predictions and the consequent effects on South African estuaries this study provides significant information with regard to the response of species to a changing environment. The study was also aimed at updating the existing botanical database for South African estuaries in terms of species occurrence in South African estuaries, taxonomic name changes of existing species, new species, common names and habitats. Species diversity indices were also calculated for different estuaries, estuary types and biogeographic zones and diagnostic descriptions of the dominant salt marsh species were developed. The objective of this was that these data should provide baseline information for determining habitat richness and plant species diversity of South African estuaries which in turn should be used in determining priority estuaries for conservation and management. The identification key, developed using the DELTA software, would also aid researchers, managers and laymen in identifying salt marsh species. Results showed that the total number of macrophyte species, including intraspecific taxa and macroalgae, was 242 in 53 estuaries that were updated . There was an increase in the number of taxa recorded in the database primarily due to 1) research focus and full taxonomic surveys on larger estuaries and the big research projects has led to the identification of more species, 2) the addition of species that are not characteristically known as estuarine species, 3) the addition of 50 macroalgal taxa and 4) minor changes due to taxonomic revisions of species and the addition of newly described species. The Shannon diversity index showed that greater species diversity was found in the Berg (Groot) Estuary (4.220) and the Uilkraals Estuary (4.025). The cool temperate bioregion was the most diverse in the number of taxa (58) with the highest Shannon index (4.736). Permanently open estuaries were the most diverse in the number of unique taxa (56) with the highest Shannon index (4.867). Estuarine managers need to be aware of the species diversity in different estuarine types as well as the associated impacts on them. Conservation planning must therefore include species. Diagnostic features of INTKEY indicated that all 57 taxa were distinguishable from each other. Contrary to expectations plant height and not floral morphology was the best diagnostic characteristic. Ecological information such as the estuarine habitat, where different life forms occur, was important in delimiting species.

Accumulation and toxicity of cadmium, lead and thallium in duckweed (Lemna minor L.) The toxicity and accumulation of lead, cadmium and thallium in the aquatic plant Lemna minor was investigated, using a modification of the Organisation for Economic Co-operation and Development (OECD) standard growth inhibition test. Plants were cultured in modified Swedish Institute Standard (SIS) at pH 6.5±0.5 under 85 µmol m-2 S-1 at 25°C and exposed to a wide range of lead, cadmium, and thallium concentrations from environmentally realistic to very high concentrations (0.001, 0.01,0.1, 1, 10, 100, 1000 and 10 000 µmol L-1) for seven days. Various physico-biochemical endpoints were measured after seven days of exposure. The concentrations of dissolved lead, cadmium, and thallium remaining in the residual solutions, and accumulation of lead, cadmium and thallium in fronds and roots were assessed using Inductively Couple Plasma – Mass Spectroscopy (ICP-MS). Over the exposure duration, lead, cadmium, and thallium concentrations in solution decreased rapidly and chlorosis was observed in fronds exposed to the three highest lead, cadmium, and thallium concentrations. After seven days of exposure, there were significant decreases in the relative growth rate (RGR), relative frond area (RFA), pigment content (chlorophyll a, b and total carotenoid) and activity of photosystem II (Fv/Fm) at concentrations of 0.1, 1, 10, 100, 1000 and 10 000 µmol L-1Pb, 10, 100, 1000 and 10 000 µmol L-1cd, 0.01,0.1, 1, 10, 100, 1000 and 10 000 µmol L-1TI. However, our results suggested that root elongation based on relative growth rate of L. minor will be an optimal and relevant endpoint in compare to other endpoints. As expected, results demonstrated that root elongation was concluded that root length was most predictive of a dose response model compared to the rest of growth endpoints and physiological and biochemical endpoints when assessing toxicity of lead, cadmium and thallium using L. minor. Toxicity testing for the floating macrophytes should include root elongation measurement which alone will be sufficient to meet sensitivity and variability requirements for toxicity testing. Cellular concentrations of lead, cadmium, and thallium were higher in roots than fronds, whereas more lead, cadmium, and thallium was adsorbed to the extracellular matrix of fronds than roots. The bio - concentration factor (BCF; i.e. lead concentration in plant tissue at day seven relative to residual lead concentration in the growth medium at day seven) indicates that L. minor is a good accumulator of lead, cadmium, and thallium particularly at lower concentration, but the physiological data shows that these metals toxic at concentrations that can be encountered in wastewater treatment facilities. The translocation factor (TF) value was found to be less than 1. Though, lead, cadmium and Thallium was mostly stored in roots, only minor amounts of lead, cadmium and thallium were trans located to fronds.

Macroinvertebrates associated with the aquatic plant, water stargrass (Heteranthera dubia), were sampled from 12 waterbodies in four regions of the United States from June to August 2005. Taxa richness, evenness, and diversity were lowest in the Lower Midwest (LMW) region, and higher in Northern sites, especially the Upper Midwest (UMW), and Northeast (NE). While relative abundance varied from site to site and region to region, utilization of the plant by functional groups remained fairly constant. Collector-gatherers consistently comprised the largest portion of invertebrates sampled. The shredder/ herbivore functional group comprised an average of 17 % of total groups. Through an exhaustive literature review, it was found that shredder/ herbivores of water stargrass have not been reported in the literature. Because of this, the herbivore group was analyzed separately and consisted of 2,383 specimens representing 23 species. The most common groups were Rhopalosiphum sp., Nectopsyche spp. and chironomids. No differences were found in herbivore diversity or evenness between sampling regions, but species richness was significantly different.

Non-native macrophytes structurally impact aquatic assemblages, yet little is known regarding how they influence energy pathways in freshwater ecosystems. Allelopathy in Eurasian watermilfoil- Myriophyllum spicatum has been shown to target basal epiphytic organisms resulting in differences in assemblage structure of colonizing epiphyton between M. spicatum and native M. sibiricum. I conducted a growth chamber experiment to investigate the hypothesis that differences in assemblage structure of colonizing epiphyton between these two macrophytes influence trophic dynamics within aquatic systems. My data suggest M. spicatum produces higher concentrations of allelochemicals, resulting in a more diverse epiphytic assemblage compared to M. sibiricum. This could result in potential transformation of trophic dynamics by decoupling carbon as it flows from primary producer to primary consumer. This work identifies a contributing mechanism responsible for M. spicatum invasiveness and provides new insight in its ecology and management of this non-native macrophyte.

Aquatic plants (macrophytes) are important components of freshwater ecosystems and serve numerous purposes, physical and biological, that help to structure aquatic communities. Although macrophytes represent an essential component of stable aquatic communities, invasive macrophytes may negatively alter ecosystem properties. Non-native, invasive species have been identified as a major cause of biodiversity loss and the increasing prevalence of invasive species has prompted studies to help understand their impacts and to conserve biodiversity. Studying mechanisms of invasion also gives insight into how communities are structured and assembled. This study examined mechanisms that contribute to macrophyte invasion. First, I reviewed literature concerning mechanisms of macrophyte invasion. Mechanisms identified with this review were then placed within the context of the invasion process and potential taxonomic biases were discussed. Second, a set of classic invasion hypotheses were tested, including biotic resistance, disturbance, and stress, using mixed-effects models on survey data collected from twenty-nine lakes across the United States. Finally, using the same survey data, I performed an observational test of Darwin’s Naturalization Hypothesis at a small (point) and large (lake) scale for two highly invasive macrophytes, Potamogeton crispus and Myriophyllum spicatum. Results of the first study indicated that many invasion mechanisms have been tested with fully aquatic macrophytes with varied levels of support. In addition, there is likely a taxonomic bias depending on geographic location of the invaded area. The second study indicated that biotic interaction, disturbance, and stress interact, often in non-linear ways to influence probability of an invasive species occurring at a location. However, models containing these variables explained a relatively low percentage of variation in probabilities. Finally, there was no support for Darwin’s naturalization hypothesis at either a point or lake scale. Future research should continue the search for mechanisms that allow introduced species to establish. It is likely that general principles do not exist, at least among comparisons across ecosystem types. However, ecologists should continue to search for general patterns within definable ecosystem units to increase understanding about factors contributing to invasibility.

This research explored fate of organic contaminants in aquatic plant systems through (i) experimental development of relationships to describe sorption, uptake and enzymatic processing of contaminants by plants and inhibition of aquatic plants by contaminants and (ii) incorporation of experimental relationships into a conceptual model which describes contaminant fate in aquatic plant systems. This study focused on interactions of aquatic plants L. minor and M. aquaticum with halogenated phenols. 2,4,5-trichlorophenol (2,4,5-TCP) and 2,4-dichlorophenol (2,4-DCP) are precursors for the highly toxic and heavily applied herbicides 2,4,5-T and 2,4-D and were examined in detail. Chlorophenols are generally resistant to microbial degradation, a property which may limit microbial remediation options as effective alternatives for clean up of contaminated sites. Relationships for fundamental interactions between plants and contaminants that dictate uptake, enzymatic processing and sequestration of contaminants by aquatic plants were established. An assay which quantified production of oxygen by plants was developed to quantify plant metabolic activity and inhibition. Uptake of chlorinated phenols depended on plant activity and aqueous phase concentration of contaminant in the protonated form. Therefore, plant activity, contaminant pKa and media pH were established as critical parameters controlling rate of contaminant uptake. A conceptual model was developed which incorporated plant activity and inhibition into a mathematical description of uptake of organic contaminants by aquatic plants. The conceptual model was parameterized using experimental data delineating effect of plant activity, inhibition and speciation on contaminant uptake and the model was verified using independently gathered data. Experimentation with radio-labeled chlorinated phenols established that contaminants were sequestered internal to plants by plant enzymatic processing. 19F NMR was established as a technique to quantify transformation and conjugation products internal to plants and contaminant assimilation by plants and demonstrated that multiple metabolites containing the parent compound were present and quantifiable internal to plants. Finally, fate of plant-sequestered contaminants in an anaerobic bioassay was examined using Desulfitobacterium sp. strain Viet1. The results of this study address the role of aquatic plants in sequestration of contaminants in surface waters that indicate the potential and limitations of use of aquatic plants in natural and engineered treatment systems.

New knowledge gained over the past 15 to 20 years on the management of riparian zones in Arizona for water yield improvement has been organized and analyzed. Hydrologic processes and principles applicable to riparian zones, the distribution and nature of riparian vegetation in Arizona, and new resource management methods, needs, and constraints have been evaluated, The relationship between vegetation management for water yield improvement and other resource based products and uses of riparian zones such as timber, range for livestock, wildlife and fish, recreation, and aesthetics was also assessed. Past studies and surveys indicate that Arizona has approximately 280,000 to 320,000 acres of riparian vegetation, However, pertinent information such as species composition, vegetation density, depth to groundwater, groundwater quality, and landownership have not been mapped accurately for many riparian zones in Arizona, A continuous survey of riparian vegetation cover by remote sensing supplemented by ground truth is suggested to remedy this situation. Analysis of hydrologic studies indicated the following identifiable trends in water use by riparian species, Saltcedar, arrowweed, cottonwood, and hydrophytes are the heaviest users of water (between four and eight feet of water annually). Intermediate water users (annual use between two and five feet) are seepwillow, mesquite, quailbrush, four-wing saltbush, and greasewood. Lesser amounts of water are transpired by grasses and sedges and evaporated from bare soil (0,5 to three feet annually). Five water yield improvement methods applicable to riparian zones are evaluated; conversion of one vegetation type to another, channelization, cottonwood thinning, antitranspirant and biological control treatments. Conversion treatments to grasses or crops may yield water savings of up to 2,5 acre-feet per acre annually during the first year, However, some or all of this water may eventually be used by replacement vegetation, Several constraints including possible loss of wildlife habitat, contamination of water supplies by chemical herbicides, lowered aesthetic quality, and increased soil erosion with the removal of riparian vegetation reduce the opportunities for converting a large percentage of riparian vegetation in Arizona, To justify operational conversion programs in Arizona follow up studies of current conversion projects should be instituted, Rates at which revegetation takes place, declines in water salvage as revegetation occurs, amount and value of increased herbage production, and long term effects on plant distribution and animal life need to be determined. Channelization projects in the Southwest have been credited with increasing water yields; however, methods for determining these increases are poorly documented. Channelization for flood control purposes is limited because flow of flood water is accelerated in the vicinity of the excavation and may contribute to flooding and sedimentation on unchanneled segments. Cottonwood thinning designed to reduce evapotranspiration and flood hazards has been conducted along the Verde River, Increased water yields have not been measured, Adverse effects on fish and wildlife have been reported as a result of thinning cottonwoods. Limited thinning of cottonwoods to prevent bridges from washing out or to protect existing structures on the floodplain may be beneficial. Application of antitranspirant foliar sprays to reduce plant water use is a potential treatment method for increasing water yield in riparian zones. Antitranspirants were effective in reducing transpiration rates of saltcedar plants by up to 38 per cent for three to five weeks in greenhouse and limited field studies, Research on the feasibility of obtaining supplementary water from riparian vegetation through the application of antitranspirants should be expanded, Antitranspirants, if proven safe and effective, may be mutually acceptable to water, recreation, and wildlife interests. Biological control of saltcedar is not effective at present.