No description available.

The Ceratium species occurring in the Vaal River since 2000, was identified as Ceratium hirundinella (O.F. Müller) Dujardin as proposed by Van Ginkel et al (2001). Ceratium hirundinella is known to cause problems in drinking water purification and has been penetrating into the final drinking water of Rand Water since 2006. Ceratium hirundinella is associated with many other water purification problems such as disrupting of the coagulation and flocculation processes, blocking of sand filters and algal penetration into the drinking water. Ceratium hirundinella also produce fishy taste and odorous compounds and causes discolouration of the water. The aims of this study were to determine the main environmental factors which are associated with the bloom formation of C. hirundinella in the source water and to investigate the influence of C. hirundinella on the production of potable water. In order to optimise treatment processes and resolve problems associated with high C. hirundinella concentrations during the production of potable water, jar testing and chlorine exposure experiments were performed. Multivariate statistical analyses were performed to determine the main environmental variables behind C. hirundinella blooms. Ten years data (2000 - 2009) from the sampling point C–VRB5T in the Vaal River, (5 km upstream from the Barrage weir) were used for this investigation, because C. hirundinella occurred there frequently during the ten year period. In this study, it was found that C. hirundinella was favoured by high pH, Chemical Oxygen Demand (COD), orthophoshapte (PO4), and silica concentrations, as well as low turbidity and low dissolved inorganic nitrogen (DIN) concentrations. No correlation was found between C. hirundinella and temperature, suggesting that this alga does not occur during periods of extreme warm or extreme cold conditions, but most probably during autumn and spring. The results of the multivariate statistical analysis performed with historical data from Vaalkop dam, indicate that the dinoflagellate C. hirundinella seems to be favoured by low temperature and turbidity, and high DIN, Fe, Methyl–orange alkalinity, Cd, PO4, Conductivity, pH, hardness and SO4 concentrations. In order to optimise treatment processes such as coagulation, flocculation and sedimentation, jar testing experiments were performed to investigate different coagulant chemicals namely: cationic poly–electrolyte only, cationic poly–electrolyte in combination with slaked lime (CaO) and CaO in combination with activated silica. Water from four different sampling localities were chosen to perform the different jar testing experiments: 1) sampling point M–FOREBAY (in the Forebay, connecting the canal to the Zuikerbosch Purification plant) near Vereeniging due to its proximity to the Zuikerbosch treatment plant, 2) M–CANAL_VD (upstream from the inflow of the recovered water from Panfontein) to determine the influence of (if any) the recovered water from Panfontein on Forebay source water, 3) source water from Vaalkop Dam (M–RAW_VAALKOP) and 4) source water from Rietvlei Dam (water from both Vaalkop and Rietvlei Dams contained high concentrations of C. hirundinella at that time of sampling) to determine which coagulant chemical is the most effective in removing high concentrations of C. hirundinella cells during the production of drinking water. The jar testing experiments with Vaalkop Dam and Rietvlei Dam source water (rich with C. hirundinella) indicated that using cationic poly–electrolyte alone did not remove high concentrations of C. hirundinella efficiently. However, when CaO (in combination with cationic poly–electrolyte or activated silica) were dosed to Vaalkop Dam source water a significant decrease of C. hirundinella concentration was observed. This indicates that the C. hirundinella cells were “shocked or stressed” when exposed to the high pH of the CaO, rendering it immobile and thereby enhancing the coagulation and flocculation process. However, when 10 mg/L CaO in combination with poly–electrolyte was dosed to Rietvlei Dam source water the turbidity and chlorophyll–665 results indicated that this coagulant chemical procedure was ineffective in removing algal material from the source water. The jar testing experiments using the cationic poly–electrolyte alone or cationic poly–electrolyte in combination with CaO on M–FOREBAY and M–CANAL_VD source water, showed a decrease in turbidity, chlorophyll–665 concentration, and total algal biomass, with an increase of coagulant chemical. When CaO in combination with activated silica was dosed, the inherent turbidity of the lime increased the turbidity of the Vaalkop Dam, M–FOREBAY and M–CANAL_VD source water to such an extent that it affected coagulation negatively, resulting in high turbidity values in the supernatant. Regardless of the turbidity values, the chlorophyll–665 concentration and total algal biomass (C. hirundinella specifically in Vaalkop Dam source water) decreased significantly when CaO was dosed in combination with activated silica. Therefore it was concluded that a cationic poly–electrolyte alone is a good coagulant chemical for the removal of turbidity, but when high algal biomass occur in the source water it is essential to add CaO to “stress” or “shock” the algae for the effective removal thereof. However, when CaO in combination with activated silica was dosed to Rietvlei Dam source water a decrease in turbidity and chlorophyll–665 concentration was found with an increasing coagulant chemical concentration. These results confirm the fact that coagulant chemicals may perform differently during different periods of the year when water chemistry changes and that certain coagulant chemicals may never be suitable to use for certain source waters. For the effective removal of algae during water purification, it is recommended that cationic poly–electrolyte in combination with CaO are used as coagulant chemical at the Zuikerbosch Water Purification Plant. Turbidity is not a good indication of algal removal efficiency during jar testing experiments. If problems with high algal concentrations in the source water are experienced it is advisable to also determine the chlorophyll–665 concentrations of the supernatant water during the regular jar testing experiments, since it will give a better indication of algal removal. Chlorine exposure experiments were performed on water from Vaalkop Dam (M–RAW_VAALKOP) and Rietvlei Dam source water, to determine the possibility of implementing pre– or intermediate chlorination with the aim to render the cells immobile for more effective coagulation. The chlorine exposure experiments with Vaalkop Dam and Rietvlei Dam source water showed similar results. The chlorine concentration to be dosed as part of pre– or intermediate chlorination will differ for each type of source water as the chemical and biological composition of each water body are unique. When the effect of chlorine on the freshwater dinoflagellate C. hirundinella was investigated, it was found that the effective chlorine concentration where 50 % of Ceratium cells were rendered immobile (EC50) was approximately 1.16 mg/L for Vaalkop Dam source water. For the source water sampled from Rietvlei Dam, it was found that the EC50 was at approximately 0.87 mg/L. Results of analyses to determine the organic compounds in the water after chlorination revealed that an increase in chlorine concentration resulted in increase in total organic carbon concentration (TOC), as well as a slight increase in MIB and trihalomethanes (CHCl3). Pre– or intermediate chlorination seem to be an effective treatment option for the dinoflagellate C. hirundinella to be rendered immobile and thereby assisting in its coagulation process. The use of pre– or intermediate chlorination to effectively treat source waters containing high concentrations of C. hirundinella is a viable option to consider. However, the organic compounds in the water should be monitored and the EC50 value for each source water composition should be determined carefully as to restrict cell lysis and subsequent release of organic compounds into the water. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2012.

The Ceratium species occurring in the Vaal River since 2000, was identified as Ceratium hirundinella (O.F. Müller) Dujardin as proposed by Van Ginkel et al (2001). Ceratium hirundinella is known to cause problems in drinking water purification and has been penetrating into the final drinking water of Rand Water since 2006. Ceratium hirundinella is associated with many other water purification problems such as disrupting of the coagulation and flocculation processes, blocking of sand filters and algal penetration into the drinking water. Ceratium hirundinella also produce fishy taste and odorous compounds and causes discolouration of the water. The aims of this study were to determine the main environmental factors which are associated with the bloom formation of C. hirundinella in the source water and to investigate the influence of C. hirundinella on the production of potable water. In order to optimise treatment processes and resolve problems associated with high C. hirundinella concentrations during the production of potable water, jar testing and chlorine exposure experiments were performed. Multivariate statistical analyses were performed to determine the main environmental variables behind C. hirundinella blooms. Ten years data (2000 - 2009) from the sampling point C–VRB5T in the Vaal River, (5 km upstream from the Barrage weir) were used for this investigation, because C. hirundinella occurred there frequently during the ten year period. In this study, it was found that C. hirundinella was favoured by high pH, Chemical Oxygen Demand (COD), orthophoshapte (PO4), and silica concentrations, as well as low turbidity and low dissolved inorganic nitrogen (DIN) concentrations. No correlation was found between C. hirundinella and temperature, suggesting that this alga does not occur during periods of extreme warm or extreme cold conditions, but most probably during autumn and spring. The results of the multivariate statistical analysis performed with historical data from Vaalkop dam, indicate that the dinoflagellate C. hirundinella seems to be favoured by low temperature and turbidity, and high DIN, Fe, Methyl–orange alkalinity, Cd, PO4, Conductivity, pH, hardness and SO4 concentrations. In order to optimise treatment processes such as coagulation, flocculation and sedimentation, jar testing experiments were performed to investigate different coagulant chemicals namely: cationic poly–electrolyte only, cationic poly–electrolyte in combination with slaked lime (CaO) and CaO in combination with activated silica. Water from four different sampling localities were chosen to perform the different jar testing experiments: 1) sampling point M–FOREBAY (in the Forebay, connecting the canal to the Zuikerbosch Purification plant) near Vereeniging due to its proximity to the Zuikerbosch treatment plant, 2) M–CANAL_VD (upstream from the inflow of the recovered water from Panfontein) to determine the influence of (if any) the recovered water from Panfontein on Forebay source water, 3) source water from Vaalkop Dam (M–RAW_VAALKOP) and 4) source water from Rietvlei Dam (water from both Vaalkop and Rietvlei Dams contained high concentrations of C. hirundinella at that time of sampling) to determine which coagulant chemical is the most effective in removing high concentrations of C. hirundinella cells during the production of drinking water. The jar testing experiments with Vaalkop Dam and Rietvlei Dam source water (rich with C. hirundinella) indicated that using cationic poly–electrolyte alone did not remove high concentrations of C. hirundinella efficiently. However, when CaO (in combination with cationic poly–electrolyte or activated silica) were dosed to Vaalkop Dam source water a significant decrease of C. hirundinella concentration was observed. This indicates that the C. hirundinella cells were “shocked or stressed” when exposed to the high pH of the CaO, rendering it immobile and thereby enhancing the coagulation and flocculation process. However, when 10 mg/L CaO in combination with poly–electrolyte was dosed to Rietvlei Dam source water the turbidity and chlorophyll–665 results indicated that this coagulant chemical procedure was ineffective in removing algal material from the source water. The jar testing experiments using the cationic poly–electrolyte alone or cationic poly–electrolyte in combination with CaO on M–FOREBAY and M–CANAL_VD source water, showed a decrease in turbidity, chlorophyll–665 concentration, and total algal biomass, with an increase of coagulant chemical. When CaO in combination with activated silica was dosed, the inherent turbidity of the lime increased the turbidity of the Vaalkop Dam, M–FOREBAY and M–CANAL_VD source water to such an extent that it affected coagulation negatively, resulting in high turbidity values in the supernatant. Regardless of the turbidity values, the chlorophyll–665 concentration and total algal biomass (C. hirundinella specifically in Vaalkop Dam source water) decreased significantly when CaO was dosed in combination with activated silica. Therefore it was concluded that a cationic poly–electrolyte alone is a good coagulant chemical for the removal of turbidity, but when high algal biomass occur in the source water it is essential to add CaO to “stress” or “shock” the algae for the effective removal thereof. However, when CaO in combination with activated silica was dosed to Rietvlei Dam source water a decrease in turbidity and chlorophyll–665 concentration was found with an increasing coagulant chemical concentration. These results confirm the fact that coagulant chemicals may perform differently during different periods of the year when water chemistry changes and that certain coagulant chemicals may never be suitable to use for certain source waters. For the effective removal of algae during water purification, it is recommended that cationic poly–electrolyte in combination with CaO are used as coagulant chemical at the Zuikerbosch Water Purification Plant. Turbidity is not a good indication of algal removal efficiency during jar testing experiments. If problems with high algal concentrations in the source water are experienced it is advisable to also determine the chlorophyll–665 concentrations of the supernatant water during the regular jar testing experiments, since it will give a better indication of algal removal. Chlorine exposure experiments were performed on water from Vaalkop Dam (M–RAW_VAALKOP) and Rietvlei Dam source water, to determine the possibility of implementing pre– or intermediate chlorination with the aim to render the cells immobile for more effective coagulation. The chlorine exposure experiments with Vaalkop Dam and Rietvlei Dam source water showed similar results. The chlorine concentration to be dosed as part of pre– or intermediate chlorination will differ for each type of source water as the chemical and biological composition of each water body are unique. When the effect of chlorine on the freshwater dinoflagellate C. hirundinella was investigated, it was found that the effective chlorine concentration where 50 % of Ceratium cells were rendered immobile (EC50) was approximately 1.16 mg/L for Vaalkop Dam source water. For the source water sampled from Rietvlei Dam, it was found that the EC50 was at approximately 0.87 mg/L. Results of analyses to determine the organic compounds in the water after chlorination revealed that an increase in chlorine concentration resulted in increase in total organic carbon concentration (TOC), as well as a slight increase in MIB and trihalomethanes (CHCl3). Pre– or intermediate chlorination seem to be an effective treatment option for the dinoflagellate C. hirundinella to be rendered immobile and thereby assisting in its coagulation process. The use of pre– or intermediate chlorination to effectively treat source waters containing high concentrations of C. hirundinella is a viable option to consider. However, the organic compounds in the water should be monitored and the EC50 value for each source water composition should be determined carefully as to restrict cell lysis and subsequent release of organic compounds into the water. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2012.

Soil P fractionation was used to examine changes in soil inorganic and organic P under grazed irrigated pasture in a long-term field trial at Winchmore in Mid-Canterbury. The soil P fractionation scheme used involved sequential extractions of soil with O.5M NaHCO₃ @ pH 8.5 (NaHCO₃ P), 0.1M NaOH (NaOH I P), 1M HCl (HCl P) and 0.1M NaOH (NaOH II P). The Winchmore trial comprised 5 treatments: control (no P since 1952), 376R (376 kg superphosphate ha⁻¹ yr⁻¹ 1952-1957, none since), 564R (564 kg superphosphate ha⁻¹ yr⁻¹ 1952-1957, none since) 188PA (188 kg superphosphate ha⁻¹ yr⁻¹ since 1952) and 376PA (376 kg superphosphate ha⁻¹ yr⁻¹ since 1952: Topsoil (0-7.5cm) samples taken from the different treatments in 1958, 1961, 1965, 1968, 1971, 1974 and 1977 were used in this study. Changes in soil P with time showed that significant increases in soil inorganic P occurred in the annually fertilised treatments (l88PA, 376PA). As expected, the overall increase in total soil inorganic P between 1958 and 1977 was greater in the 376PA treatment (159 µg P g⁻¹) than that in the 188PA treatment (37 µg P g⁻¹). However, the chemical forms of inorganic P which accumulated in the annually fertilised treatments changed with time. Between 1958 and 1971 most of the increases in soil inorganic P in these treatments occurred in the NaHCO₃ and NaOH I P fractions. On the other hand, increases in soil inorganic P in the annually fertilised treatments between 1971 and 1977 were found mainly in the HCl and NaOH II P fractions. These changes in soil P forms were attributed to the combined effects of lime addition in 1972 and increased amounts of sparingly soluble apatite P and iron-aluminium P in the single superphosphate applied during the 1970's. In the residual fertiliser treatments (376R, 564R) significant decreases in all of the soil inorganic P fractions (i.e. NaHCO₃ P, NaOH I P, HCl P, NaOH II p) occurred between 1958 and 1977 following the cessation of P fertiliser inputs in 1957. This was attributed to continued plant uptake of P accumulated in the soil from earlier P fertiliser additions. However, levels of inorganic P in the different soil P fractions in the residual fertiliser treatments did not decline to those in the control which indicated that some of the inorganic P accumulated in the soil from P fertiliser applied between 1952 and 1957 was present in very stable forms. In all treatments, significant increases in soil organic P occurred between 1958 and 1971. The overall increases in total soil organic P were greater in the annually fertilised treatments (70-86 µg P g⁻¹) than those in the residual fertiliser (55-64 µg P g⁻¹) and control (34 µg P g⁻¹) treatments which reflected the respective levels of pasture production in the different treatments. These increases in soil organic P were attributed to the biological conversion of native and fertiliser inorganic P to organic P in the soil via plant, animal and microbial residues. The results also showed that annual rates of soil organic P accumulation between 1958 and 1971 decreased with time which indicated that steady-state conditions with regard to net 'organic P accumulation were being reached. In the residual fertiliser treatments, soil organic P continued to increase between 1958 and 1971 while levels of soil inorganic P and pasture production declined. This indicated that organic P which accumulated in soil from P fertiliser additions was more stable and less available to plants than inorganic forms of soil P. Between 1971 and 1974 small (10-38 µg P g⁻¹) but significant decreases in total soil organic P occurred in all treatments. This was attributed to increased mineralisation of soil organic P as a result of lime (4 t ha⁻¹) applied to the trial in 1972 and also to the observed cessation of further net soil organic P accumulation after 1971. Liming also appeared to affect the chemical nature of soil organic P as shown by the large decreases in NaOH I organic P(78-88 µg P g⁻¹) and concomitant smaller increases in NaOH II organic P (53-65 µg P g⁻¹) which occurred in all treatments between 1971 and 1974. The chemical nature of soil organic P in the Winchmore long-term trial was also investigated using 31p nuclear magnetic resonance (NMR) spectroscopy and gel filtration chromatography. This involved quantitative extraction of organic P from the soil by sequential extraction with 0.1M NaOH, 0.2M aqueous acetylacetone (pH 8.3) and 0.5M NaOH following which the extracts were concentrated by ultrafiltration. Soils (0-7.5cm) taken from the control and 376PA annually fertilised treatments in 1958, 1971 and 1983 were used in this study. 31p NMR analysis showed that most (88-94%) of the organic P in the Winchmore soils was present as orthophosphate monoester P while the remainder was found as orthophosphate diester and pyrophosphate P. Orthophosphate monoester P also made up almost all of the soil organic P which accumulated in the 376PA treatment between 1958 and 1971. This indicated that soil organic P in the 376PA and control treatments was very stable. The gel filtration studies using Sephadex G-100 showed that most (61-83%) of the soil organic P in the control and 376PA treatments was present in the low molecular weight forms (<100,000 MW), although the proportion of soil organic P in high molecular weight forms (>100,000 MW) increased from 17-19% in 1958 to 38-39% in 1983. The latter was attributed to the microbial humification of organic P and indicated a shift toward more complex and possibly more stable forms of organic P in the soil with time. Assuming that the difference in soil organic P between the control and 376PA soils sampled in 1971 and 1983 represented the organic P derived from P fertiliser additions, results showed that this soil organic P was evenly distributed between the high and low molecular weight fractions. An exhaustive pot trial was used to examine the relative availability to plants of different forms of soil inorganic and organic P in long-term fertilised pasture soils. This involved growing 3 successive crops of perennial ryegrass (Lolium perenne) in 3 Lismore silt loam (Udic Ustochrept) soils which had received different amounts of P fertiliser for many years. Two of the soils were taken from the annually fertilised treatments in the Winchmore long term trial (188PA, 376PA) and the third (Fairton) was taken from a pasture which had been irrigated with meatworks effluent for over 80 years (65 kg P ha⁻¹ yr⁻¹). Each soil was subjected to 3 treatments, namely control (no nutrients added), N100 and N200. The latter treatments involved adding complete nutrient solutions with different quantities of N at rates of 100kg N ha⁻¹ (N100) and 200kg N ha⁻¹ (N200) on an area basis. The soil P fractionation scheme used was the same as that used in the Winchmore long-term trial study (i.e. NaHCO₃ P, NaOH I P, HCl P, NaOH II p). Results obtained showed that the availability to plants of different extracted inorganic P fractions, as measured by decreases in P fractions before and after 3 successive crops, followed the order: NaHCO₃ P > NaOH I P > HCl P = NaOH II P. Overall decreases in the NaHCO₃ and NaOH I inorganic P fractions were 34% and 16% respectively, while corresponding decreases in the HCl and NaOH II inorganic P fractions were small «10%) and not significant. However, a significant decrease in HCl P (16%) was observed in one soil (Fairton-N200 treatment) which was attributed to the significant decrease in soil pH (from 6.2 to 5.1) which occurred after successive cropping. Successive cropping had little or no effect on the levels of P in the different soil organic P fractions. This indicated that net soil organic P mineralisation did not contribute significantly to plant P uptake over the short-term. A short-term field experiment was also conducted to examine the effects of different soil management practices on the availability of different forms of P to plants in the long-term fertilised pasture soils. The trial was sited on selected plots of the existing annually fertilised treatments in the Winchmore long-term trial (188PA, 376PA) and comprised 5 treatments: control, 2 rates of lime (2 and 4 t ha⁻¹ ) , urea fertiliser (400kg N ha⁻¹ ) and mechanical cultivation. The above ground herbage in the uncultivated treatments was harvested on 11 occasions over a 2 year period and at each harvest topsoil (0-7.5 cm) samples were taken from all of the treatments for P analysis. The soil P fractionation scheme used in this particular trial involved sequential extractions with 0.5M NaHCO₃ @ pH 8.5 (NaHCO₃ P), 0.1M NaOH (NaOH P), ultrasonification with 0.1M NaOH (sonicate-NaOH p) and 1M HCl (HCl P). In addition, amounts of microbial P in the soils were determined. The results showed that liming resulted in small (10-21 µg P g⁻¹) though significant decreases in the NaOH soil organic P fraction in the 188PA and 376PA plots. Levels of soil microbial P were also found to be greater in the limed treatments compared with those in the controls. These results indicated that liming increased the microbial mineralisation of soil organic P in the Winchmore soils. However, pasture dry matter yields and P uptake were not significantly affected. Although urea significantly increased dry matter yields and P uptake, it did not appear to significantly affect amounts of P in the different soil P fractions. Mechanical cultivation and the subsequent fallow period (18 months) resulted in significant increases in amounts of P in the NaHCO₃ and NaOH inorganic P fractions. This was attributed to P released from the microbial decomposition of plant residues, although the absence of plants significantly reduced levels of microbial P in the cultivated soils. Practical implications of the results obtained in the present study were presented and discussed.

Os resíduos decorrentes da construção civil apresentam, na maioria das vezes, a predominância de materiais inertes e passíveis de reaproveitamento, que não tem em grande parte uma finalidade. Esta dissertação apresenta uma abordagem sobre destinação correta dos resíduos, utilizando resíduos de argamassa, lodo de anodização de alumínio e cal para a formação de um novo compósito. O maior objetivo desta dissertação é caracterizar os materiais como componentes de novos compósitos para a construção civil, além de identificar novas composições (ao todo são 13 composições) atendendo as normas e leis existentes, analisar os processos físico-químicos, determinar as propriedades mecânicas e adaptar tecnologias existentes no processo de fabricação, além de destinar sem danos ambientais todas as matérias primas. Para análises físico-químicas e mecânicas foram estudados os seguintes parâmetros: resistência uniaxial média, absorção de água, densidade aparente, retração linear, microscopia eletrônica de varredura (MEV), espectrometria por energia dispersiva, difração de raios-X e espectrometria de fluorescência de raios-X (FRX). Dentre as 13 composições foram escolhidas as composições 4 e 11 para analisar mais o comportamento físico-químico. A resistência à compressão média uniaxial, aos 90 dias da composição 11 alcançou 9,18 MPa, com coeficiente de absorção de água de 12%, a retração foi de 1,53% e a densidade ao longo de 180 dias de cura variou apenas 4%. Os estudos físico-químicos identificaram a presença de Carbono, Sódio, Magnésio, Alumínio, Silício e Cálcio na composição 11, e através do MEV e FRX foi possível identificar que se trata de uma estrutura amorfa. Através desses estudos propõe-se alternativas que sejam revertidas em vantagens sociais e ambientais, tais como a fabricação de blocos vazados de concreto simples para alvenaria sem função estrutural, blocos cerâmicos para alvenaria de vedação, tijolos maciços para a alvenaria em relação a categoria A, entre outros. / Waste from the construction, have in most cases the predominance of inerts materials and insusceptible reuse, which has a few purpose. This dissertation presents an approach on the correct disposal of this waste, using mortar residue, anodizing aluminum sludge and lime to form a new composite. The main objective of this project is to characterize the materials as components of new composites for the construction industry, and identify new compositions (they are 13 compositions) meet the existing standards and laws, analyze the physical and chemical processes, determine the mechanical properties and adapting existing technologies in the manufacturing process, beyond to appropriate correctly without environmental damage for all the materials. For physical-chemical and mechanical analysis, the following parameters were studied: resistance average uniaxial, water absorption, apparent density, linear retraction, environment-scanning electron microscopy, energy dispersive x-ray, x-ray diffraction and x-ray fluorescence. Between the 13 compositions, chosen compositions 4 and 11 to analyze the behavior. The average uniaxial compressive strength at 90 days composition 11 reached 9,18 MPa with 12% water absorption coefficient, the shrinkage was 1,53% and the density over 180 days varied only 4%. The physic-chemical studies have identified the presence of Carbon, Sodium, Magnesium, Aluminum, Silicon and Calcium in the composition 11 and about scanning electron microscopy and XRF identified that it is an amorphous structure. Through these studies, it was possible to propose alternatives that are reversed in social and environmental benefits, such as the manufacture of simple concrete hollow blocks brickwork without structural function, ceramic blocks for sealing brickworks and solid bricks for brickworks in relation to category A, among others.

Hazardous waste substances are solid, semi-solid or non-aqueous liquids that exhibit characteristics of corrosivity, reactivity, ignitability, toxicity and infectious property. Major available options for management of hazardous waste include direct disposal into landfill or chemical treatment/stabilization of wastes prior to landfill disposal. Hazardous wastes are accepted for direct disposal in engineered landfills if they conform to the chemical concentration limit criterion (determined by water leach test followed by estimation of the concentration of the contaminant) and compressive strength (the material should have compressive strength > 50 kPa) criterion. Lead is classified as extremely toxic metal. Elevated levels of lead in water (surface and ground water) primarily arise from industrial discharges, and aerial deposition. During its residence in surface water bodies, the lead may interact detrimentally with aquatic life or be abstracted into public water supplies. According to National drinking water standards, the permissible limit of lead in drinking water is 0.05 mg/l. Deposition of air-borne lead, disposal of sewage sludge on land and disposal of industrial effluents on lands are major sources of lead contamination of soils. When incorporated in soil, lead is of very low mobility. Lead retained in soils can be slowly leached to the groundwater thereby impacting human health if consumed for potable needs. Alternatively lead deposited in soils can be absorbed by vegetation (crops/trees) and can impact human health on their consumption. Given the negative impacts of lead contamination on human health, the strong affinity of soils to retain deposited lead and the possible release for human consumption, this thesis focuses on characterization and chemical stabilization of artificially lead contaminated soils in the context of their disposal in hazardous waste landfills. The main objectives of the thesis are: characterize artificially lead contaminated soils for water leachability of lead and undrained strength characteristics as per CPCB (Central Pollution Control Board) guidelines in the context of disposal criteria in hazardous waste landfills. Artificially lead contaminated soils in compacted and slurry states are used in the thesis. Red soil (from Bangalore District, Karnataka) and river sand are used in the preparation of compacted and slurry specimens. The red soil and red soil-sand specimens are artificially contaminated in the laboratory by employing aqueous lead salt solutions as remolding fluids. Lead concentrations of 160 to 10000 mg/l are used in this study. The results of characterization studies with artificially lead contaminated soils help identify contaminated soil materials that require chemical stabilization prior to disposal into engineered landfills. Based on the results of characterization studies with artificially lead contaminated soils, lime stabilization coupled with steam curing technique is resorted to immobilize lead in the red soil-sand slurry specimens and mobilize adequate undrained strength to meet the criteria for disposal of lead contaminated soils in hazardous landfills. After this first introductory chapter, a detailed review of literature is performed towards highlighting the need to undertake chemical stabilization of artificially lead contaminated soils in Chapter 2. Chapter 3 presents a detailed experimental program of the study. Chapter 4 presents the physico-chemical and mechanical characterization of the artificially lead contaminated soils. The ability of artificially contaminated soils to release (artificially added) lead during water leaching is explained using lead speciation results performed using the Visual MINTEQ program. Experimental results illustrated that contamination of compacted red soil and red soil + sand specimens with significant lead concentrations (21 to 1300 mg/kg) resulted in major fractions of the added lead being retained in the precipitated state. Results of water leach tests revealed that lead concentrations released in the water leachates are far less than (0.0011 to 0.48 mg/l) limits prescribed by CPCB (2 mg/l) for direct disposal of lead contaminated materials into hazardous waste landfills. Unconfined compressive strengths developed by the lead contaminated red soil and red soil-sand specimens were significantly higher (100-2700 kPa) than the strength requirement (> 50 kPa) for direct disposal of hazardous wastes in engineered landfills. Lead contamination did not affect the unconfined compression strengths of the specimens as matric suction prevalent in the unsaturated compacted soils had an overriding influence on the cementation bond strength created by the lead precipitates. Visual Minteq tool was helpful in predicting the amount of added lead that was converted to insoluble precipitate form. However the amounts of water leachable lead determined experimentally and predicted by Visual Minteq were very different-Visual Minteq predicted much higher amounts of water leachable lead than experimentally determined. Experimental results revealed that the levels of lead released by the red soil-sand slurries in water leach tests were in excess (13 to 36 mg/l) of the permissible lead concentration (2 mg/l) for direct disposal of hazardous waste in landfills. Owing to water contents generally being in excess of their liquid limit water contents (w/wL ratio > 1) the slurry specimens exhibited undrained strengths below 1 kPa. Lime stabilization and steam curing of the contaminated slurry specimens was therefore resorted to control the leachibility of lead and increase undrained strengths to acceptable limits. Chapter 5 deals with lime stabilization of artificially contaminated slurries that do not meet the leachate quality (lead concentration in water < 2 mg/l) or compressive strength (> 50 kPa). Procedures are evolved for lime stabilization of such artificially contaminated soils to meet both the water leachate quality and compressive strength criteria. Lime stabilization together with steam curing of the lead contaminated slurry specimens effectively immobilized the added lead (2500 mg/kg) and imparted adequate compressive strengths to the contaminated red soil-sand slurry specimens. The lime stabilized contaminated specimens released marginal lead concentrations (0.03 to 0.45 mg/l) in the water leach; these values are much lower than permissible limit (2 mg/l) for disposal in hazardous landfills or values exhibited by the unstabilized specimens (13 to 38 mg/l). Lime addition rendered the contaminated specimens strongly alkaline (pH values ranged between 10.68 and 11.66). Combination of the experimental and Visual Minteq results suggested that precipitation of lead as hydrocerrusite in the alkaline environments (pH 10.68 to 11.95) is not the sole factor for marginal release of lead in water leach tests of the 4, 7 and 10 % lime stabilized contaminated specimens. It is possible that fraction of lead ions are entrapped within the cemented soil matrix. Water leach tests performed at range of pH values (pH 2.5 to 9.6) with 7 % lime stabilized specimens suggested that immobilization of lead as hydrocerrusite or as entrapment in the cemented soil mass in the lime stabilized specimens is practically irreversible even on exposure to extreme pH conditions. The lime stabilized contaminated specimens developed unconfined compressive strengths ranging from 100 kPa (4 % lime stabilized 40 % red soil-60 % sand specimen) to 1000 kPa (10 % lime stabilized 100 % red soil specimen). The significant growth of compressive strength upon lime stabilization is attributed to growth of inter-particle cementation bonds by the CAH (calcium aluminate hydrate) and CSH (calcium silicate hydrate) compounds formed by lime-clay reactions, slight reduction in void ratios and growth of strong inter-particle cementation bonds the during steam curing at 800C. The results of this thesis bring out a procedure to immobilize high concentrations of lead and develop adequate compressive strength of lead contaminated slurry specimens by lime stabilization + steam curing technique. The red soil acted as pozzolana in reactions with lime, while, steam curing accelerated the lime-soil reactions. The procedure can be extended to non-organic slurry wastes that are devoid of pozzolanic material (example, lead contaminated smelting sands). In slurry wastes devoid of pozzolana, materials such as fly ash can be added and the reactions between lime and fly ash would immobilize lead + develop adequate compressive strength. Also, similar to the methodology being adaptable for any non-organic slurries, it can also be extended to other toxic metal bearing wastes, example, zinc, cadmium and nickel.

This diploma thesis solves creating of the layout study and creation of documentation for the realization of a new fire station. In the building, the location of the JPO I rescue units is considered. The territorial jurisdiction is usually considered to be within 20 minutes of dislocation. The category of the fire station will be considered as P1. The object consists of two structurally and functionally different parts. The first part is designed as a one-storey reinforced concrete skeleton roofed with pre-stressed ceiling panels. This section includes technical background and garages. The cladding of the skeletal part of the building is solved by a masonry block made of lime-sand blocks with external thermal insulation composite system. The second part is walled from lime-sand blocks with external thermal insulation composite system. There are spaces of administrative and operational character. This section has two above-ground floors. The ground plan is fractured, the maximum dimensions are 45.59 x 28.34 m. The building has no basement, roofed only with flat roofs. The object is situated in the peripheral locality of Příbor, the terrain is slightly sloping.

The aim of the thesis was to design a building named Hotel Aztec. The building will serve for accommodation and recreation. The restaurant is also part of the hotel. There is a car park near the hotel building. The hotel has four floors and basement. There are 26 suites, 2 of them are three bed rooms, 20 double or twin rooms and 4 single rooms. The south-facing orientation of the suites ensures sufficient insolation. In ground floor there is one twin room for disabled persons. In ground floor there is restaurant with kitchen connected with bar in basement. There is also wellness centre, mechanical rooms and storages. On the northeast side of the hotel there are offices and rooms for employees and training room. The loadbearing masonry is from sand-lime blocks and there are cast-in-place reinforced concrete slabs and concrete foundations. The external wall is insulated with ETICS. All roofs are warm flat, over the restaurant there is intensive green roof, The roof over the 2nd floor is walkable - roof terrace. Over the 3rd floor there is non-walkable flat roof. The building is heated by heat pumps and there is mechanical ventilation with heat recovery.

The subject of this diploma thesis is design and project documentation of a kindergarten in Velké Pavlovice. It is a separately standing structure with two floors and partial basement located in slightly sloping terrain. The building is constructed of sand-lime blocks with contact thermal insulation, supported by strip foundations. Ceiling construction is made of prestressed hollow-core slabs. This object is roofed by a simple, flat, extensive roof. This kindergarten is designed for 40 children divided into two sections which are located right in the 1st floor together with food delivery. The technical room is in the basement. The common room, multipurpose classroom and headquarters are situated on the 2nd floor. Disposition is proposed in accordance with operation of kindergarten.

The final thesis is focused on design of functional unit od Kindergarten in Křenovice (district Vyškov). The object is subdivided to 3 functional parts. The middle part is designed as a two-storey, remaining two parts are single-storey. Whole object is without cellart. This object is formed from two separate class for fifteen children each and the middle part is design for technical facilities . For every class are two teachers and in total one a head teacher. For the preparation food a cleaningup there are three employees. In the object is one office of speech therapy with barrier free access. The roofing of object is design as a warm vegetation flats roofs. The object is design as a masonry system of sand-lime block with contact thermal insulation system.