The purpose of this thesis was to study the economical aspects of the present boiler feed water treating system at the VPI Power Plant. In carrying out the investigation, two testing periods were conducted, each lasting for four weeks and the first period was preliminary in nature. The experimental results revealed that the cost on caustic soda(NaOH) could be reduced by improving the performance of the mechanical degasifier; the cost on neutralizing amines (Nalco 35) was insufficient to insure maximum protection against corrosion; the cost of blowdown was too high; and the cost on sodium orthophosphate and ligin derivatives (Nalco 728) could be reduced. Recommendations are made based on the test results and plan for future expansion of plant capacity. It is recommended that the degasifier be overhauled; the optimum blowdown quantity be studied; the Boiler No. 5 be inspected for leaks; a better method found for feeding Nalco 35; and the installation of an automatic pH meter and a continuous conductivity recorder for the main condensate return line. The average cost for feedwater treatment at the VPl Power Plant from March 25 to April 20, 1958, was $ 1.334 per thousand gallons of New River water demineralized. / Master of Science

The object of this research was to investigate and evaluate three methods for determination of sulfate and to use the obtained information as a guide in selecting an accurate analytical method with which to conduct a complete analysis of calcium sulfate deposits. The investigation of the analytical methods revealed that the gravimetric method is most accurate for high sulfate concentrations. This method was selected for all analytical work conducted in the study of the deposited material and in the development of a sodium hydroxide-alcohol-water solution for the removal of the calcium sulfate deposits. The initial phases of the development of the sodium hydroxide-alcohol-water solution were discouraging in that the results were inconsistent and could not be reproduced. It was believed that such inconsistencies resulted, primarily, from the method of mixing the solutions, since all mixing was done by weight percentages. The method of mixing was revised, and all subsequent mixing was governed by titration of the solution in order to determine the sodium hydroxide concentration. The alcohol was added after the solution was adjusted to the desired sodium hydroxide concentration. The investigation revealed that, following the immersion period, “air drying" the material had an effect upon the behavior of the sample during the second immersion period. It was seen that the disintegration of more resistant materials could be facilitated by employing such a period for drying the material before a second immersion period. A cost study revealed that application of the proposed method for removal of calcium sulfate deposits from treatment facilities is economically sound and that the cost of application of the method is very small compared to the cost of replacement of facilities. / Master of Science

No description available.

Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2022 / Calcium and magnesium are two dominant species that contribute to water hardness. The aim of this study was to develop a poly (vinylidene fluoride-co hexafluoropropylene) (PVDF-HFP) composite membrane for treatment of water hardness. The synthesis of PVDF-HFP composite membranes was confirmed by X ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The concentrations of the hardness causing agents in both the simulated and real hard water samples were investigated in batch studies wherein parameters such as pH, contact time, temperature, and adsorbent were optimised. The maximum adsorption efficiency of 56 and 45 mg/g (evaluated by Langmuir isotherm) for Ca(II) and Mg(II) ions were obtained. These were achieved at an optimum pH of 7 and adsorption dosage of 0.5 mg/L using the 3% PVDF-HFP/cellulose acetate (CA) and 1% nitrogen doped multiwalled carbon nanotubes (N-MWCNTs)/CA composite membranes respectively. The adsorption kinetics and isotherm models were all consistent with the pseudo-second order and Freundlich isotherm models for all the membranes suggesting that the sorption process met heterogeneous adsorption. Furthermore, the thermodynamic parameters indicated that the adsorption is physical and endothermic in nature. Reusability studies showed that all the PVDF-HFP based membranes can be recycled at least 3 times and for Ca(II) ions an adsorption loss of only 0.35 % was recorded while using a 3% PVDF-HFP/CA composite membrane. These results were further confirmed by XRD, TGA and inductively coupled plasma mass (ICP-MS) spectrometry. Thus, the findings from this study have shown that the PVDF-HFP based membranes could provide valuable material for hardness removal to acceptable level.

The Honey Sweet carrots were canned with Ethyienediamine tetracetic acid (CaNa 2 EDTA) and Sodium hexametaphosphate (Ha-HMP) at five different water hardness (0 , 20, 40, 80, 160 ppm of calcium and 20 of magnesium) , then stored at temperatures of 70 and 100 F. Evaluations were made at sixty-day i intervals for six months. Firmness and color degradation decreased significantly when water hardness or storage time increased. Under storage at 100 F and 0 hardness of water, the decrease of color and firmness was constantly accelerated. When hard water (above 80 ppm or below 40 ppm) was used for canning Van sweet cherries and Large Early Montgament apricots, the firmness , volatile reducing substances, and pH decreased. Sensory acceptability was maximum at 40 and 80 ppm. However, when either CaNa 2 EDTA or Na-HMP was used at the 500 ppm, it was found that they counteracted the effects of hard water and the quality of canned sweet cherries and apricots improved, when compared with control.

The survival and physiology of rainbow trout in alkaline waters was the focus of this thesis. It is known that salmonids have problems with ammonia excretion in alkaline water (Cameron and Heisler, 1983; Wright and Wood, 1985). The first set of studies attempted to increase the survival rates of rainbow trout planted into alkaline lakes by acclimating them to the alkaline conditions before their release. The first field study acclimated rainbow trout to alkaline waters by acidifying the lake water with C0₂ in order to reduce the magnitude of the pH change experienced by the fish. The second field study acclimated rainbow trout to alkaline waters by increasing the alkalinity of the hatchery water in which the fish were held, over a six day period. In both studies the acclimated fish experienced higher survival rates relative to non-acclimated fish. Plasma sodium concentrations ([Na⁺]p1) of the fish were shown to increase, while plasma chloride concentrations decreased. These changes were attributed to an increase in the exchange of external Na⁺ with endogenous H⁺, and the decrease in the exchange of endogenous HC0₃⁻ with external Cl⁻, respectively. The increased [Na⁺]pl may have also been the result of the exchange of plasma ammonium (NH₄⁺) with external Na⁺. The second set of studies investigated the physiological response of rainbow trout to alkaline waters. The first study, the chronic exposure of rainbow trout to alkaline water, showed that trout in hard alkaline water experienced higher survival rates and regulated plasma ammonia and ion concentrations more competently than trout in soft alkaline water. This increased ability to regulate plasma ammonia and ion concentrations was attributed to the possible "reactivation" of the Na⁺/NH₄⁺ exchange. The purpose of the second study, the acute exposure of rainbow trout to alkaline water, was to further investigate the mechanisms that enable fish in hard alkaline water to survive better than fish in soft alkaline water. The possible activity of the Na⁺/NH₄⁺ exchange was again observed in the hard alkaline water. The addition of amiloride to the alkaline hard treatment water increased plasma total ammonia and stabilized [Na⁺]pl′, which supported the "reactivation" of the Na⁺/NH₄⁺ exchange in hard alkaline water. As a result of these studies, the acclimation of rainbow trout to hard alkaline water before being planted into any alkaline body of water was recommended. / Land and Food Systems, Faculty of / Graduate

No description available.

No description available.

Calcium carbonate precipitation and formation of clog particles inside the leachate collection pipe can cause catastrophic failures in landfill operation. This study focuses on quantifying the effectiveness of electronic scale control to reduce the clog formation within the pipe network. A field scale model (40ft × 20ft) was constructed, featuring side-by-side flow of electronically treated and untreated composite leachate. Data obtained in the first phase of this study indicate that electronic scale control system does not have any statistically significant effect on water quality parameters. The second phase of this study identified calcite (CaCO3) to be the predominant phase present in the precipitates using XRD/XRF diffraction pattern analyzed through a search match calculation program (MATCH! Version 3.2.0) which concur with the previous studies. Furthermore, Rietveld refinement using FullProf Suite confirms that there were no differences between the treated and untreated precipitate based on the phases identified in the respective samples. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Conselho Nacional de Desenvolvimento Científico e Tecnológico / In the first study examined ammonia, urea, creatinine, protein, nitrite, nitrate, and phosphorus (P) excretion at different water hardness, humic acid or pH levels in silver catfish (Rhamdia quelen) juveniles. The fish were exposed to different levels of water hardness (4, 24, 50, or 100 mg CaCO3 L-1), humic acid (0, 2.5 or 5.0 mg L-1) or pH (5.0, 6.0, 7.0, 8.0, or 9.0) for 10 days. The overall measured nitrogen excretions were 88.1% (244 423 μmol kg-1 h-1) for ammonia, 10.9% (30 52 μmol kg-1 h-1) for creatinine, 0.02% (0.05 0.08 μmol kg-1 h-1) for protein, 0.001% (0.002 0.004 μmol kg-1 h-1) for urea, 0.5% (0.64 3.6 μmol kg-1 h-1) for nitrite, and 0.5% (0.0 6.9 μmol kg-1 h-1) for nitrate, and these proportions were not affected by water hardness or humic acid levels. The overall P excretion in R. quelen was 0.14 2.97 μmol kg-1 h-1. Ammonia excretion in R. quelen usually was significantly higher in the first 12 h after feeding, and no clear effect of water hardness, humic acid levels and pH on this daily pattern of ammonia excretion could be observed. Water hardness only affected the ammonia and P excretion of R. quelen juveniles in the initial and fifth days after transfer, respectively. The exposure of this species to humic acid decreased ammonia excretion after 10 days of exposure but did not affect P excretion. An increase in pH decreased ammonia and increased creatinine excretion but did not change P excretion in R. quelen. Therefore, when there is any change on humic acid levels or pH in the culture of this species nitrogenous compounds must be monitored because their excretion rates are variable. On the other hand, P excretion rates determined in the present study are applicable to a wide range of fish culture conditions. The aim of the second study was to determine the preferred pH in silver catfish Rhamdia quelen acclimated to different water hardness and the effect of shelters and infection by Ichthyophthirius multifiliis. Fish were acclimated for two weeks at different water hardness levels (4, 24, 50, or 100 mg CaCO3 L-1) and then transferred to a polyethylene tube with a pH gradient ranging from 3.5 to 11.7. The position of the fish in the pH gradient was observed at 1, 2, 4, 6, 8, 10, and 12 h after transference. Acclimation to different water hardness did not change pH preference of uninfected silver catfish (pH 7.30-7.83), and the presence of a shelter at the preferred pH or outside this preferred pH did not change the chosen pH range, either. Consequently silver catfish favored the acid-base regulation over shelter seeking tendency. Juveniles infected with I. multifiliis acclimated to water hardness of 24 mg CaCO3 L-1 preferred alkaline pH (9.08-9.79). This choice is not explained by the higher Na+ levels at alkaline pH compared to neutral pH because infected and uninfected fish choose the same waterborne Na+ levels in a Na+ gradient with the same pH. / No primeiro estudo analisou-se a excreção de amônia, ureia, creatinina, proteína, nitrito, nitrato e fósforo (P) em diferentes níveis de dureza da água, ácido húmico ou pH em juvenis de jundiás (Rhamdia quelen). Os peixes foram submetidos a diferentes níveis de dureza da água (4, 24, 50 ou 100 mg CaCO3 L-1), ácido húmico (0, 2,5 ou 5,0 mg L-1) ou pH (5,0, 6,0, 7,0, 8,0 ou 9,0) durante 10 dias. A excreção nitrogenada global medida foi de 88,1% (244 423 μmol kg-1 h-1) para amônia, 10,9% (30 52 μmol kg-1 h-1) para creatinina, 0,02% (0,05 0,08 μmol kg-1 h-1) para proteína, 0,001% (0,002 0,004 μmol kg-1 h-1) para ureia, 0,5% (0,64 3,6 μmol kg-1 h-1) para nitrito e 0,5% (0,0 6,9 μmol kg-1 h-1) para nitrato, e estas proporções não foram afetadas pelos níveis de dureza da água ou ácido húmico. A excreção global de P em R. quelen foi 0,14 2,97 μmol kg-1 h-1. A excreção de amônia em R. quelen, em geral, foi significativamente maior nas primeiras 12 horas após a alimentação e nenhum efeito claro dos níveis de dureza da água, ácido húmico e do pH pode ser observado sobre este padrão diário de excreção de amônia. A dureza da água afetou apenas a excreção de amônia e de P de juvenis de R. quelen no primeiro e quinto dias após a transferência, respectivamente. A exposição desta espécie ao ácido húmico diminuiu a excreção de amônia após 10 dias de exposição, mas não afetou a excreção de P. Um aumento no pH diminuiu a excreção de amônia e aumentou a excreção de creatinina, mas não alterou a excreção de P em R. quelen. Portanto, quando houver qualquer alteração nos níveis de ácido húmico ou pH na cultura desta espécie os compostos nitrogenados devem ser monitorados, pois suas taxas de excreção são variáveis. Por outro lado, as taxas de excreção de P determinados no presente estudo são aplicáveis a uma ampla gama de condições na cultura de peixes. O objetivo do segundo estudo foi determinar o pH preferido em jundiá Rhamdia quelen aclimatados a diferentes durezas da água e o efeito de abrigos e infecção por Ichthyophthirius multifiliis. Os peixes foram aclimatados durante duas semanas em diferentes níveis de dureza da água (4, 24, 50 ou 100 mg de CaCO3 L-1) e então transferidos para um tubo de polietileno com um gradiente de pH de 3,5 a 11,7. A posição do peixe no gradiente de pH foi observada 1, 2, 4, 6, 8, 10 e 12 h após a transferência. A aclimatação a diferentes durezas da água não afetou o pH preferido de jundiás não infectados (pH 7,30-7,83) e a presença de um abrigo no pH preferido ou fora deste pH também não alterou a faixa de pH preferida. Portanto, jundiás favorecem a regulação ácido-base em detrimento a uma tendência de procurar abrigo. Em juvenis infectados com I. multifiliis aclimatados à dureza da água de 24 mg de CaCO3 L-1 o pH preferido é alcalino (9,08-9,79). Esta escolha não é explicada pelos maiores níveis de Na+ em pH alcalino que em pH neutro porque peixes infectados e não infectados escolheram os mesmos níveis de Na+ na água em um gradiente de Na+ com o mesmo pH. Palavras-chave: piscicultura, gradiente de pH, ácido húmico, dureza da água