Five diagrams in pocket.

Submitted in fulfillment of the academic requirements of the degree of Master of Applied Sciences in Chemistry, Durban University of Technology, Chemistry Department, Durban, South Africa, 2016. / Cellulose is a sustainable, abundant biopolymer derived from a variety of living species such as plants, animals, bacteria and some amoebas. An attractive source of cellulose for industrial uses is agricultural waste, as this use does not jeopardize food supplies and improves the local rural economy. Sugarcane bagasse (SCB) is one of the main biomass wastes from sugar production and represents 30–40 wt % of sugar production waste. In 2008, South Africa produced on average 22 million tons of sugar cane each season from 14 sugar mill supply areas which resulted in 7,9 million tons of “waste” bagasse. In this study cellulose nanocrystals were prepared from soda pulped sugarcane bagasse by acid hydrolysis followed by separation using centrifugation, ultrasonication and dialysis. Transmission Electron Microscopy (TEM) images showed nanocrystals of approximately 300 nm in length and 20 nm in width. Thermogravimetric Analysis and Differential Thermogravimetry (TGA and DTG) profiles of FD CNC, MCC and Pulped bagasse all had characteristic onset and decomposition temperatures indicating a change in the structure after chemical treatments. Particle size distribution measurements corroborated with the TEM and FE - SEM results and showed that the majority of the nanocrystals were in the 100 – 300 nm range. Attenuated Total Reflectance – Fourier Transform Infra Red (ATR - FTIR) analysis showed functional group changes as the amorphous regions of the polymer were removed revealing the ordered crystalline portions. These were further confirmed by an increase in the Lateral Orientation Index (LOI) of the samples as the nanocrystals were isolated. X - Ray Diffraction (XRD) Crystallinity Index (CrI) calculations showed a steady increase in the crystallinity of the materials from pulped bagasse to MCC to FD CNC. / M

O objetivo desse experimento foi avaliar a inclusão (7 e 15% com base em MS), de 2 co-produtos, derivados da indústria de ácido cítrico: Micélio (77% de FDN e 0,5% de lignina com base em MS) e Raffinate (25,5% de açúcares solúveis e 32% de fibra solúvel com base em MS) em dietas com alto teores de milho do tipo Flint para 200 tourinhos Nelore em terminação (peso inicial = 396,4 ± 37,7kg). Os animais foram blocados com base no peso inicial e foram distribuídos aleatoriamente em 25 baias. A dieta controle conteve 11,73% de bagaço de cana de açúcar, 67,2% de milho moído, 18% de farelo proteinoso de milho, 2,07% de suplemento mineral e 1% de ureia. Os outros 4 tratamentos foram: Micélio 7, Micélio 15, Raffinate 7 e Raffinate 15. Os co-produtos substituíram parcialmente o milho nas dietas. Os parâmetros avaliados foram ingestão de matéria seca (IMS), ganho médio diário (GMD), eficiência alimentar (GMD/IMS) e características de carcaça. Os dados foram analisados pelo PROC MIXED do SAS e as médias foram comparadas por contrastes, considerando blocos como efeito aleatório e tratamento como efeito fixo. A inclusão de 7 e 15% de Micélio na dieta (base seca) em substituição parcial ao milho \"flint\" moído aumentou (P=0,1) de forma quadrática o CMS. Já os animais alimentados com dietas contendo Raffinate apresentaram aumento linear no CMS (P<0,1) em relação ao tratamento controle e também maior CMS quando comparados com os animais que receberam o tratamento Micélio (P<0,1). Não houve diferença na eficiência alimentar (GPD/CMS) entre os tratamentos (P > 0,1). A inclusão de ambos co-produtos (Micélio ou Rafinatte) resultou em aumento no GDP dos animais (P< 0,1). O efeito positivo foi quadrático (P<0,1) para a inclusão de Micélio e linear (P<0,1) para a inclusão de Raffinate. A densidade energética das dietas não foi alterada pela inclusão de co-produtos. Não houve efeito de tratamento (P> 0.01) para as características de carcaça. Os valores médios para rendimento de carcaça (%), espessura de gordura subcutânea (mm) e áreas de olho de lombo (cm2) foram 53,79, 2,84 e 64,08 respectivamente. A inclusão de 7% de Micélio ou de 15% de Raffinate melhora o GPD dos animais em virtude do maior CMS. Micélio, Rafinate e milho \"flint\" moído têm o mesmo valor energético para bovinos em Terminação. / The objective of this experiment was to evaluate the inclusion (7 and 15%, DM basis) of two corn by-products derived from the citric acid industry: Micelio (77% NDF, 0.5% lignin, DM basis) and Raffinate (25.5% soluble sugars, 32% soluble fiber, DM basis) in diets with high levels of flint corn fed to 200 finishing Nellore bulls (initial BW = 396.4 ± 37.7 kg). Animals were blocked according to initial BW and randomly allocated to 25 pens. The control diet contained 11.73% sugarcane bagasse, 67.2% corn, 18% corn gluten feed, 2.07% mineral supplement and 1% urea. The other four treatments were Micelio 7, Micelio 15, Raffinate 7 and Raffinate15. The by-products partially replaced corn in the diets. The parameters evaluated were dry matter intake (DMI), average daily gain (ADG), feed efficiency (ADG/DMI) and carcass traits. The data were analyzed using PROC MIXED of SAS and means were compared by contrasts, considering the block as random effect and treatment as fixed effect. The inclusion of 7 and 15% of Micelio in the diet (dry basis) in partial replacement of ground corn increased (P = 0.1) DMI quadratically. The animals fed diets containing Raffinate showed linear increase in DMI (P <0.1) compared to the control treatment and DMI was, also higher when compared with animals that received the Micelio treatment (P <0.1). There were no differences in feed efficiency (ADG / DMI) among treatments (P> 0.1). The inclusion of both by-products (Micelio or Rafinatte) resulted in an increase in ADG animals (P <0.1). The positive effect is quadratic (P <0.1) for adding Micelio and linear (P <0.1) for adding Raffinate. The energy density of the diet was not altered by the inclusion of by-products. There was no treatment effect (P> 0.01) for carcass traits Average values for dressing (%), back fat thickness (mm) and rib eye area (cm2) were 53.79, 2.84, and 64.08, respectively. The inclusion of 7 or 15% of Micelio or Raffinate in partial replacement of ground flint corn in finishing diets does not affect cattle performance. The inclusion of 7% of Micelio or a 15% Raffinate improved ADG of animals because of the increased DMI. Micelio, Raffinate and ground corn have the same energy value for cattle finishing.

Disinfectants such as chlorine are used in drinking water treatment to protect the public health from pathogenic microorganisms. However, disinfectants also react with humic material present in raw water sources and produce by-products, such as trihalomethanes. Total trihalomethanes (TTHMs) include four compounds: chloroform, bromodichloromethane, dibromochloromethane and bromoform. TTHMs are carcinogenic and have been found to cause adverse pregnancy outcomes. Therefore, the United States Environmental Protection Agency (U.S. EPA) has set the maximum contaminant limit for TTHMs at 80 ìg/L. Additional regulations require reliable drinking water disinfection for resistant pathogens and treatment plants must simultaneously control TTHMs and achieve proper disinfection. Research has shown that THM formation depends on several factors. THM concentrations increase with increasing residence time, increased temperature and increased pH. The disinfectant type and concentration is also significant: THM concentrations can be minimized by using lower disinfectant doses or alternative disinfectants to chlorine such as chloramines. Chloramines are formed by the addition of both chlorine and ammonia. The Worcester Water Filtration Plant in Holden, MA currently uses both ozone and chlorine for primary disinfection. Chlorine is also used for secondary disinfection. This study analyzed the effect of using chloramines versus free chlorine on TTHM production at the plant. Water samples were collected from the plant, dosed with chlorine/chloramines and stored for their designated residence times. The residual chlorine was then quenched with sodium thiosulfate and the samples were analyzed for TTHM concentration using a GC-MS. Experiments were conducted in December of 2001, April of 2002 and February of 2003, and examined varying residence times, pH conditions, temperatures, chlorine to nitrogen ratios and free chlorine reaction periods. The study found that as the pH increased the TTHMs increased. For the free chlorine samples, as residence time increased, the TTHMs increased. For the chloramination samples it was found that most of the TTHMs were formed in the first six hour reaction period with free chlorine before ammonia was added. Therefore, reducing this free chlorine contact period to 0 or 3 hours would reduce THM formation further. Chlorine to nitrogen ratios between 3:1 and 7:1 were all effective at reducing THM concentrations. Using chloramination at a 3:1 ratio (with a 6 hour free chlorine time) reduced THM formation by approximately 38% for a 54 hour residence time compared to using free chlorine.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Vita. / Digitized by Kansas Correctional Industries

Combustion properties of kraft black liquor solids were studied using a laminar entrained flow reactor. The tendency of black liquors to release fume (compounds containing Na⁺, K⁺, Cl⁻, SO₄²⁻, SO₃²⁻, S₂0₃²⁻ and C0₃²⁻) during combustion were observed at 1000°C. Black liquor solids with a size fraction of 63 to 100 μm were burned in a mixture of 4% 0₂ and 96% N₂ at a residence time of 0.67 seconds. Combustion properties of one black liquor (liquor #3) were studied by varying the solids feed rate from 0.47 to 1.08 g/min (liquor feed rate study). Combustion properties of five North American and Finnish black liquors were studied at a target solids feed rate of 0.73 g/min (liquor to liquor study). Black liquor fuming was observed to be a decreasing function of solids feed rate and an increasing function of excess oxygen. The appearance of char residues varied from black and porous at high solids feed rates to white and dense at low solids feed rates. Combustion may have been enhanced at low solids feed rates by liquor swelling due to a combination of heat and mass transfer effects and limited at high solids feed rates by inter-particle and bulk gas mass transfer limitations. For the liquor to liquor study, black liquors were observed to release fume differently. Chars produced during this study varied in appearance, indicating that the black liquors had unique combustion properties. Variations in temperature and mass transfer effects resulting from liquor swelling properties were likely responsible for the variability in liquor fuming behavior. The liquors that contained the most NaCl and had the highest anionic equivalents as C0₃²⁻ (or other chemical species) produced the most fume. Sodium vaporization varied from 25.2% to 33.7%: Liquors #2 and #5 vaporized the most sodium and also had the lowest concentrations of measured anions in their char residues. Potassium and chloride enrichment factors for the five liquors were slightly lower than those of common industrial boilers. Liquor #3 had a concentration of Cl⁻ that was (roughly) an order of magnitude higher than the other liquors studied; however, it also had the lowest chloride enrichment factor. / Graduation date: 2002

Graduation date: 1997

Four experiments were conducted to evaluate guar meal as a source of prebiotic galactomannans for laying hens. In the 1st experiment, late phase laying hens were fed diets with 0, 5, 10% guar meal (GM) for 56 days or 15% GM for 28 days then switched to the 0% GM diet for the final 28 days. In the 2nd experiment, young pullets were fed guar germ (GG) or GM at 0, 2.5 or 5% for 20 weeks. In the 1st and 2nd experiments, egg production and feed consumption were not affected by feeding up to 5% guar by-products whereas feed efficiency was decreased by guar feeding. Feeding of GG or GM did not affect egg weight or shell quality, but decreased the egg yolk color and Haugh units. Guar increased absolute and relative liver weight, but did not affect the weights of the pancreas, spleen, or the incidence of fatty liver or liver hemorrhage. Feeding 10% GM depressed feed consumption and increased body weight loss. Feeding 15% GM severely depressed egg production followed by a recovery of production after returning to 0% GM feeding. In the 3rd and 4th experiments, late phase laying hens were induced to molt by feed withdrawal (FW) or feeding 15 or 20% GM with or without β-mannanase (Hemicell??). All hens except those fed 15% GM with enzyme obtained a complete cessation of lay in 10 days. Compared to FW birds, hens fed GM had lower body weight reduction and mortality, while hens fed 20% GM with enzyme had higher post-molt egg production. Salmonella enteritidis (SE) present in 6 organs (crop, liver, spleen, ovary, oviduct and cecum), and SE in cecal contents were significantly reduced by 20% GM feeding with and without enzyme. The results showed that GG or GM can be safely fed to laying hens up to 5% without adverse effects on performance. An alternative molting method employing 20% GM with or without β-mannanase is preferable to FW because GM feeding results in a complete molt and decreases mortality, as well as enhances the resistance to SE of molted hens.

Four experiments were conducted to evaluate guar meal as a source of prebiotic galactomannans for laying hens. In the 1st experiment, late phase laying hens were fed diets with 0, 5, 10% guar meal (GM) for 56 days or 15% GM for 28 days then switched to the 0% GM diet for the final 28 days. In the 2nd experiment, young pullets were fed guar germ (GG) or GM at 0, 2.5 or 5% for 20 weeks. In the 1st and 2nd experiments, egg production and feed consumption were not affected by feeding up to 5% guar by-products whereas feed efficiency was decreased by guar feeding. Feeding of GG or GM did not affect egg weight or shell quality, but decreased the egg yolk color and Haugh units. Guar increased absolute and relative liver weight, but did not affect the weights of the pancreas, spleen, or the incidence of fatty liver or liver hemorrhage. Feeding 10% GM depressed feed consumption and increased body weight loss. Feeding 15% GM severely depressed egg production followed by a recovery of production after returning to 0% GM feeding. In the 3rd and 4th experiments, late phase laying hens were induced to molt by feed withdrawal (FW) or feeding 15 or 20% GM with or without &#946;-mannanase (Hemicell??). All hens except those fed 15% GM with enzyme obtained a complete cessation of lay in 10 days. Compared to FW birds, hens fed GM had lower body weight reduction and mortality, while hens fed 20% GM with enzyme had higher post-molt egg production. Salmonella enteritidis (SE) present in 6 organs (crop, liver, spleen, ovary, oviduct and cecum), and SE in cecal contents were significantly reduced by 20% GM feeding with and without enzyme. The results showed that GG or GM can be safely fed to laying hens up to 5% without adverse effects on performance. An alternative molting method employing 20% GM with or without &#946;-mannanase is preferable to FW because GM feeding results in a complete molt and decreases mortality, as well as enhances the resistance to SE of molted hens.