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Lead corrosion in premise plumbing systems from materials, such as lead pipes, soldered joints, and brass, can cause elevated lead in drinking water. This work examined mechanisms by which galvanic corrosion of lead solder:copper joints is accelerated by high chloride, low sulfate, and high nitrate in the water. Galvanic corrosion studies conducted using simulated copper plumbing joints showed lowered pH and concentrated anions at the lead solder surface. A combination of low pH and high chloride can prevent passivation of the solder surface, indefinitely sustaining high corrosion rates and lead contamination of potable water supplies. The mass of lead leached to water correlated with predictions based on Faraday's law, although a portion of the oxidized lead remained attached to solder in a scale layer. When the level of sulfate in water increased relative to chloride, galvanic currents and associated lead contamination could be greatly reduced. The impact of chloride-to-sulfate mass ratio (CSMR) on lead leaching from 50:50 lead:tin solder galvanically coupled to copper was examined at the bench scale.The CSMR can be affected by coagulant changeover, use of desalinated water, anion exchange, brine leaks, and other treatment changes. Consistent with prior experiences, increasing the CSMR in the range of 0.1 to 1.0 produced dramatic increases in lead leaching from this source. Above this range, while lead leaching was generally very high, there was little correlation between lead release and CSMR. The impact of nitrate was tested at the bench scale using synthesized water. Results consistently showed that increasing nitrate in the range of 0 to 10 mg/L NO??N, could dramatically increase lead leaching from simulated soldered pipe joints. Although higher nitrate slightly increased the galvanic current, the main factor affecting lead release appears to be initiation of non-uniform corrosion, with small pieces of solder detaching into the water. Under some circumstances, the decay of chloramine after it leaves the treatment plant, and formation of nitrate via nitrification, can markedly increase corrosivity of distributed water to lead solder. The bench scale experiments conducted in this work illuminated many issues related to accelerated lead corrosion of solder. However, future research is necessary to further elucidate the mechanisms behind nitrate-accelerated corrosion, as well as methods for inhibition of corrosion due to chloride and nitrate. / Master of Science

The study of lignin with the aim of correlating data, which may lead to a greeter utilization of this wood waste product, has been the subject of investigations since 1838. Previous investigations by Othmer, Harris, Sherrard and others have indicated that chlorinated lignin had potential value as a plastic. The purpose of this investigation was to study the chlorination reaction of lignin obtained from the black liquors of the sulfate process of paper manufacture. Results of preliminary experimental work indicated that the optimum method of chlorinating lignin was by suspending or dissolving the lignin in methyl alcohol. The sulfate lignin was chlorinated in two liter wolff flask which was equipped with a motor driven stirrer, and the chlorine flow was measured by a calibrated U-tube differential gage. The flask was charged with the alcohol-lignin mixture and chlorinated from one to seven hours. The rates of chlorine flow for the tests were 0.472, 0.85 and 1.084 gm. Cl₂/min at temperatures of 25 and 65ºC. The reactant gases were passed through a condenser to return the vaporized alcohol to the reaction flask and then into a 3 normal sodium hydroxide solution to react the excess chlorine gas. Samples of the reaction gas, which were analyzed for chlorine, were collected in a 1.5 normal sodium hydroxide solution at 10 minutes intervals. With this information the progress of the reaction could be plotted and the rate of chlorination measured. The chlorination of a suspension of lignin in methyl alcohol in a ratio of l to 20 was possible at 25°C. The critical temperature above which the lignin would not stay in solution was 43°C. The reaction was exothermic and produced an orange colored product containing 25 per cent chlorine. Increasing the rate of chlorine flow from 0.85 to 1.084gm. Cl₂/min. increased the chlorine consumption from 0.74 to 0.833 gm Cl₂/min. The chlorination of lignin dissolved in methyl alcohol produced two chlorinated products. One was precipitated as an orange red powder from solution during the chlorination reaction, and had a chlorine percentage as high as 29 per cent. The other lignin remained dissolved in the alcohol solution. When precipitated from solution by ice water this chloro-lignin was a light yellow powder with a chlorine percentage as high as 28.0 per cent. Increasing the rate or chlorine flow trom 0.472 to 1.084 gm Cl₂/min. during tests at 25°C resulted in increasing the rate of chlorination from 0.454 to 0.935gm Cl₂/min. Adding ferric chloride, as a catalyst, increased the chlorine consumption from 0.768 to 0.967 gm Cl₂/min. Raising the reaction temperature from 25 to 65°C decreased the chlorine consumption trom 0.935 to 0.768 gm. Cl₂/min. The chlorinated product showed definite bonding value when mixed with sawdust and pressed at a temperature or 112°C and pressures from 1000 to 5000 lb/in². The percentage lignin in the samples was varied from 5 to 60 per cent. The lignin-sawdust samples were light yellow in color and firmly bonded and water resistant. / Master of Science

Removal of organic matter is increasingly important to drinking water utilities and consumers. Organic matter is a significant precursor in the formation of disinfection by-products (DBPs). The maximum contaminant levels for (DBPs) are decreasing and more DBPs are believed carcinogenic. Traditional coagulation focuses on the removal of particulate matter and in the last decade soluble species have also been targeted with high coagulant doses. However, colloidal matter is smaller than particulate matter and therefore not easily removed by conventional drinking water treatment. This research focused on the conversion of soluble organic matter to colloids using relatively low doses of ferric sulfate coagulant and the subsequent removal of the colloids by filtration during drinking water treatment. The goal is to achieve enhanced removal of soluble organic matter with minimal chemical costs and residual formation. This study investigated the effects of pH, iron coagulant dose, turbidity, organic matter concentration, and temperature on colloid formation. Characterization of the colloidal organic matter was attempted using zeta potential and sizing analyses. Cationic low molecular weight, nonionic high molecular weight, and cationic medium molecular weight polymers were evaluated on their removal of colloidal organic matter. Colloidal organic matter formation was affected by changes in coagulation pH, coagulant dose, and organic matter concentration, whereas turbidity and temperature did not significantly impact colloid formation. Decreased coagulation pH caused increased organic carbon removal. As coagulant dose was increased, colloid formation initially increased to maximum and subsequently rapidly decreased. Colloid formation was increased as the organic matter concentration increased. Due to low sample signal, the colloids could not be characterized using zeta potential and sizing analyses. In addition, polymers were ineffective for aggregating colloidal organic matter when used as flocculant aids. / Master of Science

Calcium sulphate was found to have a dissociation temperature some 60°-90°C. lower than the values reported by other workers. / Master of Science

A study was made cf the cost per pound of magnesium sulfate monohydrate produced by a "Krystal" crystallizer at recirculation rates from 20 to 40 gallons per minute and operating temperatures from 150 to 180 °F. From these tests, the optimum operating conditions within the range of these variables were derived. The problem was studied by operating the equipment at all sixteen combinations of these variables in unit steps of ten. The crystallizer was operated at each set of conditions, the product collected, and the cost per pound determined. The operating conditions were found to affect power and steam costs greatly, varying from 1.689 mills/lb at 50 gallons per minute and 170 °F to 0.737 mills/lb at 20 gallons per minute and 180 °F, representing a decrease. cf 0.952 mills per pound upon correct choice of operating temperature and recirculation rate. / Master of Science

Dollar spot is one of the most common diseases of warm- and cool-season turfgrass stands and is especially devastating on creeping bentgrass (Agrostis stolonifera L.). The fungus Sclerotinia homoeocarpa degrades the foliage by creating silver, dollar-sized depressions of dead and bleached turf. Frequent fungicide applications and cultural management strategies are required throughout the growing season to prevent or reduce severity of this disease. Previous research has demonstrated that ferrous sulfate applied at 48.8 kg ha-1 suppresses dollar spot epidemics without traditional fungicides. In vitro studies showed 100 to 1,000 mg kg-1 of ferrous sulfate directly suppressed S. homoeocarpa growth of an isolate collected from an established, intensively-maintained creeping bentgrass putting green. Genetic diversity of S. homoeocarpa segregates isolates into two groups; strains generally associated with warm-season and cool-season grasses. It is unknown whether isolates of each group react similarly in the presence of ferrous sulfate. Our research explored use rates of ferrous sulfate required to suppress 50% of dollar spot in the field and in vitro. Ferrous sulfate (heptahydrate 20% Fe, Valudor Products Inc) rates in field trials included 0, 4.88, 24.4, 48.8, and 97.6 kg ha-1. Our results indicate a hyperbolic relationship between ferrous sulfate rate and dollar spot reduction. Using this model, 26.4 kg ha-1 reduced dollar spot incidence by 50%. We concluded that ferrous sulfate suppresses 50% of S. homoeocarpa mycelial growth at between 480 and 720 mg L-1 concentration in 0.25 strength potato dextrose agar in vitro, and fungitoxic activity of ferrous sulfate was dependent primarily on historical fungicide inputs at isolate collection sites. The use of ferrous sulfate may supplement traditional fungicide use. Chlorothalonil is the most common fungicide used to suppress dollar spot in turfgrass. Annual site-use limitations of chlorothalonil often prevent turf managers from achieving acceptable dollar spot control throughout the season. It is not known how ferrous sulfate may contribute to a successful chlorothalonil fungicide program. Therefore, we examined whether ferrous sulfate can be used to minimize chlorothalonil requirements through reducing active ingredient concentrations and extending the longevity, while still maintaining acceptable disease control. Chlorothalonil treatments were applied at 0, 2.28, 4.57, 6.86, and 9.16 kg ai ha-1 (Daconil WeatherStik) across plots treated with and without 48.8 kg ha-1 ferrous sulfate applied bi-weekly. Ferrous sulfate reduced the chlorothalonil rates necessary for 80% disease reduction by 36 to 51% across all trials. Additional studies showed that ferrous sulfate applied with chlorothalonil increased duration of disease control by five days and eliminated two seasonal treatments. Our research expands the guidelines for practical ferrous sulfate usage for dollar spot suppression by elucidating the rate-to-disease relationship and providing best management practices involving admixtures with chlorothalonil. / Master of Science / Turfgrass systems offer many environmental and recreational benefits. Managing turfgrass stands that are free of damaging turf pests is essential to providing aesthetically pleasing lawns, golf courses, and sports fields. Creeping bentgrass is one of the most common turfgrass types found on golf course putting greens but is also used on golf course fairways and tee boxes. There are many diseases that can be found on creeping bentgrass when environmental conditions are favorable. Of these diseases, dollar spot is the most common. When dollar spot is present, half-dollar sized spots of bleached turf can be seen. In order to prevent these easily noticeable spots from appearing, fungicide applications are required in a given growing season to prevent the pathogen from infecting. Available fungicides are very effective at providing control but can be very costly. Beyond fungicide use, other research has shown various cultural practices to reduce disease incidence. Previous research has shown that iron sulfate applied to creeping bentgrass can reduce dollar spot epidemics without the use of fungicides. Laboratory studies have shown a similar trend as ferrous sulfate at varying concentrations directly suppressed dollar spot pathogen growth. In both cases, a limited range of ferrous sulfate rates was tested. To obtain more information we explored use rates of ferrous sulfate required to suppress 50% of dollar spot in the field and in vitro. Ferrous sulfate rates in field trials ranged from 0 to 97.6 kg ha⁻¹ . Results from these trials were used to create a hyperbolic regression. Using this model, we were then able to determine that 26.4 kg ha⁻¹ iron sulfate was required to suppress 50% of the dollar spot in the field. For the laboratory studies we concluded that ferrous sulfate suppresses 50% of the dollar spot pathogen mycelial growth between 480 and 720 mg L ⁻¹ iron sulfate concentrated potato dextrose agar. Although there are many different fungicides available for dollar spot control, the active ingredient chlorothalonil is the most common used. Due to the mode of action which chlorothalonil exhibits, it is much less likely that the pathogen causing dollar spot can become resistant. Although resistance is not an issue, governmental annual site-use limitations restrict turf managers from achieving desirable control. The use of iron sulfate in conjunction with chlorothalonil has not been previously studied. Chlorothalonil treatments were applied at a range of labeled use rates across plots treated with and without 48.8 kg ha⁻¹ ferrous sulfate applied bi-weekly. Ferrous sulfate reduced the chlorothalonil rates necessary for disease reduction. If a threshold of 80% is used, up to 50% reduction in chlorothalonil use was observed. Supplemental studies investigating the duration of control achieved by the combination showed an increase of up to 5 days and eliminated the need for two applications across one season. This research fills a huge gap in our knowledge base on the practical use of iron sulfate for dollar spot control.

Two soils from the Fernow Experimental Forest near Parsons, West Virginia were characterized and evaluated in terms of their susceptibility to enhanced soil acidification via acidic atmospheric inputs. After initial physical, chemical, and mineralogical characterization, the soils were analyzed for their ability to adsorb and retain sulfate (SO₄²⁻) through a series of batch adsorption and desorption experiments. Reconstructed soil profiles were then subjected to water leaching as the preliminary step to a base release study in which each soil will be placed under simulated acid rain and evaluated for base cation release and subsequent changes in soil chemistry. Experiments with SO₄²⁻ adsorption and desorption divide the soils into two categories: (i) shallow surface horizons with high organic matter and little Fe oxide content which had little ability to adsorb additional SO₄²⁻ and low capacity to retain SO₄²⁻; and (ii) deeper subsurface soils with low organic matter and high Fe oxide content which could adsorb SO₄²⁻ at solution concentrations above 0.5 mmol/L. All soil horizons desorbed SO₄²⁻ and had no ability for additional adsorption at solution concentrations below 0.5 mmol/L, which implies that the site may be saturated with respect to natural conditions. Initial mass (IM) and Langmiur modeling were used to illustrate SO₄²⁻ dynamics and make correlations with soil physical, chemical, and mineralogical properties. Fe oxides and Al-saturated organic matter were shown to be the preferential sites for SO₄²⁻ adsorption but may be already saturated or very near saturation. Preliminary results from the base release study indicate that the two soils are dominated by different chemical processes and hence release ions into soil solution at different rates. Ion release is shown to be a function of both reactions on the exchange complex and the dissolution of mineral components. / Master of Science

From a study of the 25℃ isotherm the following factors are evident: Two hydrates of zinc sulphate exist at this temperature, the heptahydrate and the monohydrate. The transition point between the ZnSO₄·7H₂O and ZnSO₄·H₂O is given as 22.25% sulphuric acid and 22.81% zinc sulphate. The transition point between the ZnSO₄·H₂O and anhydrous ZnSO₄ is given as 88.08% sulphuric acid and .22% zinc sulphate. The solubility of the zinc sulphate in the sulphuric acid shows a marked decrease at 46% to 48% sulphuric acid is very low in the 97.25% sulphuric acid having only .03% zinc sulphate. There was no evidence of an acid salt of zinc sulphate being formed at this temperature. / M.S.