Issues of Disinfection By-Product (DBP) formation in response to chlorination in drinking water treatment systems is a common issue encountered by WTP operators. Efforts to minimize DBP formation are complicated by the presence of zebra mussels, which may inhabit the raw water intake of WTPs. While chlorination at the intake to control zebra mussel populations is effective, the formation of DBPs is exacerbated. Methods for reducing DBPs are explored, including adjusting the location for chlorine additions in the treatment sequence. Multivariate models for Total Trihalomethane (TTHM) and Haloacetic Acid (HAA) subspecies are employed to show that in some instances pre-chlorination can be reduced to lower DBP formation, while post-chlorination can be increased. A Regression model (R2 of 0.75) predicts that DBP levels can be lowered by post-chlorination rather than pre-chlorinating raw water for portions of the year except during the combatable life stage to assist in zebra mussel control. A second multivariate regression model for TTHM (R2 = 0.91) which includes bromide, a variable which, due to lack of data, was previously unused, is described and demonstrates that DBP levels can be reduced by lowering pre-chlorination levels. Finally, a Bayesian network is developed using the Webweavr-IV Toolkit, utilizing causal relationships between raw water quality parameters in the form of conditional probabilities. The results show that the average cancer risk can be decreased by while still maintaining zebra mussel control and simultaneously decreasing the incremental cancer risk, which currently fluctuates between 1 in 50,000 to 100,000 in Ontario. / Canada Research Chair Program, Ontario Research Foundation

Natural organic matter (NOM) is present in all surface waters as a result of decaying vegetation, biological activity, and organic soil. Alternative NOM removal processes such as anion exchange resins (AERs) have shown NOM removals typically ranging between 50 to 90%, with up to 99% removal achieved in some cases. The first portion of this study evaluated the performance of two AERs; a conventional Type 1 AER and magnetic ion exchange resin (i.e. MIEX®) for NOM removal from surface water quantified by UV254, dissolved organic carbon (DOC), and specific UV absorbance (SUVA). Samples were also characterized for chloride, sulphate, and chloride-to-sulphate mass ratio (CSMR) to provide additional information on water quality characteristics of AER treated waters. Overall, the results showed that both AERS were effective for removing NOM. However, the MIEX® resin provided greater removal of NOM with shorter contact times compared to the conventional resin investigated. Water treated with MIEX® resin showed significantly higher chloride and lower sulphate concentrations than the conventional AER. Higher CSMR values were found with MIEX® treated water compared to conventional AER system, although both resins showed CSMR much greater than 0.5, which can increase galvanic corrosion effects with lead. Bench-scale jar tests were conducted to investigate the impact of temperature on the efficacy of three NOM removal treatment technologies; enhanced coagulation with alum, MIEX® and a combined MIEX® treatment followed by coagulation with a low dose of alum. Higher settled water turbidity was observed during cold water operating conditions for all three processes. At cold-water operating conditions, DOC removal was reduced with combined MIEX® -Alum treatment, and UV254 removal was impacted for both MIEX® and MIEX® -Alum processes. The combined MIEX®-Alum process was found to provide the lowest THMFP and HAAFP at both temperatures to concentrations lower than current regulatory maximum acceptable concentration (MAC) guidelines in Canada. Surface charge analysis experiments were performed at bench-scale using synthetic water containing humic acid to determine the relationship between NOM and the charge of AER-treated waters. Further bench and pilot-scale studies were performed to investigate the use of surface charge measurements to monitor and optimize NOM removal during treatment with AER systems. Strong correlations were observed between UV254 and respective charge measurements (i.e. ZP, SC) of AER-treated synthetic and raw waters. The results of this research has shown that it is possible to use charge to optimize the MIEX® process for NOM removal. Additionally, it was found that SC measurements could be used as an operational tool for AER processes, where deviations in SC from optimum treatment would indicate the requirement for fresh resin addition or resin regeneration.

No description available.

The sugar refinery process used by Lantic Sugar Ltd generates three by-products having characteristics that give them potential as soil amendments or fertilizers, particularly as a phosphorous and calcium source. Laboratory and a field trials were conducted in order to examine the changes in agronomic properties of soil produced by the application of these residues. / During the laboratory experiment, the by-products examined were spend bone char (SBC), filter-press mud (FPM), clarification scum (SCU) and a compost (COM) produced using FPM and SCU, where as in a field experiment, COM, SBC and a mixture (MIX) made of FPM and SCU, were compared to a commercial fertilizer (TSP) and non-treated soils. / The orthic humic gleysol of clay texture and low pH soil conditions in which the field experiment was conducted resulted in high P fixation of all the applied residues. Contrasts analysis showed that TSP behaved as the soils unamended P for all nutrient concentrations in tissues over two cropping seasons (1993 and 1994), on two crops, namely wheat (Triticum aestivum, L.) and corn (Zea mays, L.). Treatments (residues at different rates of application) did not significantly increase the Ca levels in COM plots nor did they increase the wet aggregate stability of soil under either crop. (Abstract shortened by UMI.)

A compost consisting 95% of the sugar mill byproducts: bagasse, filter press mud, and fly ash, applied at 5 t ha$ sp{-1}$, increased vesicular-arbuscular mycorrhizal infection of sugarcane roots in one of three experimental fields in Barbados. In a plant cane field, compost stimulated formation of intracellular hyphal coils and arbuscules, but not vesicles or hyphae. Infection was greater in roots 35 cm and 65 cm than 5 cm distant from the plant stem, and compost effects were not significant at 5 cm. Two other sources of phosphorus, filter press mud and triple superphosphate, did not affect and suppressed mycorrhizal infection, respectively. Two ratoon crops showed no residual effect of compost on mycorrhizal infection. Compost also stimulated tillering, phosphorus content, and perhaps yield of cane, but did not differentially effect high versus low tillering or sloped versus flat areas. Root length, weight, and specific root length were unaffected by compost addition, but root branching was decreased.

Fertilizer P fixation and fertilizer N losses in soils may be reduced through additions of polyphenolic compounds. The influence of ammonium lignosulfonate (NH$ sb4 sp+$-LS) on triple superphosphate (TSP) efficiency was investigated in a soil incubation study using three Quebec soils and in a growth bench study using one soil. For the incubation study, soils were analyzed for pH and P extractability, as a function of NH$ sb4 sp+$-LS rate and time. In the growth bench study, TSP and NH$ sb4 sp+$-LS were applied at varying rates and corn (Zea mays L.) dry matter yields and nutrient compositions analyzed. Similar studies were conducted in subsequent growth bench studies, to evaluate combinations of NH$ sb4 sp+$-LS, diammonium phosphate (DAP), and urea on two soils. / Ammonium LS increased soluble P levels when applied with TSP. The effect was most significant in fine textured soils, and increased with time. This improved P availability to plants, without affecting growth. The optimum NH$ sb4 sp+$-LS:P$ sb2$O$ sb5$ application ratio was approximately 2.8:1. Ammonium LS did not improve availability of DAP-P in either of the subsequent experiments, nor did it improve urea fertilizer efficiency. Some NH$ sb4 sp+$-LS-urea-DAP formulations did, however, improve corn growth beyond that obtained when only urea and DAP were applied in combination. In nutrient amended soils, applying NH$ sb4 sp+$-LS DAP was detrimental to growth and, for some application rates, reduced nutrient uptake.

In the current era, oil deficit countries around the world seriously consider shifting dependence from conventional gasoline to renewable bio-ethanol fuel in the transport industry. Arguably, blending l0vol% dry ethanol with 90vol% unleaded gasoline enables ethanol fuel to penetrate the fuel market at relatively lower development costs. Despite creating an important market for the ethanol industry, fuels containing dry ethanol of differential proportions multiply the local risks associated with fuel combustion. Making a sale of one drop of ethanol fuel, for example, is intrinsically tied to the sale of more drops of imported gasoline. Furthermore, an increase (decrease) in conventional fuel prices directly influences a decline (increase) in daily sales of ethanol fuel. Blending bio-ethanol fuel with conventional gasoline in various proportions fails to address the multifaceted fossil fuel crisis in oil deficit countries. Although reducing bio-ethanol production costs can buffer fuel prices to a significant degree when blended in higher ratios, industrial competition for bio-feedstock is a serious limitation for bio-ethanol development in all parts of the globe. Nevertheless, advances in biotechnology may allow the use of a wide range of cheaper ethanol feedstocks (e.g. lignocellulose) leading to an important reduction in ethanol production costs. Temporal and spatial variability of lignocellulosic ethanol potentials in the sugar industry is investigated over southern Africa as a whole. The influence of extremely low (high) production of sugar cane on the potentials development of lignocellulosic ethanol plants is demonstrated in this work. Characterization of bioethanol fuel markets on the basis of blending with gasoline is undertaken at the subcontinental scale. The connectivity between development, consumption per capita, population growth, bio-ethanol energy demand, as well as the critical limits of land stock potentials is examined in this study. On the basis of the special influence that each of the processes indicated above have on bio-ethanol fuel development, an integrated approach toward optimizing the total value of bio-ethanol fuel in the region is formulated. This approach allows the investigation to determine whether critical and beyond critical conditions of land stock lead to a collapse of a human consumption type or whether bio-ethanol fuel development is a totally viable process. Finally, this work ascertains whether sustainable biofuel development is an oxymoron because human development demands a constantly growing fuel consumption per capita, or because of increasing the lower limit, with an infinite upper limit for human development, or as a product of the combined effects of increasing human population with a higher consumption rate per capita of non-growing and non-developing land stock units. / Thesis (Ph.D.)-University of KwaZulu Natal, Durban, 2004.

The South African sugar industry generates excessive amounts of sugar cane bagasse (~ 25 wt% of feed) as a byproduct during the extraction of sugar juice from cane. Although bagasse is extensively consumed in various processes, a substantial amount remains unexploited. The industry's core business is the production of refined sugar which involves among others, a step of decolourising raw sugar liquor. Activated carbons are well known adsorbents and their excellent decolourisation capabilities have been established since 1800 in the sugar industry. The possibility of making suitable in-house activated carbons from sugar cane bagasse to aid the decolourisation process of raw sugar liquor is of interest to the growing South African sugar industry. The purposes of this research study were to develop an understanding on the manufacture of activated carbons from sugar cane bagasse, produce suitable activated carbons on a laboratory scale, characterize them and subsequently determine their sugar decolourisation capabilities under simulated conditions. The application of the two-step physical method of processing was found to be the most effective and feasible route to produce activated carbons from sugar cane bagasse for the purposes of decolorizing unrefined sugar. A semi-batch process was developed whereby compressed sugar cane bagasse was pyrolysed under a nitrogen atmosphere at a heating rate of 10 °C/min to the final pyrolysis temperature for a desired hold time resulting in bagasse chars with a rudimentary pore structure. These bagasse chars were subsequently subjected to partial and controlled gasification with a steam/nitrogen mixture at higher temperatures to produce the final activated carbon product. Both pyrolysis and activation were carried out in a pyrolysis furnace that was modified to represent a fixed bed reactor system. The process was designed such that it included a steam supply and a gas cleaning system. Feasible processing conditions were established by varymg the temperature, hold time and partial pressure of steam in the pyrolysis furnace. The bagasse chars and final activated carbons were characterized with respect to surface area, pore volume, pore size distribution, methylene blue number, iodine number and molasses number. The optimum pyrolysis conditions were found to be at heating rate of 10°C/min to the final pyrolysis temperature of 680 °C for a hold time of 1 hour, which gave rise to microporous carbons. Increasing the steam partial pressure and activation temperature during activation of bagasse chars resulted in the gasification reaction proceeding at a much faster rate leading to well developed mesoporous activated carbons having high adsorption capacity for large colour bodies present in molasses and sugar liquor. This was achieved by activating bagasse chars at a temperature of 900°C for 2 hours with a steam / nitrogen mixture of 1:0.6 which resulted in 50% bum-off being reached. Excellent powder and granular activated carbons were produced from sugar cane bagasse fibres by the established process with the latter being mixed with refined sugar prior to pyrolysis and activating for half an hour extra. A typical final activated carbon produced in this research possessed a BET surface area of 995 m2/g, pore volume of 0.82 crrr'zg, iodine number of 994 mg/g, molasses number of 700 and methylene blue number of 256 mg/g. High ash content in the bagasse raw material tends to decrease the surface area and pore volume for adsorption of the final activated carbon. Both granular and low ash bagasse activated carbons possess high adsorption capacity to remove large colour bodies from molasses and brown liquor solutions and compare well with commercial Norit N2 carbon . Approximately 80% colour removal was achieved using 0.5 g carboni 100g brown liquor. The bagasse activated carbons were stable in acidic and basic brown liquor solution and maintained their high decolourisation potential. The ability of bagasse activated to replace commercial activated carbons has been proven in this study. The option of producing both granular and powder activated carbons provide flexibility of the sugar industry to choose between batch and continuous adsorption systems during sugar decolourisation. This research has established that the fact that excellent sugar decolourising activated carbons can be produced from South African sugar cane bagasse fibres. However, more research needs to be carried out in order for the sugar industry to take this project to the commercial stage and it is suggested that a pilot study and an economic study be carried out. / Thesis (M.Sc.)-University of Natal, Durban, 2003.

Dissolved organic carbon (DOM) is one of the largest cycled organic carbon pools on Earth and an important biogeochemical factor in aquatic systems. DOM can act as an energy source for microorganisms, alter the depth of the photic zone for photosynthesis, absorb harmful ultraviolet radiation, as well as alter the transport and toxicity of contaminants. The purpose of this research project was to characterize DOM in the Grand River watershed in Ontario, Canada using a wide range of qualitative and quantitative techniques and determine the impact of anthropogenic activities as well as seasonal and longitudinal changes on DOM processes. To reach the study objectives, historical data was analyzed to determine the seasonal cycle in the Grand River watershed. Intensive longitudinal sampling surveys were undertaken to evaluate the DOM characteristics and processes in the Grand River. Surveys of the less impacted Burnt River watershed were used as a comparison watershed to the Grand River to evaluate allochthonous and autochthonous indicators of DOM source and human impacts on DOM processes. Drinking water surveillance data was used to evaluate the effect of DOM in the Grand River on formation of disinfection by-products (DBPs). Different trends were seen in the Grand River in terms of longitudinal area and season. The headwaters of the river showed more autochthonous DOM in the spring and winter compared to the fall and summer. The lower-central river peaked in autochthonous DOM in the summer and was more allochthonous in the winter. DOM generally became more autochthonous downstream in the Grand River and was most autochthonous below the large sewage treatment plants (STPs) in the central portion. Protein content, measured as protein-like fluorescence normalized to DOC concentration, was strongly related to ??15N of DON; both are associated with autochthonous DOM in the Grand River and show the effects of the major STPs. The increase in autochthonous DOM below the STPs is likely associated with nutrient enrichment stimulating primary production and macrophyte growth. Based on the comparison of the Burnt River with the more impacted Grand River, the effect of lakes and photodegradation can make discrimination of autochthonous and allochthonous DOM more difficult. The ratio of DOC/DON and protein-like fluorescence proved to be robust indicators despite photodegradation. Human impacts on the Grand River watershed result in a greater seasonal cycle, high primary production in the summer and a downstream trend of increasing autochthonous DOM compared to the Burnt River. Based on drinking water surveillance data and literature review, autochthonous DOM caused greater DBPs in the drinking waters fed by the Grand River. This is currently a threat to human health and DBPs in sewage treatment plant effluent may be a threat to ecosystem health.

Source water quality plays a critical role in maintaining the quality and supply of drinking water, yet it can be negatively affected by human activities. In Pennsylvania, coal mining and treatment of conventional oil and gas drilling produced wastewaters have affected source water quality for over 100 years. The recent unconventional natural gas development in the Marcellus Shale formation produces significant volumes of wastewater containing bromide and has the potential to affect source water quality and downstream drinking water quality. Wastewater from coal-fired power plants also contains bromide that may be released into source water. Increasing source water bromide presents a challenge as even small amounts of bromide in source water can lead to carcinogenic disinfection by-products (DBPs) in chlorinated finished drinking water. However, bromide is not regulated in source water and is not removed by conventional drinking water treatment processes. The objective of this work is to evaluate the safe bromide concentration in source water to minimize the cancer risk of trihalomethanes - a group of DBPs - in treated drinking water. By evaluating three years of water sampling data from the Monongahela River in Southwestern Pennsylvania, the present analysis reached three conclusions. First, bromide monitoring for source water quality should be taken at drinking water intake points. Water sample types (river water samples vs drinking water intake samples) can lead to different water quality conclusions and thus affect regulatory compliance decision-making. Second, bromide monitoring at drinking water intake points can serve as a predictor for changes in heavily brominated trihalomethanes concentrations in finished water. Increasing bromide in source water can serve as an early warning sign of increasing formation of heavily brominated trihalomethanes and their associated cancer risks in drinking water. Finally, this work developed a statistical simulation model to evaluate the effect of source water bromide on trihalomethane formation and speciation and to analyze the changing cancer risks in water associated with these changing bromide concentrations in the Monongahela River. The statistical simulation method proposed in this work leads to the conclusion that the bromide concentration in source water must be very low to prevent the adverse health effects associated with brominated trihalomethanes in chlorinated drinking water. This method can be used by water utilities to determine the bromide concentration in their source water that might indicate a need for process changes or by regulatory agencies to evaluate source water bromide issues.