Water stress is an ongoing problem in many places in the world, while the demand for clean and safe freshwater is growing due to the increasing population. In many developing countries, water supplies often are contaminated with arsenic, fluoride, etc. Therefore, it is important to realize that water scarcity and contamination issues concern only one sector but many. HVR Water Purification AB is developing a water purification prototype – ELIXIR 500 - using the air gap membrane technology and is implemented in Odisha, India, aiming to supply with 200 litre water daily. This thesis aims to estimate future energy sources to supply this prototype and explore the possibilities of using only renewable energy resources from technical, economic, and environmental perspectives. These are achieved by firstly identifying the energy possibilities in Odisha, India, and then calculating the feasibility of each solution chosen and finally analyzing the results. Among the energy sources, which are power grid, wind and solar power, diesel generator and solar-diesel hybrid system. It is found that the energy source to the prototype supplied by the power grid is 0.057 USD per litre water, which is the cheapest option. However, it is not feasible due to the lack of electrification from the local network. Meanwhile, the solar-diesel hybridized energy system is the most economical option if renewable energy sources are integrated with 0.11 USD per litre water. / Vattenstress ett pågående problem på många ställen i världen medan efterfrågan på rent och säkert dricksvatten växer på grund av den ökande befolkningen. I många utvecklingsländer är vattenförsörjningen ofta förorenade med arsenik, fluor osv. Det är därför viktigt att inse att vattenbrist och föroreningar inte bara rör en sektor utan många. HVR Water Purification AB utvecklade en prototyp för vattenrening - ELIXIR 500 - med hjälp av luftspaltmembrantekniken (eng: air gap membrane distillation och implementeras redan i Odisha, Indien, med målet att förse 200 liter rent vatten dagligt. Denna avhandling syftar till att uppskatta de framtida energikällorna för att tillhandahålla denna prototyp och utforska möjligheterna att endast använda förnybara energikällor ur tekniska, ekonomiska och miljömässiga perspektiv. Dessa uppnås genom att först identifiera de olika energimöjligheter i Odisha, Indien, följt av beräkningar om utförbarhet för varje vald lösning och slutligen en analys av resultaten. Bland energikällorna elnät, vind, sol, diesel generator och sol-diesel hybrid system har visat sig att energikällan till prototypen som levereras av elnätet som kostar 0.057 USD per liter vatten som det billigaste alternativet, men det är inte möjligt på grund av bristen på elektrifiering från det lokala elnätet. Å andra sidan är det hybridiserade energiskombinationen med solkrafts och diesel det billigaste alternativet om förnybara energikällor ska integreras, resultatet visade att vara 0.11 USD per liter vatten.

The study of nitrate utilization as the final electron acceptor in biological phosphorus removal systems was investigated. The objectives of the study were (1) to determine whether polyphosphate (polyP) microorganisms can use nitrate as the final electron acceptor, and (2) to evaluate and compare polyP accumulation in the biomass of the system using nitrate as the terminal electron acceptor to the system using oxygen as the terminal electron acceptor. Two lab-scale biological phosphorus removal systems were operated as the A/O Process under the same conditions except for the terminal electron acceptor involved. The first system, System I, was operated as an Anaerobic/Anoxic process and the other, System II, was operated as an Anaerobic/Anoxic process. Both systems were operated at a 5-day sludge age and the same nominal hydraulic retention time of 9.1 hours (2.9 hours anaerobic, 6.2 hours anoxic or aerobic). The sludge recycle flow rate was equal to the influent flow rate. The two systems were fed with the same domestic wastewater spiked with sodium acetate and potassium phosphate to give the wastewater a COD concentration of 300-400 mg/L and a phosphorus concentration of 13-14 mg/L as P. Nitrate was fed to the second reactor of System I, while the second reactor of System II was aerated. The results showed that polyP microorganisms can use nitrate as the final electron acceptor. In this research, the Anaerobic/Anoxic system removed more phosphorus (74 mg P/day) from solution than the Anaerobic/Aerobic system (64 mg P/day). The phosphorus content of the sludge in the Anaerobic/Anoxic system was greater than that of the Anaerobic/Aerobic system, i.e. 6.5% as compared to 5.6%. The above evidence strongly confirms that polyP microorganisms can use nitrate as the final electron acceptor and that excess biological phosphorus uptake occurs under anoxic condition. The implication is that COD stored in the anaerobic reactor can be used to simultaneously remove nitrogen and phosphorus, which can substantially reduce the amount of COD required for combined nutrient removal. / Master of Science

The hypothesis tested in this study is that the application of ozone to reuse aquaculture water provides more favorable conditions for hybrid striped bass at production levels. Evaluation of water quality in fish culture systems being treated with ozone was made during a production trial (1200 fish/14,OOO 1). Originally, a control and four ozonated systems with doses of 3, 13, 25, and 45 g O3/kg feed/day supported fish for experimentation but, due to mechanical failure, only the control, the 13 and 25 g O3/kg feed/day treatments completed the full 35 week study. On an equal feeding basis, concentrations of dissolved organic carbon (DOC), carbonaceous biochemical oxygen demand (CBODs), and chemical oxygen demand (COD) were lowest in the most heavily ozonated systems. Ozone increased the biodegradation of DOC. Total suspended solids, particle size and distributions were impacted by ozone's flocculating properties. The percentages of particles in the smallest size range, 5-20 microns, were greater in the control system than the ozonated systems during weeks of equal feeding rates. When feeding rates differed, the control system maintained a larger number total particles per kilogram of feed administered. The pH of the ozonated systems was lower than the control which favored the ionized (less toxic) form of ammonia. Enhanced biodegradation of organics in the ozonated systems may have increased carbon dioxide production and caused a decline in pH. Greater nitrification in the ozonated systems may have also decreased the pH. Higher total ammonia nitrogen (TAN) levels were produced in the control on an equal feeding basis. Average weekly TAN t unionized ammonia (NH3), nitrite and nitrate concentrations remained at acceptable levels across treatments and throughout the production trial. Overall, the major indication of improved system conditions due to ozone treatment was that fish raised in the ozonated systems fed steadily throughout the growth trial while the control system's culture experienced periods of reduced feeding. / Master of Science

This project determined the thermodynamic potentials for various reactions between reduced manganese (Mn²), manganese oxide (MnO₂(s)), chlorine dioxide (Cl0₂), and potassium permanganate (KMnO₄). Based on these findings, laboratory analyses were performed to determine if these reactions would occur under simulated water treatment plant conditions. In addition, a speciation procedure was developed to quantify the various species of manganese and chlorine dioxide present in a single sample. The reactions and the speciation procedure were evaluated at TOC concentrations ranging from < 1.0 mg/L to 5.0 mg/L and at pH 6.0 and 8.0. The speciation procedure yielded a reliable measure of Mn², insoluble manganese, and Mn⁺⁷; however, the Mn⁺⁷ evaluation could be disrupted by the presence of free chlorine. The determination of Cl0₂ and Cl0₂- concentrations was also possible; however, the C10₂- concentration was subject to error. The laboratory analyses revealed that Cl0₂ was unable to oxidize either Mn² or MnO₂(s) to Mn⁺⁷ under any of the thermodynamically favored conditions. Both KMn0₄ and Cl0₂ selectively oxidized reduced organic material before reducing the concentration of Mn². When C10₂ and KMnO₄ were added simultaneously, the ClO2 reacted preferentially with the reduced materials. Only after the Cl0₂ concentration was exhausted did the MnO₂⁻ begin to oxidize the reduced species. / Master of Science

Past research regarding complexed iron has focused on the resistance to and kinetics of oxidation by O₂(aq) and the extent of stabilization. The 0.45 um filter was typically used to differentiate between dissolved and particulate iron. This research investigated Fe(II) oxidation by free chlorine and ClO₂ in the presence of DOC by varying the pH, DOC to Fe ratios, DOC sources, oxidant dosages, and contact time. Complexed iron removal by alum coagulation with and without oxidant addition was also examined. Particulate, colloidal, and soluble iron were differentiated by the use of 0.2 um filters and 100K ultrafilters. Ultrafiltration and oxidation studies revealed that, at the DOC-to-iron ratios used for this research, not all of the Fe(II) in solution was actually complexed. Thus, oxidation studies represented the oxidation of uncomplexed Fe(II) to Fe(III), which was then complexed by the higher molecular weight DOC. Results indicated that particulate iron formation (as defined as retention by a 0.2 um filter) was a function of the DOC source and oxidant used for testing. The formation of colloidal iron (as defined by retention on 100K ultrafilter) due to oxidation was dependent upon the initial DOC-to-iron ratio and the DOC source. A correlation between DOC adsorption to iron oxide solids and the solution pH, initial DOC-to-iron ratio, and the oxidant used was also evident. Complexed Fe(II) was removed from solution by alum coagulation. Oxidant addition to alum coagulation was necessary to effectively remove uncomplexed Fe(II) (in the presence of DOC) from solution. / Master of Science

Most taste-and-odor problems in the United States are caused by algal blooms in rivers and reservoirs. In the past, most of the attention has been focused on the formation of geosmin and MIB by blue-green algae (cyanobacteria), which cause earthy and musty odors, respectively. Little work has been performed, however, on equally obnoxious odors caused by other golden-brown and yellow-brown algae which are responsible for fishy, grassy, floral, and melon odors. Additionally, the production of odorous compounds can occur upon oxidation of a nonodorous parent compound. The objective of this research was to determine the effect of three oxidants - chlorine, potassium permanganate, and chlorine dioxide - on solutions of pure odorous as well as nonodorous compounds and algal extracts containing a mixture of odor-related compounds. Oxidant dosages used were in the ranges expected during water treatment. Rashash (1994) identified several odor-causing compounds in pure cultures of golden-brown, yellow-brown, green, and blue-green algae. The compounds selected for oxidation during this study were isolated by Rashash (1994) and are as follows: isovaleric acid (rancid, dirty socks), β-cyclocitral (tobacco, grape), phenethyl alcohol (roses), myristic acid (odorless), palmitic acid (odorless), linoleic acid (odorless), and linolenic acid (watermelon). All seven compounds were oxidized and evaluated by a trained flavor panel for sensory analysis. Because the three oxidants used in this study produced substantial changes in the odors of linoleic acid and linolenic acid, test solutions buffered to a pH of 7 of linoleic acid and linolenic acid were further evaluated by Flavor Profile Analysis (FPA) for sensory determination and gas chromatography/mass spectroscopy (GC/MS) for quantitative measurement of odorous compounds. Volatile compounds produced by Synura petersenii (fishy/cucumber) were also analyzed and evaluated. When linoleic acid (odorless) was treated with potassium permanganate (0.25 mg/L, 1.0 mg/L, and 1.5 mg/L) and chlorine dioxide (1.0 mg/L and 2.0 mg/L), a grassy odor was produced at an FPA intensity of 2-4 (weak). The compound causing this odor was confidently identified from GC/MS analysis as n-hexanal. The compound 2,4-decadienal, which exhibits a frying odor, was also identified in oxidized samples and could contribute to off-odors. Chlorine dioxide and potassium permanganate at the same doses were also effective in eliminating watermelon odors in linolenic samples. Flavor Profile Analysis of samples treated with chlorine was inconclusive since chlorine and acetone, which was used as an organic solvent, produce an alcohol odor at an FPA intensity of approximately 2 (weak) which masked other odors present. Flavor Profile Analysis of oxidized Synura extracts indicated that the fishy odor was destroyed and cucumber or grassy odors were unmasked. Potassium permanganate at a concentration of 0.25 mg/L was effective in eliminating all odors in Synura culture samples. Chlorine and chlorine dioxide at concentrations of 2.0 mg/L and 3.0 mg/L, respectively, eliminated the fishy odor in Synura samples. In both cases, however, vegetation or grassy odors were detected at an FPA intensity of less than 2 (very weak). / Master of Science

The major objectives of this study were to investigate the effects of seasonal changes in Lake Manassas and its watershed (late winter to late summer), the impoundment of Broad Run, and the stratification of Lake Manassas on trihalomethane (THM)-precursors in Broad Run, upstream and downstream of the reservoir, and in Lake Manassas. An additional objective was to determine the molecular-size distributions of the dissolved organic carbon, and the THM precursors of the organic carbon pool in Lake Manassas during stratification. Raw water samples were collected from March through August on Broad Run immediately upstream of the reservoir, at two sites in the reservoir-- one approximately 0.27 miles from the dam and the second, at a more central location, 0.73 miles from the dam, and on Broad Run 2.81 miles below the dam. During stratification two samples were collected from each lake site-- one from the epilimnion, and the second from the hypolimnion. All of the samples were size fractionated by ultrafiltration and chlorinated for determination ofTHMFP. The differences in THMprecursor characteristics were determined by assessing the differences in the total organic carbon (TOC) concentrations and THM-formation potentials (THMFPs) of the various size fractions. The TOe and THM concentrations generally increased from late winter to late summer at all stations. The concentrations in Lake Manassas and in Broad Run below the dam were consistently higher than those observed in Broad Run upstream of the lake, indicating that impoundment causes an increase in levels of THM precursors. In addition, during stratification higher THM yields were produced by the predominantly low-molecular-weight precursors « 5,000) in the epilimnion of Lake Manassas, while the predominantly high-molecular-weight precursors (> 5,000 daltons) were low-yielding-THM precursors. / Master of Science

Chlorine dioxide is used as both a pre-oxidant and/or a post-disinfectant in several water treatment plants in the United States. Chlorine dioxide is associated with its byproducts chlorite and chlorate. Chlorine dioxide, chlorine, chlorite and chlorate were sampled in four distribution systems where chlorine dioxide is used for disinfection purposes: Charleston, WV, Columbus, GA, New Castle, PA, and Skagit, WA. The fate of chlorine dioxide and its by-products in distribution systems is discussed. A constituent transport model (TRAK) was applied to New Castle, PA distribution systems to assess times of travel. No relationship was found between the concentrations of chlorine, chlorine dioxide, chlorite and chlorate and the computed travel times. Water treatment plant and distribution system data received from Galveston, TX where the use chlorine dioxide has being tested is analyzed and discussed. Median chlorine dioxide concentrations are relatively constant in distribution systems with a value of approximately 0.2 mg/L; however, chlorine dioxide dosages applied at the treatment plant can induce different concentrations in the distribution system. Median chlorite concentrations in distribution systems range from 0.5 to 0.8 mg/L while median chlorate concentrations are generally lower in a range between 0.1 to 0.3 mg/L. The effects of distribution systems skeletonization in constituent transport modeling are also presented. Skeletonization does not affect significantly computed times of travel when the median percentage of constituent has to be detected. However, depending on the layout of each distribution system, small variations can be observed. / Master of Science

Chlorine (Cl₂(sq»' chlorine dioxide (ClO₂ ) and potassium permanganate (KMnO₄) were evaluated as oxidants for the removal of grassy and cucumber odors associated with the pure compounds, cis-3-hexenol and trans-2, cis-6-nonadienal, respectively, and for the removal of fishy odors associated with a culture of an alga, Synura petersenii. The effects of the oxidants on the pure compounds were assessed both by Flavor Profile Analysis (FPA) and gas chromatography/mass spectrometry (GC/MS). The effects of the oxidants on the algae culture were evaluated by FPA only. In addition, an unoxidized sample of Synura petersenii was analyzed by gas chromatography coupled with mass spectrometry (GC/MS) for possible identification of fishy-smelling compounds. Chlorine (1-6 mg/L) and KMn04 (0.25-4 mg/L) markedly reduced grassy and cucumber odors associated with the two compounds. Gas chromatography/mass spectrometry confirmed that these compounds were reduced to below method detection limits. Levels of Cl₂(&q) required (up to 6 mg/L) to reduce the grassy odors associated with cis-3-hexenol were higher than those of KMnO₄ â ¢ The high Cl₂(&q) doses may have contributed to the formation of chemical odors observed by panelists. Two isomers of chlorohexenol were confidently identified as byproducts of cis-3-hexenol chlorination and may have contributed to the chemical odors that developed after CI2(aq) treatment. Chlorine and KMnO₄ (both at 10 mg/L) either reduced or destroyed the fishy odor associated with the culture of Synura petersenii; however, oxidation caused either the development or unmasking of fruity, cucumber, melon and grassy odors. Chlorine dioxide (3 mg/L) did not reduce the grassy and cucumber odors associated with cis-3-hexenol and trans-2, cis-6-nonadienal , respectively. Gas chromatography and mass spectrometry confirmed that concentrations of these compounds were not reduced to below method detection limits. Furthermore, at a concentration of 10 mg/L, Cl₂ did not effectively reduce either the fishy or other objectionable odors associated with Synura petersenii culture. Hexanal, with an odor described as "green" or "like lettuce heart," and trans-2, cis-6-nonadienal (cucumber odor) were confirmed as algal products in a two-week-old culture of Synura petersenii. In addition, decatrienal was confidently identified as a product of Synura and may have contributed to the fishy odor associated with this alga. / Master of Science

In the past few years, the contamination by pesticides and heavy metals in surface water and groundwater has increased. Reverse osmosis is a unit process that has demonstrated capacity to remove dissolved pesticides and heavy metals from aqueous solution, and it is therefore worthwhile to consider this treatment process as a potential removal technique for hazardous constituents. The purpose of this investigation was to determine the effectiveness of a field scale reverse osmosis unit, with a spiral wound poly(ether/urea) membrane, in removing pesticides and heavy metals from a contaminated source. The removal efficiency for a single contaminant alone and a part of a mixture was examined. The performance of new and used membranes over time was also investigated. The average removal of pesticides was better than 99 percent. Reverse osmosis separation of pesticides was found to be dependent on the characteristics of the membrane and the physical/chemical properties of the pesticides. Pesticides in the mixed solution were found to behave independently. Sorption of the pesticides onto the reverse osmosis membrane was found to play a major role in the overall removal efficiency. Better than 99 percent average removal was achieved for all the metals except arsenic. The importance of the physical/chemical properties of the metal ions such as solubility, ionic radius, and electronegativity were determined. In tests to compare removal efficiency between new membrane and membrane which had been used, virtually no differences occurred. / Master of Science