Alkaline conditions induced by algae growth in wastewater stabilization ponds create deprotonated ammonium ions that result in ammonia gas (NH3) volatilization. If algae are utilized to remediate wastewater through uptake of phosphorus, the resulting nitrogen loss will hinder this process because algae generally require a stoichiometric molar ratio of N16P1. Lower ratios of N/P due to loss of ammonia gas will limit the growth and yield of algae, and therefore will reduce phosphorus removal from the water phase into the algae phase. In order to reduce nitrogen loss through volatilization, an ammonium selective zeolite, clinoptilolite, can be used to sequester nitrogen from the water phase as ammonium ion and in a form that is bioavailable for uptake and growth of algae. A novel algae biofilm rotating photo bioreactor (RPB) with clinoptilolite integrated to the outermost surface as the substratum for algae biofilm attachment and growth has been designed, constructed, and tested for ammonium capture and algae biomass production, with simultaneous removal of the algal nutrient phosphorus from water. The clinoptilolite‐based RPB (cRPB) provides algal biomass that can serve as feedstock for biofuel production through uptake of zeolite‐based nitrogen and water phase phosphorus.

Detection of organic molecules present on the surface of dust particles is important in homeland security, agriculture, and several other applications. The research presented reports the ability of the aerosol mass spectrometer (AMS) to detect molecules on the surface of dust particles without detecting the particle core. Experiments were carried out to detect semi-volatile organic compounds adsorbed onto the surface of particulates without interference from the dust particle core. Methyl salicylate, oleic acid, and organophosphorus pesticides such as Malathion were detected on the surface of particles representative of dust-type materials. Zeolite powders were used as aerosol support, representative of a typical silica mineral aerosol present in the atmosphere. Mass spectral fingerprint information was gained by first directly detecting atomized species to record their clean electron impact mass spectrum. This facilitated detection during later experiments of organic molecules coated on an inorganic support. Spectra obtained give mass spectrometric signatures of molecules coated on inorganic particles without detection of the particle core. An important feature of the AMS is the ability to equate an ion rate detected in the mass spectrometer to a mass concentration of a given chemical species in a sample using its ionization efficiency. Based on an average inlet flow rate of 1.2 cm 3sec -1 the ionization efficiencies obtained were 5.89x10-5, 1.15x10-6, and 1.62x10-5 for Malathion, methyl salicylate, and oleic acid, respectively. These experiments and the results obtained show that detection and characterization of organic species adsorbed onto inorganic dust particles are possible at µg m-3 concentrations using the AMS.

Arsenic contamination in drinking water has been a cause of serious concerns across the United States as well as throughout the world. Over 70 million people in Eastern India, Bangladesh, Vietnam, Taiwan, and Northern China have been victims of arsenic poisoning. The USEPA has classified arsenic as a Class A carcinogen and recently reduced the Maximum Contaminant Level (MCL) in drinking water from 50ppb to 10ppb. The deadline for all the water utilities to meet this level is 23rd January 2006. To meet those drinking water standards, small water utilities need low cost and effective arsenic removal techniques. Natural zeolites such as Chabazite are excellent sorbents for several metallic and radioactive cations. Modifying the zeolite structure can effectively enhance the adsorption capacities of these zeolites for removal of heavy metals. The present work investigates the adsorption capacities of Cuprous and Ferrous treated Chabazite for removal of arsenic. This investigation is a part of a broader project directed at developing an effective pretreatment process that uses modified Chabazite in conjugation with Microfiltration (MF) or Ultrafiltration (UF) for removal of organic and inorganic contaminants. The goal of this research is to determine how well Cuprous and Ferrous treated Chabazite sorbs arsenic in its trivalent and pentavalent state. The other objectives of this research are to examine which modification of the chabazite has the higher removal efficiency of arsenic. This study will also compare arsenic adsorption on the modified zeolites in response to competitive adsorption of various anions present in natural source waters such as sulfates, hydroxides, and chlorides. The potential benefit of this study is to find the most effective treatment of for removal of arsenic species from aqueous solutions. This investigation may provide small water utilities, with a cost effective way for removal of arsenic and thus meet the recommended new regulatory maximum contaminant level (MCL).

In dieser Arbeit werden die Ergebnisse mehrerer verschiedener Synthesemöglichkeiten für eine Optimierung der katalytischen Leistung durch Hierarchisierung zweier Molekularsiebe vorgestellt. Dabei wurde der ZSM-5 als Vertreter der Alumosilikate und der SAPO-34 (Silizium Aluminium-phosphat) ausgewählt, da diese als entsprechende MTH-Katalysatoren bereits wirtschaftliche Bedeutung erlangt haben. Die verschiedenen Möglichkeiten, ein solches hierarchisches Netzwerk zu generieren, werden dabei in Bezug auf die katalytische Leistung der jeweiligen Katalysatoren evaluiert und bewertet.

The purpose of this work is to develop a reliable procedure for determination of liquid phase heats of adsorption via a flow calorimetric technique. The second objective is to study heats of adsorption of target sulfur compounds on potential desulfurization sorbents. Thirdly, we strive to relate the data obtained to the properties of both the sorbent and sorbates studied. Finally, the ultimate goal of this research is to use the data obtained to develop a high capacity selective adsorbent for the desulfurization of diesel fuel. Liquid phase flow adsorption experiments were conducted on sodium-Y zeolite (NaY), nickel exchanged NaY zeolite (NiY) and cesium-exchanged NaY zeolite (CsY). The solutions used in calorimetric experiments included naphthalene in n-hexadecane (C16), dibenzothiophene (DBT) in C16, and quinoline in C16. These solutions were used to model the adsorption of aromatic, sulphur-containing and nitrogen-containing compounds in diesel fuel, respectively. Additional experiments were conducted using equimolar concentrations of all three species in C16 to examine competitive adsorption behaviour of the mixture. During heat flow experiments, effluent samples were collected and analysed to obtain breakthrough curves for the systems. Heat of adsorption data were obtained via flow microcalorimetry using a novel procedure developed by this group. In this study, some experiments were conducted to examine the repeatability and utility of this new method. Characterization experiments were also conducted including BET surface area analysis, X-Ray diffraction (XRD) analysis and Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) analysis to determine the properties of the sorbents. These properties were then related to data obtained in flow adsorption calorimeter experiments. A detailed discussion on the development of a novel method for determination of liquid phase heats of adsorption is presented. Analysis of calculation results using this new method show good repeatability relative to the previous method used. Equilibrium adsorption relationships are developed using the Langmuir adsorption model, and these results are compared to flow adsorption results obtained from the calorimeter. Results indicate that in terms of desulfurization capability, NaY appeared to be the best sorbent. Heats of adsorption were only moderate on NaY, indicating that regeneration of the sorbent would not be difficult, and NaY had the highest sulfur capacity of the sorbents studied. This result was not in agreement with literature results, and it is proposed that the discrepancy is the result of disruption of the crystalline structure of our sorbents during the modification process. Recommendations are presented for ongoing work, including important calorimeter experiments, modifications for improvement of experimental procedure and apparatus, additional sorbent characterization for elucidation of adsorption mechanisms, and finally experiments for verification and further validation of our innovative experimental technique.

The purpose of this work is to develop a reliable procedure for determination of liquid phase heats of adsorption via a flow calorimetric technique. The second objective is to study heats of adsorption of target sulfur compounds on potential desulfurization sorbents. Thirdly, we strive to relate the data obtained to the properties of both the sorbent and sorbates studied. Finally, the ultimate goal of this research is to use the data obtained to develop a high capacity selective adsorbent for the desulfurization of diesel fuel. Liquid phase flow adsorption experiments were conducted on sodium-Y zeolite (NaY), nickel exchanged NaY zeolite (NiY) and cesium-exchanged NaY zeolite (CsY). The solutions used in calorimetric experiments included naphthalene in n-hexadecane (C16), dibenzothiophene (DBT) in C16, and quinoline in C16. These solutions were used to model the adsorption of aromatic, sulphur-containing and nitrogen-containing compounds in diesel fuel, respectively. Additional experiments were conducted using equimolar concentrations of all three species in C16 to examine competitive adsorption behaviour of the mixture. During heat flow experiments, effluent samples were collected and analysed to obtain breakthrough curves for the systems. Heat of adsorption data were obtained via flow microcalorimetry using a novel procedure developed by this group. In this study, some experiments were conducted to examine the repeatability and utility of this new method. Characterization experiments were also conducted including BET surface area analysis, X-Ray diffraction (XRD) analysis and Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) analysis to determine the properties of the sorbents. These properties were then related to data obtained in flow adsorption calorimeter experiments. A detailed discussion on the development of a novel method for determination of liquid phase heats of adsorption is presented. Analysis of calculation results using this new method show good repeatability relative to the previous method used. Equilibrium adsorption relationships are developed using the Langmuir adsorption model, and these results are compared to flow adsorption results obtained from the calorimeter. Results indicate that in terms of desulfurization capability, NaY appeared to be the best sorbent. Heats of adsorption were only moderate on NaY, indicating that regeneration of the sorbent would not be difficult, and NaY had the highest sulfur capacity of the sorbents studied. This result was not in agreement with literature results, and it is proposed that the discrepancy is the result of disruption of the crystalline structure of our sorbents during the modification process. Recommendations are presented for ongoing work, including important calorimeter experiments, modifications for improvement of experimental procedure and apparatus, additional sorbent characterization for elucidation of adsorption mechanisms, and finally experiments for verification and further validation of our innovative experimental technique.

Zeolite structure can profoundly promote the activity of supported platinum. In addition, catalytic performances of Pt/ZSM-12 catalysts vary dramatically with platinum deposition procedure, namely ion exchange (IE) and impregnation procedure (IMP). Supported platinum prepared by IMP is more active than the Pt prepared by IE. The MCP/MCH ratio in benzene hydrogenation as an indication of bifunctional catalysis is significantly higher for IE Pt than IMP Pt. IE preparing platinum is located inside ZSM-12 pore and IMP preparing platinum is deposited on the external surface of ZSM-12. After steam treatment, it is found that Pt-atom perfectly migrates from internal channel to external surface and agglomerates into larger particle size for Pt(IE,0.100%,c) and Pt(IMP,0.123,a) catalysts. In contrast to the results of pure benzene hydrogenation at lower temperature (210¢J/240¢J), they are found that if all prepared various Pt/ZSM-12 catalysts were above the inversion temperature (Ti) then the benzene hydrogenation conversion over Pt(IE,0.100%,c) sample is higher than over Pt(IMP,0.123%,a) sample owing to latter provides less Pt-H+ active sites, as well as Pt(IMP,0.123%,a) sample is the most effective catalyst for toluene disproportionation and transalkylation with 1,2,4-trimethylbenzene. Owing to transformation generally is performed at higher temperature, such as above 400¢J, their operation temperatures are indeed above the inversion temperature (Ti) for all Pt/ZSM-12 catalysts. In situ comparing their benzene hydrogenation in transformation, including disproportionation and transalkylation, is suitable and valuable for understanding and determinating the characteristics of Pt/ZSM-12 zeolite catalysts. Relative conversion of benzene hydrogenation in transformation is the probe of characterizing the Pt-location onto ZSM-12 zeolite.

Zeolite beta has been synthesized using hydrothermal methods. In order to synthesize zeolite beta an aqueous gel having a molar batch composition of 2.2 Na2O&amp / #8729 / Al2O3&amp / #8729 / x SiO2&amp / #8729 / 4.6 (TEA)2O&amp / #8729 / 444 H2O was utilized. The synthesis parameters were SiO2/Al2O3 ratio (20 &amp / #8804 / x &amp / #8804 / 50) and crystallization time (6 &amp / #8804 / t &amp / #8804 / 16 days). Pure zeolite beta was crystallized from the experiments which were performed with the batch composition having SiO2/Al2O3 of 20 and 30 in 6 to 16 days period. For SiO2/Al2O3 of 20 and 30, the highest yield was obtained for 12 days. Therefore, the rest of the experiments, in which SiO2/Al2O3 was 40 and 50, were carried out keeping the synthesis time constant (12 days). Pure zeolite beta was also synthesized for SiO2/Al2O3 of 40 and 50. The highest yield and the most crystalline zeolite beta sample were obtained from the experiment performed at SiO2/Al2O3 of 50 with a synthesis time of 12 days. The morphology and crystal size of the zeolite beta samples were identified by using scanning electron microscope (SEM). It was observed that, zeolite beta samples had spheroidal morphology with the crystal size of about 0.5 &amp / #956 / m. According to the thermogravimetric analyses (TGA), it was found that template molecules and moisture constituted nearly 18 % by weight of the zeolite beta samples. The surface area of the calcined zeolite beta sample was determined by N2 adsorption and was found to be 488 m2/g. Gravimetric sorption analyses yield that, the limiting sorption capacity of Na-Beta for methanol, ethanol, isopropanol and n-butanol at 0&deg / C was about the same with a value of 0.25 cm3/g. For o-xylene, m-xylene and p-xylene that value was 0.21 cm3/g, 0.22 cm3/g and 0.24 cm3/g, respectively.

In this work, the steady-state performance of zeolite-based Cu-ZSM-5, vanadium based honeycomb monolith catalysts (V), vanadium-titanium based pillared inter layered clay catalyst (V-Ti PLIC) and vanadium-titanium-tungsten-based honeycomb monolith catalysts (V-Ti-W) was investigated in the selective catalytic reduction process (SCR) for NO removal using NH3 in presence of oxygen. The objective is to obtain the expression that would predict the conversion performance of the catalysts for different values of the SCR process parameters, namely temperature, inlet oxygen concentration and inlet ammonia concentration. The NOx emission, its formation and control methods are discussed briefly and then the fundamentals of the SCR process are described. Heat transfer based and chemical kinetics based SCR process models are discussed and widely used rate order based model are reviewed. Based on the experimental data, regression analysis was performed that gives an expression for predicting the SCR rate for the complete temperature range and the rate order with respect to inlet oxygen and ammonia concentration. The average activation energy for the SCR process was calculated and optimum operating conditions were determined for each of the catalyst. The applicable operating range for the catalyst depends on the NO conversion as well as on the ammonia slip and the N2O and NO2 emission. The regression analysis was repeated for the applicable range and an expression was obtained that can be used to estimate the catalyst performance. For the Cu-ZSM-5, the best performance was observed for 400oC, 660 ppm inlet ammonia concentration and 0.1% inlet oxygen concentration. For the V based honeycomb monolith catalyst, the best performance was observed for 300oC, 264 ppm inlet ammonia concentration and 3% inlet oxygen concentration. For the V-Ti based PLIC catalyst, the best performance was observed for 350oC, 330 ppm inlet ammonia concentration and 3% inlet oxygen concentration. For the V-Ti-W based honeycomb monolith catalyst, the best performance was observed for 300oC, 330 ppm inlet ammonia concentration and 3% inlet oxygen concentration. The conversion performance of all of these catalysts is satisfactory for the industrial application. At the operating conditions listed above, the N2O emission is less than 20 ppm and the NO2 emission is less than 10 ppm. The results were validated by comparing the findings with the similar work by other research groups. The mechanism of SCR process is discussed for each of the catalyst. The probable reactions are listed and adsorption and desorption process are studied. The various mechanisms proposed by the researchers are discussed briefly. It is concluded that V-Ti-W and Cu-ZSM-5 catalyst are very promising for SCR of NOx. The expressions can be used to estimate the conversion performance and can be utilized for optimal design and operation. The expressions relate the SCR rate to the input parameters such as temperature and inlet oxygen and ammonia concentration hence by controlling these parameters desired NOx reduction can be achieved with minimal cost and emission.

The crisis of the water resources become a serious problem in recent years. Besides the global warming the problem mostly comes from quick population growth, intense industrial developments and low efficiency agricultural implementations. Biofilters are widely been used to either reduce pollution loads or also as a water conservation tool. And the vertical-flow biofilters act as a kind of bio-filter has gain the advantages of low maintenance, small footprint, greater capacities on both the hydraulic and organic loadings. It often used in to treat aquaculture wastewater for recycling during the filter stage. This study is, therefore, focusing on the bio-treatment processes to recycle the wastewater discharged from Chlorella production. Preserving water resources is one big issue of this study, Reuse the nutrients is another tough objective. For reusing the water with as much nutrients as possible and get the organic content off the water is the major target of the study. This study has been separated in two stages. A preliminary study has first been carried out in order to understand the Chlorella behaviors in more detail. Second phase includes the treatment tests with conventional activated sludge (AS) method and the bio-filters. The results have shown that ammonia is preferred by Chlorella as the nitrogen source. Light plays an important role on the treatment for removing algae activities. Aerobic digestion has shown better efficiency. AS can accept as high as 20% of daily input to the system volume, the system is not capable to bear more. While the biofilters, using either zeolite and LECA as the media, have shown satisfied results. When the hydraulic loading stay between 0.30 ~ 2.09 m3 m-2 day-1 to the system, the SS, COD, Chl-a removal rates can reach 90%, and more than 96% of total inorganic nitrogen (TIN) and 76% phosphorus can be preserved in the recycled water, respectively.