PhD, University of Cincinnati, 2004, Engineering : Environmental Engineering

Biofiltration has developed into a promising technology for the abatement of volatile organic compounds (VOCs), odors, and hazardous air pollutants in waste gas streams. Many factors, however, are still creating an environment for greater innovation as well as new products for biofiltration processes. Rotating drum biofilters (RDBs) are such an innovation. The objectives of this investigation are to develop and understand RDBs and consequently to design and operate RDBs properly. Three RDBs, a single-layer RDB, a multi-layer RDB, and a hybrid RDB, were developed and evaluated at various design and operation conditions in this investigation. Spongy medium that was used to support the biofilms was mounted on a cylindrical drum frame that was rotated at a preset speed. Diethyl ether, toluene, and hexane were chosen as the model VOC. Results showed that the RDBs were readily started up and removed VOCs with high water solubility and a low value of Henry' constant efficiently with more than 6 month duration without any biomass control measures. The single-layer and hybrid RDBs usually reach the lowest and highest VOC removal efficiency. VOC removal efficiency decreased with increased VOC loading rate and decreased gas empty contact time (EBCT). Nitrate in the liquid phase of the RDBs can be rate-limiting for diethyl ether removal. With increased drum rotating speed, the change in VOC removal efficiency depends on VOC properties, VOC loading rate, drum rotating speed value, and biofilter configurations. The microbial community structure along medium depth are almost identical for each of the RDBs , however, the structure changes with the operation conditions and biofilter configuration. Review of the biomass accumulation rates among different layers reveals four biomass accumulation patterns which represent different removal mechanisms: surface biofiltration, in-depth biofiltration, shallow biofiltration, and reverse biofiltration. The dominant biomass accumulation patter (open full item for complete abstract)

Committee: Dr. Makram Suidan (Advisor) Subjects: Engineering, Environmental

PhD, University of Cincinnati, 2002, Engineering : Chemical Engineering

Major technical challenges confronting biofiltration technology are: effective support media for biotrickling filters, understanding of biofiltration of mixed contaminants, biofiltration of contaminants at very low concentration, and biofilm model calculation for concentration distribution within a biofilm. In this research work, a composite media was designed and tested in bench scale biotrickling filters. The media were made of a polymeric support media coated with either activated carbon or sand. The resulted media will inherit properties such as high void fraction, high interfacial area, and low bulk density from the original packing, plus enhanced surface suitable for biofilm attachment and growth. The new media were evaluated along with the original media in bench scale biotrickling filters. A fibrous packing medium was evaluated in the biofiltration of ethanol in biotrickling filters and microbiofilters. The microbiofilter system, operating according to a new experimental protocol, can be used to determine both reaction rate constants and mass transfer coefficient with the help of a concise mathematical model. The identified parameters are then used to calculate concentration profiles inside a biotrickling filter and to predict its biofiltration performance. This fibrous packing medium was later used in a pilot scale biotrickling filter test to treat ethanol emission found in exhaust gases from baking ovens. The same fibrous media as well as the experimental protocol were also used in studying mixed contaminants biofiltration. Biofiltration of mixed contaminants was studied using target compounds of alcohols, acetone, acetaldehyde in biotrickling filters and microbiofilters using the fibrous medium. In a batch system, the preference of individual contaminant by the biomass can be carefully examined. Meanwhile, their respective biodegradation kinetics can be investigated by employing a mathematical model, which was also developed to portray the biofiltration p (open full item for complete abstract)

Committee: Dr. Rakesh Govind (Advisor) Subjects:

MS, University of Cincinnati, 2016, Engineering and Applied Science: Environmental Engineering

This dissertation includes a detailed review on the application of two different biofiltration systems, 1. Classical biofilters and 2. Biotrickling filters, for the removal of various air pollutants. The biofiltration of volatile organic compounds, fuel emissions, biogas, off gases and malodorous gases are studied in detail. The removal mechanisms including aerobic and anaerobic processes involved in the breakdown of the gas phase contaminants within natural and synthetic biofiltration units are studied. This is followed by an experimental evaluation of the performance of a controlled trickle bed air biofilter (TBAB) for the removal of chloroform. Chloroform is a higher chlorinated methane and a highly volatile compound. It is directly emitted into the atmosphere through several industrial sources such as pharmaceutical, pulp and paper industries. It is also formed as a byproduct of chlorination disinfection in water and wastewater sources and subsequently volatilized into the atmosphere. Chloroform, also known as trichloromethane, contains three chlorine atoms making it very recalcitrant and stable in the environment. It is also a highly hydrophobic compound making it an extremely difficult candidate for biodegradation. In this study, this challenge is overcome by evaluating the biodegradation potential of chloroform in the presence of a cometabolite, ethanol, and using filamentous fungi as the principle biodegrading consortium within the TBAB. The TBAB receives chloroform and ethanol in its gas phase and enriching nutrients in a buffered liquid phase. Chloroform and Ethanol were supplied at different feed ratios including 1:5, 1:10, 1:20, 1:30, 1:40 with ethanol concentrations ranging from 25 to 200 ppmv. A removal efficiency of 80.9% was observed when treating 5 ppmv of chloroform with 200 ppmv of ethanol and an elimination capacity of 0.238 g/m³.h was achieved. The study further extends to the determination of the removal kinetics for chloroform and q (open full item for complete abstract)

Committee: George Sorial Ph.D. (Committee Chair); Soryong Chae Ph.D. (Committee Member); E Sahle-Demessie Ph.D. (Committee Member) Subjects: Environmental Engineering

Master of Science, The Ohio State University, 2016, Food, Agricultural and Biological Engineering

All over the world, upland nutrient loading from non-point sources is wreaking havoc on downstream reservoirs, causing problems like harmful algal blooms and hypoxia. In Lake Erie and the Maumee River watershed, subsurface drainage and trapezoidal ditches provide rapid delivery of phosphorus (P) to aquatic environments. Development of a biofilter to capture and remove dissolved reactive P (DRP) from agricultural runoff could reduce P draining from fields. This study was part of a larger project which aimed to develop a DRP biofilter, employing a P-filter substrate to capture DRP and retain it within the biofilter, as well as prairie grasses to take up the P from the substrate and assimilate it into biomass. An experimental matrix was developed, in which each of four substrates, zeolite (Z), Bold and Gold TM (BG), gypsum (G), and pea gravel (PG) were mixed with soil, placed in a pot, and planted with each of three prairie grasses, Switchgrass (panicum virgatum), Virginia wildrye (Elymus virginicus), and Big bluestem (Andropogon gerardii), as well as a control in which no grasses were planted. A mass balance experiment was conducted; the mass of P added to each pot via watering and fertilizer dosing was analyzed, as was the mass of P that leached from the bottom of the pot, remained dissolved in the soil void space, and was assimilated into root biomass and above-ground biomass. Any P unaccounted for was assumed to be bound to the substrate. ANOVA analyses were to be conducted to determine if one of the substrates removed more P than others, if one of the prairie grasses assimilated more P than others, and if a substrate-grass combination outperformed the rest. Green foxtail (Setaria viridis) outcompeted other plants in the pots regardless of what grass was sewn. Among all four groups of grass, green foxtail was the dominant species, to the extent that the plant growing in the pots was not statistically different among the groups (chi-square = 0.189). Th (open full item for complete abstract)

Committee: Jon Witter (Advisor); Ward Andy (Committee Member) Subjects: Agricultural Engineering

PhD, University of Cincinnati, 2013, Engineering and Applied Science: Environmental Engineering

Biofiltration systems demonstrated to very effective in removal of volatile organic compounds (VOCs) from air operating under dynamic loading rates and stressed conditions. More interestingly, Trickle Bed Air Biofilters (TBABs) offer more optimal and controllable operations which result in low maintenance costs over traditional biofilters. Furthermore, due to their higher removal efficiency, consistent performance, and harmless by-products generated they became an attractive option for controlling VOCs emissions from various industrial processes. Yet, biofiltration systems face a number of challenges to compete new proposed techniques such as two-phase bioreactors and oil emended biofilters. Characteristically, hydrophobic compounds, with higher Henry's law constant, present a great challenge for these systems as they are not soluble in water. Limited bioavailability of these VOCs could trigger mass transfer to be rate limiting from gas to liquid phase and hence negatively affecting biofilters performances. Moreover, as biofilters are biologically dependent systems, the exact characterization of the microbial community structures within the active biomass need to be developed in order to get deep insight of the species involved to make the biofiltration technique more efficient, reliable, and oriented either to specific VOCs as well as to be flexible in handling a variety of VOCs. Most importantly, air emissions are always mixture of different type of gases rather than a sole VOC. Hence, inhibitory effect among VOCs could hinder the widespread application of these systems in facilities where off gases are a combination of hydrophilic and hydrophobic VOCs. Finally, variability in waste gases flow and fluctuations in their concentrations limit the treatment efficiency of the biofiltration systems. In this regard, the current study investigated several techniques to effectively biodegrade hydrophobic contaminants. Responding to this aim, the solutions presented (open full item for complete abstract)

Committee: George Sorial Ph.D. (Committee Chair); Ashraf Aly Hassan Ph.D. (Committee Member); E Sahle-Demessie Ph.D. (Committee Member); Makram Suidan Ph.D. (Committee Member); David Wendell Ph.D. (Committee Member) Subjects: Environmental Engineering

PhD, University of Cincinnati, 2001, Engineering : Electrical Engineering

In this work, new micromachined magnetic particle separators and integrated biofilters have been proposed, developed, and successfully characterized for an integrated magnetic bead-based biochemical detection system. Physical behavior of magnetic particles has been investigated to develop a dynamic monitoring method of magnetic bead separation. In addition, magnetic separation force on the magnetic beads has been simulated by analytical and numerical methods to optimize performance. Developed magnetic particle separators and biofilters have been fully characterized for both dynamic monitoring capability of magnetic bead separation and biofiltering performance. The developed biofilters and biosensors have been integrated with a microfluidic system to realize an integrated microfluidic biochemical detection system for fast and small volume immunoassays using magnetic beads, which are used as immobilization surfaces as well as bio-molecule carriers. Magnetic bead-based immunoassay, as a typical example of biochemical detection and analysis, has been performed on the integrated microfluidic biochemical detection system that includes a surface-mountable biofilter and immunosensor. From the immunoassay performed with the biochemical detection system, 50 ng/ml of sample concentration (e.g., mouse IgG) has been successfully detected and analyzed. Total analysis time required for the full immunoassay was less than 20 minutes including sample incubation time. Sample volume used was less than 10 ul during one immunoassay. Protein sampling capability has been also demonstrated by capturing target antigens. The methodology developed in this work can be also applied to generic bio-molecule detection and analysis systems by replacing antibody/antigen with appropriate bio receptors/reagents such as DNA fragments or oligonucleotides, which will be useful for DNA analysis and high throughput protein analysis.

Committee: Dr. Chong H. Ahn (Advisor) Subjects:

PhD, University of Cincinnati, 2010, Engineering and Applied Science: Environmental Engineering

Biological treatment represents low-cost and environmental friendly option for air pollution as compared to incineration, catalytic oxidation and adsorption. It has several advantages like minimal power consumption, few byproducts and cost effectiveness. However, several challenges face biological treatment processes such as variability of flow rate and composition of contaminants in waste streams. Furthermore, hydrophobic compounds are not readily available for the microorganisms, creating a deficiency for the use of biological treatment in the industry. Biofiltration for VOCs control is best operated at steady loads of hydrophilic VOCs. In practice the existence of hydrophobic compounds in waste streams is inevitable. In addition, variations in contaminant loads are common in real applications. The objectives of this study are to introduce biological treatment as an effective technique for non-methane hydrocarbon removal from air under stressed operating conditions. Emphasis is being placed on hydrophobic compounds which are known to be recalcitrant to biological treatment. Two hydrophobic compounds; n-hexane and benzene, which are carcinogenic and toxic, were utilized as model compounds. Both compounds were studied separately under different operating conditions. Loading rates up to 48 and 77 g/(m3 h) for n-hexane and benzene were applied at the inlet prividing elimination capacities of 39 and 61 g/(m3 h) , respectively. These elevated elimination capacities have not been achieved by any reported research for hydrophobic compounds at practical removal efficiencies as obtained in this study (minimum 78%). Surfactants were introduced in the biofiltration system as means for enhancing solubility. The effect of two different surfactants; Triton X-100 and Tomadol 25-7, were investigated at different loading rates for the biodegradation of n-hexane operating under neutral pH. Other means of increasing the bioavailability of hydrophobic compounds was the introduction o (open full item for complete abstract)

Committee: George Sorial PhD (Committee Chair); Margaret Kupferle PhD, PE (Committee Member); Paul Bishop PhD (Committee Member); E Sahle-Demissie PHD (Committee Member) Subjects: Environmental Engineering

PhD, University of Cincinnati, 2007, Engineering : Chemical Engineering

The first part of this thesis encompasses fundamental studies on the attachment and growth of biofilms onto synthetic non adsorbing, macroporous solid foams aiming at supporting bioactive microorganisms in the removal of intricate hydrogen sulfide polluted airstreams in trickle bed columns at negligible pressure drop. A new theoretical model that predicts the performance of biofilters packed with non adsorbing, macroporous media was simultaneously developed based in the distribution of the fouled airstream within the porous media and around it, so that the geometric properties of the packing media can be chosen as to maximize the amount of air passing within the media where most microorganisms are located. During the experimental phase of this study, colonization of such non adsorbing, macroporous media with microorganisms was enhanced by the addition of positively charged, polymeric coatings which increase the attachment and spreading of the biofilms due to cell binding and electrostatic charge cancellation at physiological pH. Impedimetric tests using golden microelectrodes were applied separately to corroborate such results, and other cofactors reported in the Literature for the attachment of animal cells onto plastic surfaces were tested with the methodology. The use of such cofactors for biofilm attachment purposes and the impedimetric tests for the determination of the kinetics of the biofilm morphology development based in the transient change of observables such as resistance and capacitance, are the first attempts on such approaches to date. In the second part of this thesis, the macroporous, non adsorbing foams were replaced by adsorbing, reactive units of similar geometric properties but containing iron (III) (oxy)(hydr)oxides operating as adsorption towers and trickle bed biofilters. The abiotic H2S removal capability of such iron bearing media was found to be enhanced by dripping water down the bed, which allowed for complete elimination of the sulfide (open full item for complete abstract)

Committee: Dr. Rakesh Govind (Advisor) Subjects:

PhD, University of Cincinnati, 1999, Engineering : Environmental Engineering

Increasing regulatory pressure for VOC emissions reduction has accelerated the development of more cost effective VOC air pollution control (APC) technologies. Biofiltration is a viable technology to fill this role, for the purification of air streams polluted with biodegradable VOCs. In the biofilter, these pollutants diffuse from the air stream into a stationary mass of moist biological film, where they are oxidized by enzymatic catalysis at ambient pressures and temperatures. Properly operated, this natural, biological mineralization process will produce only benign by-products, such as inorganic salts, carbon dioxide, and water, with some additional biomass. Although research into the science and development of the technology of biofiltration has been performed for over fifteen years, biofiltration remains not widely accepted as a proven technology for VOC APC. This perception is especially true for applications treating high influent VOC concentrations and requiring high VOC removal efficiencies. This research was undertaken to develop a new, cost effective biofiltration technology which can reliably treat air streams polluted with high VOC concentrations and achieve very high removal (elimination) efficiencies. Investigations were made to evaluate different biological attachment media, in order to identify the medium most suited to such an application. Using this medium, a reliable biofiltration technology was developed and extensively tested, which can achieve the goal of reliably treating high concentrations of VOCs at high loadings with high removal efficiency. Techniques for the management and control of the accumulating by-product biomass were developed. Procedures are presented for the calculation of VOC solubility and biological kinetic parameters, at the biofiltration operating temperature. A procedure for estimating the upper limit for biofiltration for the influent air VOC concentrations is presented. A simple, explicit biofilter design equation was (open full item for complete abstract)

Committee: Makram Suidan (Advisor) Subjects:

MS, University of Cincinnati, 2001, Engineering : Environmental Engineering

The United States Environmental Protection Agency does not regulate the air emissions of volatile compounds from municipal waste treatment plants as of this writing. There have been proposals for changes in this requirement. California has already enacted legislation to limit the emissions from wastewater treatment plants, and many municipalities recognize that the regulations to limit these emissions are inevitable. In order to be prepared for new regulations, The Metropolitan Sewer District of Greater Cincinnati has taken a proactive approach to limiting their volatile emissions. This approach will make it easier to comply with the proposed regulations. The purpose of this research project was to determine the emission of volatile organic compounds (VOC's) and other hazardous materials from a biofilter operating at a representative municipal wastewater treatment plant. The research involved the monitoring of a biofilter that controls the gas emissions from a sludge holding tank. A correlation was developed between an operating biofilter and the physical and biological properties of the biofilter. The study was performed at the Polk Run Wastewater Treatment Plant. This plant treats primarily residential sewage. The average daily flow is 3.5 million gallons. This plant serves the residential community of Loveland, Ohio and the surrounding suburban area. This study confirmed that a biofilter is an effective method for controlling odors and emission of volatile compounds from a sludge holding tank at a municipal wastewater treatment plant. The main gaseous emission identified and the source of the predominant odors was determined to be hydrogen sulfide gas. The bacteria and fungi found in the biofilter controlled this odor by reducing the concentration of hydrogen sulfide gas. The bacteria found in the biofilter were identified as Pseudomonas aeruginosa and Salmonella. These bacteria are commonly found in wastewater. The wood bark in the biofilter provided the medium (open full item for complete abstract)

Committee: Dr. Paul Bishop (Advisor) Subjects: Engineering, Environmental

Master of Science (MS), Ohio University, 2010, Environmental Studies (Arts and Sciences)

The efficiency of vegetated biofilters to mitigate highway stormwater runoff was assessed utilizing two constructed biofilters and applying simulated stormwater runoff with high and low concentrations of metals at varying slopes. In this study the efficiency of vegetated biofilters was determined, the contaminant removal mechanisms and the soil fractions that retained the metals. Results from these tests concluded that the vegetated biofilters were very efficient in mitigating highway stormwater runoff, with percent removals ranging from 92.5% - 99.0% for the high concentration tests and 31.3% - 91.2% for the low concentration tests. Metals were predominantly removed by adsorption to the suspended solids added to the influent, settling within the bed, and then further taken up by the leaves and roots. Chemical fractionation results indicated that the majority of the metals were concentrated in the Fe-Mn oxide and organic fractions of the soil, indicating that future remobilization of these metals was unlikely, because metals bound to these fractions are strongly retained.

Committee: Guy Riefler PhD (Advisor); Jared DeForest PhD (Committee Member); Glen Jackson PhD (Committee Member) Subjects: Environmental Science

Master of Environmental Science, Miami University, 2010, Environmental Sciences

This report is an inventory of types of stormwater management practices, both the poor and the best, in the City of Oxford. A structure or practice is regarded as a “poor stormwater management practice” if it increases peak flow, decreases base flow, increases or does not eliminate pollution, exacerbates erosion and degrades aquatic habitats. These practices include connected impervious surfaces, poorly designed or poorly managed stormwater infrastructure, uncollected trash and pet waste. A structures and practices is regarded as a stormwater “best management practice” if it reduces peak flow, increases baseflow, eliminates or does not contribute to stormwater pollution and does not degrade streams and aquatic habitats. Such practices include pervious pavers, filter strips, storm drains, rain gardens, disconnected impervious surfaces, street sweeping, vegetated depressions and retention gardens. This study does not attempt to uncover issues of policy regarding stormwater management in the city. Some recommendations on how the City of Oxford could encourage stormwater best management practices are given in the end. A glossary of key stormwater terms is also provided.

Committee: Mark R. Boardman PhD (Advisor); David L. Prytherch PhD (Committee Member); Donna S. McCullom PhD (Committee Member) Subjects: Hydrology

Master of Science (M.S.), University of Dayton, 2012, Civil Engineering

Nutrient contamination, specifically regarding nitrogen and phosphorous, is widely recognized as an environmental concern. A significant and currently unregulated portion of nutrient pollution is produced from agricultural non-point sources. Previous studies have identified possible methods for treating nutrients from agricultural runoff; however, few studies have produced a treatment system capable of removing both nitrogen and phosphorous. Additionally, several previous studies utilized treatment methods which were expensive or difficult to maintain. The purpose of this study was to research several laboratory scale treatment systems in an effort to identify sustainable methods for treating nitrogen and phosphorous from synthetic agricultural runoff. Three laboratory scale treatment configurations were developed and examined to determine the effectiveness of biological treatment methods. Configuration #1 consisted of an anaerobic denitrification biofilter with wood chip media. Configuration #2 included an anaerobic denitrification biofilter with corn residue media. Finally, Configuration #3 consisted of an aerobic nitrification trickling filter with shredded tire media as well as an anaerobic denitrification biofilter with wood chip media. Synthetic agricultural runoff was conveyed through each configuration for four weeks, and samples were collected to measure the influent and effluent nutrient concentrations. Assessments of the sample data included advanced statistical analyses. Additionally, a laboratory scale adsorption experiment was conducted to determine how effectively physical treatment methods reduce phosphorous contamination. Using crushed gypsum as the test substance, a series of adsorption isotherms were conducted by combining various masses of gypsum with test solutions of various phosphate concentrations. Samples were taken from each of these combinations to measure the adsorption of total phosphorous and reactive phosphorous over time. Data was (open full item for complete abstract)

Committee: Denise Taylor PhD (Advisor); Kenya Crosson PhD (Committee Member); John Doty PhD (Committee Member) Subjects: Agriculture; Civil Engineering; Environmental Engineering; Hydrology; Water Resource Management