Engineering Commons^™

Nanobubble Technology For The Removal Of Mib And Geosmin From Drinking Water, Meryem Soyluoglu

All Dissertations

The presence of taste and odor (T&O) compounds in drinking water has been historically a major challenge for water utilities. They are difficult to remove using conventional water treatment processes, a combination of coagulation, flocculation, sedimentation, filtration, and chlorination. However, activated carbon (AC) adsorption, advanced oxidation processes, and biofiltration can be effective. The seasonal nature of T&O events makes it difficult to justify installing dedicated treatment technologies. Additionally, incorporating these technologies into existing water treatment plants can be expensive and require significant upgrades. Therefore, water utilities are always interested in exploring new approaches to minimize the occurrence and removal of …

Colloidal Behavior Of Nanobubbles And Their Application In Enhancing Plant Growth: Mechanisms Of Nanobubble Interactions With Microbial And Soil Species, Shan Xue

Dissertations

Climate change has resulted in increasing uncertainties of water resources and disturbance on agricultural activities. For example, the shortage of water resources, land erosion and pollution from runoff significantly affect agricultural sustainability. This dissertation research focuses on the fundamental studies of nanobubble (NB) water and explores the benefits for irrigation to enhance plant germination and growth. Unlike bulk bubbles, NBs exhibit prolonged stability in water and possess large surface areas that facilitate efficient mass transfer and potential tailored reactions (e.g., disinfection). However, the enhancement mechanisms for NBs on seed germination and plant growth remain elusive.

This research first evaluated the …

Lab-Scale Data And Microbial Community Structure Suggest Shortcut Nitrogen Removal As The Predominant Nitrogen Removal Mechanism In Post-Aerobic Digestion (Pad), Fabrizio Sabba, Patrick J. Mcnamara, Eric Redmond, Mike Young, Leon Downing

Civil and Environmental Engineering Faculty Research and Publications

Implementing an aerobic digestion step after anaerobic digestion, referred to as “post aerobic digestion” (PAD), can remove ammonia without the need for an external carbon source and destroy volatile solids. While this process has been documented at the lab-scale and full-scale, the mechanism for N removal and the corresponding microbial community that carries out this process have not been established. This research gap is important to fill because the nitrogen removal pathway has implications on aeration requirements and carbon demand, that is, short-cut N-removal requires less oxygen and carbon than simultaneous nitrification–denitrification. The aims of this research were to (i) …

Dairy Manure Flushwater Treatment By Algae Raceway Ponds And Aerated Biofilm Reactors, Darin Son

Master's Theses

Nitrogen removal technologies can help dairy industries meet their nutrient management needs. This thesis investigated two separate treatment technologies for total ammonia nitrogen (TAN) removal: algae raceway ponds and aerated biofilm reactors. Six 1000- liter algae raceway ponds and four 1000-liter tote tanks, each equipped with 10 sheets of nonwoven geotextile (i.e., thermally bonded or needle-punched) biofilm substrate, were used to treat the effluent from a flush dairy in central coastal California (TAN = 251 mg/L, cBOD5 = 204 mg/L). For the algae raceway ponds (TAN loading rate = 7 - 35 g/m³-day among 7-, 10- and 14-day hydraulic residence …

Automated Calibration Of Electrochemical Oxygen Sensors For Use In Compost Bedded Pack Barns, John T. Evans, Michael P. Sama, Joseph L. Taraba, George B. Day

Biosystems and Agricultural Engineering Faculty Publications

The objective of this study was to develop an automated calibration process for a galvanic cell type oxygen sensor. The manufacturer recommended a two-point calibration at room temperature; however, testing revealed that the response was not linear when both the temperature and oxygen concentrations varied. Thus, additional points were needed to generate a representative calibration equation and to reduce the sensor prediction interval. The calibration process needed to be capable of automatically recording sensor response (voltage) at an array of temperatures and oxygen concentrations. Calibration gases were used to precisely control the oxygen concentration inside a small manifold, and an …

Application Of Mechanically Fluidized Reactors To Lignin Pyrolysis, Valentina Lago

Electronic Thesis and Dissertation Repository

Lignin has great potential for the production of aromatics currently derived from petroleum, since it is the most abundant source of aromatics in nature. At present, Kraft lignin is used as fuel within the pulping process but, alternatively, it could be converted to high-value chemicals using thermochemical processes such as pyrolysis. Kraft lignin, however, is a very cohesive and thermally sensitive powder with foaming and agglomerating tendency under reaction conditions. Therefore, new reactor designs are necessary to efficiently process this raw material.

Consequently, a novel reactor design, designated as Mechanically Fluidized Reactor (MFR) has been developed to successfully process Kraft …

Development Of A Method For In-Situ Testing Of Oxygen Concentrations In Compost Bedded Pack Barns, John T. Evans Iv

Theses and Dissertations--Biosystems and Agricultural Engineering

Compost bedded pack barns are a relatively new type of dairy housing system that is being implemented in Kentucky. Extensive research has been done on the composting of animal manure, however, little has been done on composting animal manure in place. One of the most concerning challenges is aeration. Improper aeration can cause system failure. The ability to quickly and accurately measure the oxygen concentration would allow researchers the ability to determine which methods of tillage/aeration are most effective in compost bedded pack barns. The research in this thesis focused on the development of a method for simultaneously testing oxygen …

A Sustainable Remediation Approach For Complete Destruction Of Chloroethanes In Groundwater, Michael Joseph Cheatham

LSU Master's Theses

An up-flow column study was operated in a greenhouse composed of a sand/peat mixed media to investigate the effectiveness of an aerobic zone on the disappearances of chloroethane. The oxygen was supplied by mean of porous Silastic tubing under pressure with a breathing air gas cylinder. Chloroethane was generated via reductive dechlorination of 1,1,1-trichloroethane (TCA) and 1,1-dichloroethane (DCA) in anaerobic bioreactors (ABRs). The columns study was conducted with two duplicate reactors (operated in parallel) that underwent separate perturbations of breathing air introduction. Aqueous samples were collected in 160 mL microcosm bottles and analyzed on a GC equipped with a Flame …

Design Of A Sustainable Toilet, Meghan Pranger, Tommy Lauderdale, Joseph Benyon, Kyle Moore

Mechanical Engineering

No abstract provided.

Process Design For Aeration Of Facial Prosthetic, Nathaniel J. Urciuoli

Industrial and Manufacturing Engineering

Facial prosthetics are becoming a necessary step for the recovery of injured veterans and civilians who have suffered severe facial burning. Current users of such prosthetics are not able to wear the prosthetic for an extended period of time due to uncomfortable conditions created by the silicone material. A solution for this problem was to develop a process for creating small holes similar to skin pores that will both ventilate and aid in the evaporation of accumulated sweat under the prosthetic.

The main steps of this process were to create a flexible fixture capable of supporting and securing the prosthetic …

Gas Transfer In Air-Lifts Used To Recirculate Aquaculture Systems, Ryan Anthony Hearn

LSU Master's Theses

The following studies were conducted to determine hydraulic, aeration, and degasification characteristics associated with various air-lift pumps. The first study presented data on a 20.3 cm air-lift used to support adult Yellowtail broodstock (Seriola lalandi) in an oligotrophic warmwater marine RAS (recirculating aquaculture system). Empirical relationships were used to estimate actual oxygen and carbon dioxide mass transfer rates (AOTR & ACTR) as the inlet oxygen or carbon dioxide concentrations were perturbed under lift heights of 30.5, 38.1, and 45.7 cm. Transfer rates, kg of constituent per day, were found to be dependent on air injection depth and volume, aqueous gas …

Airflow Resistance Of Wheat Bedding As Influenced By The Filling Method, J. Łukaszuk, M. Molenda, J. Horabik, B. Szot, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

A study was conducted to estimate the degree of variability of the airflow resistance in wheat caused by the filling method, compaction of the sample, and airflow direction. Two types of grain chambers were used: a cylindrical column 0.95 m high and 0.196 m in diameter, and a cubical box of 0.35 m side. All factors examined were found to influence considerably the airflow resistance. Gravitational axial filling of the grain column from three heights (0.0, 0.95 and 1.8 m) resulted in the pressure drops of 1.0, 1.3, and 1.5 kPa at the airflow velocity of 0.3 m/s. Consolidation of …

Airflow Resistance Of Seeds At Different Bulk Densities Using Ergun's Equation, Marek Molenda, Michael D. Montross, Samuel G. Mcneill, Jozef Horabik

Biosystems and Agricultural Engineering Faculty Publications

Airflow resistance of grains and oilseeds has been extensively studied. Traditionally the data has been presented using Shedd’s curves. However, this assumes that airflow resistance is independent of grain depth. Grain undergoes compaction during storage that changes the bulk density, porosity, and therefore the airflow resistance. Ergun’s equation is a function of particle size and porosity of the granular material. Airflow resistance by Ergun’s equation was used to predict the pressure drop across a column of corn, soft white winter wheat, soft red winter wheat, and soybeans at three moisture content levels and two bulk densities. The maximum root mean …

Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Numerous factors influence the sizing of aeration fans for summer-harvested crops. Thirty years of weather data for Lexington, Kentucky, were analyzed and the cost of aeration was compared for two axial fans (afan1, afan2) and one centrifugal fan (cfan1). Aeration costs were defined as the sum of the following components: the cost of owning the fan, the cost of electricity for operating the fan, a cost for wheat shrinkage during aeration, and a cost for dry matter loss (DML). The fans were selected to deliver airflow rates of approximately one, two, and three times the recommended aeration rate of 0.11 …

Validation Of A Finite-Element Stored Grain Ecosystem Model, Michael D. Montross, Dirk E. Maier, Kamyar Haghighi

Biosystems and Agricultural Engineering Faculty Publications

An axisymmetric finite–element model was validated with respect to predicting the heat, mass, and momentum transfer that occurred in upright corrugated–steel storage bins due to conduction, diffusion, and natural convection using realistic boundary conditions. Hourly weather data that included hourly total solar radiation, wind speed, ambient temperature, and relative humidity were used to model the corn temperature and moisture content during storage with no aeration, and with ambient and chilled aeration. Periods of aeration were simulated assuming a uniform airflow rate through the grain mass. Sixteen bins with a capacity of 11.7 t each and instrumented with temperature cables were …

Development Of A Finite-Element Stored Grain Ecosystem Model, Michael D. Montross, Dirk E. Maier, Kamyar Haghighi

Biosystems and Agricultural Engineering Faculty Publications

An axisymmetric finite–element model was developed that predicts the heat, mass, and momentum transfer that occurred in upright corrugated steel storage structures due to conduction, diffusion, and natural convection using realistic boundary conditions. Weather data that included hourly total solar radiation, wind speed, ambient temperature, and relative humidity were used to model the temperature, moisture content, dry matter loss, and maize weevil development during storage with no aeration, and with ambient and chilled aeration. Periods of aeration were simulated assuming a uniform airflow rate through the grain mass. Heat and mass balances were used to calculate the temperature and absolute …

Reconditioning Corn And Soybeans To Optimal Processing Moisture Contents, Michael D. Montross, Dirk E. Maier

Biosystems and Agricultural Engineering Faculty Publications

Experimental trials were carried out to evaluate the technical feasibility of reconditioning overly dry corn and soybeans to optimal market and processing moisture contents. Data obtained from experimental trials were used to validate an aeration simulation model. This model was used to evaluate the feasibility of reconditioning soybeans and corn. Reconditioning of grain was feasible at low airflow rates (0.11 m³ min^–1 t^–1) over a six-month period when an automatic aeration controller was used. Using downflow aeration and monthly unloading of the bin allowed for the greatest net economic gain. Predicted reconditioning in Des Moines, Iowa, …

Optimization Of Solid-State Fermentation Parameters For The Production Of Xylanase By Trichoderma Longibrachiatum On Wheat Bran In A Forced Aeration System, Elizabeth R. Ridder, Sue E. Nokes, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

The effect of aeration on the production of xylanase by Trichoderma longibrachiatum on wheat bran in a solid-state fermentation (SSF) system has not been investigated. This study was conducted to investigate the interactive effects of aeration, initial moisture content of the substrate, and depth of the substrate on xylanase activity produced in a tray fermenter. The experiment was conducted as a split plot experiment with factorial treatments and three replications of each treatment combination. The whole plot treatment was aeration rate (0, 2.9, 5.7 L/min/kg bran). Initial moisture content (45, 55, 65% w.b.) and depth of substrate (1.0 and 2.5 …

Jet Velocity Dissipation And Modelling With Aeration, Stephen J. Schlenker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of natural aeration and fall height upon velocity dissipation and modelling were studied. Underwater velocities and void ratios (proportion of air volume to total volume) were measured along the jet centerline at various depths in the receiving pool under 1- and 2-inch diameter vertical circular free-falling jets. Maximum air bubble penetration depths were also measured. In the tests, the nozzle velocities were designed so that the two differently sized models would have equivalent Froude numbers for direct comparison of respective underwater parameters. Air entrainment-the natural development of air bubbles within a pool receiving a free-falling jet-causes voids to …

An Aeration Duct Design Model For Flat Grain Storage, Thomas C. Bridges, Douglas G. Overhults, Samuel G. Mcneill, G. M. White

Biosystems and Agricultural Engineering Faculty Publications

Traditionally most grain is stored in circular type bins which provide a convenient means for handling and management. With the excess grain production and government loan programs of the past few years, some producers have used rectangular structures and covered piles to complement their round storages. The recommended management practices used with round bins are still required in those alternative storages and may be more critical in obtaining a quality end product.

One such recommended practice used with round bins is aeration. This practice is used to maintain a uniform temperature in the grain mass, preventing condensation and "hot" spots …