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Full-Text Articles in Life Sciences

Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss, Jolie Higgins Jun 2019

Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss, Jolie Higgins

Master's Theses and Project Reports

Estuaries are dynamic environments that are strongly affected by natural variability, as well as direct and indirect anthropogenic impacts. A better understanding of the drivers of carbon fluxes and biogeochemical variability in estuarine systems is needed, particularly with the increasing threat of ocean acidification. Morro Bay in Central California is a small nationally protected estuary, with seasonally low freshwater inputs. Since 2007, the bay has experienced a significant loss of native seagrass, Zostera marina, which is an important component of the marine ecosystem. Because seagrass photosynthesis decreases carbon dioxide and increases oxygen in the water column, the loss of seagrass ...


The Effect Of Destoning And Enzymatic Pretreatments On The Biofuel Production From Olive Cake, Patrick Tai Jul 2018

The Effect Of Destoning And Enzymatic Pretreatments On The Biofuel Production From Olive Cake, Patrick Tai

Master's Theses and Project Reports

More than 16,000 tons of olive cake was produced in the United States in 2017. Olive cake is a by-product of olive oil extraction, which has limited animal feed potential, and poses an environmental threat when landfilled due to its high organic load and polyphenol content. This residue has potential for biofuel (bioethanol and biomethane) production because it is rich in polysaccharides such as pectin, hemicellulose, and cellulose. Yet, olive cake contains olive stones that can impede its conversion to biofuel. Therefore, two methods of destoning, centrifugation and screening by horizontal screw press, were first compared. Both methods removed ...


Effect Of Bioaugmentation Product Biowish® Aqua™ On Nitrogen Removal In Wastewater, Patrick Cassidy Kalvass Jun 2018

Effect Of Bioaugmentation Product Biowish® Aqua™ On Nitrogen Removal In Wastewater, Patrick Cassidy Kalvass

Master's Theses and Project Reports

Biological nutrient removal (BNR) from wastewater, and specifically nitrogen removal, is a growing concern to wastewater dischargers such as municipalities. Excess nutrients in effluent can create problems such as eutrophication, toxicity to aquatic life, and dissolved oxygen depletion in receiving waters. BNR systems have been installed in many locations with success, but their operation presents operational and financial demands greater than conventional biological treatment. Nitrogen removal is typically performed in sequential autotrophic nitrification and denitrification, which increases needed energy input, operational complexity, and therefore cost. Simultaneous nitrification-denitrification (SNdN) achieved in a single system has also been successfully implemented, however operational ...


Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts Dec 2015

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses and Project Reports

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO2-supplemented raceway ponds, each with a 33-m2 surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously ...


Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson Dec 2014

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses and Project Reports

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced ...


Optimization Of Growth Parameters For Algal Regrowth Potential Experiments, Chadwick D. Boggess Jun 2014

Optimization Of Growth Parameters For Algal Regrowth Potential Experiments, Chadwick D. Boggess

Master's Theses and Project Reports

Water cost is one of the key deterrents in making algal biofuels a feasible alternative to traditional petroleum fuels. Research into recycling of algal media was conducted in a laboratory setting at the California Polytechnic State University in San Luis Obispo. A growth assay was created to allow for algal cultures, specifically Ward’s Chlorella sp., to proliferate in sealed culture vessels. Bold’s Basal Medium (BBM) was selected as the media due to its extensive use with freshwater algal strains. However, this medium can limit algal growth through nutrient limitation and it became necessary to augment the original recipe ...


Lipid Production By Microalgae Treating Municipal Wastewater, James Edward Kelley Dec 2013

Lipid Production By Microalgae Treating Municipal Wastewater, James Edward Kelley

Master's Theses and Project Reports

Microalgae hold much promise as a feedstock in liquid biofuel production. Lipid content of microalgae cells range from 30-80% dry weight of biomass. It is projected that microalgae can produce between 1,000-6,500 gallons/acre/year of oil. Currently, production of industrial algae operates in open raceway ponds that use minimal capital and energy inputs to culture algae. Raceway ponds can also be used to grow microalgae from municipal waste streams. Although high biomass productivity can be achieved in these systems, there remains a large production gap between large volumes of biomass cultivation and high lipid content from microalgae ...


Settling Performance In Wastewater Fed High Rate Algae Ponds, Elliott Blake Ripley Jun 2013

Settling Performance In Wastewater Fed High Rate Algae Ponds, Elliott Blake Ripley

Master's Theses and Project Reports

Although high rate algae ponds (HRAPs) are a proven wastewater treatment technology with numerous environmental, social, and economic benefits, their widespread use has been hindered by inconsistent and unreliable settling performance. Hence, the goal of this thesis is to investigate how specific operational parameters affect the settling performance of HRAPs. Nine HRAPs (30 m2 surface area, 0.3 m depth) were operated as three triplicate sets, with each set run on either a 2, 3, or 4 day HRT continuously from January 25, 2012 through April 11, 2013. Settling performance was determined (i) by measuring the TSS of Imhoff ...


Investigating Wood Welding Parameters Using A Prototype Welding Machine, Timothy R. Melin Dec 2010

Investigating Wood Welding Parameters Using A Prototype Welding Machine, Timothy R. Melin

Master's Theses and Project Reports

Understanding how different processing variables influence wood welded bonds is vital if the technique will ever be used to create engineered lumber without using adhesives. A variation of vibration welding, wood welding uses pressure and friction to bond materials together. During welding, heat causes a softening in the wood, a naturally occurring composite material. This softening leads to fiber entanglement and a bond forms upon cooling.

The goal of this research was to investigate several processing aspects of the wood welding procedure. A prototype wood welding machine, designed and fabricated from the ground up, was used to investigate the effects ...


Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz Feb 2009

Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz

Master's Theses and Project Reports

Microalgae are considered one of the most promising feedstocks for biofuel production for the future. The most efficient way to produce vast amounts of algal biomass is the use of closed tubular photobioreactors (PBR). The heat requirement for a given system is a major concern since the best algae growth rates are obtained between 25-30 °C, depending on the specific strain. A procedure to determine temperature influence on algal growth rates was developed for a lab-scale PBR system using the species Chlorella. A maximum growth rate of 1.44 doublings per day at 29 °C (optimal temperature) was determined. In ...