Environmental Engineering Commons^™

Removal Of Boron From Produced Water By Co-Precipitation / Adsorption For Reverse Osmosis Concentrate, Imran Yusuf Rahman, Yarrow Nelson, Tryg Lundquist

Master's Theses

Co-precipitation and absorption methods were investigated for removal of boron from produced water, which is groundwater brought to the surface during oil and natural gas extraction. Boron can be toxic to many crops and often needs to be controlled to low levels in irrigation water. The present research focused on synthetic reverse osmosis (RO) concentrate modeled on concentrate expected from a future treatment facility at the Arroyo Grande Oil Field on the central coast of California. The produced water at this site is brackish with a boron concentration of 8 mg/L and an expected temperature of 80°C. The future overall …

Simultaneous Nitrification And Denitrification Of Wastewater Using A Silicone Membrane Aerated Bioreactor, Kirk Hjelte Waltz

Master's Theses

The purpose of this thesis is to investigate the use of a single reactor to biologically treat wastewater by simultaneously oxidizing ammonia, and reducing nitrate and nitrite. The Environmental Protection Agency (EPA) places strict discharge restrictions on these compounds due to their inherent toxicity to humans, wildlife, and ecosystems. The use of a simultaneous system can assist the conventional wastewater treatment technology that requires separate systems, by creating a system that needs less time and smaller size to reach effluent requirements. To conduct this research, a bench-scale membrane aerated biofilm reactor was built using silicone tubing for aeration. Batch and …

Performance Of A Catch Basin Filter And Leachate From Biocidal Media For Stormwater Treatment, Ryan Scott Maclure

Master's Theses

The feasibility of installing biocidal beads into a catch basin filter insert for simultaneous stormwater disinfection and contaminant removal was tested. The catch basin filter insert (DrainPac®) was tested for its sediment, oil and grease, and coliform bacteria removal efficiency in conjunction with bench-scale testing of biocidal polymer beads. DrainPac® catch basin filters are composed of a metal frame, polypropylene filter fabric, and a high-density polymer support basket, and are installed below storm drains. A 12 x 41 in. DrainPac® filter (United Stormwater, Inc.) insert was set in a flume that simulated a large-scale catchment basin. Pond water was gravity …

Impacts Of Delayed Drawdown On Water Quality And Aquatic Biota In Seasonal Wetlands Of The Grassland Ecological Area, Los Banos, California, Kyle Nathan Poole

Master's Theses

The 178,000-acre Grassland Ecological Area in California’s San Joaquin Valley is managed to provide overwintering habitat to waterfowl on the Pacific Flyway. The major management activity is the fall flooding and spring drawdown of wetlands, timed to optimize the availability of forage vegetation and invertebrates for ducks and shorebirds. Wetland drainage contains salt, boron, and trace elements that are, in part, derived from imported surface water but also concentrate during storage in the wetland impoundments. The spring drawdown drainage contributes to occasional water quality violations in the San Joaquin River (SJR) during dry years. Compliance with water quality objectives may …

Phytoremediation Of Weathered Petroleum In Groundwater By Arroyo Willows In Nutrient Amended On-Site Mesocosms, Sarah E. Bragg-Flavan

Master's Theses

PHYTOREMEDIATION OF WEATHERED PETROLEUM IN GROUNDWATER BY ARROYO WILLOWS IN NUTRIENT AMENDED ON-SITE MESOCOSMS

SARAH BRAGG-FLAVAN

A large-scale mesocosm study was conducted to determine if vegetation with willow trees enhances biodegradation and to evaluate the mechanisms of natural biodegradation of weathered petroleum compounds under field conditions. The mesocosms were designed to model conditions at a former oil field where mid-range petroleum distillates were used as a diluent for pumping crude oil contaminated the soil and groundwater at the site with petroleum compounds. Ten mesocosms were constructed at the field site using un-impacted soil and diluent-impacted groundwater from the site. Five …

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

Master's Theses

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 addition, …

Bioflocculation For Control Of Wastewater Pond Microalgae, Daniel Thomas Frost

Master's Theses

Investigates several hypotheses regarding the use of bioflocculation as a harvesting method for wastewater pond microalgae. Research performed on pilot-scale high rate ponds (HRPs) on the California Central Coast.

Lipid Productivity Of Algae Grown On Dairy Wastewater As A Possible Feedstock For Biodiesel, Ian C. Woertz

Master's Theses

The objective of this thesis is to develop a biological wastewater treatment system that utilizes algal growth to simultaneously create renewable energy in the form of biodiesel and digester biogas, remove polluting nutrients, and abate greenhouse gases. Research under the Department of Energy Aquatic Species Program during 1978-1996 concluded that cultivating algae for biofuels was cost prohibitive at that time and that an integrated approach should be studied that combined wastewater treatment with algal biofuel production. Nutrient removal, in particular nitrogen and phosphorus, from wastewater is a growing regulatory need and the use of algae cultivation could create a unique …