A5073788307- Mine drainage and remediation techniques
- Wastewater Treatment and Nitrogen Removal
- Tailings Management and Properties
- Metal Extraction and Bioleaching
- Radioactive element chemistry and processing
- Constructed Wetlands for Wastewater Treatment
- Extraction and Separation Processes
- Water Treatment and Disinfection
- Water-Energy-Food Nexus Studies
- Membrane Separation Technologies
- Mining and Resource Management
- Anaerobic Digestion and Biogas Production
- Wastewater Treatment and Reuse
- Material Properties and Failure Mechanisms
- Asphalt Pavement Performance Evaluation
- Groundwater flow and contamination studies
- Odor and Emission Control Technologies
- Atmospheric and Environmental Gas Dynamics
- Minerals Flotation and Separation Techniques
- Radioactivity and Radon Measurements
- Geochemistry and Geologic Mapping
- Recycling and Waste Management Techniques
- Infrastructure Maintenance and Monitoring
- Phosphorus and nutrient management
- Microbial Fuel Cells and Bioremediation
Colorado School of Mines
2015-2024
Stanford University
2022-2023
Universidad Nacional de Colombia
2022
European Grid Infrastructure
2018-2019
ExxonMobil (United States)
2014
Denver School of Nursing
2010
Instituto de Aeronáutica e Espaço
2010
Instituto Tecnológico de Aeronáutica
2010
Tetra Tech (United States)
2007
Colorado State University
2005
Wildfires at the wildland–urban interface (WUI) are increasing in frequency and intensity, driven by climate change anthropogenic ignitions. Few studies have characterized variability metal content ash generated from burned structures order to determine potential risk human environmental health. Using inductively coupled plasma optical emission spectroscopy (ICP-OES) mass spectrometry (ICP-MS), we analyzed leachable trace concentration soils Marshall Fire, a WUI fire that destroyed over 1000...
ABSTRACT The kinetics for the reduction of sulfate alone and concurrent uranium [U(VI)] reduction, by mixed pure cultures sulfate-reducing bacteria (SRB) at 21 ± 3°C were studied. culture contained SRB Desulfovibrio vulgaris along with a Clostridium sp. determined via 16S ribosomal DNA analysis. was desulfuricans (ATCC 7757). A zero-order model best fit data from 0.1 to 10 mM. lag time occurred below cell concentrations mg (dry weight) cells/ml. For culture, average values maximum specific...
The reduction kinetics of soluble hexavalent uranium (U(VI)) to insoluble tetravalent U(IV) by both a mixed culture wild-type sulfate-reducing bacteria (SRB) and pure Desulfovibrio desulfuricans (ATCC 7757) were studied at variable cell concentrations. SRB grown in chemostats, the evaluated from batch experiments 21 °C. initial U(VI) concentration was 1 mM, while varied 0.18 1.27 mg dry wt/mL. A modified nongrowth Monod model best fit data across all For culture, average values for maximum...
ABSTRACT: The effects of particulate and soluble organic matter (BOD) on nitrification were investigated in laboratory experiments using a bench‐scale rotating biological contactor (RBC). This work was initiated by lower than expected rates the second stage biofilm processes at Longmont Waste Water Treatment Plant (LWWTP). It hypothesized that this due to since BOD influent low. For range 12 82 mg/L total pilot RBC; found inhibit same degree as BOD. In fact, (soluble plus particulate) be...
Abstract A nondestructive method of measuring extracellular polysaccharides (ECP) in activated sludge floes using Ruthenium Red dye adsorption was developed at the Environmental Engineering Laboratory University Colorado Boulder. The effects pH, buffer solution, concentration, mass, temperature, and incubation time on determined. to bacterial found fit a Brunauer–Emmett–Teller (BET) isotherm model. Of other environmental conditions system, pH have strongest effect flocs. amount extra...
Gold cyanidation facilities in the Arequipa Region of Peru are challenged by availability and quality water for processing an arid environment. The reuse decant which recycles residual cyanide but also undesirable constituents. To understand impact intensive recycling on metals concentrations, we collected barren water, tailings samples from six gold with ore capacities 10-430 tons per day. Processing recycle all effluents, waters making up 58 ± 11 % process waters. Decant contained...
The effect of alkalinity on nitrifying biofilm activity was determined by collecting 21‐day‐old samples from the top a full‐scale trickling filter and evaluating bench‐scale nitrate plus nitrite generation rates at (1) various initial carbonate concentrations (2) with four types available alkalinity: only, phosphate hydroxide, carbonate. Initial were varied between 308and 20 mg/L as calcium (CaCO 3 ). Ammonia, nitrite, measured time zero, 90 minutes, 180 270 minutes. Generation in grams...
The objective of this study was to evaluate the lifecycle impacts anaerobic primary treatment domestic wastewater using baffled reactors (ABRs) coupled with aerobic secondary relative conventional and sludge/biosolids systems through application modeling three lifecycle-based analyses: environmental assessment, net energy balance, costing. Data from two pilot-scale ABRs operated under ambient temperatures were used model process. To address uncertain parameters in scale-up reactor data,...
Fluorescent in situ hybridization (FISH) was used to quantify the ammonia‐oxidizing populations within intact biofilm samples collected from a full‐scale nitrifying trickling filter (NTF). Ammonia, nitrite, and nitrate concentrations were measured for aqueous taken conjunction with at multiple depths. Correlation coefficients individual sampling events, calculated by simple linear regression of FISH signal area ammonia removal rates, ranged 0.558 when using probe NEU23a 0.982 Nso190. The...
Anaerobic hybrid reactor system for the generation of methane-rich biogas and energy. An energy-positive alternative to conventional primary treatment raw domestic wastewater.
Modeled electrical energy generation from anaerobic primary treatment of domestic wastewater with baffled bioreactors. Energy methane production exceeded use by conventional activated sludge in some scenarios.