Kelly Rusch - Academia.edu (original) (raw)

Papers by Kelly Rusch

Environmental engineering, 1999

The objective of this study was the design, construction and evaluation of a natural, marsh-based... more The objective of this study was the design, construction and evaluation of a natural, marsh-based system using a sand/soil bed in a shallow upwelling field to remove fecal coliforms from coastal dwelling wastewater. Wastewater was injected at a 15 foot depth and movement of the wastewater was monitored with wells at 5, 10, and 15 foot depths. Monitoring salinity showed development of an extensive fresh water plume at the 5 foot depth, less at the 10 foot and none at the 15 foot depth; the system effectively reduced the fecal coliform concentrations to <1 colony per 100 mL as the wastewater traveled through the soil.

The Louisiana State University (LSU) College of Engineering’s ENG Project is designed to increase... more The Louisiana State University (LSU) College of Engineering’s ENG Project is designed to increase the number of engineering and construction management graduates through retention programs aimed at developing and maintaining a sense of community among the students and faculty, enhancing academic skills of the students, and providing a framework for interactions between faculty, students and industry personnel. The project hosts three main programs: a Faculty Development Workshop, the Encounter Engineering Bridge Camp (E), and a freshman course, ENGR 1050 Introduction to Engineering. The project also hosts several of its professional development and academic enhancement activities in the Engineering Residential College (ERC), a residential hall for freshmen. Finally, the project is expanding Peer Mentoring, which emerged from the bridge camp team captains, and now is incorporated into ENGR 1050. Assessment includes individual program elements and overall impact on retention. Feedback...

This research studied the impact of salinity on sorption and transport of MS-2 in saturated sand ... more This research studied the impact of salinity on sorption and transport of MS-2 in saturated sand through one-dimensional column experiments. MS-2 was used as a surrogate to understand viral fate and transport in subsurface environment. The controlled conditions in all experiments included constant flow rates (4.0 cm/min), neutral condition (pH=7.0 ± 0.5), and constant temperature (25 ± 0.2 0 C). Bromide was adopted as the conservative tracer to evaluate the dispersion coefficient of MS-2 in the column. The MS-2 in nanopure water showed weak adsorption effect due to its same negative charge as the sand. The MS-2 in saline water showed dramatically enhanced adsorption effect. This result can be explained by two-site sorption process. Salinity could increase MS-2 attachment by compressing double layers on reversible sorption site, increasing charge intensity on irreversible sorption site, and reversing charges on the surface of silica powder. A fate and transport model, coupled with tw...

Proceedings of the Water Environment Federation, 2004

The marshland upwelling system (MUS) was designed as an economical alternative onsite domestic wa... more The marshland upwelling system (MUS) was designed as an economical alternative onsite domestic wastewater treatment system for campsites in coastal areas of Louisiana. Domestic wastewater produced at campsites is equalized in a large primary distribution/collection tank then injected deep (3.05 m-7.62 m) into the substrata marsh environment via a progressing cavity pump. The density gradient created between the fresh wastewater and the saline native groundwater provides the driving force to push the wastewater up through the marsh toward the surface. In theory, this is similar to an upside-down sand filter or vertical subsurface flow wetland. Bacterial pathogens are removed from the wastewater through physical straining, adsorption, and predation via the natural soil matrix. Over time, fixed-film anaerobic bacteria develop in the marsh substrata soil environment and break down the soluble and particulate organic matter in the injected wastewater, complementing or increasing the removal rate of bacterial pathogens through biofilm development. Although the majority of the solids (60-80 %) are removed in the primary wastewater distribution/collection tank through settling and floatation, a considerable amount of suspended organic and inorganic solids are injected into MUS over time. The organic solids degrade to soluble CBOD 5 (sCBOD 5) in the subsurface environment of the marsh. This has both a positive and negative effect on the system. Increased solid loadings to the MUS system decreases the hydraulic conductivity of the system over time by filling the interstitial pore spaces of the soil matrix, but the organic nature of the majority of suspended solids injected provides a continuous source of substrate needed to maintain a healthy and productive biological community. The slightly negative charge associated with the clayey soils of the substrata marsh environment provides excellent adsorption sites for the cationic pollutants commonly associated with domestic wastewaters (i.e. Nutrients-Ammonia). KEYWORDS Organic matter, carbonaceous biochemical oxygen demand (CBOD 5), subsurface flow wetlands (SSF), constructed wetlands, soil adsorption fields, onsite domestic wastewater treatment, decentralized domestic wastewater treatment.

Journal of Physics: Condensed Matter, 2009

Different coalescence processes on 1D silver nanostructures synthesized by a PVP assisted reactio... more Different coalescence processes on 1D silver nanostructures synthesized by a PVP assisted reaction in ethylene glycol at 160 °C were studied experimentally and theoretically. Analysis by TEM and HRTEM shows different defects found on the body of these materials, suggesting that they were induced by previous coalescence processes in the synthesis stage. TEM observations showed that irradiation with the electron beam eliminates the boundaries formed near the edges of the structures, suggesting that this process can be carried out by the application of other means of energy (i.e. thermal). These results were also confirmed by theoretical calculations by Monte Carlo simulations using a Sutton-Chen potential. A theoretical study by molecular dynamics simulation of the different coalescence processes on 1D silver nanostructures is presented, showing a surface energy driven sequence followed to form the final coalesced structure. Calculations were made at 1000-1300 K, which is near the melting temperature of silver (1234 K). Based on these results, it is proposed that 1D nanostructures can grow through a secondary mechanism based on coalescence, without losing their dimensionality.

Water Environment Research, 2001

The Marshland Upwelling System (MUS), a potential alternative wastewater treatment strategy for c... more The Marshland Upwelling System (MUS), a potential alternative wastewater treatment strategy for coastal dwellings, was examined to assess its ability to remove fecal coliforms (FC) from domestic wastewater as a step towards total treatment. Wastewater was intermittently injected down a 4.6‐m injection well into the surrounding salt marsh. Optimal performance was achieved at an injection flowrate of 1.9 L/min and injection frequency of 30 minutes every 3 hours. Average influent concentrations of 930 000 ± 650 000 colonies/100 mL were reduced to effluent counts of 4.6 colonies/100 mL. Coliform removal followed exponential decay versus vector distance traveled with predicted surface concentrations less than or equal to 0.1 colony/100 mL. Hydraulic performance was acceptable with no significant reductions in permeability observed. Increasing flows to 3.8 L/min produced localized hydraulic dysfunction as indicated by sudden increases in effluent bacterial counts and injection pressures. ...

Synthesis Lectures on Engineers, Technology and Society, 2008

Proceedings of the Water Environment Federation, 2004

The marshland upwelling system (MUS) was installed in a f loating marsh along the banks of the Ba... more The marshland upwelling system (MUS) was installed in a f loating marsh along the banks of the Bayou Segnette Waterway in the Barataria-Terebonne Estuary, Louisiana. The site is characterized by native groundwater with low salinity regimes. The system was evaluated for its effectiveness in removing fecal coliforms from settled, raw wastewater. A suite of studies typified by injection flowrates of 0.9 and 1.9 L/min were performed to determine fecal coliform removal efficacy. In addition, a worse case study was performed to investigate the impacts of excessive loading rates on bacterial removal. The worst-case study proved most effective in removing fecal coliforms. The depth of injection and biofilm development processes may be responsible for the observed removal trend. Mean influent concentrations of 92,510±489,614 were reduced to effluent concentrations of 4.0±7.6 (observed in the 2.7 m wells). Four-log reductions in influent concentrations were observed within a one-meter radial distance from the injection point. Overall removal followed a first-order decay relationship with respect to vector distance. Removal rate constants for fecal coliforms ranged from 1.5-2.0 m-1 for fecal coliforms, while that for E. coli ranged from 1.6-3.6 m-1. Continuous injection experiments performed in one-dimensional columns packed with clayey soils from the field recorded bacterial retardation factors of between 7.3 and 14.5 with respect to the conservative wastewater tracer. Higher limitations to bacterial transport would be expected under field-scale conditions. Laboratory simulated conditions under varying salinity concentrations and differing temperatures were used to determine inactivation rates for fecal coliforms. Rapid inactivation rates were recorded for each temperature studied (up to day 3), after which the die-off process slowed down. The higher temperature (25 o C) was more detrimental to fecal coliform survival than the 20 o C study. Variability in salinity concentrations appeared to be detrimental to fecal coliform survival in instances where there was synergism with temperature variations.

... During the 1970&amp;amp;#x27;s, more attention was paid to the problems associated with t... more ... During the 1970&amp;amp;#x27;s, more attention was paid to the problems associated with the aquatic life found in tainted waters. Originally, Thaysen and $1 ©1988lEEE Page 2. ... 5. 97 pp. Thaysen, AC 1936. The origin of an earthy or muddy taint in fish, I. The nature and isolation of the taint. ...

Proceedings of SPIE, Feb 28, 2017

Proceedings of the Water Environment Federation, 2004

Journal of Environmental Engineering, Nov 1, 2007

The marshland upwelling system (MUS) was developed as a treatment alternative for wastewater deri... more The marshland upwelling system (MUS) was developed as a treatment alternative for wastewater derived from coastal communities. This research assessed the treatment efficiency of the MUS for removing both total phosphorus and ortho-phosphate from domestic wastewater under low (<10 ppt) background, saline conditions. Over 23 months of operation, wastewater was intermittently injected at a depth of 4.3 m using flow rates of 0.9 (15 min/h) and 1.9 L/min (two studies; 15 and 30 min/h). Removal rate coefficients of 1.26, 1.09 and 1.20 m −1 were obtained for the 0.9 (15 min/h), 1.9 L/min (15 min/h) and 1.9 L/min (30 min/h) studies, respectively. Treatment efficiency was >99% for all three studies, with predicted travel distances ranging from 4.63 to 6.41 m to reach a target effluent of 0.1 mg-P/L. Predicted, required travel distances increased during the study as phosphorus saturation developed. The MUS system is unique in that it does not have fixed boundaries. Subsequently, wastewater can move past the zones of saturation to sediments that have active adsorption sites, thus providing increased capacity and treatment efficiency.

Meeting abstracts, 2016

In this work, we present a fluorescent sensing system capable of simultaneously detecting two spe... more In this work, we present a fluorescent sensing system capable of simultaneously detecting two species during microalgal co-culture, in which microalgae (C. vulgaris) and cyanobacteria (Leptolyngbya sp.) are the target species for detection. The sensing system has two different excitation light sources for stimulating chlorophyll ain microalgae and phycocyanin pigment in cyanobacteria, respectively, and a photodetector to measure corresponding fluorescent signals. This work is a significant improvement over our previous report on a fluorescent sensing system for single species [1]. Microalgae are one of the promising alternative energy sources [2]. Recent reports show that a co-culture system enhances biofuel production [3] and it is desired to monitor the population of each species. The co-inoculation of microalgae and cyanobacteria promotes the growth rate and lifespan of microalgae [4,5]. It is highly desired to simultaneously monitor the populations of microalgae and cyanobacteria in order to obtain highly efficient biofuel production. A common method is bench-top flow cytometry, which is time consuming, expensive, and difficult to deploy for on-site detection. The proposed portable fluorescent sensing system can be a viable option for on-site monitoring of co-culture solution containing microalgae and cyanobacteria. For the fluorescent sensing system, blue LEDs (448 nm peak wavelength) were selected for stimulating microalgae and amber LEDs (590 nm) for cyanobacteria. A highly sensitive silicon photomuliplier, MicroFC (SensL Inc., Cork, Ireland), was implemented to detect a low fluorescent signal from phycocyanin in cyanobacteria. Chlorophyll aand phycocyanin emit fluorescent light with the peak wavelength around 680 nm and 645 nm, respectively. Two long-pass filters, a dichroic filter with 647 nm cut-off (PIXELTEQ, Largo, FL, USA) and a color filter with 645 nm cut-off (Edmund Optics, Barrington, NJ, USA), are placed in front of the silicon photomultiplier to block the excitation light as illustrated in Figure 1. Measured results show that the photocurrent increases with the population of microalgae under the blue excitation light while its change is not significant to the amber light. Likewise, the photocurrent increases with the concentration of phycocyanin pigments under the amber excitation light while its response to the blue light is minimal. In summary, we have developed and demonstrated a portable fluorescent sensing system that is capable of differentiating microalgae and cyanobacteria. With further optimization, the developed system can be deployed in a biofuel production system for continuous monitoring of co-culture solution. Future work will also include integrated electronic circuitry for a fully standalone fluorescent detection system. References: [1] Y.-H. Shin, J. Z. Barnett, E. Song, M. T. Gutierrez-Wing, K. A. Rusch and J.-W. Choi, Microelectronic Engineering. 144 (2015) 6-11. [2] Y. Chisti, Biotechnology Advances. 25 (2007) 294-306. [3] A. Silaban, R. Bai, M. T. Gutierrez-Wing, I. I. Negulescu, and K. A. Rusch. Engineering in Life Sciences. 14 (2014) 47-56. [4] L. E. Gonzalez and Y. Bashan, Applied And Environmental Microbiology. 66 (2000) 1527-1531. [5] L. E. de-Bashan, Y. Bashan, M. Moreno, V. K. Lebsky, and J. J. Bustillos, Canadian Journal of Microbiology. 48 (2002) 514-521. Figure 1

Letters in Applied Microbiology, Sep 11, 2012

Aims: To design a primer set enabling the identification through PCR of highquality DNA for routi... more Aims: To design a primer set enabling the identification through PCR of highquality DNA for routine and high-throughput genomic screening of a diverse range of cyanobacteria. Methods and Results: A codon-equivalent multiple alignment of the phycocyanin alpha-subunit coding sequence (cpcA) of 22 cyanobacteria was generated and analysed to produce a single degeneracy primer set with virtually uniform product size. Also, an 18S ribosomal RNA detection set is proposed for rejecting false positives. The primer sets were tested against five diverse cyanobacteria, Chlorella vulgaris, Saccharomyces cerevisiae, and Escherichia coli. All five cyanobacteria showed positive amplification of cpcA product with homogeneous fragment length, and no products were observed for any other organism. Additionally, the only product formation observed for the 18S rRNA set was in C. vulgaris and S. cerevisiae. Conclusions: The newly proposed primer set served as effective check primers for cyanobacteria. Cyanobacteria gDNA had a positive, homogenous result, while other bacteria, eukaryotes and alga tested were negative. Significance and Impact of the Study: These novel, broad-spectrum primers will greatly increase the utility of PCR on newly discovered cyanobacterial species.

Engineering in Life Sciences, Feb 28, 2017

Light effect on cultures of microalgae has been studied mainly on single species cultures. Cyanob... more Light effect on cultures of microalgae has been studied mainly on single species cultures. Cyanobacteria have photosynthetic pigments that can capture photons of wavelengths not available to chlorophylls. A native Louisiana microalgae (Chlorella vulgaris) and cyanobacteria (Leptolyngbya sp.) co-culture was used to study the effects of light quality (blue-467 nm, green-522 nm, red-640 nm and white-narrow peak at 450 nm and a broad range with a peak at 550 nm) at two irradiance levels (80 and 400 μmol m −2 s −1) on the growth, species composition, biomass productivity, lipid content and chlorophyll-a production. The co-culture shifted from a microalgae dominant culture to a cyanobacteria culture at 80 μmol m −2 s −1. The highest growth for the cyanobacteria was observed at 80 μmol μmol m −2 s −1 and for the microalgae at 400 μmol m −2 s −1. Red light at 400 μmol m −2 s −1 had the highest growth rate (0.41 d −1), biomass (913 mg L −1) and biomass productivity (95 mg L −1 d −1). Lipid content was similar between all light colors. Green light had the highest chlorophyll-a content (1649 μg/L). These results can be used to control the species composition of mixed cultures while maintaining their productivity.

Environmental engineering, 1999

The objective of this study was the design, construction and evaluation of a natural, marsh-based... more The objective of this study was the design, construction and evaluation of a natural, marsh-based system using a sand/soil bed in a shallow upwelling field to remove fecal coliforms from coastal dwelling wastewater. Wastewater was injected at a 15 foot depth and movement of the wastewater was monitored with wells at 5, 10, and 15 foot depths. Monitoring salinity showed development of an extensive fresh water plume at the 5 foot depth, less at the 10 foot and none at the 15 foot depth; the system effectively reduced the fecal coliform concentrations to <1 colony per 100 mL as the wastewater traveled through the soil.

The Louisiana State University (LSU) College of Engineering’s ENG Project is designed to increase... more The Louisiana State University (LSU) College of Engineering’s ENG Project is designed to increase the number of engineering and construction management graduates through retention programs aimed at developing and maintaining a sense of community among the students and faculty, enhancing academic skills of the students, and providing a framework for interactions between faculty, students and industry personnel. The project hosts three main programs: a Faculty Development Workshop, the Encounter Engineering Bridge Camp (E), and a freshman course, ENGR 1050 Introduction to Engineering. The project also hosts several of its professional development and academic enhancement activities in the Engineering Residential College (ERC), a residential hall for freshmen. Finally, the project is expanding Peer Mentoring, which emerged from the bridge camp team captains, and now is incorporated into ENGR 1050. Assessment includes individual program elements and overall impact on retention. Feedback...

This research studied the impact of salinity on sorption and transport of MS-2 in saturated sand ... more This research studied the impact of salinity on sorption and transport of MS-2 in saturated sand through one-dimensional column experiments. MS-2 was used as a surrogate to understand viral fate and transport in subsurface environment. The controlled conditions in all experiments included constant flow rates (4.0 cm/min), neutral condition (pH=7.0 ± 0.5), and constant temperature (25 ± 0.2 0 C). Bromide was adopted as the conservative tracer to evaluate the dispersion coefficient of MS-2 in the column. The MS-2 in nanopure water showed weak adsorption effect due to its same negative charge as the sand. The MS-2 in saline water showed dramatically enhanced adsorption effect. This result can be explained by two-site sorption process. Salinity could increase MS-2 attachment by compressing double layers on reversible sorption site, increasing charge intensity on irreversible sorption site, and reversing charges on the surface of silica powder. A fate and transport model, coupled with tw...

Proceedings of the Water Environment Federation, 2004

The marshland upwelling system (MUS) was designed as an economical alternative onsite domestic wa... more The marshland upwelling system (MUS) was designed as an economical alternative onsite domestic wastewater treatment system for campsites in coastal areas of Louisiana. Domestic wastewater produced at campsites is equalized in a large primary distribution/collection tank then injected deep (3.05 m-7.62 m) into the substrata marsh environment via a progressing cavity pump. The density gradient created between the fresh wastewater and the saline native groundwater provides the driving force to push the wastewater up through the marsh toward the surface. In theory, this is similar to an upside-down sand filter or vertical subsurface flow wetland. Bacterial pathogens are removed from the wastewater through physical straining, adsorption, and predation via the natural soil matrix. Over time, fixed-film anaerobic bacteria develop in the marsh substrata soil environment and break down the soluble and particulate organic matter in the injected wastewater, complementing or increasing the removal rate of bacterial pathogens through biofilm development. Although the majority of the solids (60-80 %) are removed in the primary wastewater distribution/collection tank through settling and floatation, a considerable amount of suspended organic and inorganic solids are injected into MUS over time. The organic solids degrade to soluble CBOD 5 (sCBOD 5) in the subsurface environment of the marsh. This has both a positive and negative effect on the system. Increased solid loadings to the MUS system decreases the hydraulic conductivity of the system over time by filling the interstitial pore spaces of the soil matrix, but the organic nature of the majority of suspended solids injected provides a continuous source of substrate needed to maintain a healthy and productive biological community. The slightly negative charge associated with the clayey soils of the substrata marsh environment provides excellent adsorption sites for the cationic pollutants commonly associated with domestic wastewaters (i.e. Nutrients-Ammonia). KEYWORDS Organic matter, carbonaceous biochemical oxygen demand (CBOD 5), subsurface flow wetlands (SSF), constructed wetlands, soil adsorption fields, onsite domestic wastewater treatment, decentralized domestic wastewater treatment.

Journal of Physics: Condensed Matter, 2009

Different coalescence processes on 1D silver nanostructures synthesized by a PVP assisted reactio... more Different coalescence processes on 1D silver nanostructures synthesized by a PVP assisted reaction in ethylene glycol at 160 °C were studied experimentally and theoretically. Analysis by TEM and HRTEM shows different defects found on the body of these materials, suggesting that they were induced by previous coalescence processes in the synthesis stage. TEM observations showed that irradiation with the electron beam eliminates the boundaries formed near the edges of the structures, suggesting that this process can be carried out by the application of other means of energy (i.e. thermal). These results were also confirmed by theoretical calculations by Monte Carlo simulations using a Sutton-Chen potential. A theoretical study by molecular dynamics simulation of the different coalescence processes on 1D silver nanostructures is presented, showing a surface energy driven sequence followed to form the final coalesced structure. Calculations were made at 1000-1300 K, which is near the melting temperature of silver (1234 K). Based on these results, it is proposed that 1D nanostructures can grow through a secondary mechanism based on coalescence, without losing their dimensionality.

Water Environment Research, 2001

The Marshland Upwelling System (MUS), a potential alternative wastewater treatment strategy for c... more The Marshland Upwelling System (MUS), a potential alternative wastewater treatment strategy for coastal dwellings, was examined to assess its ability to remove fecal coliforms (FC) from domestic wastewater as a step towards total treatment. Wastewater was intermittently injected down a 4.6‐m injection well into the surrounding salt marsh. Optimal performance was achieved at an injection flowrate of 1.9 L/min and injection frequency of 30 minutes every 3 hours. Average influent concentrations of 930 000 ± 650 000 colonies/100 mL were reduced to effluent counts of 4.6 colonies/100 mL. Coliform removal followed exponential decay versus vector distance traveled with predicted surface concentrations less than or equal to 0.1 colony/100 mL. Hydraulic performance was acceptable with no significant reductions in permeability observed. Increasing flows to 3.8 L/min produced localized hydraulic dysfunction as indicated by sudden increases in effluent bacterial counts and injection pressures. ...

Synthesis Lectures on Engineers, Technology and Society, 2008

Proceedings of the Water Environment Federation, 2004

The marshland upwelling system (MUS) was installed in a f loating marsh along the banks of the Ba... more The marshland upwelling system (MUS) was installed in a f loating marsh along the banks of the Bayou Segnette Waterway in the Barataria-Terebonne Estuary, Louisiana. The site is characterized by native groundwater with low salinity regimes. The system was evaluated for its effectiveness in removing fecal coliforms from settled, raw wastewater. A suite of studies typified by injection flowrates of 0.9 and 1.9 L/min were performed to determine fecal coliform removal efficacy. In addition, a worse case study was performed to investigate the impacts of excessive loading rates on bacterial removal. The worst-case study proved most effective in removing fecal coliforms. The depth of injection and biofilm development processes may be responsible for the observed removal trend. Mean influent concentrations of 92,510±489,614 were reduced to effluent concentrations of 4.0±7.6 (observed in the 2.7 m wells). Four-log reductions in influent concentrations were observed within a one-meter radial distance from the injection point. Overall removal followed a first-order decay relationship with respect to vector distance. Removal rate constants for fecal coliforms ranged from 1.5-2.0 m-1 for fecal coliforms, while that for E. coli ranged from 1.6-3.6 m-1. Continuous injection experiments performed in one-dimensional columns packed with clayey soils from the field recorded bacterial retardation factors of between 7.3 and 14.5 with respect to the conservative wastewater tracer. Higher limitations to bacterial transport would be expected under field-scale conditions. Laboratory simulated conditions under varying salinity concentrations and differing temperatures were used to determine inactivation rates for fecal coliforms. Rapid inactivation rates were recorded for each temperature studied (up to day 3), after which the die-off process slowed down. The higher temperature (25 o C) was more detrimental to fecal coliform survival than the 20 o C study. Variability in salinity concentrations appeared to be detrimental to fecal coliform survival in instances where there was synergism with temperature variations.

... During the 1970&amp;amp;#x27;s, more attention was paid to the problems associated with t... more ... During the 1970&amp;amp;#x27;s, more attention was paid to the problems associated with the aquatic life found in tainted waters. Originally, Thaysen and $1 ©1988lEEE Page 2. ... 5. 97 pp. Thaysen, AC 1936. The origin of an earthy or muddy taint in fish, I. The nature and isolation of the taint. ...

Proceedings of SPIE, Feb 28, 2017

Proceedings of the Water Environment Federation, 2004

Journal of Environmental Engineering, Nov 1, 2007

The marshland upwelling system (MUS) was developed as a treatment alternative for wastewater deri... more The marshland upwelling system (MUS) was developed as a treatment alternative for wastewater derived from coastal communities. This research assessed the treatment efficiency of the MUS for removing both total phosphorus and ortho-phosphate from domestic wastewater under low (<10 ppt) background, saline conditions. Over 23 months of operation, wastewater was intermittently injected at a depth of 4.3 m using flow rates of 0.9 (15 min/h) and 1.9 L/min (two studies; 15 and 30 min/h). Removal rate coefficients of 1.26, 1.09 and 1.20 m −1 were obtained for the 0.9 (15 min/h), 1.9 L/min (15 min/h) and 1.9 L/min (30 min/h) studies, respectively. Treatment efficiency was >99% for all three studies, with predicted travel distances ranging from 4.63 to 6.41 m to reach a target effluent of 0.1 mg-P/L. Predicted, required travel distances increased during the study as phosphorus saturation developed. The MUS system is unique in that it does not have fixed boundaries. Subsequently, wastewater can move past the zones of saturation to sediments that have active adsorption sites, thus providing increased capacity and treatment efficiency.

Meeting abstracts, 2016

In this work, we present a fluorescent sensing system capable of simultaneously detecting two spe... more In this work, we present a fluorescent sensing system capable of simultaneously detecting two species during microalgal co-culture, in which microalgae (C. vulgaris) and cyanobacteria (Leptolyngbya sp.) are the target species for detection. The sensing system has two different excitation light sources for stimulating chlorophyll ain microalgae and phycocyanin pigment in cyanobacteria, respectively, and a photodetector to measure corresponding fluorescent signals. This work is a significant improvement over our previous report on a fluorescent sensing system for single species [1]. Microalgae are one of the promising alternative energy sources [2]. Recent reports show that a co-culture system enhances biofuel production [3] and it is desired to monitor the population of each species. The co-inoculation of microalgae and cyanobacteria promotes the growth rate and lifespan of microalgae [4,5]. It is highly desired to simultaneously monitor the populations of microalgae and cyanobacteria in order to obtain highly efficient biofuel production. A common method is bench-top flow cytometry, which is time consuming, expensive, and difficult to deploy for on-site detection. The proposed portable fluorescent sensing system can be a viable option for on-site monitoring of co-culture solution containing microalgae and cyanobacteria. For the fluorescent sensing system, blue LEDs (448 nm peak wavelength) were selected for stimulating microalgae and amber LEDs (590 nm) for cyanobacteria. A highly sensitive silicon photomuliplier, MicroFC (SensL Inc., Cork, Ireland), was implemented to detect a low fluorescent signal from phycocyanin in cyanobacteria. Chlorophyll aand phycocyanin emit fluorescent light with the peak wavelength around 680 nm and 645 nm, respectively. Two long-pass filters, a dichroic filter with 647 nm cut-off (PIXELTEQ, Largo, FL, USA) and a color filter with 645 nm cut-off (Edmund Optics, Barrington, NJ, USA), are placed in front of the silicon photomultiplier to block the excitation light as illustrated in Figure 1. Measured results show that the photocurrent increases with the population of microalgae under the blue excitation light while its change is not significant to the amber light. Likewise, the photocurrent increases with the concentration of phycocyanin pigments under the amber excitation light while its response to the blue light is minimal. In summary, we have developed and demonstrated a portable fluorescent sensing system that is capable of differentiating microalgae and cyanobacteria. With further optimization, the developed system can be deployed in a biofuel production system for continuous monitoring of co-culture solution. Future work will also include integrated electronic circuitry for a fully standalone fluorescent detection system. References: [1] Y.-H. Shin, J. Z. Barnett, E. Song, M. T. Gutierrez-Wing, K. A. Rusch and J.-W. Choi, Microelectronic Engineering. 144 (2015) 6-11. [2] Y. Chisti, Biotechnology Advances. 25 (2007) 294-306. [3] A. Silaban, R. Bai, M. T. Gutierrez-Wing, I. I. Negulescu, and K. A. Rusch. Engineering in Life Sciences. 14 (2014) 47-56. [4] L. E. Gonzalez and Y. Bashan, Applied And Environmental Microbiology. 66 (2000) 1527-1531. [5] L. E. de-Bashan, Y. Bashan, M. Moreno, V. K. Lebsky, and J. J. Bustillos, Canadian Journal of Microbiology. 48 (2002) 514-521. Figure 1

Letters in Applied Microbiology, Sep 11, 2012

Aims: To design a primer set enabling the identification through PCR of highquality DNA for routi... more Aims: To design a primer set enabling the identification through PCR of highquality DNA for routine and high-throughput genomic screening of a diverse range of cyanobacteria. Methods and Results: A codon-equivalent multiple alignment of the phycocyanin alpha-subunit coding sequence (cpcA) of 22 cyanobacteria was generated and analysed to produce a single degeneracy primer set with virtually uniform product size. Also, an 18S ribosomal RNA detection set is proposed for rejecting false positives. The primer sets were tested against five diverse cyanobacteria, Chlorella vulgaris, Saccharomyces cerevisiae, and Escherichia coli. All five cyanobacteria showed positive amplification of cpcA product with homogeneous fragment length, and no products were observed for any other organism. Additionally, the only product formation observed for the 18S rRNA set was in C. vulgaris and S. cerevisiae. Conclusions: The newly proposed primer set served as effective check primers for cyanobacteria. Cyanobacteria gDNA had a positive, homogenous result, while other bacteria, eukaryotes and alga tested were negative. Significance and Impact of the Study: These novel, broad-spectrum primers will greatly increase the utility of PCR on newly discovered cyanobacterial species.

Engineering in Life Sciences, Feb 28, 2017

Light effect on cultures of microalgae has been studied mainly on single species cultures. Cyanob... more Light effect on cultures of microalgae has been studied mainly on single species cultures. Cyanobacteria have photosynthetic pigments that can capture photons of wavelengths not available to chlorophylls. A native Louisiana microalgae (Chlorella vulgaris) and cyanobacteria (Leptolyngbya sp.) co-culture was used to study the effects of light quality (blue-467 nm, green-522 nm, red-640 nm and white-narrow peak at 450 nm and a broad range with a peak at 550 nm) at two irradiance levels (80 and 400 μmol m −2 s −1) on the growth, species composition, biomass productivity, lipid content and chlorophyll-a production. The co-culture shifted from a microalgae dominant culture to a cyanobacteria culture at 80 μmol m −2 s −1. The highest growth for the cyanobacteria was observed at 80 μmol μmol m −2 s −1 and for the microalgae at 400 μmol m −2 s −1. Red light at 400 μmol m −2 s −1 had the highest growth rate (0.41 d −1), biomass (913 mg L −1) and biomass productivity (95 mg L −1 d −1). Lipid content was similar between all light colors. Green light had the highest chlorophyll-a content (1649 μg/L). These results can be used to control the species composition of mixed cultures while maintaining their productivity.