Curriculum Enhancements in Environmental Engineering:

Principal Investigators

Dr.  Subramania I. Sritharan (Professor and Dean, College of Science and Engineering)

Dr. Krishnakumar V. Nedunuri (Professor and Chair, Water Resources Management)

Co-Principal Investigators

Dr. Suzanne Seleem (Associate Professor, Department of Natural Sciences)

Dr. Marvin Thrash (Assistant Professor, Paper and Chemical Engineering)

Miami University (MU)

International Center for Water Resources Management (ICWRM)

Central State University

Wilberforce, Ohio 45384

Phone: (937) 376-6212

E-mail: knedunuri@csu.ces.edu.

Project Summary

The International Center for Water Resources Management (ICWRM) at Central State University (CSU) is unique amongst the HBCU institutions in the Nation in having an interdisciplinary program in WRM at the undergraduate level. With support from the NSF, through an HBCU-UP grant, CSU has introduced an Environmental Engineering (ENE) Program at the baccalaureate level in response to the need for environmental engineers globally beginning in Fall of 2007.  The department, under the ENE Program has identified industrial water/wastewater treatment as an emerging area with an increasing global focus. This is also a signature area where ultra pure filtration of emerging pollutants identified by the US EPA using nanotechnology offers immense research possibilities.   Education and research experience in this area would allow our students to compete for opportunities both in the domestic and international water sectors. 

ICWRM enhanced the quality of its current program through infusion of industrial wastewater treatment into its curriculum. This was accomplished by revamping existing course content and instructional delivery in the areas of water and wastewater treatment and by expanding current capabilities of the water quality laboratory through acquiring additional analytical instrumentation. The enriched curriculum allowed students to gain an understanding of the fate and transport of heavy metals and other inorganic ions in the environment, particularly in the industrial effluents.  Other areas that benefitted include the chemistry program within the Natural Sciences Department.  It supplemented the analytical support required for the Forensic science program that was developed within Chemistry and Biology departments. In anticipation of future work force needs in industrial water treatment, ICWRM also conducted undergraduate educational research on feasibility of using nanofibers in ultra pure filtration of trace metals from drinking water and industrial effluents.

Intellectual Merit

 The infusion of latest advances in industrial wastewater treatment and in water treatment in the ENE program enabled CSU to prepare environmental engineers with much sought after capabilities.  Both the exposure to instrumentation and the new curriculum in industrial waste/water treatment opened doors to promising careers for the graduates of the ENE program and other related STEM areas at CSU. Uniquely, we have introduced students to nanotechnology filtration methods for water/wastewater treatment studies. Engaging students in this endeavor improved retention of ENE majors including chemistry and environmental sciences. The study was conducted by a CSU-Miami University (MU) partnership through which CSU ICWRM undergraduate students received training on the use of advanced analytical instrumentation for environmental analysis. 

Anticipated Broader Impact

The instrumentation helped CSU students majoring in Water Resources, Biology, Chemistry and ENE to gain state-of-the-art knowledge in sciences, promote their ability to conduct research, and gain real-world work exposure.  This program served as a model to bolster the nation-wide efforts in recruitment, retention and graduation of STEM majors in Historically Black Colleges and Universities by engaging them in latest advances in sciences such as nanotechnology. It also motivated STEM majors to consider careers in emerging areas of Environmental Science and Engineering such as Industrial wastewater treatment. This targeted infusion was sought with the long term view of engaging in green engineering field instruction and research in collaboration with the Manufacturing Engineering (MFE) Program at CSU.

Student oral surveys and end of the term evaluations revealed greater interest among students to learn concepts than what has normally been found in a traditional engineering classroom.  The enhanced curriculum benefitted weaker students more than those who were academically strong.

Fig. 6 ENE students were visiting RUMPKE recycling facility in Cincinnati, Ohio

Fig. 7 ENE students making observations on the composition of waste on the feed conveyor

Fig. 9 ENE students collecting samples from the Mad River, Ohio by the Huffman Dam

Reference: S. K. Lunsford, Nedunuri K.V., Michael Sandy, Teaching chemical equilibrium concepts using field-lab experiences in a multi-disciplinary integrated environment, Analytical Science Digital Library, 5(4), 2007.

Background Information Heavy metals pose a serious environmental threat due to their carcinogenicity. About 5.4 million cubic yards of coal ash containing heavy metals such as Arsenic and Lead at dangerous levels were spilled into the nearby Emory River, TN by the Tennessee Valley Authority in December 2008 causing great alarm to residents (US EPA, 2009). 85 million people are currently at risk in Bangladesh due to highly toxic levels (greater than current WHO standards of 10 µg/l) of inorganic Arsenic in groundwater (Hossain, 2005).   Blood lead and cadmium levels in children of ages between 6 months and 6 years were shown to exceed 0.5 µg/dl in 85% of children tested in an industrial area in Turkey (Yapici et al., 2006). While remediation methods such as soil washing, chemical precipitation, and reverse osmosis have been proven to be effective, these are expensive, energy intensive, and environmentally destructive. Nevertheless, these are technologies unaffordable by the poorer nations of the world where the problem is more severe.   In this study, we have uniquely tested a cheap and easily available processed switch grass for its potential to remove heavy metals from simulated industrial waters.

Hypothesis The following hypotheses were constructed as part of the study.

Materials and Methods The simulated industrial water consisted of aqueous samples of Cd and Pb (40, 50 and 100 ppm). The effect of pretreatment of switch grass using alkaline solution was studied. The raw switch grass (1 g) was milled and blended with a commercial grade blender. The actual treatment used the switch grass after it was treated over night with 10 ml of 0.5% NaOH. The control consisted of using the same switch grass without pretreatment using the alkali solution. The treated samples were later thoroughly washed with de-ionized water and air dried. The switch grass samples were centrifuged with the aqueous solutions of Pb and Cd and then were allowed to sit overnight. The next day, the solutions were filtered and stored in vials at 4 deg. C until analysis.  Each experiment was conducted in triplicate. 

Results and Discussion

Switch grass has an intricate cellular structure composed of lignin (Fig. 11). Lignin allows switch grass to maintain an upright position in it’s natural environment. Treatment with NaOH breaks down the lignin structure (Nlewem, 2009). Scanning Electron Microscope (SEM) picture of the switch grass before pretreatment does not show porous network at the nanoscale.   However, significant increase on porosity in the sub micron or nano scale can be observed after pretreatment.

 Fig. 11 SEM of switch grass without (left), with (middle) alkaline (NaOH) pretreatment and the effect of pretreatment (right)

Comparisons were made to see if pretreatment of the switch grass increased the heavy metal uptake. Due to the resulting large surface area/volume ratio of its cellulosic molecular structure upon pretreatment, switch grass can have a strong affinity for heavy metals.  Samples dosed with 40, 50, and 100 ppm of Cd and Pb to the deionized water were filtered through treated switch grass.  Concentrations of Pb and Cd remaining in the solution were measured using Agilent 7500 CX ICP MS (shown in Fig. 12 a) after preparing a 1 to 1000 dilution of original solutions.   Fig. 12 c shows a screenshot of the Pb concentrations in pretreated and untreated samples exposed to 50 ppb and 100 ppb. One of the 50 ppb standard solutions was analyzed as 37 ppb by the ICP MS suggesting that particular sample was contaminated.  The reagent blank showed less than detectible lead suggesting that de-ionized water used to prepare samples passed the quality control test.   The internal standard showed sufficient constancy suggesting satisfactory precision from the instrument. One of the 50 ppb calibration standards was measured as 48.5 ppb suggesting 3% error in the measurement of the standard which might have occurred from sample dilutions.  89% reduction in Pb concentration in water samples was observed when untreated switch grass exposed to 50 ppm Pb, where as 97% reduction resulted when the treated switch grass exposed to 50 ppm Pb. Results showed significant variability when water samples dosed at 100 ppm were exposed to switch grass.  These experiments are currently being repeated.

   

Fig. 12 a Schematic of Agilent 7500 CX ICP MS showing RF generated plasma, octopole reactor for enhanced interference removal, and quadruple mass spectrometer.

Fig. 12 b Bryan Smith checking the nebulizer and argon torch before starting the plasma for analyzing Cadmium samples using ICP-MS.

Fig 12 c Pb concentrations in both treated and untreated samples with ISTD and calibration curve. 

Experiments on cadmium adsorption to switch grass yielded accurate results with low variability. These results were shown below in Fig. 13.   Switch grass treated with NaOH removed greater Cd than untreated control at all initial concentrations of Cd in water. Porosity of the structure was enhanced due to the breakdown of lignin upon addition of NaOH. This resulted in greater physical surface made available for adsorption. Untreated switch grass yielded lower reduction in Cd from higher concentrated waters due to its poor retention to grass fibers at low porosities. Adsorbed Cd concentrations on the treated switch grass increased with higher doses of Cd in water where as the trend was opposite for the untreated switch grass.  Pretreatment with NaOH created adequate steric hindrances to trap the ions where as untreated switch grass was unable to provide a pore size adequate for retention of these ions resulting in exclusion.

        

Fig. 13 Sorption of Cd on treated/untreated switch grass and percent reduction in water in Cd concentrations.

Our preliminary study thus established the potential of switch grass in adsorbing Cd from highly concentrated aqueous solutions typical of industrial effluents. Experiments to determine the simultaneous effects of pH, initial concentration of Cd, and pretreatment on Cd adsorption to switch grass are underway.  Further research should establish synergistic/antagonistic effect of adding both lead and cadmium. Extending these results from ongoing batch sorption studies to columns including flow and dispersion characteristics of these metals will be attempted. Both batch and column scale experiments will lead to optimizing the filtration process for the scale up to industrial ultra filtration of heavy metals.

References

Hossain, M.F., Arsenic contamination in Bangladesh – An overview; Agriculture, Ecosystem, and Environment, 113 (1-4), pp. 1-16, 2005.

Nlewem, K.C., Effect of different treatments on Enzymatic Hydrolysis of Switch grass, M.S. Thesis, Miami University, 2009.

U.S. EPA, Summary of Past and Current EPA Response Activities Regarding The TVA Kingston Coal Ash Spill, 2009.

Yapici, G., G. Can, A.R. Kiziler, I.H. Timur, A. Kaypomaz, Lead and Cadmium contamination in Children in coal mining area in Turkey, Toxicology and Industrial Health, 22(8), 357-362, 2006.

The NSF TIP project on “Curriculum Enhancements in Environmental Engineering” has provided enhancements to the traditional curriculum in water treatment and wastewater treatment through inclusion of industrial wastewater and through adapting environmental trace metal analysis using analytical instrumentation such as ICP-MS.  The salient activities included field trips to industrial facilities as part of course curriculum enhancements (10 ENE students), undergraduate research on industrial water filtration (3 ENE students) and exposure to analytical instrumentation in ENE 3309 water chemistry course (18 ENE and WRM students).  Three additional elective courses in Forensic chemistry are being benefitted from water quality instrumentation. These enhancements improved academic profiles of our graduating students. Seven undergraduate students from ENE and chemistry have been provided training to conduct research at graduate institutions Miami University and University of Cincinnati. Three water operators from the City of Dayton Water treatment plant and a Water Resources Graduate were provided training for three days on ICP MS by a certified methods specialist from Agilent as part of continuing workforce development. Seven undergraduate students from ENE and chemistry have been provided training to conduct research at graduate institutions Miami University and University of Cincinnati.

The enrollment in ENE program has seen steady increases from 5 students in Fall, 2008 to 15 in fall, 2009 to 20 students in 2010 to 25 students in 2011.