Clean water is a crucial factor that contributes to the health of eco-systems and their inhabitants. Testing local surface water is an exciting way to engage freshman undergraduates in research which shows them the importance of protecting their communities and environment. Two affordable methods: a Colorimeter and Ion-Selective Probe were used to analyze nitrate, phosphate and ammonia levels in local surface water samples. The samples were collected from the Muskingum River which runs through Southeastern Ohio (Muskingum County) and were collected at 2 mile increments. We believe that this set of experiments would be beneficial if implemented into a college freshman level chemistry lab, thereby, promoting self-awareness of water safety, eco-system safety and community involvement. In addition, the students will learn how our environment is effected by our actions when we neglect to properly monitor the type of pollutants we allow into our water ways.
Testing surface water brings chemistry and environmental biology together by teaching students the impact humans have on their environment. Such practices as the use of industrial fertilizers on farm lands, and dumping of waste materials from fracking, when in large quantities, can be harmful to both the environment and to the species which thrive in these eco-systems. The need for our water systems to be routinely checked and monitored is ever growing and should be of up most importance. Southeastern Ohio’s Surface water which includes rivers, streams, and ponds are often subjected to minerals from the ground like calcium, sodium and potassium. Surface waters can also be subjected to gases from the air like nitrogen oxide, carbon dioxide and sulfur dioxides. Nitrate, ammonium and phosphate ions are typically found in commercial fertilizers and enter surface waters (see
These ions, for the most part, are natural components of the environment, however, each of these can become a concern and even dangerous when spring runoff occurs. Most of the danger comes from fertilized farm fields which line waterways connect directly to filtration facilities used for the purification of everyday drinking water. Water plants often support large populations, thereby allowing pollutants to affect a larger percentile of the nearby population. Elevated nitrates have been linked to spleen damage in adults as well as blue baby syndrome (methemoglubinemia-tissue hypoxia in babies caused by a shift in the oxygen-Hemoglobin dissociation curve) and even death in severe cases [
The first method we utilized for our research was the Ion-Selective Electrode [
All the technical tips that were followed in this paper are included with the purchase of the electrodes from the manufacturer and are available on their website [
The Ion selective electrode that goes with the data collecting device was purchased from Vernier and uses a sold polymer membrane technology to measure the nitrate and ammonia concentrations in the collected water sample. The probes sold be Vernier are combination style electrodes, meaning that the voltage develops in relation to an Ag/AgCl internal electrode. Once the equipment is received, before testing begins, the probe requires
Site | Nitrate Level (mg/L) | |
---|---|---|
Spring | Fall | |
Mississippi River, Clinton, IA | 0.55 | 1.20 |
Mississippi River, Memphis, TN | 1.60 | 2.90 |
Rio Grande River, El Paso, TX | 0.38 | 0.59 |
Ohio River, Benwood, WV | 0.87 | 1.30 |
Willamette River, Portland, OR | 0.28 | 0.98 |
Missouri River, Garrison Dam, ND | 0.40 | 0.14 |
Hudson River, Poughkeepsie, NY | 0.49 | 0.64 |
Platte River, Sharpes Station, MO | 1.90 | 1.30 |
that a low and high standard is used to calibrate the tool. Once calibration is complete, the water sample must hold enough solution that the probe can be properly submerged. According to Vernier this depth should not be shallower that 1.1 inches. The calculation, by which the computer program finds the concentration of ions, in the sample, is the Nernst Equation. Specifically, the equation for this test is written as E = E0 + m (ln a), where E is the measured voltage, E0 is the standard potential for the combination of the two half cells, m is the slope, ln is the natural logarithm, and a is the activity of the measured ion species. The response by the ISE produces a linear equation that is produced on a graph in the Logger Pro software where results can be seen and recorded. Over all, this method has a reproducibility rate of ±10% when calibrated 10 to 1000 mg/L. The Ion-Selective Electrodes from Vernier costs $179.00 to $189.00, LabQuest2 for $329.00, and lastly Logger Pro for $249.00. Additionally, the Logger Pro software that is needed to analyze the data was purchased from the same company.
The second method we explored was the Water Quality Colorimeter and Kit [
must be followed. In each kit, however, you will receive procedural instructions, 30 ampoules, and an indicator solution. After completing the snap vial test kit, each ampoule proceeds to be inserted into the colorimeter where Beer’s Law is used to calculate the ion concentration.
Beer’s law measures the concentration of the sample by finding the absorbance of light waves that are projected threw your sample, after the ion indicator is added. The common way to present Beer’s equation is written as A = εbc, where A is absorbance; ε is the molar absorptivity; b is the path length of the sample; and c is the concentration of the compound in the solution. In this case, nitrate, ammonia, and phosphate were the ions being sampled. The more saturated the color becomes, the higher the ion concentration in the sample. This Colorimeter utilizes Beer’s Law as well as built in calibration curves to accurately calculate the ion concentration in each solution. The concentrations are then presented on a graph for analysis. The colorimeter sensor (
The primary purpose of this research is to provide two affordable methods that both students and the general public alike can implement; thereby, allowing us as a community to understand the environmental footprint we all leave on our environment. What is unique about this research is that we studied two methods that are not restricted to a lab setting. The ISE probe and Colorimeter are both examples of instruments that can be utilized at home or in the field; thereby, allowing the average day citizen to conduct his or her own experiments at an affordable price. In addition, to the affordability, having the public and commercial businesses aware of what is in their water supply will promote healthier living. The research has attracted attention from The Times Recorder [
The water samples were taken at 2 mile increments from the Muskingum River and were collected in November 2014 (see
Distance | PH Levels | Nitrate*** Levels | Ammonium*** Levels | Acceptable Nitrate Levels* | Acceptable Ammonium Levels** |
---|---|---|---|---|---|
Mile 0 | 8.2 | 2.3 mg/L | 0.1 mg/L | 10 mg/L | 0.5 mg/L |
Mile 2 | 8.0 | 2.4 mg/L | 0.2 mg/L | 10 mg/L | 0.5 mg/L |
Mile 4 | 8.0 | 2.4 mg/L | 0.1 mg/L | 10 mg/L | 0.5 mg/L |
Mile 6 | 8.1 | 2.1 mg/L | 0.2 mg/L | 10 mg/L | 0.5 mg/L |
Mile 8 | 8.0 | 2.0 mg/L | 0.2 mg/L | 10 mg/L | 0.5 mg/L |
Mile 10 | 8.1 | 2.1 mg/L | 0.2 mg/L | 10 mg/L | 0.5 mg/L |
Mile 12 | 7.9 | 2.1 mg/L | 0.2 mg/L | 10 mg/L | 0.5 mg/L |
Mile 14 | 8.0 | 1.7 mg/L | 0.2 mg/L | 10 mg/L | 0.5 mg/L |
Mile 16 | 7.9 | 2.4 mg/L | 0.2 mg/L | 10 mg/L | 0.5 mg/L |
Mile 18 | 7.9 | 1.9 mg/L | 0.5 mg/L | 10 mg/L | 0.5 mg/L |
*Maximum Contaminant Level (MCL) = 10 milligrams per Liter (mg/L) or 10 parts per million (ppm) (Environmental Protection Agency). **Maximum Contaminant Level for Drinking Water (MCLDW) = 0.5 milligrams per Liter (mg/L) (Water Quality with Vernier). ***Reproduction consistence ±10%.
Distance | Nitrate Levels** (mg/L) | Phosphate Levels** (mg/L) | Ammonium Levels** (mg/L) |
---|---|---|---|
Mile 0 | 1.56 | 0.23 | 0.05 |
Mile 2 | 1.47 | 0.24 | 0.03 |
Mile 4 | 1.60 | 0.16 | 0.08 |
Mile 6 | 1.14 | 0.07 | 0.07 |
Mile 8 | 1.36 | 0.02 | 0.11 |
Mile 10 | 1.30 | 0.02 | 0.06 |
Mile 12 | 1.36 | 0.09 | 0.05 |
Mile 14 | 1.43 | 0.04 | 0.04 |
Mile 16 | 1.35 | 0.12 | 0.04 |
Mile 18 | 1.24 | 0.08 | 0.05 |
*±10% error at 2.25 ppm ± 20% error at 0.75 ppm ± 30% error at 0.20 ppm; **Results found using PASCO software and method.
The results we calculated from both methods were within the range of the EPA results. This indicates that the river segment that we tested has not been exposed to high concentration of nitrate, phosphate and ammonia at the time and season of testing. One of the goals of this research was to train students to operate the pre-stated methods for testing water quality. These methods are inexpensive and simple enough that freshman college students can benefit from the experimental learning of being involved in this kind of research, data collection, and analysis. Also, by having two methods, this enhances the student’s learning experience by adding a dynamic of interpreting results. Having to weigh the pros and cons between the tests and further distinguish which is more reliable, adds a feature which is designed to build critical thinking skills. Furthermore, by introducing students to the idea that water testing is not an intimidating or complex process, they will be positioned to become better informed of the important need to care for their environment. As more people become aware and learn how to read waterways for contaminants, and carry out studies of their own, the impact on Ohio’s waterways and ecosystems will be observed.
To conclude, the research presented above shows educational, health, and community benefits, all produced by the implementation of two methods for testing water quality. What is most noticeable about this research is that these methods are affordable, user friendly, and most importantly, not confined to a laboratory. The two affordable methods we discussed above allow for the testing of surface water either at home or by the river side, and only require a basic freshman level chemistry background to fully grasp all the concepts [
We would like to thank students Bryce Hina and Trevor Reed for their help collecting the water samples. In addition, we wish to thank Ohio University for their financial support (1804 grant to Shadi Abu-Baker), and for providing all necessary equipment to carry out this research. The undergraduates wish to thank their mentors Dr. Shadi Abu-Baker and Dr. Shahrokh Ghaffari for their help planning and processing the data. We would like to thank Dr. Hannah Nissen, the Academic Division Coordinator at Ohio University-Zanesville for her generous financial support to undergraduate research.
Shadi Abu-Baker,Christian Frazier,Nathaniel Frazier,Shahrokh Ghaffari, (2016) Engaging Freshman Undergraduate Students in Faculty Environmental Science Research: Testing the Local Surface Waters for Nitrate, Phosphate, and Ammonium Ions Using Two Affordable Methods as an Example. Green and Sustainable Chemistry,06,143-149. doi: 10.4236/gsc.2016.63014