1. Chemical Analysis of Water
Diane Lokou , Eled Gebrehiwot, and Semira Adella
PSLSAMP, Georgia Perimeter College, 555 North Indian Creek Dr, Clarkston, GA 30021 
Introduction
Methods
Conclusion
Water covers about two thirds of the planet Earth and it is essential for humans’, animals’ and plants’ life. Chemical analysis of water give us insights into physical and chemical properties that enable us measure the safety level in different water bodies and drinking water. The parameters inspected in this study include turbidity, conductivity, pH, hardness, phosphates and nitrates content.
Turbidity is a measure of the cloudiness of water, high turbidity level is often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. Conductivity is useful as a general measure of stream water quality. Significant changes in conductivity can be an indicator of pollution by substances like oil. pH affects many chemical and biological processes. Living organisms need water with pH ranges close to that of their body fluid. The total concentration of alkaline earth metal ions, such as calcium and magnesium in water determines the hardness of water. Many industrial and domestic water users are concerned about hardness because hard water requires more soap and synthetic detergents. Phosphates and Nitrates constitute nutrients for aquatic plants; however, too high concentrations can be toxic causing excessive eutrophication and leading to death of aquatic animals. pH
The pH of all of the samples was around neutral range (slightly acidic or slightly basic). Filtration did not change the pH significantly.
Conductivity
The conductivity of all samples was in the acceptable range both before and after filtration. Filtered samples were found to be more conductive than the unfiltered ones, indicating possible ion release form the Nalgene membranes.
Hardness
As expected, our water samples were very soft to medium hard due to the geological soil composition of the Atlanta area, naturally low in alkaline-earth metal content.
Turbidity
GPC fountain water, Crystal BW and well water satisfy the drinking standards for turbidity while the other samples satisfy the requirement for surface water. The highest turbidity was found for unfiltered stone mountain runoff. Filtered samples all had significantly lower turbidity.
Phosphates
All samples were found to contain phosphate concentrations greater than the ranges set for uncontaminated water bodies. While high phosphate contents in drinking waters do not pose health concerns, high phosphates in environmental water bodies indicate potential for accelerated growth of aquatic plants and consequent hypoxic conditions for other aquatic animals.
Nitrates
All water samples had nitrates concentration in the appropriate range with the exception of the well water sample which was found to contain levels higher than the MCL. This result is alarming considering that prolonged human consumption of water with high nitrate content can cause health problems such as the Blue Baby Syndrome.
Water samples where filtered through m Nalgene filters from ThermoSci. All parameters were measured on filtered and unfiltered samples.
Turbidity was measured using Hach pocket turbidimeter.
Conductivity was determined using the ORION mode 150 conductivity meter .
EDTA compleximetric titration was used to determine water hardness.
Aquarium Pharmaceuticals Freshwater Master Test Kit was used to test pH.
LaMotte kit code and Genesys 20 UV-vis spectrometer were used to determine the Phosphates content.
LaMotte Octaslide kit code was used to measure Nitrate-Nitrogen content.
Results
Goals
The goal of this study was to test the quality of different water samples with respect to the following standards.
1- Turbidity
Drinking water: < NTU
Ambient Water: Depends on States and water classification on average <25-50 NTU
2- Conductivity
Rivers in the United States generally range from 50 to 1500 µmhos/cm. Studies of inland fresh waters indicate that streams supporting good mixed fisheries have a range between 150 and 500 µhos/cm.
3-Hardness
It is measured as mg CaCO3/L. < 15 very soft, soft, medium hard, hard, and > 200 very hard.
4-pH
pH indicates how acidic or basic a solution is.
Drinking water 6.5 – 8.5 pH
Animals preference 6.5 – 8.0 pH
5-Phosphates
0.01 – 0.03 mg/L (1 mg/L = 1 ppm) uncontaminated
0.025 – 0.1 mg/L plant growth stimulation
0.1 mg/L accepted max to avoid accelerated eutrophication (depletion of oxygen in water)
>0.1 mg/L accelerated growth – problems
6-Nitrates
MCL (Maximum Contaminant Level) of 10mg/L
The above parameters were measured for both unfiltered and filtered water samples from Lake Lanier(LAN), Chattahoochee river(CHA),Stone mountain runoff (SMR), Park Briarcliff Apartments (PAR), GPC fountain (FOU), Well(WEL), Stone mountain lake( SML), Pond(PON), and Crystal bottle water(BW).
Citations
LaMotte Phosphate kit instructions
LaMotte Nitrate kit instructions
Vogel’s Testbook of Qualitative Chemical Analysis, 5th Ed. John Wiley & Sons inc. New York p. 703
Cotton & wilkinson, advanved Inorganic Chemistry, 3rd Ed. John Wiley & Sons, New York, p
Aquarium Pharmaceutical Freshwater Test Kit instructions
Acknowledgments
Faculty advisors:- Dr. Manuela Trani , Mr. Pablo Pedroso and
Dr. David Jeffery(preparation only)
Funding: Research Funded by: NSF Grant: HRD
Special Thanks to:-Ms.Margaret Major and Ms.Naranja Davis