2012 Stream Chemistry

STREAM CHEMISTRY: New Hope Creek, Gate 26 Duke Forest, 25 July 2012

Stream Chemistry I by Moneet Virk, Princess Malik, and Ransom Pate

Today we continued our research on New Hope Creek by studying the chemistry of the stream. Ransom Pate, Princess Malik and Moneet Virk tested the pH, dissolved oxygen, and the chloride levels of New Hope Creek.

pH

We first gathered a sample of the stream water in a sterile plastic bag to avoid any contaminations that would interfere with the testing results. After gathering the sample, we took a pH strip and dipped the part of the strip that had the square into the water and quickly took it out. After about 15 minutes or so the square turned into an turquoise green color which landed between a 6 and 7, which gave us a result pH reading of 6.5. We repeated the test to make sure we received accurate results, and we got another pH reading of 6.5 which is an appropriate level to sustain aquatic life.

Dissolved Oxygen

High Range: To test for the dissolved oxygen level, we filled the mixer with the sample water from the stream until it was overflowing and then carefully putting a stopper to prevent any air bubbles from forming. Then we added one packet of Dissolved Oxygen 1 Reagent Powder and one packet of Dissolved Oxygen Reagent Powder and then inverted the bottle several times to allow for the precipitate to form and then settle to the bottom. We then added one packet of Oxygen 3 Reagent Powder and the precipitate turned to yellow which indicated that oxygen was present. We then measured out one measuring tube and transported it to a square bottle and added Sodium Thiosulfate Solution and counted the number of drops it took for the color to change from yellow to colorless. It took 8 drops and gave us a result of 8 mg/L which is safe for sustaining aquatic life.

Low Range: The leftover solution that was in the initial bottle was used for the low range test. We used about 30 mL of the prepared sample and added Sodium Thiosulfate Solution and counted each drop until the color changed from yellow to colorless which took us about 37 drops. We multiplied this value by 0.2 to give use a sample result of 7.4 which is also safe for aquatic life.

Chloride

High Range: We filled a tube of the sample stream water and poured it into a mixing bottle. We then added one packet of Chloride 2 Indicator Powder and swirled the bottle so that it can be mixed properly (the water should turn yellow). We then added Silver Nitrate Titrant and counted the number of drops it took for the water to change from yellow to orange which was 1 drop. We then multiplied this value by 20 to give us a sample result of 20 mg/L. This is safe for sustaining aquatic life.

Low Range:  We filled the mixing bottle with about 23 mL stream water and added Chloride 2 Indicator and swirled it until the water turned yellow. We added Silver Nitrate Titrant and counted the number of drops it took for the water to change from yellow to orange which was 2 and we multiplied that by 5 to give us a sample result of 10 mg/L.  This level of chloride is safe for sustaining aquatic life.

Parameter

Actual Reading

Adjustment

Result

Safe Levels

pH

6.5

N/A

6.5

6.5-9

DO-High

8 drops

N/A

8

≥ 5 mg/L

DO-Low

37 drops

X 0.2

7.4

≥ 5 mg/L

Chloride-High

1 drop

X 20

20

≤ 250 mg/L

Chloride-Low

2 drops

X 5

 10

≤ 250 mg/L

Stream Chemistry II – by Seyi Gbadegesin and Trevor Hamlet

Trevor and I observed the dissolved oxygen levels and phosphate levels in the New Hope Creek. Our observations are in the table below.

Parameter Actual Reading Observed Sample Result Levels Safe for Aquatic Life
High Range (1 – 20 mg/L):   Dissolved Oxygen (Hach OX -2P) 7 Drops 7mg/L > 5 mg/L
Phosphate (Hach PO-19) 0 0mg/L Less than .05 mg/L

 

According to our observations, the dissolved oxygen levels in the New Hope Creek are safe enough for aquatic organisms to thrive. The phosphate levels in the creek are safe enough for aquatic organisms as well.

 

Stream Chemistry III by Emily Bierman & Tim Schutz

Parameter Actual Reading Observed Adjustments to Reading Sample Result Levels Safe for Aquatic Life
pH 7 Just write it down in the next box. 7 6.5-9
Nitrate (Hach NI-14) 0 0X10 (Multiply reading by 10 to obtain the mg/L nitrate nitrogen   present in sample) 0 Less than 22 mg/L
HIGH RANGE: 0-400 mg/L Chloride (Hach 8-P) 1 1X20 (Multiply number of drops by 20 to obtain mg/L of Cl present in   sample) 20 Less than 250 mg/L
LOW RANGE: 0-100 mg/L Chloride(Hach 8-P) 3 3X5 (Multiply number of drops by 5 to obtain mg/L of Cl present in   sample) 15 Less than 250 mg/L

Sampling Problems: Nitrates tested not present for both high and low range testing.

Stream Chemistry IV by Emma Brereton & Charlie Brereton

Water Chemistry Testing

Parameter Sample Result (mg/L)
Nitrate (Hach NI-14)   (High-Range) 8.0
Phosphate (Hach PO-19)   (High-Range) 0.6
Phosphate (Hach PO-19)   (Low-Range) 0.213

 

All water samples were taken from the same site at New Hope Creek. Once the experimental procedures were completed for each test, the actual readings were observed and recorded. These numbers were then multiplied and/or divided by other constant(s) to determine the above sample results. The sample result of the nitrate test demonstrates the mg/L of nitrate nitrogen present in the sample. The sample results of both phosphate tests demonstrate the mg/L of phosphorus present in the samples.

Stream Chemistry V by Justin Witherspoon & Katie Reiter-Lavery

Stream Chemistry Data Reporting Forms

Parameter Actual Reading Observed Adjustments to Reading Sample Result Levels for safe Aquatic Life
pH

7

Just write it down in the next box.

7

6.5-9
High Range (1-20 mg/L): Dissolved Oxygen (Hach OX-2P)

6 drops

Just write it down in the next box.

6

> 5 mg/L
Low Range: 0-100 mg/L Chloride (Hach 8-P)

4 drops

4*5 (Multiply number of drops by 5 obtain mg/L of CL present in sample

20

250 mg/L

pH: The pH test was pretty simple. We removed a test strip from the bottle and placed it into the creek and removed it quickly. After letting it dry we compared it to the scale. The pH was about a 7.

Dissolved Oxygen: To find the amount of dissolved oxygen in the stream, we followed the directions provided and added multiple substances. The last substance we added in drops and the number of drops represents the amount of dissolved oxygen present in mg/L.

Chloride: Finding the amount of chloride present was basically the same as finding the amount of dissolved oxygen; we followed the directions provided, but the number of drops had to be multiplied by 5 to find the amount of chloride present. We also had a bit of difficulty finding the safe level of chloride for aquatic life, because the information provided did not match with the outcomes everyone was getting. When we got back from the field, the acceptable levels of chloride were looked up and the necessary changes were made.