Experiment No. 2
Analysis of Surface Water
I.
Introduction
Surface water refers to water found on the surface of the earth. Lakes, rivers, streams and wetlands
are all examples of surface water. Surface water may be a source of drinking water but it is not
recommended unless properly filtered, disinfected and monitored to ensure good water quality.
In this experiment, the quality of the surface water from Tumagbok River in Miag-ao was measured
through conducting physical and chemical analyses specifically in terms of Temperature, Dissolved
oxygen, Total Suspended Solids and Phosphate determination.
Location: Tumagbok River, Miag-ao, Iloilo
Latitude: 10.698
Longitude: 122. 237
Elevation: 19 m
Weather condition: Slightly rainy
A. Physical Parameter
I.
Introduction
Water temperature is a measure of the degree of hotness or coldness of water. Water
temperature regulates ecosystem functioning both directly through physiological effects on
organisms, and indirectly, as a consequence of habitat loss. Photosynthesis and aerobic
respiration, and the growth, reproduction, metabolism and the mobility of organisms are all
affected by changes in water temperature. Aquatic organisms can only survive within a
particular temperature range. If temperature goes too far above or below the tolerance range
for a given species, its ability to survive may be compromised.
II.
Data and Interpretation of Results
Temperature
Average
Trial 1
27
26.5
Trial 2
26
According to ---. Results show (refer to Table -) that the recorded average temperature
of 26.5 was --B. Chemical Analysis
1. Dissolved Oxygen
I.
Introduction
Dissolved oxygen (DO) is the amount of oxygen that is dissolved in water and is
essential to healthy streams and lakes. It is an indication of how polluted the water
is and how well the water can support aquatic plant and animal life. A higher
dissolved oxygen level usually indicates better water quality. If dissolved oxygen
levels are too low, some fish and other organisms may not be able to survive
(Stevens Institute of Technology, The Global Water Sampling Project 2007).
II.
Data and Interpretation of Results
RAW DATA:
1.1. Standardization of Thiosulfate
Initial volume of
titrant
Trial 1
24.8 mL
0.0 mL
Trial 2
1.2 mL
1.2. Determination of Dissolved Oxygen
Initial volume of
titrant
Trial 1
20.3 mL
Trial 2
15 mL
Final volume of Total volume used
titrant
50.0mL
(26.2 + 1.2) mL =
26.4 mL
1.2 mL
27.6 mL
26.4 mL
Final volume of Total volume used
titrant
25 mL
4.7 mL
18.2 mL
3.2 mL
2. Total Suspended Solids
I.
Introduction
Total Suspended Solids parameter measures the amount of undissolved solid
particles in water such as level of siltation, decaying plant and animal matter, and
domestic and industrial wastes. The residue obtained after the thoroughly mixed
water sample is filtered and dried represents the amount of solids suspended in the
sample which can be used as a general indicator of its overall quality.
RAW DATA:
Trial 1
Filter paper + Residue + Evaporating Dish (weight in grams)
Mass of evaporating
dish
After 1 hour
29.7460
Mass of
evaporating
dish
After 30 mins
29.7460
Difference (+/-)
0.000
Trial 2
Mass of Filter paper + Residue + Evaporating Dish (in grams)
Initial
29.0277
After 1 After 30 Difference
hour
mins
(+/-)
29.0318
29.0328
0.001
After
30 mins
29.0321
Difference
(+/-)
0.0007
Sample Volume filtered (V): 0.025 L
Initial mass of filter (B)
Average Mass of filter + residue
(A)
Trial 1
88.8 mg
93 mg
Trial 2
89.4 mg
94.15 mg
TSS
Trials
168 mg/L
190 mg/L
Calculations:
Average
179 mg/L
Standard
TRIAL 1:
𝟗𝟑−𝟖𝟖.𝟖
0.025
TSS=
=168 mg/L
TRIAL 2:
TSS = (94.15 – 89.4)/0.025
=190 mg/L
`
Based on the recorded data (refer to Table and -) and the calculations above, the
resulting average TSS value of the two trials exceeded the standard --- of the –(reference).
Therefore, the water sample is considered -3. Phosphate Determination
I.
Introduction
Phosphates are one of the major important nutrients in natural water. Yet, the
addition of large quantities of these to waterways accelerates algae and plant
growth; enhancing eutrophication and depleting the water body of oxygen,
resulting harm in other species. Thus, its content in water is critical in
determining the level of algal growth that the water will support.
II.
Data and Interpretation of Results
Concentration
0
0.02
0.04
0.06
0.08
0.1
0.2
0.3
0.5
Absorbance
0
0.027
0.046
0.058
0.073
0.085
0.165
0.227
0.385
Phosphate Standard Calibration Curve
0,45
0,4
y = 0,737x + 0,0135
R² = 0,999
Absorbance
0,35
0,3
0,25
0,2
0,15
0,1
0,05
0
0
0,1
0,2
0,3
0,4
0,5
0,6
Concentration (ppm)
Trial 1
Trial 2
Concentration
Absorbance
0.313 ppm
0.482 ppm
0.244
0.369
Standard
for concentration
In analyzing the phosphate content of the water sample, absorbance values for each
corresponding prepared standard iron concentrations were first determined through the use of a
spectrophotometer (refer to Table 2). These values (concentration versus absorbance) were then
plotted to serve as the standard/calibration curve (as shown in the blue trend line of Fig. 1) and to
be able to establish an equation of the line using Microsoft Excel. The resulting equation is: y =
0.737x + 0.0135
Where:
Determined absorbance values for each trial from spectrophotometer reading were then
substituted to the equation to solve for the value of phosphate concentration as demonstrated in
the calculations below:
Trial 1:
y = 0.737x + 0.0135
x = 0.312754
Trial 2:
x = 0.482361
For both Trial 1 and 2, the resulting concentration of --- and ---, respectively, were found to
be ---- as it --- the standard value of – according to ---.