Effect of Water Hyacinth infestation on the Physicochemical parameters of canal water in Karumalloor, Aluva, Kerala, India at The Cochin College
Water hyacinth infested canal in Karumalloor, Aluva was the sampling location. Sampling was done before and after the removal of water hyacinth during January and February 2024. Samples were collected 1-2 week after the removal of water hyacinth, this was done to determine the difference in physico-chemical and microbial parameters of the water sample due to water hyacinth infestation. Sampling was done at 3 points (close to canal wall, 100 meters away from the wall and from the center of the canal) in selected location. All the parameters, except microbial, listed below were analyzed for water samples from the 3 points and the mean/average of the three points were used to compare the effect of water hyacinth removal.
METHODOLOGY
Sampling Location: Water hyacinth infested canal in Karumalloor, Aluva was the sampling location. Sampling was done before and after the removal of water hyacinth during January and February 2024. Samples were collected 1-2 week after the removal of water hyacinth, this was done to determine the difference in physico-chemical and microbial parameters of the water sample due to water hyacinth infestation. Sampling was done at 3 points (close to canal wall, 100 meters away from the wall and from the center of the canal) in selected location. All the parameters, except microbial, listed below were analyzed for water samples from the 3 points and the mean/average of the three points were used to compare the effect of water hyacinth removal.
Figure1 – Map showing the sampling location
1. ESTIMATION OF DISSOLVED OXYGEN
Winkler’s method is used for the estimation of dissolved oxygen
PRINCIPLE
In Winkler’s method oxygen released from water is used to liberate iodine from potassium iodine and this iodine liberated in turn is estimated using standard Sodium thiosulphate (Na2S2O3). When manganese sulphate (MnSO4) is added to a sample of water followed by strong alkaline potassium iodide. Manganese hydroxide [Mn (OH) 2] will be formed. This combines with dissolved oxygen in water. This on acidification with conc.Sulphuric acid in the presence of alkaline potassium iodide, release iodine equivalent to the amount of oxygen dissolved in the sample water. The amount of iodine liberated is estimated by titrating the sample solution against 0.01N Sodium thiosulphate.
PROCEDURE
a) Fixation of water samples
Water was taken in a BOD bottle of 250 ml immersed into the pond with minimum disturbance, taking care to avoid the formation of air bubble in it. Close the bottle with the
stopper while under water. Now remove the stopper of the water and add 2 ml of manganese sulphate solution followed by 2 ml of alkaline iodide solution into the water sample collected. Add the reagent in such a way that the tip of the pipette touches the bottom and gradually pull them upward. Close the bottle tightly with the stopper and avoid the formation of any air bubble inside. Shake the sample very well, in order to complete the formation of precipitate inside the bottle. Leave the sample undisturbed for some time so that the precipitate settles down completely.
b) Titration of water sample
Add 2 ml of conc. Sulphuric acid carefully to the precipitate and close the bottle with the stopper. Mix the content very well to dissolve the precipitate completely to form a brown coloured solution. From this pipette out 20 ml into a clean conical flask and titrate the same against 0.01N sodium thiosulphate solution from the burette and stop titration when the solution in the beaker turns pale yellow. Now add 1 ml of freshly prepared starch solution as indicator. The solutions become blue in colour. Note down the burette reading and repeat the titration for concordant value.
2. LIGHT AND DARK BOTTLE EXPERIMENT
The rate of photosynthesis or primary productivity is estimated using light and dark bottle experiment. For this two measuring cylinder of 250ml is filled with water without minimum disturbance, taking care to avoid the formation of air bubbles in it. Close the bottle with the stopper while under the water. Cover one of the bottles completely with black paper or painted completely to exclude the bottle from sunlight. And the other bottle is left as it. Now tie both the bottles and immerse the bottles into the water to some depth. Keep this arrangement undisturbed for 24 hours. After 24 hours the bottle is taken out of the water and Winkler’s method is done for estimating the dissolved oxygen, so that the rate of photosynthesis can be determined.
3. ESTIMATION OF DISSOLVED CARBON DIOXIDE Dissolved carbon dioxide in the water sample is estimated using the following method PRINCIPLE
Carbon dioxide dissolved in water to form carbonic acid, which subsequently dissociates into H+ and HCO3-. If water contains a high amount of CO2, it becomes acidic. An acid can be titrated against a standard alkali using phenolphthalein as indicator to determine its acidity. If the water is alkaline, due to a higher amount of bicarbonate ions, it should be titrated against a standard acid using methyl orange as indicator.
PROCEDURE
pH of the water sample is estimated using pH paper. If the sample is acidic, it is titrated NaOH using phenolphthalein as an indicator. If it is alkaline, it should be titrated against HCl, using methyl orange as an indicator. 50 ml of givens sample of water is carefully measured and transferred into a conical flask with minimum disturbance and add few drops of methyl orange indicator to the water and titrate against 0.1N HCl from the burette. The mixture in the flask is gently titrated. During titration, the end point is indicated by the appearance of pale orange colour which persists for 20 seconds. Note down the burette reading and repeat the titration for concordant value.
4. TEST FOR pH
PROCEDURE
● 10 ml of water sample is taken in the test tube.
● 3-4 drops of pH reagent -1 is added and mixed well.
The colour that formed is compared with the pH colour chart and pH value is recorded.
5. TEST FOR TOTAL ALKALINITY
PROCEDURE
● 25 ml of water sample is taken in the test bottle.
● 4-5 drops of TA-2 are added and mixed until an orange-yellow colour is formed. ● Then TA-1 is added drop by drop and shaken well after each drop until the colour changes from orange yellow to orange red.
● No. of drops of TA-1 required for the colour change is counted.
Total alkalinity = No. of drops x 5
6. TEST FOR RESIDUAL SULPHITE OR SULPHITE
PROCEDURE
● Take 25 ml of water sample in the test bottle.
● Add 1 ml of Sulphite Reagent-1(S1-1) and mix well.
● Add a pinch of Sulphite Reagent-2(S1-2) and mix well until a distinct white colour develops.
● Add Sulphite Reagent-3(S1-3) shake well after each drop until the colour changes from white to dark blue.
No. of drops of S1-3 required for the colour change is counted.
7. PHOSPHATE TESTING METHOD
PROCEDURE
● Take 5 ml of water sample in the test tube.
● Add 5 drops of Phosphate reagent-1(PR-1) and one drop of Phosphate reagent-2(PR-2).
● Mix the contents and wait for 2-3 minutes for colour to develop.
The colour that formed is compared with the phosphate colour chart provided and record the phosphate value.
8. IRON TESTING METHOD
PROCEDURE
● Take 5 ml of water sample in the test tube.
● Add 5 drops of Iron Reagent-1(Fe-1).
● Add 1 drop of Iron reagent -2(Fe-2).
● Mix and add 5 drops of Iron reagent-3(Fe-3).
● Mix the contents and wait 2-3 minutes for colour to develop.
The colour that formed is compared with Iron colour chart and record the iron value.
9. TEST FOR CALCIUM HARDNESS
PROCEDURE
● Take 25 ml of water sample in the test bottle.
● Add 10 drops of Calcium Hardness Reagent-2(CH-2) and mix well. ● Add 10 drops of Calcium Hardness Reagent-3(CH-3) and mix.
● Add a few specs of Calcium Hardness Reagent-1(CH-1) and mix until a distinct pink colour develops.
● Add Calcium Hardness Reagent-4(CH-4). Shake well after each drop until the colour changes from pink to purple.
● Count the No. of drops of CH-4 required for the colour change
Calcium Hardness = No. of drops x 5
10. TEST FOR FLUORIDE
PROCEDURE
● Add 5 ml of water sample in test tube.
● Shake well the sample with Fluoride Reagent-1(F-1).
● Then add 5 drops of water sample. Mix the contents.
The colour that formed is compared with the Fluoride colour chart and record the fluoride value.
11. TEST FOR CHLORIDE
PROCEDURE
● Take 25 ml of water sample in the test bottle.
● Add 5 drops of Chloride Reagent-1(CL-1).
● Mix until a distinct yellow colour develops.
● Add Chloride Reagent-2(Cl-2) drop by drop and shake well until the colour changes from yellow to red.
● Count the No. of drops of Chloride Reagent-2(Cl-2) required for the colour change. Chloride (mg per liter) = No. of drops x 10
12. TEST FOR RESIDUAL CHLORINE
PROCEDURE
● Take 5 ml of water sample in the test tube.
● Add 5 drops of Residual Chlorine-1(RC-1) and mix well.
● The colour that formed is compared with the Residual Chlorine colour chart and record the value.
13. MEASUREMENT OF TRANSPARENCY AND TURBIDITY BY USING SECCHI DISC
The transparency of water is influenced by turbidity which is caused by clay and soil particles and plankton and algae. The measurement of turbidity and transparency is most commonly determined by a simple instrument called Secchi disc.
PROCEDURE:
Lower the Secchi disc into the water body and note the depth at which it disappear. Now lift up the disc and note the depth at which the disc reappears. The average of these reading is considered to be the limit of visibility. Repeat the procedures for 2-3 times.
Total Plate Count (TPC)
The total plate count (TPC) is a method used to estimate the total number of viable microorganisms present in a sample. It's a common technique employed in microbiology to assess the overall microbial load in various samples, including water. Below is a general protocol for performing a total plate count using a water sample:
Procedure:
Preparation of Nutrient Agar Plates:
● Prepare the nutrient agar according to the manufacturer's instructions. ● Pour the molten agar into sterile Petri dishes and allow it to solidify. ● Label the plates with appropriate sample information and a unique identifier. Collection of Water Samples:
● Use sterile containers to collect water samples from the source.
● Collect samples in a manner that minimizes contamination.
Dilution Series :
● Prepare a series of dilutions of the water sample to obtain a suitable range of colony counts.
● Typically, serial dilutions of 10-fold are performed. For example, 1 mL of the sample is added to 9 mL of sterile diluent to make a 1:10 dilution, then 1 mL of this dilution is added to another 9 mL of diluent to make a 1:100 dilution, and so on.
Inoculation:
● Pipette 1 mL of each dilution onto separate sections of the agar surface of the labeled Petri dishes.
● Spread the liquid evenly over the surface of the agar using a sterile glass spreader.
Incubation:
● Invert the agar plates and incubate them at the appropriate temperature (usually around 37°C) for a suitable period (typically 24-48 hours) to allow microbial growth.
Counting Colonies:
● After incubation, examine the plates for colony growth.
● Count the colonies on plates with colony counts between 30 to 300 colonies. Plates with counts outside this range may need to be re-inoculated with a different dilution.
● Record the colony counts for each dilution.
Calculation:
● Calculate the total number of colony-forming units (CFUs) per mL of the original water sample using the colony counts and dilution factors. ● The formula is: Total CFU/mL = (Number of colonies counted × Dilution Factor) / Volume of sample plated.
Conclusions
● The removal of water hyacinth had significant impacts on pH, turbidity, DO, Productivity, Dissolved CO2.
● The presence of water hyacinth had an impact on the pH of water in the canal, a low pH of 6.7 was observed before removal. After water hyacinth removal the pH of the water was found to be in the normal pH range of open waters.
● Another significant difference was observed in dissolved oxygen, dissolved oxygen could not be detected in infested waters which could be due to the dense growth of water hyacinth which consumes more oxygen through processes such as decomposition of organic matter within the mats. This consumption can deplete oxygen levels in the water column, especially in areas where water flow is restricted by the dense mats. DO might be undetected also due to the sensitivity of the method (Winkler’s method), Winkler method have limitations in detecting very low levels of dissolved oxygen, especially in environments with high levels of oxygen consumption.
● The detection of DO and primary productivity in the samples after removal is clear sign of the impact of the infestation in water quality.
● The same changes in pH and DO was reported by Uka et al (2007) in their studies of water hyacinth infestation of AWBA Reservoir, Ibadan, South-West, Nigeria. ● Significant difference was also observed in the dissolved carbon dioxide level, a decrease in its level was found after removal. This is due to the inverse relationship between DO and dissolved carbon dioxide. This means that when the concentration of dissolved oxygen decreases, the concentration of carbon dioxide increases. This also have an effect on the pH of the water, as more carbon dioxide dissolves in water, the concentration of carbonic acid increases, leading to a decrease in pH.
● Chloride, fluoride and iron was absent in the infested water samples but was observed in water samples after removal, this might be due to the absorption of these by water hyacinth (Xu et al, 2022).
● There was no significant change in the total alkalinity, calcium hardness and sulphate levels.
● Total plate count (TPC) did not show any significant difference before and after removal of water hyacinth.
● As this was a preliminary/pilot study of the effect of removal of water hyacinth on the physicochemical and microbial parameters of the canal water at Karumalloor, Aluva. Further studies are required to confirm the above results.
References
U.N. Uka and K.S. Chukwuka, 2007. Effect of Water Hyacinth Infestation on the Physicochemical Characteristics of AWBA Reservoir, Ibadan, South-West, Nigeria. Journal of Biological Sciences, 7: 282-287.
Xu J, Li X, Gao T, 2022. The Multifaceted Function of Water Hyacinth in Maintaining Environmental Sustainability and the Underlying Mechanisms: A Mini Review. Int J Environ Res Public Health. 13;19(24):16725. doi: 10.3390/ijerph192416725. PMID: 36554606; PMCID: PMC9779344.
Programme Expenditure
| Sl | Particulars | Amount |
|---|---|---|
| 1 | TA | 300 |
| Total | 300 |
Report of the programme Download