The lower parts of St. Johns River is an estuarine river that has salinity rivers fluctuating with changes in tides. The dark coloration of the rivers is due to the extremely high levels of tannins from decaying matter. Turbidity, the dark coloration and other matters prevent the penetration of light deep into the water. As such, the growth of submerged vegetation happens in the shallow regions of the river. The river is fed from tributaries some of which are salty, the Atlantic ocean, tributaries and human wastes from industries and treatment plants for waste water. The lab report presents and discusses the findings and results regarding the physical or chemical properties, microbes and planktons from samples taken from the St. Johns River.
Materials and methods
Materials
The following materials were used during this experiment: -
- Protective material for the eye
- Refractometer
- Thermometer
- Hand held dissolved oxygen meter
- A rope with a weight attached at the end
- Digital hydro-tester meter
- Conductivity meter
- Ammonia range reader
- Stop watch
- Turbidity meter
Methods
The following measurements were taken at the dock;
Firstly, the water samples were collected from the river and a stream. The weather measurements were also taken. The weather measurements entailed whether it was sunny, windy, cloudy or partially cloudy. The depth of the water was taken in meters. A long rope with a weight attached to the end of the rope was lowered into the river until it reached the river bed. Care was exercised to ensure that the rope was erect and not bent on its way down. The depth of the river was then recorded in meters. A dissolved oxygen meter was used to measure the amount of dissolved oxygen in both the river and the stream.
These measurements were taken inside the laboratory.
A refractometer was used to measure the salinity of the water samples taken. While a hydro-tester was used to measure the pH of the water samples, a conductivity meter was used tio measure the conductivity. The levels of ammonia in the samples was measured using an ammonia range reader. The following procedure was used to measure the amount of nitrite in the water samples.
- The samples of water were put in two flasks.
- One of the flasks only contained water while the other flask contained ammonia powder.
- The flask with ammonia powder was swirled until the ammonia powder dissolved.
- The solution was then allowed to settle for fifteen minutes.
- After fifteen minutes the color of the solution was compared to colors on a standard wheel used to measure nitrites.
- The color that matched the one in the solution was recorded.
In order to measure turbidity, a turbidity meter was used. The metal part of the meter was used to immersed in water. The sample was then strirred until the number on the meter stabilized
Results
The total depth of the river was 2.40 metres in River Lab A, 2.50 metres in River Lab B and 2.40 metres in River Lab C while that of the stream was 0.15 metres in River Lab A, 0.20 in River Lab B and 0.15 in River Lab C. the turbidity levels were higher in the river than in the stream. The results also show that the more the conductivity in a sample, the higher the turbidity. There were varied results of salinity from the various samples taken from the same source. For instance, the salinity levels in samples taken from the river vary significantly.
Discussion
Turbidity is caused by the presence of insoluble material in the water in suspension form (Pressdee et al., 52). The suspension could be because of insoluble soild particles or wastes from water treatment facilities. Such water migh contain freen ions thereby raising the conductivity of samples from such sources. Conductivity on the other hand is due to the presence of inorganic material in water. These include chloride, nitrite, potassioum and sodium ions among others. Free ions in water act as electrolytes and conduct when current is passed through the sample. As seen from the data, increased turbidity led to increased conductivity. This can be attributed to freen electrolytes in the water. As such, the water from St. Johns river is of low quality. Ranges higher than 10000 mS/cm signify the presence of industrial waters in the sample (Manivanan 98). This is because while distilled water has a conductivity of 0.5 to 3 mS/cm, many rivers have a conductivity of between 150 to 1500 mS/cm (Perry & Elizabeth 66).
Data
Graph 1 showing the levels of various parameters measured from samples taken from the river and the stream on Wednesday lab.
Graph 2showing the levels of various parameters measured from samples taken from the river and the stream on thursday lab.
Works cited
Manivanan, R. Water Quality Modeling: Rivers, Streams, and Estuaries. New Delhi: New India Pub. Agency, 2008. Print.
Perry, Jim, and Elizabeth L. Vanderklein. Water Quality: Management of a Natural Resource. Chichester: John Wiley & Sons, 2009. Internet resource.
Pressdee, J R, S Veerapaneni, H L. Shorney-Darby, J A. Clement, and der H. J. P. Van. Integration of Membrane Filtration into Water Treatment Systems. U.S.A: AWWA Research Foundation, 2006. Print.
