A deailed Study on the Impact of Refinery Effluent on Eloor River and Analysis of the Physicochemical Properties of Water from Sources in and around Kochi

By Jinu George, Jorphin Joseph, Franklin J, Thommachan Xavier*
March 2011

The Authors are Professors at the P G and Research Department of Chemistry, Sacred Heart College, in Thevara, Kochi, Kerala, India.
* Corresponding Author

Water samples were collected from different parts of Eloor and analyzed for various water quality parameters. Effects of industrial wastes, municipal sewage, and agricultural runoff on river water quality were investigated. The study was conducted in Ernakulum District which is significant due to the high population density and presence of major fertilizer industries (e.g. FACT) and pesticide industries. This study involved determination of physical, biological and chemical parameters of water at different points. It was found that the water samples collected from Eloor, which is situated very near to the FACT Udyogmandal, contained high concentration of electrolyte and almost 10 times salinity than the normal drinking water. Moreover, the high BOD indicates the high degree of pollution still existing in the arena even after the stringent measures taken by the pollution control board. Present study also revealed high BOD in the Corporation drinking water which can be a major concern. Even the village areas are not free from different kinds of water pollutants as evidenced by the markedly high pH of the well water samples collected from Muppathadam.

Keywords: Salinity, BOD, Water Quality

Figure 1
Fig. 1: Study areas in Ernakulam district

Ernakulum, the industrial capital of Kerala contains at least 3.1 million population making it one of the most densely populated areas of our country. Besides, the industrial units such as Fertilizers and Chemicals Travancore (FACT), Travancore Cochin Chemicals (TCC), Hindustan Insectiside Limited, Indian Rare Earths (IRE) etc. are situated in this region. So it is of vital importance to monitor the water quality parameters of this region to ascertain whether the water is still useful for drinking and domestic purposes.

The objectives of the present study are:

In this paper, an attempt has been taken to study and compare the environmental conditions and the pollution status. The study area is shown in figure 1.

Results and Discussion

The physicochemical qualities of water samples collected from various locations were investigated, and the results were analyzed with regard to the environmental conditions. The sources were carefully chosen so as to include outskirts of villages, premises of factory and corporation area. The types of sources vary as river, well or tap water too. Standard methods were adapted for the sampling and analysis [1].

Table 1 · Environmental parameters of water quality analysis of various sampling stations
pH Conductivity
µS cm-1
mg L-1
Dissolved Oxygen
1. 6.07 142.8 157.1 134.0 5.44 64.2
2. 6.79 480.9 505.4 454.9 3.72 50.4
3. 6.62 710.6 750.4 681.4 5.12 64.5
4. 6.70 345.9 363.6 323.2 5.25 71.7
5. 6.62 298.6 312.7 277.3 5.61 65.5
6. 4.75 152.8 158.9 139.6 3.73 46.8
7. 5.26 162.2 170.2 150.2 5.63 68.3
8. 5.97 14.5 15.13 17.04 4.35 56.9
9. 7.06 72.46 76.98 70.35 5.79 70.0
10. 10.0 5.1 12.85 21.08 5.73 74.4
*TDS - Total Dissolved matter   # BOD - Biological Oxygen Demand
Figure 2
Fig. 2: pH of water at different sampling stations

Water samples were collected from different sources like river, well etc. from different parts of Ernakulam district. The samples are designated accordingly as:

  1. Kongorpilly well water
  2. Varapuzha well water
  3. Eloor river water (near FACT premises)
  4. Kaitharam well water
  5. Vennala well water
  6. Muppathadom well water
  7. Panayikulam well water
  8. Ezhikkara river water
  9. Corporation tap water taken from Vennala
  10. Deionised water from lab
Figure 3
Fig. 3: Conductivity of water at different stations

BOD is a measure of the oxygen used by microorganisms to decompose organic wastes such as dead plants, manure, sewage, food waste etc. If there is a large quantity of organic waste in the water supply, there will also be a lot of bacteria present working to decompose this waste. In this case the BOD level will be high. When BOD levels are high, dissolved oxygen (DO) levels decrease because the oxygen that is available in the water is being consumed by the bacteria. Since less DO is available in the water, fish and other aquatic organisms may not survive. The high BOD content indicates the high degree of pollution still existing in the arena even after the stringent measures taken by the pollution control board. In the case of dissolved oxygen(DO), standard for sustaining aquatic life is 4mg/l whereas for drinking purposes it is 6mg/l. DO values obtained for different samples is listed in the table1.

Figure 4
Fig. 4: Water salinity at different sampling stations

pH is a measure of hydrogen ion activity. The standard for any purpose in terms of pH in surface water systems is 6.5 -8.5. In that respect, the mean value for pH in table 1 indicates slightly acidic water. A water with low pH (<6.5) could be acidic, soft & corrosive & could contain toxic metal ions. Following figure 4 graphically shows the pH data of ten sampling points.

Electrical conductivity estimates the amount of TDS or the total amount of dissolved ions in water. Deionised water has very low electrical conductivity & hence very low TDS. EC of water smples is used as an indicator of how salt free, ion free or impurity free the sample is. The purer the water, the lower the conductivity.

Table 2 · Various drinking water quality standards [2]
Parameter WHO Standard
pH 6.5-8.5
TDS(mg/L) 1,000
Nitrate(mg/L) 10

This high value of TDS indicates a high waste assimilation capacity. Higher values of total solids are mainly due to the presence of silt and clay particles in the analyzed samples. Following Table 1 shows the TDS data of ten sampling points. Standard for TDS in terms of drinking water is 1000 mg/L. So in this respect we can conclude that the Eloor river water has markedly high levels of TDS which is not acceptable from the drinking water perspective.

Electrical conductivity is also a measure of salinity in water. Salinity describes the level of different salts such as NaCl, MgSO4, CaSO4, bicarbonates, nitrates etc in water.

Figure 5
Fig. 5: BOD data of ten sampling points

The water sample from Eloor river near the FACT premises contains nitrate ion in the amount-0.1 mg/L. The primary health hazard from drinking water with nitrate ion occurs when it is transformed to nitrite in the digestive system, which oxidizes iron in the hemoglobin of the RBC to form methemoglobin. This creates the condition known as Methemoglobinemia (some times referred to as BLUE BABY SYNDROME) in which blood lacks the ability to carry sufficient oxygen to the individual body cells causing the veins and skin appear blue.

The results from data analysis show that, the water is certainly unfit for drinking purposes without any form of treatment, but for various other surface water usage purposes, it still could be considered quite acceptable. But as we know, once a trend in pollution sets in, it generally accelerates to cause greater deterioration. So few years from now, serious water quality deterioration could take place. However, there could be gross differences in the test results of some samples at different laboratories in the country, which could limit the use of these data for sensitive policy issues. The differences might be attributed to the approach adopted by laboratories in sample preservation, quality of chemicals used, testing method applied or qualification or expertise of the technicians or test performers.

Figure 6
Fig. 6: Dissolved oxygen at different sampling stations

This study involves determination of physical, biological and chemical parameters of surface water at different points. Moreover, it is clear from the analysis that industries have negative impact on ground water resources near the industrial area. This study has shown that refinery effluent discharged into the Okrika arm of the Bonny River estuary resulted in the presence of high concentrations of pollutant in the water and sediment. The toxicants have been shown to be present in concentrations which may be toxic individually to different aquatic organisms. Pollution of the aquatic ecosystem poses a serious threat to aquatic organisms and ultimately the entire ecosystem.

Here a careful study of the data exhibited demand a conscious effort to take measures to stop different types of pollutions that spoil the virginity of water not only near the factories or town but also village outskirts which are believed to be non polluted.

Experimental Section

The analysis samples were analyzed using a water analyzer-PCD-650 Eutech Instruments &HI 83099 Multiparameter Bench Photometer, Hanna Instruments, USA. The parameters analyzed were-pH, Conductivity, TDS, Salinity, BOD, Dissolved oxygen & Nitrate ion content.


The water quality parameters of samples collected from different sources and areas in Ernakulam district were analyzed and the effects of industrial wastes, municipal sewage, and agricultural runoff on water were investigated. Determination of physical, biological and chemical parameters of water at different points has led us to draw the following conclusions.


  1. Laxen D. P. H, Harrison G.V. Analytical Chemistry, 53, 345, 1981.
  2. Md. J.B. Alan, M.R. Islam, Z. Muyen, M. Mamun, S. Islam, 4(1), 157-169, 2007.


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