EFFECT OF WATER QUALITY PARAMETERS ON BIOTA

Abstract

The study of pollution in an ecosystem is an area of global interest particularly as it directly or indirectly affects living beings. One of the major sources of pollution in river ecosystem is water which is polluted by mixing of sub-water stream containing industrial or sewage waste. As the water of river and streams are extensively used for many purposes such as water supply, irrigation and general amenities, it is highly desirable that the sources of water should be kept free from undesirable pollutants so that the interests of the community can be safe guarded. Saharanpur is an important major industrial city of Western Uttar Pradesh. The waste from numerous industries is mixed in the river Dhamola, which passes through the city. The water of this river is used for agriculture purposes including bathing and drinking by domestic mammals. The water of the river Dhamola just before entering in Saharanpur (North side of city) is colourless and visually looks pure, whereas, after about twelve kms south of entering in Saharanpur, the grey colour of the water can be easily seen. Essential micro and macro nutrients in the river are very much influenced by the mixing of waste discharge. Hence the contamination by sewage and other waste products causes pollution by disturbing the water quality. Apart from this, the sewage has high population of certain pathogenic micro and macro organism which in a rainy season, further affects the

aquatic life and water quality. As the visual changes indicated pollution in the river Dhamola within Saharanpur City, it was considered interesting to study the extent of pollution in this river and is the subject matter of this thesis. The studies include an in-depth analysis of various physico-chemical and biological factors at selected points of the river Dhamola. It has been concluded that the water of this river is not sufficiently pure and hence should not be used for bathing or drinking by human beings and domesticated animals. Attempts have also been made to minimise the pollution load by using certain vascular hydrophytes. The first chapter of the thesis is General Introduction and highlights the importance of pollution study in present days. The second chapter of the thesis has been devoted to the Literature Review. It reveals the important relevant references reported in the literature relating to the present studies on water pollution. The different methods of water analysis and techniques for reduction of pollutants have been discussed. Biological treatment processes by different species of algae, cyanobacteria and higher vascular hydrophytes and significant results relevant to the present study have also been incorporated at proper places. The next chapter is devoted to the Materials and Methods. The different methods of analysis of

physico-chemical and biological parameters of river water, industrial and domestic effluents according to the methods specified in ''Standard Methods for the Examination of Water and Waste Water'1 [American Public Health Association, 1987] has been discussed. The details of the experiments for minimising the pollution load of all the samples by using certain vascular hydrophytes (biological treatment), are also presented in this chapter. Three distinct aquatic plant species, viz., Eichhornia crassipes, Lemna minor and Ceratophyllum demorsum were used in stages I to III, whereas in stages IV and V a combination of E. crassipes, L. minor and L. minor, C. demorsum were used. The treatment of the industrial effluent as well as domestic sewage was allowed upto four weeks and the physico-chemical and biological parameters were determined at an interval of one week. The results obtained on the above studies form the fourth chapter of the thesis. Various parameters determined for the water samples collected at different places of river Dhamola are presented. The samples were collected for a period of two years, i.e., from July 1988 to June 1990 and the results of physico-chemical analysis are presented. The various parameters of the waste water samples collected from sampling stations 4 (domestic sewage) and 5 (industrial effluent) mixing in the river Dhamola clearly indicated that the values of BOD, COD, CO MPN and SPC are much higher than the tolerance limit of

Indian Standard for the discharge of waste water into the inland surface water. Also the samples had a very low value of DO during the entire course of investigation. The water samples obtained from sampling station 5 did not indicate the presence of any planktonic population whereas, in domestic sewage only protozoans were found in all the seasons. Algae was also detected during the rainy season in domestic sewage. The analysis of Dhamola river water at sampling station 1indicated the qualityof water with the parameters(mg/1) DO [min.7.2], BOD [max.20.5], COD [max.49.0], C02 [max. 1-1], chloride [max.22.0], total solids [max. 489 ] and total hardness [max.151 ]. Thus, the water at sampling station 1 was found sufficiently pure for the bathing and agricultural purposes. Due to the discharge of waste water into the river Dhamola, after the entering into the Saharanpur city, the quality of river water changes and the analysis at sampling station 2 (two kms. downstream of the merging point of waste water) indicated it to be polluted. It was found that the values of BOD, COD, CO total hardness, MFN, SPC, diatoms and protozoans increase tremendously whereas, the values of DO and algae (primary producer) decrease. The values observed for physico-chemical and biological parameters indicated that the water at sampling station 2 was not suitable for bathing purposes due to high value of BOD and coliform bacteria. It's use in bathing may lead to several chronic diseases. Analysis of water samples obtained from sampling station 3 also indicated the high values for BOD and coliform bacteria. Therefore, it was concluded that the water of the river Dhamola is not suitable for domestic purposes even after seven kms of the mixing of waste water. Other physico-chemical and biological parameters of the water at sampling station 3 are slightly better due to the self purification of river water. The content of the dissolved oxygen in river water reduced significantly at sampling station 2 in comparison to sampling station 1 due to the mixing of organic matter of the waste water. But at station 3 it was found that the concentration of dissolved oxygen increased due to the self purification. The values of different physico-chemical and biological parameters of river water have also been correlated with each other using a package of LOTUS program. An excellent statistical correlation was observed among the following parameters: turbidity - total solids, DO with BOD, COD and algae, BOD with CCD, SPC and algae, COD with SPC and algae and diatoms - protozoans. Attempts have also been made to use various vasuclar hydrophytes and their combination for the treatment of industrial and domestic effluents to reduce the pollution load of the waste products. Eichhornia crassipes was found most effective in the reduction of pollution load in all the seasons of the year. The values of DO was found to increase in four weeks treatment whereas BOD, CO , COD, MPN and SPC decreased. The decrease in the value of chloride ions was about 40-50% in comparison to control. As E. crassipes has large leaf area, well developed arenchyma and root systems, more transpiration occurs during photosynthesis and possibly causes an increase in DO value. L. minor used in stage II was found particularly useful for the removal of chloride (CI"), C02, turbidity, total solids and SPC. Hence the combination of E. crassipes and L. minor used in stage IV was found most effective in reducing the pollution load of domestic sewage as well as industrial effluent. It was observed that before entering in Saharanpur city the water of river Dhamola is pure as indicated by normal values of physico-chemical parameters, but the value of these parameters was fovnd to increase significantly at the mixing point and after mixing point of industrial/domestic discharge into the river. This indicated that a high pollution load has been added in the river in Saharanpur city due to which there is increase in the turbidity, total hardness, total solids, BOD, COD, chloride, C02, MPN, SPC, protozoans etc. Thus, the present studies clearly indicate that the river Dhamola becomes polluted after entering into Saharanpur city. The use of plant species, viz., E. crassipes and L. minor can reduce the pollution created by domestic sewage and industrial effluent to some extent and Vll then water of the river Dhamola will be suitable for bathing purposes. A more vigrous treatment, however, is needed for making it suitable for drinking purposes. It is worth mentioning at this stage that the aquatic plant species used in the present investigation are not only useful for pollution removal but their biomass can also be successfully used for the production of methane gas.