INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 4, No 5, Copyright by the authors - Licensee IPA- Under Creative Commons license 3.

Transcription

1 INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 4, No 5, 2014 Copyright by the authors Licensee IPA Under Creative Commons license 3.0 Research article ISSN Physicochemical analysis of some water ponds in and around Santiniketan, West Bengal, India (Joshi) Department of Botany, VisvaBharati, Santiniketan , West Bengal, India. doi: /ijes ABSTRACT The present study reports some physicochemical characteristics of the surface water of some ponds in and around Santiniketan. Determination of physical (ph, electrical conductivity and alkalinity) and chemical (sodium, potassium, chlorinity, salinity, free CO2 and COD) parameters were done to determine the surface water quality. The study revealed huge variations in the physicochemical parameters of water in different ponds. The values of the parameters ranged from ph 5.8 to 8.5, electrical conductivity to µmhos cm 1, alkalinity 39.4 to ppm bicarbonates, Na to 8.6 ppm, K to 16.5 ppm, chlorides to ppm, free CO to ppm and COD 2.7 to 52.3 ppm. Correlation analysis indicated high significant relationship (P<0.001, P<0.01) and also significant negative relationship (P<0.05) among the parameters. Churamani was the most polluted among all the ponds. Key words: Pond water, physicochemical parameters, water quality, pollution. 1. Introduction Water is one of the most abundant compounds in earth approximately covering threefourth of the earth s surface. Majority of water available on earth is saline in nature; only a small quantity exists as fresh water. Fresh water has become a scarce commodity due to over exploitation and pollution (Ghose and Basu, 1968; Gupta and Shukla, 2006; Patil and Tijare, 2001; Singh and Mathur, 2005). Industrial, sewage and municipal wastes are being continuously added to the water reservoirs affecting the physicochemical quality of water making it unfit (Dwivedi and Pandey, 2002). Uncontrolled discharge of domestic waste water into the ponds has resulted in eutrophication of ponds (Pandey and Pandey, 2003). Physicochemical properties (ph, conductivity, free CO2, COD, alkalinity, chlorinitysalinity, ions such as Na + and K + ) of water in any aquatic system are largely governed by the existing meteorological condition, and are essential for determining the structural and functional status of natural water. Hydrological condition of water affects the aquaculture activities, fish productivity and species composition of aqua fauna, eutrophication and overall loss of biodiversity that results in degradation of pond ecosystem. The magnitude and dynamics of oxidationreduction reaction by various elements present in water plays an important role in governing most of the chemical, biochemical and microbial behaviors in the pond water, and also maintaining congenial environmental condition. The major changes associated with electrochemical properties of pond water are reflected by the ph and electrical conductivity. Neutral to slightly alkaline ph ranges for water are considered to be congenial for aquatic production owing to greater availability of most of nutrient elements and also due to increased biological activities under this ph range. Apart from providing nutrients, potassium along with sodium serves as important components of base saturation of the pond soil and maintains alkaline ph in the pond environment. Bicarbonate (HCO3 ) and carbonate (CO3 2 ) Received on December 2013 Published on March

2 constitute major anions in fish pond ecosystem and provide CO2 in water which are required for photosynthesis. Hydroxyl (OH ) is occasionally present especially under highly alkaline condition. A wide range of organic substances occur in pond water. Chemical oxygen demand (COD) of water provides a measurement of organic matter in water. The study of different physicochemical parameters is very important for understanding the metabolic events in aquatic ecosystem. The parameters influence each other and govern the distribution and abundance of flora and fauna (Shinde et al, 2011). There were no such studies from this region and therefore a study of some physicochemical parameters was undertaken in different ponds from Santiniketan and adjoining areas (Bolpur and Sriniketan) to check the pond water quality. 2. Materials and methods 2.1 Study area Santiniketan is situated in the rural surroundings of Birbhum district (23 30' N 24 45' N and 87 21' E 88 10' E) West Bengal. Considering the undulation and slopes of the land, the altitude ranges maximally from 35m 40m, and minimally 20m 25m above sea level. The rainfall is about 150mm between the months of JuneSeptember which is 80% of the total rainfall. There are many water bodies present in and around Santiniketan including several ponds and marshy lands with varied aquatic vegetation. Ten ponds were selected for this study namely Kalishayer, Hathi pukur, Bandher par 1, Bandher par 2, Lalbandh, Churamani, Bhut pukur, Mohon pukur, Kal pukur and Saradha sagar. Many of these ponds are used by animals for drinking purpose, and by humans for washing, bathing and several household works. Water samples were collected in 1 liter plastic container from surface water between 9 a.m. to a.m. from February to April 2012, and brought in the laboratory for analysis. 2.2 Methods Physiochemical analysis of water samples were done following standard methods (Chattopadhyay, 1998). The ph was determined with a ph meter (Systronics ph meter) at room temperature (25 C). The electrical conductivity (EC) was estimated with a Systronics conductivity meter at room temperature (25 C). Sodium and potassium ions were estimated by flame photometric method. Free CO2 was estimated titrimetrically using phenolphthalein as indicator. Total alkalinity in terms of concentration of hydroxide (OH ), carbonate (CO3 2 ) and bicarbonate (HCO3 ) ions was estimated by titration with acid using phenolphthalein and methyl orange as indicators. Chlorinity was estimated by titration with silver nitrate (AgNO3) in presence of chromate ions. Salinity was estimated from chlorinity as Salinity = Chlorinity x Chemical oxygen demand (COD) was estimated by oxidation with potassium dichromate followed by back titration with ferrous ammonium sulphate. 3. Results and discussion The mean values of physicochemical parameters of water samples are given in tables 1 and 2. Correlation coefficients among the physicochemical parameters are shown in table

3 Table 1: Mean values (along with standard deviations) of physical parameters of water samples. S. No Pond name ph Electrical Conductivity (µmhos/cm) CO 3 2 HCO 3 Total 1. Kalishayer 6.67 ± ± ± ± Bandher Par ± ± ± Bandher Par ± ± ± ± Hathi Pukur 5.81 ± ± ± Lalbandh 6.78 ± ± ± Mohon Pukur 7.52 ± ± ± Saradha Sagar 6.71 ± ± ± Kal Pukur 7.30 ± ± ± Bhut Pukur 7.50 ± ± ± Churamani 8.55 ± ± ± ± WHO standard ph: ph is defined as the intensity of the acidic or basic character of a solution at a given temperature. In this study ph ranged from moderately acidic to slightly alkaline, with two ponds having ph below the WHO standard. Highest ph was found in Churamani (8.55) while lowest in Hathi pukur (5.81). ph showed highly significant positive relationship with chlorinity, salinity and COD (table 3). Mondal et al. (2011) reported positive relation between quality of pond water and ph of water and sediments. Importance of pond water ph has been studied for long in India. Banerjee (1967) reported neutral to slightly alkaline ph range to be most favourable to fish ponds. This ph range is considered to be congenial for aquatic production owing to greater availability of most of the nutrient elements, and also due to increased biological activities under this ph range (Boyd, 1978). 3.2 Electrical Conductivity: Electrical conductivity (EC) is a numerical expression of ability of an aqueous solution to carry electric current. The highest EC was recorded in Bhut pukur (712.5 µmhos cm 1 ), and lowest in Bandher par 2 (1.174 µmhos cm 1 ). Natural waters usually have EC values of 20 to 1500 µmhos cm 1 (Boyd, 1978). However, the standard limit set by WHO is 250 µmhos/cm. Six out of ten studied ponds exceeded the WHO standard. The EC value depends on several factors like the presence of ions, their concentration, mobility, valance and temperature of measurement. Sastry et al. (1999) found the concentration of dissolved solids to be proportional to the ionic strength and proposed that the increase in conductivity may be due to leachate infiltration from soil. Electrical conductivity showed significantly negative correlation with chlorinity and salinity. 3.3 Alkalinity: Alkalinity is a measure of capacity of water to neutralize strong acid. Total alkalinity is the sum of hydroxides, carbonates and bicarbonates. Presence of hydroxides was not recorded in any pond; bicarbonate was the major ion responsible for alkalinity in all the ponds. In this post winter season, total alkalinity exceeded the WHO standard in all but four ponds. The maximum bicarbonates were present in Bhut pukur and Mohon pukur (391.2 ppm) followed by Churamani (388.0 ppm). Hathi pukur had minimum bicarbonates (39.4 ppm). The uptake or 678

4 release of carbon dioxide by organisms may change the proportion of carbonates and bicarbonates in water (Boyd, 1984). In this study, carbonates showed significant negative correlation with free carbon dioxide, and were reported in only two ponds where free carbon dioxide was absent. S. I. Table 2. Mean values (along with standard deviation) of chemical parameters of water samples. All the values are in ppm. Pond name Na + K + Chlorinity Salinity Free CO2 COD 1. Kalishayer Bandher par 1 Bandher par 2 Hathi Pukur 5. Lalbandh Mohon Pukur Saradha Sagar 8. Kal Pukur 9. Bhut Pukur 10. Churamani WHO standard 6.5 ± 8.6 ± 7.9 ± 5.8 ± 7.6 ± 5.1 ± 2.7 ± 1.7 ± 5.0 ± ± 2.1 ± ± ± 0.29 ± ± ± ± 6.7 ± 16.5 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±0 5.7 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± Potassium: Potassium is one of the major cations in water and soil. In this study, the concentration of potassium ions varied from as low as 0.29 ppm (Hathi pukur) to as high as 16.5 (Bhut pukur). Fish ponds are usually considered to be fairly well supplied with potassium (Mandal and Chattopadhyay, 1992). High clay and organic matter content of productive fish pond soils (Singh and Ram, 1974), associated with alkaline ph values usually tend to maintain moderate to good amount of potassium (K) in pond soil and water (Chattopadhyay, 1995). However, with increasing use of N and P fertilizers, potassium is gradually becoming the limiting nutrient, and estimation of potassium ion in pond water is becoming important (Chattopadhyay, 1998). May be due to these factors Bhut pukur has more amount of potassium (16.5 ppm) than any other ponds. Boyd (1978) considered a concentration of 1.3 ppm to be critical level of potassium in fresh water ponds. The potassium ion concentration did not show significant concentration with any other parameter. Sodium: Generally, sodium (Na) is not included in regular analysis of pond water. However, in brackish water ponds Na occurs in very high concentration and determination of this element may be felt necessary. In the present study, the sodium ion content was low ranging from 1.7 ppm (Kalpukur) to 8.66 ppm (Bandher par 1). Sodium ion concentration showed significant negative correlation with free CO2 concentration. 679

5 Table 3. Correlation matrix among physicochemical properties of the studied ponds ph EC CO3 2 HCO3 Na K Chlorinity Salinity Free CO2 COD ph 0 EC (µmhos cm 1 ) CO HCO Sodium Potassium Chlorinity 0.755** 0.604* Salinity 0.755** 0.604* Free CO * 0.604* COD 0.828** *** 0.874*** *** = Correlation is highly significant at P<0.001 level; ** = Correlation is highly significant at P<0.01 level; *= Correlation is highly significant at P<0.05 level; = indicates negative correlation. 3.5 Chlorinity and salinity: Chloride anion is generally present in natural waters. Chloride concentration is higher in organic wastes and its higher concentration in natural water is definite indication of pollution from domestic sewage. The ecological significance of chloride lies in its potential to regulate salinity of water. Most of the water soluble salts in a pond environment generally remain in Cl form and hence the amount of Cl ions in pond water indicates very closely the amount of soluble salts present. In the present study, chlorinity and salinity was found to be highest in Churamani pond ( ppm and ppm, respectively) and lowest in Hathi pukur (30.70 ppm and ppm, respectively). Chlorinity and salinity were highly significantly correlated among themselves, and also with chemical oxygen demand (COD) value. The optimum concentration of chloride ions in freshwater aquaculture are lacking ppm concentrations are usually considered to be favourable (Chattopadhyay, 1998). However, the standard limit set by WHO is 250 ppm. All the ponds recorded values less than the WHO standard although Churamani almost approached it. 3.6 Free CO2: Apart from its important role in photosynthesis of primary fish food organisms, free CO2 has interdependence with ph and bicarbonatecarbonate equilibrium. However, if present in higher concentration, it may exert adverse effects on respiration and other physiological functions of aquatic life (Chattopadhyay, 1998). In the present study free CO2 was absent in three ponds. Mohon pukur recorded the highest free CO2 ( ppm), and Hathi pukur the lowest (4.75 ppm). Various critical levels of free CO2 in aquatic habitat have been suggested by many workers. Ellis (1937) stated that the water supporting good fish population usually contains less than 5 ppm of free CO2. Free CO2 showed significant negative correlation with carbonate content and sodium ion concentration. 680

6 4. Chemical Oxygen Demand The chemical oxygen demand (COD) is a measure of the total amount of oxygen which is required to oxidize all the organic matter in a sample to CO2 and H2O (Boyd, 1998). Like BOD, it is also an index of organic enrichment of pond water. In the present study, the COD ranged from 2.7 ppm (Lal Bandh) to 52.3 ppm (Churamani). Chattopadhyay (1998) considered the optimum COD value of fish ponds to be between 80 and 100 ppm. However, the standard limit set by WHO is 10 ppm. All but two ponds exceeded the WHO standard. COD showed highly significant positive correlation with ph, chlorinity and salinity in this study. 5. Conclusions Though it is a baseline study done in a particular season, some conclusions can be definitely drawn. The parameters which were taken into consideration varied greatly in different ponds. Correlation analysis indicated significant correlation between various parameters. Most of the parameters were within the acceptable limit, except alkalinity, electrical conductivity and COD. Among all the studied ponds, Churamani was the most polluted, and recorded highest values for ph, chlorinity, salinity and COD. It was due to excessive use of the pond by the local people and damping of household wastes into it. Hathi pukur recorded the lowest values for ph, potassium, chlorinity, salinity and bicarbonates. Further detailed analysis in different seasons involving other related parameters as well, will throw more light on the status of these ponds. 6. References 1. Banerjee, S.M. (1967), Water quality and soil conditions of fish ponds in some states of India in relation to fish production. Indian Journal of Fisheries, 14, pp Boyd, C.E. (1978), Water Quality in Warm Water Fish Ponds. Agricultural Experiment station, Auburn University, pp Boyd, C.E. (1982), Water Quality Management for Pond Fish Culture. Elsevier Scientific Publishing Corporation, New York, pp Chattopadhyay, G.N. (1998), Chemical Analysis of Fish Pond Soil and Water. Daya Publishing House, Delhi pp Chaurasia, M. and Pandey, G. C. (2007), Study of PhysicoChemical Characteristics of Some Water Ponds of AyodhyaFaizabad, Indian Journal for Environmental Protection, 27(11), pp Dwivedi, B.K. and Pandey, G. C. (2002), PhysicoChemical Factors and Algal Diversity of Two Ponds, (Girija and Maqubara Pond), Faizabad. Pollution Research, 21, pp Ellis, M.M (1937), Detection and measurement of Stream Pollution. Bull 22, US Bureau of Fisheries. 8. Ghose, B.B. and Basu. A. K. (1968), Observation on Estuarine Pollution of the Hooghly by the Effluents from a Chemical Factory Complex at Reshasa, West Bengal. Environmental Health, 10, pp

7 9. Gupta, S. and Shukla, D. N. (2006), PhysicoChemical Analysis of Sewage Water and its Effect on Seed Germination and Seedling Growth of Sesamum indicum. Journal of Research in National Development, 1, pp Mondal, N.K., Datta, J.K., and Banerjee, A. (2011), Pond alkalinity: A study in Burdwan municipality, Burdwan, West Bengal, India. International Journal of Environmental Sciences, 1, pp Pandey, A. K. and Pandey, G. C. (2003), PhysicoChemical Charateristics of City Sewage Discharge into Saryu at FaizabadAyodhya. Himalayan Journal of Environment and Zoology, 17, pp Patil, D. B. and Tijare, R. V. (2001), Studies on Water Quality of Godchiroli Lake. Pollution Research, 20, Pp Sastry, K.V., Rathee, P. and Sukla, V. (1999), Ground Water Characteristics of Rohtak and Bahadurgarh. Environmental Ecology, 17, pp Shinde, S.E., Pathan, T.S., Raut, K.S. and Sonawane, D.L. (2011), Studies on physicochemical parameters and correlation coefficient of Harsoolsavangi Dam, District Aurangabad, India. MiddleEast Journal of Scientific Research, 8(3), pp Singh, R.P. and Mathur, P. (2005), Investigation of Variation in PhysicoChemical Characteristics of a Fresh Water Reservoir of Ajmer city, Rajasthan. Indian Journal of Environmental Science, 9, pp Singh, S. and Ram, H. (1971), A Comparative Study on Pond and Adjoining Cultivated Soils. Indian Journal for Agricultural Chemistry, 4(1), pp Theroux, F.R., Elridge, E.F. and LeRoy, M.W. (1943), Laboratory Manual for Chemical and Bacterial Analysis of Waters and Sewage. McGraw Hill Inc, London, pp Yadav, B.R. and Khera, M.S. (1993), Analysis of Irrigation Waters. In: HLS Tandon (Ed.) Methods of Analysis of Soils, Plants, Waters and Fertilizers. FDCO, New Delhi, pp