当前世界环境

Introduction

The main sources of water pollution in India at present are city sewage, discharge of industrial wastage, intensive use of fertilizers, insecticides and pesticides in agriculture. Excessive use of fertilizers has increased the level of nitrates in shallow ground water sources. The nitrate content in well water in Mahendragarh district in Haryana was found to be as high as 1310 mg/L. In Howrah district, intensive agriculture has contributed to high levels of such pesticides as DDT in the ground water. Satna district abounds in minerals like calcium, iron, aluminium and silicon and their concentration in water has been reported to be positive and in some cases touching the alarming limit of W.H.O. Several industries are set up in this region, prominent among them are lime and cement factories contributing inorganic and organic pollutants.

This paper reports on the drinking water quality of Satna (M.P.) by analyzing 5 samples of river water and 5 samples of ground water collected from different rivers and handpumps.

Methodology

Five samples from different rivers were collected in clear polythene bottles and incubated at normal temperature immediately. In the similar way five samples of ground water were collected in clear polythene bottles. Analysis of several parameters like hardness, fluorides, nitrates, calcium, iron, chloride, turbidity, conductivity, B.O.D and C.O.D as well as MPN of coliforms were conducted within 48 hours of sampling. Analysis of calcium, iron and nitrate was done by simple analytical methods. Calcium was estimated by E.D.T.A complexometric titration method. Estimation of iron was done by redox titration method. B.O.D. was determined by five days B.O.D. determination method. C.O.D. was determined by using Potassium Dichromate as oxidizing agent in acidic medium using FAS solution to determine unused Potassium Dichromate. D.O. was determined by Winkeler’s method. Fluoride concentration was determined spectrophotometrically using SPANDS method while other parameters were determined by APHA (1991) standard methods and results were compared with the standards prescribed so far.

Table 1: Status of Trace Elements in River Water (The results of chemical characteristics in mg/l) Click here to view table

Table 2: Status of Trace Elements in Ground Water (The results of chemical characteristics in mg/l) Click here to view table

Results and Discussion

本研究调查了溶解氧contents of surface water is comparatively more than that of ground water. D.O. contents in months of Nov., Dec. are more than D.O. contents in the months of July and August. B.O.D. and C.O.D values for the surface water are more than that of ground water in all the months of investigation. Although these values are more in rainy season than in winter but B.O.D and C.O.D. values for ground water are nil representing good quality of ground water of this region. Calcium concentration in both the seasons and in both kinds of water exceeds its maximum limit of 75 mg/L ( OSPC board organization) consequently stone patients are reported in this region. The concentration of fluoride in Satna, Unchehara and Nagod Tehsil is above its standard limit of 1.5 mg/l. In Ateraha, Gurhuru and Gorriya of Rampur Tehsil fluoride concentration is 1.25, 2.1 and 2.15 mg/l respectively which is suspicious for fluorosis. Unchehara Tehsil has even 3.31 mg/l concentration of fluoride attracting remedial precautions. Even in Nagod Tehsil fluoride concentration in marha tola 2.05 mg/l which is a matter of anxiety. Nitrate concentrations in surface water is more than that in ground water in both the seasons but its concentration even in ground water in Rampur Tehsil is beyond its maximum permissible concentration. Nitrate ion concentration in rainy season is more indicating uncontrolled use of urea and ammonium sulphate as fertilizers. Iron and fluorides concentration are within the permissible limits. Coliform cells are more in winter than in rainy season and is nil in ground water. Silica is either nil or present in little concentration in Tamas river water. Chloride concentration is much lower in both type of water in both the seasons. On comparing the observations with the permissible limits(BIS&WHO 1989) it is obvious that ground water of Satna is too safe for drinking and domestic purposes but river water needs its treatment for disinfection. Calcium concentration should be minimized because its concentration is more in both types of water in both the seasons. The observations are also compared with observations of MINARS and GEMS and are found within the permissible limits except calcium, nitrate and fluoride. Hardness in ground water in both the seasons is more than the permissible limit.

References