Journal of Indian Water Works Association 230 July – September (2003)

Journal of Indian Water Works Association, July – September (2003) : 230 - 233

EVALUATION OF SUITABILITY OF AMBANALA

WATER, AMRAVATI, FOR IRRIGATION KHEDKAR, D. D*. AND A. J. DIXIT**

* P. G. Department of Botany

Govt. Vidarbha Institute of Science & Humanities, Amravati-444604.

(E-mail - sonudin@yahoo.co.in)

** P. G. Department of Botany

Vidyabharati Mahavidyalaya, Amravati-444602.

INTRODUCTION

The structural and functional attributes of water have to be analyzed both quantitatively and

qualitatively in order to have a comprehensive evaluation of the water quality; essential for judging

it’s suitability for irrigation. Sewage farming is an important development in water resource

management and this practice was initiated mainly due to the scarcity of alternative water supplies

and need to increase the local food production (Rowe & Abdul Majid, 1995). In India, several

wastewater irrigation schemes are operating, serving an area of about 73,000 hectares (Shende, 1988).

The historical city of Amravati (M. S.), endowed farmers by the streamlined flow of domestic wastewater generated by the city, through the Ambanala. This wastewater is utilized by the farmers in

the vicinity of the nala for irrigation of wheat, spinach, cauliflower, cabbage, carrot and a few other

crops. The direct use of the wastewater by the farmers necessitates evaluation of the quality of the

water for the effects, if any, on the fertility of the soil, health of the farm workers, and quality of the

vegetables grown on it. As the Ambanala does not receive any industrial wastewater discharges, it

becomes significant for irrigation. The domestic waste contains garbage, paper, plastic bags, besides

dirt and ash, but, in terms of the nutrients and fertilizing properties, it approaches manure (Yagodin,

1984). The aim of the present investigation was, therefore, to characterize the domestic wastewater of

Ambanala and to evaluate its suitability for irrigation.

MATERIAL AND METHODS.

Wastewater samples were collected from five different sites selected on the Ambanala, where

direct uptake of the wastewater for irrigation is the general practice for the last 3-4 decades. The water

samples were collected fortnightly, from April 2000 to March 2002, from the five sampling sites i.e. I:

Near Ekvira Devi Temple; II: Near Ingole Farm; III: Near Jaiswal Wadi; IV: Confluence point of

Ambanala and nala from Radha Nagar near village Lalkhadi; V: Confluence point of Ambanala and

Pedhi River near village Haturna.

The distance between two consecutive sites, upto the site- IV, is about three kms.; whereas the site- V

is located at a distance of about six kms. from the site-IV. Various physical parameters, which are

important to evaluate the suitability of water for irrigation, were determined on the site with the help

of a water analysis kit (VSI-07 Model). The chemical analysis was carried out for BOD by incubation

method, COD by KMnO4 method; Chloride ( Cl - ) , Calcium ( Ca

+2 ), and Magnesium ( Mg

+2 ) by

volumetric methods; while Sulphate ( SO4-2

) and Phosphate (PO4-3

) by spectrophotometric

methods; Nitrogen ( N ) by Kjeldahl’s method and Sodium ( Na+ ) and Potassium ( K

+ ) by

flamephotometry ( APHA, 1998). The respective averages (from two-year data) for all the parameters

have been reported in Table-1. The suitability of the wastewater for irrigation was evaluated by using

the irrigation water quality indices given by the Central Pollution Control Board (CPCB, 1990) and

United State Salinity Laboratory (Gupta, 1999) with special reference to percent sodium (% Sodium),

Sodium Adsorption Ratio (SAR), Sodium Calcium Activity Ratio - SCAR- (Goel & Sharma, 1996).

The values of all the parameters considered for suitability determination were expressed as averages

of the two-year analysis during April 2000 to March 2002 (Table-2).

Journal of Indian Water Works Association 231 July – September (2003)

RESULTS AND DISCUSSION.

The physico-chemical data reveal that the water temperatures at all the five sites ranged between

28.31oC and 28.73oC, showing identical environment throughout the stretch of the Ambanala. The pH

values of the wastewater at all the five sites were 7.56, 7.51, 7.54, 7.08 and 7.81, respectively,

reflecting slightly alkaline nature. These values were within the permissible range of pH (6.5-8.5) for

irrigation waters. The ORP of the wastewater shows satisfactory oxidation levels, indicating an

adequate amount of oxygen supply to the plants. The TDS values increased at sites IV (1046 mg/l)

and V (1004 mg/l) where the nala water receives domestic wastes from additional areas of the city.

The EC values also showed a trend of lower or higher values, corresponding with those of the

respective values of the TDS. The DO was recorded in the range of 3.0 and 4.83 mg/l. The highest

value of DO, recorded at site-V (4.83 mg/l ), might be due to the mixing of the wastewater with the

Pedhi river water. The low concentration of DO at all the sites, with corresponding higher values of

BOD and COD indicates pollution from domestic sources; this fact has been clearly confirmed from

values of these parameters at site-II which is almost in the center of the city and receives huge

quantities of the domestic sewage and other organic substances. The high COD shows the presence of

bulk of accumulated organic matter, which reflects it’s incomplete oxidation. The cause of high BOD

may be excessive growth ( eutrophication ) of aquatic flora in the water which could be fatal for

aquatic fauna ( Sharma, 2000 ). The Kjeldhal’s Nitrogen values were similar at all the five sites, and

were found to be indicative of some nutritional potential of the nala water, and of an easily

decomposable organic matter content. The organic matter mainly involves sewage and consists of

proteins, ammonia, urea and other similar compounds. Due to the varying inflows of sewage and

aquatic fauna, the amount of phosphate exceeded the range of the minimum desirable and maximum

permissible values (2.5-5.0 mg/l); at the site-V, the phosphate concentration is slightly lower than that

at other sites, which might be due to dilution of the wastewater by mixing with the river water.

Amongst the cations, the concentration of K+ was the lowest. Presence of this nutrient is favourable

for crop growth as it lowers the negative effect of salinity. Moreover, in conformity with Sharma

(1998), as potassium has higher bonding energy than sodium to the soil surface, it’s presence renders

low adsorption of sodium on the soil thereby reducing the sodicity hazards. The pH of the water

samples indicated slightly alkaline nature, which necessitates estimation of sodium. It was found in

higher concentration than that of potassium. Small quantities of sodium and potassium are always

desirable in irrigation waters. Saline water has more amount of sodium (Gupta, 2000). The same fact

was observed in the wastewater of Amravati where sodium concentration exceeds 3 meq/l. The

amounts of calcium and magnesium were found to be within the respective permissible limits in

irrigation waters (3.75 and 12.5 meq/l respectively). High amount of sulphate also showed the

richness of organic material in the wastewater. These values are also within the permissible limit (192

mg/l).

Evaluation of the quality of the wastewater on the basis of percent sodium is excellent. Percent

Sodium is defined here:

% Na = Na+ X 100/ ( Na++ K++ Ca+2+ Mg+2);

where, the individual ions are expressed in meq/l. The acceptable % Na values are 60-75 vide the

USDA (Gupta, 1999). The observed values of % Na for the Ambanala water samples were below 60

(Table-2). Quantitatively, United State Salinity Laboratory proposed, for the first time, a better index

called ‘Sodium Adsorption Ratio’ (SAR) to confirm the hazardous level of sodium (Maiti et. al.,

1992). SAR has been defined as given here:

SAR = Na+/ {( Ca

+2 + Mg

+2 )/2}

1/2

Where, the individual ions have been expressed as meq/l. Moreover, the parameter SCAR, defined as

Na+/ (Ca+2)1/2, where the individual ions are expressed as meq/l, also helps to determine suitability of

water for irrigation. The present investigation revealed that on the basis of percent sodium, the water

quality is good to excellent for irrigation. The SAR values fall within the standard of USSL (< 10),

and the water has been evaluated suitable for all crops, except sensitive ones. SCAR values also

reflected the suitability of water for all type of crops. Moreover, the remaining parameters, like TDS,

Journal of Indian Water Works Association 232 July – September (2003)

sulphates, chlorides and EC confirm the suitability of the wastewater for irrigation. The present

findings are in conformity with those of Stewart and Nielsen (1990), which indicated that domestic

wastewater is rich in nutrients but poses some salinity hazard as well as sodium toxicity throughout

the year. The investigations of Jagtap et. al. (2002) in relation to 1) high concentration of sodium, 2)

TDS, 3) SAR and suitability of Purna river water, Buldana, were almost in agreement with the

present results. The variation in chemical composition and nutrient status of the wastewater at

different sites was due to differences in the sources of wastewater discharges. In addition to the

nutrient status of the Ambanala water, the water also has sufficient amount of DO. When this

wastewater is supplied to the soil for crop irrigation, it will certainly improve the crop yield, but the

sodicity may pose a threat to the soil physical condition.

CONCLUSIONS

The results of suitability evaluation indicate that there is no major pollution hazard in wastewater of

Ambanala. Moreover, the points to be taken into consideration, before application of the wastewater

to the soil are, removal of the sodicity, cultivation of crops tolerant to high sodium levels, prevent

accumulation of high TDS in the soil and maintain adequate nutrient level in the soil.

ACKNOWLEDGEMENTS

The authors are very much indebted to the University Grants Commission, New Delhi, for

providing financial assistance to the Minor Research Project and to Dr. C. K. Kale, Retd. Scientist,

NEERI, Nagpur for his noteworthy suggestions. We also extend deep sense of gratitude towards Dr.

K. N. Patil, Principal, Vidyabharati Mahavidyala, Amravati for providing the laboratory facilities.

REFERENCES

� Goel, P. K. and K. P. Sharma. Environmental Guidelines and Standards in India. 1st ed.

Technoscience Puble., Jaipur.1996.

� Gupta, I. C.. Evaluation of quality of irrigation waters and industrial effluents discharged on land

for irrigation. Journal I.W.W.A. 31 (1 ): 47-56. 1999.

� Gupta, P. K. Methods of Environmental Analysis, Water, Soil and Air. 1st ed. Agrobios Publ.,

Jodhpur. 2000.

� Jagtap, J., B. Kachwe, L. Deshpande and P. Kelkar. Water quality assessment of the Purna river

for irrigation purpose in Buldana Distriict, Maharashtra. Indian J.Environ. Hlth. 44 (3 ): 247-257.

2002.

� Maiti, P. S., K. D. Salr, S. K. Gupta and S. K. Banarjee. Evaluation of sewage sludge as a source

of irrigation and manure. Ind. Soc. Soil Sci. Vol. 40: 168-172. 1992.

� Rowe, D. R. and I. M. Abdul-Majid. Handbook of Wastewater Reclamation and Reuse. CRS

Press Inc. P.550. 1995.

� Sharma, H. S., P. K. Agrawal and S. Prabha. Water quality of sewage drains entering Yamuna

river at Mathura ( U.P. ). J. Envron. Biol. 21 (4 ): 375-378.2000.

� Sharma, S. Agricultural use of sewage wastes in Gwalior : Ionic quality assessment. Ind. J. Env.

Hlth. 40 (1): 51-57. 1998.

� Shende, G. B. Status of wastewater treatment and agricultural re-use with special reference to

Indian experience and research and development needs. In ‘ Treatment and Use of Sewage Effluent

for Irrigation’. Pescod, M. B. and A. Arar Eds. Butterworths, London. 1988.

� Standard Methods for Examination of Water and Wastewater. 20th ed.. American Public Health

Association, Washington, D. C. 1998.

� Stewart, B. A. And D. R. Nielsen. Irrigation of Agricultural Crops. American Society of

Agronomy. p. 1218. 1990.

� The Status of Water Supply and Wastewater Collection , Treatment and Disposal in Class-I

Cities. Central Pollution Control Board, New Delhi. CUPS/30/1989-90.

� Yagodin, B. A. ( ED. ). Agricultural Chemistry-2. Chapter-3-Manure. Mir. Publishers, Moscow.

p. 108. 1984.

Journal of Indian Water Works Association 233 July – September (2003)

Table-1: Average values of physico-chemical parameters for the two-year study

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Sr. No. Parameters Wastewater Sampling Sites

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I II III IV V

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1. Temperature; oC 28.42 28.73 28.36 28.31 28.37

2. pH 7.56 7.51 7.54 7.08 7.8

3. ORP; mV 118.1 112.3 108.7 112 101.2

4. TDS; mg/l 946.8 976.5 982.5 1046 1004

5. EC; µS/cm 1486 1532 1541 1640 1575 6. DO; mg/l 4.6 4.8 3.0 3.3 7.4

7. BOD; mg/l 112 131 111 113 119

8. COD; mg/l 314 368 312 317 336

9. Nitrogen; mg/l 8.4 8.2 8.2 8.0 8.1

10. Phosphate; mg/l 7.7 7.8 7.9 8.0 7.5

11. Potassium; meq/l 0.29 0.28 0.29 0.30 0.30

12. Sodium; meq/l 6.1 6.6 7.0 7.7 7.4

13. Calcium; meq/l 3.32 3.92 3.87 3.74 3.6

14. Magnesium; meq/l 3.8 3.15 2.86 3.2 3.02

15. Sulphate; mg/l 24.3 22.7 23.0 23.0 24.0

16. Chloride; mg/l 153 145 157 163 156

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Table-2 : Suitability of the Ambanala water used by the farmers for irrigation throughout

year.

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Sr. Parameters Observed CPCB Class of Suitabilityfor

Values Standards Water irrigation

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1 TDS; mg/l 991.12 700-2000 II Good - Injurious

2 Sulphates; mg/l 23.42 < 192 I Excellent - Good

3 Chlorides; mg/l 154.8 142-355 II Good - Injurious

4 Percent Sodium 49.07 60-75 * I Excellent - Good

5 EC; µS/cm 1425.8 750-2295* II Good - Injurious

6 SAR 3.75 < 10 * I Excellent - Good

7 SCAR 3.76 < 10 * I Excellent - Good

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* United State Salinity Laboratory Standards.