In India, canal system is one of the major requirements for the sustainable utilization of water in river basins. Ganga canal is one such example of canal system created on River Ganga Basin in India; it originates at Bhimgoda Barrage, Haridwar. In the present study, water of Main Kalda Distributory Irrigation Canal, a tributary of Upper Ganga Canal in Dadri, Gautam Buddha Nagar, UP was analysed for some of the important physico-chemical parameters of water quality during April 2015. Five sampling points were selected based on the canal passing through agricultural fields or habitation of Chithera and Bodaki Villages in Dadri Tehsil. First sampling point was at Mat Branch of Ganga Canal (Khatana Distributory) of Upper Ganga Canal and four sampling points were at Main Kalda Distributory Irrigation Canal; GPS observations were recorded of the sampling points. All along the canal where the sampling points were located observations were recorded on dumping of waste, opening of household/municipal drains, drains from the adjacent dairies which contributed to to the pollution of canal water.
The analysis of water samples showed that the values of most of the parameters were within the ISI Standards. The conductivity ranged in between 165 (Site 2) and 225 (Site 4), TDS between 91 (Site 3) to 123 (Site 4), pH between 6.88 (Site 4) to 9.37 (Site 3), DO between 5.41 (Site 4) to 8.54 (Site 5), BOD between 1.45 (Site 4) to 3.54 (Site 2), Turbidity between 10.2 (Site 3) to 14.4 (Site 4), Alkalanity beteen 20 (Site 1 and 2) to 72 (Site 5), and Hardness between 64 (Site 2) to 140 (Site 5); Coliform Bacteria were tested positive in all the samples. It may be concluded from the results that of the five sampling sites, the canal water at Sites 4 and 5 was the most polluted having high TDS, DO,BOD, Turbidity, Hardness values which is due to the garbage disposal, opening of domestic and dairy waste drains in the canal. Poor quality of water in the Canal is likely to have an adverse impact on agricultural crops in terms of seed grain quality.
The following physical and chemical parameters were selected for the water quality study. Five observations were taken from each sample and mean, SD and SE calculated.
- Turbidity (NTU) was measured using a Nephelometer.
- Conductivity (Siemens/cm) and Total Dissolved Solids (mg/l) were measured with the help of digital portable kit TOSHICON model.
- pH of water samples was measured using an electronic pH meter.
(i) Dissolved Oxygen (DO) (mg/l): Dissolved oxygen (DO) was determined through the Winkler Iodometric Method, where the Manganese sulphate reacts with the alkali (KOH) to form a white precipitate of Manganese Hydroxide which is presence of oxygen gets oxidized to a brown coloured compound. In the strong acid, medium manganic ions are reduced by iodine which get converted into iodine equivalent tothe original concentration of oxygen in the sample. The iodine was titrated against thiosulphate using starch as an indicator.
(ii) Biochemical oxygen demand (BOD) (mg/l) : Biochemical oxygen demand (BOD) test was carried out by measuring the dissolved oxygen concentrations in water sample before and after incubation in the dark at 20°C for five days. It was determined through Winklers Iodometric method, using redox titration.
- Alkalinity (mg/l): Total alkalinity, carbonates, biocarbonatses, was estimated by titrating the sample with a strong acid first at pH 8.3 using phenolphthalein as an indicator and then further at pH between 4.2 and 5 with methyl orange or mixed indicator; in first case, the value is called as Phenolphthalein Alkalinity (PA) and in second case, it is Total Alkalinity (TA).
- Hardness (mg/L), an index to measure the concentration at Ca2+ and Mg2+ ions in water, was determined by titrating a known volume of water with a standard EDTA solution using Erichrome Black-T (EBT) indicator to show the end point of the reaction.
- Coliform bacteria: The test for the total Coliform, as an "indicator organism" for the water quality was performed using a Coliform bacteria test kit. All the parameters were analyzed in laboratory after samples preservation as per Khanna et al., 2011, Bureau of Indian Standards (BIS 1991) and American Public Health Association (APHA 2005) guidelines. The colorimetric analyses were done with UV Spectrophotometer Cary 60. The statistical analysis was carried out using Minitab 16 to identify the correlation between selected water quality parameters.
RESULTS AND DISCUSSION
Irrigated agriculture is dependent on an adequate water supply of usable quality. Water quality concerns have often been neglected because good quality water supplies have been plentigul and readily available. This situation is now changing in many areas. Intensive use of nearly all good quality supplies means that new irrigation projects and old projects seeking new or supplemental supplies must rely on lower quality and less desirable sources. To avoid problems when using these poor quality water supplies, there must be sound planning to ensure that the quality of water available is put to the best use.
Conceptually, water quality refers to the characteristics of a water supply that will influence its suitability for a specific use, i.e. how well the quality meets the needs of the user. Quality is defined by certain physical, chemical and biological characteristics. Even a personal preference such as taste is a simple evaluation of acceptability. In irrigation water quality, emphasis is given to chemical and physical characteristics of the water and only rarely are any other parameter considered important.
Water used for irrigation can vary greatly in quality depending upon type and quantity of dissolved salts. Salts are present in irrigation water in relatively small but significant amounts. They originate from dissolution or weathering of the rocks and soil, including dissolution of lime, gypsum and other slowly dissolved soil minerals. These salts are carried with the water to wherever it is used. In the case of irrigation, the salts are applied with the water and remain behind in the soil as water evaporates or is used by the crop.
The suitability of a water for irrigation is determined not only by the total amount of salt present but also by the kind of salt. Various soil and cropping problems develop as the total salt content increases, and special management practices may be required to maintain acceptable crop yields.
Water Quality parameters and pollution
Major point sources of pollution in river Ganga are discharge of untreated/partially treated sewage from- -urban- centres- discharge from open drains, carries sewage, industrial wastewater, returned storm water, discharge from major tributaries discharge of untreated/partially treated/treated wastewater from industrial units.
Water pollution is a major global problem which requires ongoing evaluation and revision of water resource policy at all levels (international down to individual aquifers and wells). It has been suggested that water pollution is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily. An estimated 580 people in India die of water pollution related illness every day. In addition to the acute problems of water pollution in developing countries also continue to struggle with pollution problems.
Matta (2014) assessed the water quality of upper Ganga Canal for various parameters in different seasons. During investigation maximum Turbidity (233.8 ±104.60 JTU), Total Solids (933.00 ±216.44 mgl-1) and minimum Velocity (0.93 ±0.355 ms-1), Free CO2 (1.85 ±0.14 mgl-1) and Transparency (0.22 ±0.15 m) were recorded in monsoon season at site 2. While maximum pH (8.1 ± 0.1), Total Hardness (84.38 ±4.65 mgl-1) and Dissolved Oxygen (8.64 ± 1.02 mgl-1) were recorded in summer season at Site 2 in comparison with Site 1. The mean values of these parameters were compared with WHO and ISI standards and found significant differences (p<0.05) in the mean values of Turbidity, Total solids (TS), pH, Dissolved Oxygen (DO), Free CO2 and Total Hardness (TH) with sampling Sites. The Turbidity of both the Site 1 and 2 was recorded above the permissible limit, but higher at site 2 in comparison to Site 1. The values of the studied parameters were more during rainy season and summer season at Site 2 as compared with Site 1. The results indicated that most of the physico-chemical parameters from Ganga canal system were within or at margin in comparison to permissible limit of ISI and WHO for drinking water and therefore, may be suitable for domestic purposes, but it require noticeable consideration due to extreme changes in climate and increase in pollution.
In general, it was observed that when the Canal passed through the agricultural fields the water quality appeared to be much cleaner as there were no household drains or deposits of waste along ore in the canal and there was growth of aquatic weeds and algae which purified the water through bioremediation. However, as the Canal passed through the habitation of Chithera and Palla Villages numerous household drains, dairy drains and even municipal waste drains opened in the canal polluting the water to various degrees and the water was highly polluted because of the incursion of sewage, industrial effluent, commercial and domestic wastes.
The water quality analysis of the irrigation canal showed that the canal water was highly polluted for all the parameters tested. This will certainly have an impact on the quality of crops and the food grains produced by irrigating the polluted water. Among all the sites, although Site 5 appeared to be highly polluted with lot of waste, garbage, domestic waste and dead animals in the canal The details of quality of canal water analysed for different parameters are given below.
The Turbidity of any water sample is the reduction of transparency due to the presence of particulate matter such as silt, finely divided organic matter, plankton and other microscopic organisms. Turbidity of water is an important parameter, which influences the light penetration inside water and thus affects the aquatic life. During the present study maximum turbidity was recorded from Site 4 (14.4) as compared to Site 3, having the minimum turbidity of 10.2..
The reason for the high turbidity at Site 4 could be due to opening of dairy waste drains, domestic/household drains and garbage waste disposals in the canal between sampling site 3 and 4. Higher turbidity at Site 1, the main tributary of Upper Ganga Canal could be due to fast flow of water with lot of sand particles. The values of turbidity are much lower than reported by Matta (2014). However, as compared to ISI standards of 5 the water quality at the sampling sites was found to be highly turbid.
Conductivity of a substance is defined as 'the ability or power to conduct or transmit heat, electricity, or sound'. Its units are Siemens per meter [S/m] in SI and millimhos per centimeter [mmho/cm] in U.S. customary units. Its symbol is k or s. Electrical conductivity (EC)
Conductivity is the measure of the ability of an aqueous solution to carry electric current. The ability depends on the presence of ions, on their total concentration, mobility, valence and on the temperature of measurement. Solutions of most inorganic compounds are good conductors while those of organic compounds conduct current poorly.
Overall, the conductivity was much lower than the standards. It means that the water was very poor in salts and ions which could conduct the electrical current.Highest conductivity was recorded at Site 4 (225) and lowest at Site 2 (165). The average of all the five samples is 186.4 which is much below the ISI standards.
The lowest conductivity at Site 2 could be due to the fact of cleaner water in the canal passing through agricultural fields and profuse growth of aquatic weed Potemogeton spp. The highest conductivity at Site 4 is possibly because of presence of high concentrations of ions released from domestic waste and dairy waste/fertilizers in the Canal in between Site 3 and 4
Total Dissolved Solids
Dissolved solids refer to any minerals, salts, metals, cations or anions dissolved in water. Total dissolved solids comprise inorganic salts (principally Calcium, Magnesium, Potassium and Sodium etc.) and some amount of organic matter that are dissolved in water in general; it is the sum of cations and anions in water.
The highest TDS were recorded from Site 4 (123 mg/l) and lowest at Site 3 (91 mg/l). All the values in five samples were much lower than the ISI standards.
pH is considered an important chemical parameter that determines the suitability of water for various purposes. pH of water important for the biotic communities because most of the aquatic organism are adapted to an average pH. Optimal pH range for sustainable aquatic life is pH 6.5-8.2. pH of an aquatic system is an important indicator of the water quality and the extent pollution in the watershed areas.
During the present study the overall highest mean value of pH were observed (9.37 ) at Site 3 in comparison to Site 4 where it was 6.88. There was not much fluctuation recorded in pH values. Higher value of pH at Site 3 may be due to influx of sewage effluents and garbage disposal and low level of water. Recent studies of Matta (2014) reported average pH as 8.01 while Joshi et al. (2009) reported the pH of the Ganga River at Haridwar slightly alkaline ranging from 7.06 to 8.35.
Dissolved Oxygen is one of the important parameters in water quality assessment. Its presence is essential to maintain variety of forms of life in the water and the effect of waste discharge in a water body are largely determined by the oxygen balance of the system. It can be rapidly removed from the waste waters by discharge of the oxygen demanding waste. Inorganic reducing agents such as H2S, ammonia, nitrite, ferrous iron and certain oxidizable substances also tend to decrease dissolved oxygen in the water.
In the present study highest DO was recorded from the Site 5 and lowest from Site 4 (Table 6). Matta (2014) reported that DO reduced during the summer season as compared to winter and monsoon months which could be due to higher temperature, oxygen demanding wastes, inorganic reductant and seasonal variation the overall lowest and highest mean value of dissolved oxygen as 7.70 mgl-1± 0.23 at Site 2 in comparison to Site 1. The lowest value at Site 2 indicates load of pollution in comparison to Site 1. Ganga water contained highest dissolved oxygen during winter season, followed by a gradual decrease to its lowest values during monsoon season (Chauhan and Singh, 2010). The higher concentrations of DO were recorded during winter season mainly due to low turbidity and increased photosynthetic activity of the green algae found on the submerged stones and pebbles. The maximum 12.10 mg/L oxygen content of water was recorded in winter season (Jan 2007) at site 3 and minimum 7.14 mg/L at site 2 during monsoon season (July 2008).
Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period.
The highest BOD was recorded from Site 2 and lowest from Sites 4. The average of all the samples is 2.333 which is much less than ISI standards indicating the polluted nature of canal water.
Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize an acid. Measuring alkalinity is important in determining a stream's ability to neutralize acidic pollution from rainfall or wastewater. It is one of the best measures of the sensitivity of the stream to acid inputs.
The highest Alkalanity was recorded from Site 5 (72) and lowest from Sites 1 and 2 (20). All the values of five samples and their average (37.6) are much lower than the ISI standards. This could be due to less alkalanity in the canal water.
The hardness of water is not a pollution indicator parameter but indicates water quality mainly in terms of Ca2+ and Mg2+, bicarbonate, sulphates, chloride, and nitrates. Water with less than 75 mg-1 of CaCO3 is considered soft and above 75 mg-1 of CaCO3 as hard. It is an important criterion for determining the usability of water for domestic, drinking and many industrial supplies.
In the present study, maximum hardness was recorded at Site 5 (140) and lowest at Site 2 (64) (Table 9). TH (84.38 ±4.65 mgl-1) Matta (2014) reported maximum hardness in monsoon season at Site 2 in comparison to Site 1. This was in accordance with the results who reported that seasonal behaviors of TH were more or less similar at all the sites. It was lowest at Site 1 (90 ppm) in summer season and even highest at site 1 (200 ppm) in winter and monsoon of Ganga River water at Bhagalpur (Bihar), India respectively. This was due to result from poor dilution owing to low precipitation rate.
Of four different Sites of the River Ganga in Haridwar city (Site 1: Harkipauri, Site 2: Birla ghat, Site 3: Mayapur and Site 4: Singhdwar) for a period of 1 year. The maximum (163.52 mg-1) hardness of water was recorded at second Site and the minimum (60.00 mg-1) in comparison to other three site (Khanna et al., 2013).
All the water samples gave positive results of coliform bacteria. All the sample had violet colour before keeping in the incubator which turned yellow after five days which confirmed the presence of the bacteria.