**3. Result and discussion**

The river is characterized by sluggish flow throughout the year, except during the monsoon season, when heavy rainfall causes a manifold increase in the runoff causing more turbid of water. The summaries of result for physicochemical and heavy metals are presented in **Figures 1**–**3**.

**Figure 1.**

*Graphical representation of physicochemical parameters in the Gomti River water [in mg/L except pH and EC (μS/cm)].*

**Figure 2.**

*Graphical representation of physicochemical parameters in the Gomti River water (in mg/L).*

#### **3.1 Physical parameter in the Gomti River water**

Electrical conductivity varied from 523 to 874 μS/cm and it depended upon the presence of cations and anions, mobility, valence and temperature of water which was a good measure of total amount of salt present in water. Spot temperature were measured in the ranged from 27.8 to 29.1°C (**Figure 1**). Temperature is one of the critical and influencing physical parameter of water quality because it influences the *Evaluation and Quantification of Anionic Surfactant in the Gomti River at Lucknow City, India DOI: http://dx.doi.org/10.5772/intechopen.93517*

**Figure 3.** *Graphical representation of trace elements in the Gomti River water (in mg/L).*

aquatic life by altering the dissolve oxygen (DO) and other concentration in the water making oxygen less available for respiration and metabolic activity of aquatic organisms [42, 43]. Turbidity was measured by the Turbidity meter and average value is recorded between minimum 10.0 NTU at IIM Road and maximum 29.0 NTU at Gomti Barraj. Obtained turbidity was very high in all the studied locations and found above the prescribed limits by BIS (10500-2012) [44]. Comparatively high turbidity in Gomti Barraj may be due to the mixing of large amount of sewage water, disposal ash and organic pollutants from the surrounding locality. The increase in turbidity by organic pollutants resulting eutrophication of water bodies which consequently diminish the light transmission into water and thus gradually condense overall productivity.

The average value of TSS in river was recorded 25.6 mg/L, which was well within the standard limit (150 mg/L) prescribed by WHO in terms of inland surface water. The amount of total dissolve solids (TDS) in water indicates salinity of water and may also be used as an indicator for rapid plankton growth and sewage contamination. In this study average TDS value is measured value were ranged from 412 to 687 mg/L at IIM Road (**Figure 1**).

The lowest and highest values of Hardness were observed 188.0 mg/L at IIM road and 268.0 mg/L at Gomti Barraj location. Hardness is caused due to presence of cations like Ca+2, Mg+2, Fe+3 etc. This is the property of water to precipitate soap by formation of complex with calcium, magnesium present on water. The calcium and magnesium are exists in surface and ground water mainly as carbonates and bicarbonates. River water contributed calcium as due to higher proportion of calcium in the surrounding rocks and soils which is essential for plant precipitation of lime, bone building etc. The main source of magnesium is sewage inflows and minerals generate from soil erosion and are important for enzyme activation, growth of chlorophyll and phytoplankton [45]. In the present study calcium content were found to 126 mg/L and magnesium 11.18 to 16.30 mg/L. The lowest values of calcium and magnesium were observed 31.62 and 4.68 mg/L at Dilkusha, while highest 126.3 and 16.3 mg/L at Khatu Shyam location respectively.

#### **3.2 Chemical parameters in the Gomti River water**

The pH value of all the studied water samples is measured by digital pH meter and average pH is recorded between 7.8 and 8.4 which was found very approximate to the high limit (6.5 to 8.5) prescribed by the BIS (10500-2012) [44]. As per measurement, pH values were found lowest (7.8) in Khatu Shyam location and highest (8.4) found in Gau Ghat location (**Figure 2**). pH that maintains the acidic or alkaline property is a vital characteristic of any aquatic ecosystem since all the biochemical activities and retention of physicochemical attributed to the water are greatly depend on pH of the surrounding water [46]. It also prevails in biological and physicochemical attributes of surrounding water.

DO was measured between 3.4 and 8.9 mg/L whereas the highest concentration at IIM Road was found and lowest concentration at Dilkusha. The aquatic life distressed when DO levels drop from 4 to 2 mg/L [47] and as DO level falls undesirable changes in odor, taste and color reduce the usefulness of water [43]. Biochemical oxygen demand (BOD) is also an important parameter of water quality which measures the quantity of oxygen consumption by microorganisms during decomposition of organic matter present in the water. BOD of the water river was measured by using method APHA 5210. For drinking purpose, BOD of water should be zero. High BOD than the prescribed value was found in the studied river where the minimum average value was found 5.4 mg/L at IIM Road and highest was found in 19.9 mg/L at Gomti Barraj (**Figure 2**). The alkalinity express the buffering capacity of the water which appreciably maintain the pH by absorbing access H<sup>+</sup> ions and protects the water body from pH fluctuation. Whereas carbonates and bicarbonates associated with sodium and potassium contribute only alkalinity not hardness because of incapability of sodium and potassium to form complex with electron donor ligands. In this study, lowest and highest alkalinity was found to be 280.0 mg/L at Gau Ghat and Gomti Barraj respectively whereas the average value of alkalinity was found to be 300.8 mg/L. The alkalinity values were found higher than the prescribed limit by IS-10500, 2012 standard. The average value of potassium was recorded 2.53 mg/L were ranged from 1.24 mg/L at Dilkusha to 5.30 mg/L at Pakka Pul. In this study, the Sodium content is measured between 8.90 and 15.90 mg/L whereas the highest concentration at Pakka Pul is found and lowest concentration at Hanuman Setu. In this study, the oil and grease was observed between 0.6 and 2.1 mg/L, whereas the highest concentration at Khatu Shyam, while lowest concentration at Gomti Barraj. The chemical oxygen demand (COD) was analyzed by using open reflex digestion method and COD varied from 42.0 to 89.0 mg/L with an average value was 13 mg/L. The maximum value of COD was found to be 89.0 mg/L at Khatu Sham station. Mixing and accumulation of sewage discharges from nonpoint sources resulted high COD at this location. The Hanuman Setu and Gau Ghat are contributing lowest and highest value of CO2 concentrations were 6.6 to 24.2 mg/L respectively and the average values was found to be 13.9 mg/L. The activity of the microorganisms increase due to organic load of water results the increase the level of CO2 in river water.

Chloride is not harmful to humans but high concentration of chloride increase the corrosive property of water. The chloride content was within permissible limit as prescribed by BIS and average values were recorded as lowest and highest (14.5 to 47.1 mg/L) at Shaheed Smarak and Gomti Barraj, whereas the average values of chloride was 30.0 mg/L. The value of sulfate were recorded between 6.9 and 20.7 mg/L. Comparatively lowest and highest amount of sulfate was recorded at IIM Road (6.9 mg/L) and at Gomti Barraj (20.7 mg/L), which is might be due to discharge of municipality sewage and dumping of domestic waste into the lakes. The average value of nitrate and phosphate were found 1.20 and 1.0 mg/L respectively

(**Figure 2**). High level of nitrates is found in rural areas because of extensive application of nitrogenous fertilizers in agriculture. In urban areas sewage water rich in nitrates contaminate surface water thus increases the nitrate amount [48].
