Abstract

Study on water quality parameters of Harike Wetland, Punjab was conducted from June 2018 to August 2019 at three representative sites: Site 1, Site 2, Site 3 and mean value was calculated. The study period was divided into various seasons: Rainy (June to August), Autumn (September to November), Winter (December to February), Spring (March to Mid April) and Summer (Mid April to end June). The different water quality parameters include: water temperature, pH, alkalinity, dissolved oxygen, total dissolved solids, nitrates and phosphates. The average values of all parameters were compared with ISI, ICMR and WHO standards for drinking water quality. Correlation coefficient between various physico-chemical parameters was recorded using Pearson Correlation analysis. High Impact of pollution load from various sources on seasonal variations and water quality parameters were observed especially on pH, nitrates and phosphates. pH showed significant negative correlation with all other water quality parameters except phosphates. However, water temperature (except DO), alkalinity, TDS and nitrates represented significant positive correlation with all other physico-chemical parameters. The water quality values were observed to be 53.56 thus, it can be concluded that overall water quality at Harike wetland is “Poor” due to human activities and pollution load (industrial effluents) which affect its quality and quantity. The inadequate availability of freshwater resources can pose serious threat to aquatic biodiversity and render its unfit for human consumption.

1. Introduction

Wetlands, often referred as “Earth’s kidneys,” are transitional zone between terrestrial and aquatic system ¹. Wetlands have been playing an important role in purifying the polluted water for centuries. Majority of wetlands have been exploited for their natural cleansing capacity for assimilating various pollutants including heavy metals and pesticides ². Human population growth and its numerous activities directly affect the water quality. Approximately, 50,000 large and small lakes are contaminated to the spot of being considered ‘dead’ ³. The major contaminants are agricultural runoff, sewage and industrial pollution which may enclose herbicides, fertilizers and pesticides ⁴. Pollution is a major problem of wetlands and constitutes a potential threat to the health and well-being of their entire populations. Anthropogenic activities and direct discharge of industrial waste (Solid, liquid and gaseous wastes) into the freshwater resources can affect the aquatic life thus disrupting the whole systems and pose a threat to human health directly or indirectly ⁵. Toxic metals present in industrial waste along with suspended solids, inorganic and organic chemicals, high biochemical oxygen demand, chemical oxygen demand, grease and oil, cause detrimental effects on the fish when released into water bodies. In order to ensure safe drinking water supply, it is therefore, mandatory to monitor the quality of water resources at regular intervals of time ².

Hence, present research conducted to find out the water quality index of Harike wetland on the basis of physico-chemical indices. The prosperous biodiversity of the wetland plays a crucial role in maintaining the precious hydrological balance in the catchment with its vast concentration on migratory fauna of waterfowls including plenty of globally threatened species has been responsible for the recognition accorded to this wetland in 1990, by the Ramsar convention, as one of the Ramsar site in India, for development, conservation and preservation of the ecosystem. Every year during winter season approximately, 200 species of birds visit at this wetland ⁶. Harike wetland also supports vulnerable, rare and endangered plants, fish and other faunal species ⁷. The Ministry of Environment and Forest, Government of India, declared it a wildlife sanctuary in 1982. From many years Harike wetland has been facing immense threats from various quarters like sewage, solid waste, industrial effluents, encroachments, poaching and reclamation, etc. The discharge of heavy metal pollutants in this wetland poses a big threat to the reproduction efficacy of various inhabitants ^{4, 8}.

Ludhiana city of Punjab state was founded on the ridge of Buddah Nullah. The rapid growth of industrialization and increasing population pressure has brought in a host of environmental problems and Buddha Nullah which enters and after passing through highly polluted city Ludhiana, drains its polluted water into the Sutlej river. The Buddha Nullah carries the industrial effluents of almost 1060 industries of Ludhiana city and another drain known as Kala Sanghian drain which carries polluted water of almost 52 industries from Jalandhar district and adjoining cities. The high concentration of industrial effluents ultimately reaches at Harike wetland (Ramsar site) which poses a serious threat to the valuable biodiversity existing there. The accumulation of toxic substances in fish and water resources due to industrialization has led to pollution of water bodies in Punjab which alter the physico-chemical parameters of water bodies ⁹. Therefore, present study revealed and recorded high level of pollution at the wetland under study which can cause serious threats to valuable flora and fauna. Hence, this study recommends that continuously monitoring of this wetland should be carried out to keep its flora and fauna intact for upcoming years.

2. Materials and Methods

This man made, riverine wetland spreads into three districts i.e. Kapurthala, Ferozepur and Taran Taran in Punjab. The wetland was formed by building the headworks across the river Sutlej and Beas in the year 1952 with the objective of storing and supplying drinking and irrigation water to neighboring state Rajasthan and to the parts of southern Punjab. This wetland (Figure 1) falls between 31⁰ 08’N to 31⁰ 23’N latitude and 74⁰ 90’E to 75⁰ 12’E longitudes ¹⁰.

Water samples were collected in 1 litres reagent bottle during morning hours in five different seasons of the year from July, 2018 to August, 2019 from three sites (Site 1, Site 2 and Site 3) at Harike Wetland. Physico-chemical parameters such as water temperature, dissolved oxygen, total dissolved solids and pH were analyzed on the spot with the help of water analysis kit (Merck multi-line p4 kit). Whereas, alkalinity, nitrates and phosphates were analyzed in the laboratory by standard methods ^{11, 12}. The recorded results were compared with standard values prescribed by World Health Organization ¹³, Indian Standards Institute ¹⁴ and Indian Council of Medical Research ¹⁵.

WQI can be defined as the index which reflects the combinational effect of various water quality parameters and provides a single number which gives information about the overall water quality of the water body under study. Six parameters namely Alkalinity, TDS, pH, Dissolved oxygen, nitrates and phosphates were detected on seasonal basis at three representative sites of Harike wetland to calculate WQI especially at, site1, site 2 and site 3, because site 1 area is on the right side of the wetland which receive the water of river Beas. Hence, due to less pollution lot of biodiversity exist here and considered safe for wildlife. The occurrence of biodiversity reflects that it is less polluted as compared to other two sites, consequently, it is considered as safe zone for flora and fauna. Site 2 area is a confluence point of both the rivers, i.e. Beas and Sutlej. At this site, polluted water of river Sutlej mixes with the water of river Beas. Site 3 is highly polluted, reservoir area because polluted water from the river Sutlej being stored here.

Weighted arithmetic water quality index method classified the water quality according to the degree of purity by using the most commonly measured water quality variables. The method has been widely used by various scientists and the calculation of WQI was made by using the following equation ¹⁶:

The quality rating scale (Qi) for each parameter is calculated by using this expression

Where, Vi is estimated concentration of i^th parameter in the analyzed water Vo is the ideal value of this parameter in pure water Vo = 0 (except pH = 7.0 and DO = 14.6mg/l), Si is the recommended standard value of i^th parameter. The unit weight (Wi) for each water quality parameter is calculated by using the following formula:

Where, K = proportionality constant and can also be calculated by using the following equation:

The statistical calculations such as: average, standard deviation and range were done in Microsoft Excel version MSO (12.0.4518.1014). Pearson correlation coefficient in PAST software version 4.03 was calculated for the determination of relationship between various physico-chemical parameters of this wetland.

3. Results and Discussion

The average results of the water quality parameters of collected water samples are depicted in Table 1. The average values of water temperature (ºC), recorded in the present course of study, at the three selected sites were 26.5±0.7, 24.0±1.31, 22.23±0.25, 23.7±0.81 and 27.5±0.5, respectively during rainy, autumn, winter, spring and summer seasons. Highest value (28.0°C) of water temperature was observed in summer at site 3 and lowest value (22.0°C) was reported in winter season at site 1. These recorded values in the present work were found to be higher than those reported by other workers ¹⁷ and close to those reported by other scientists ¹⁸. The mean values of pH recorded at three different studied sites were 8.76±0.32, 7.3±0.1, 8.13±0.25, 7.73±0.15 and 7.53±0.05, respectively in rainy, autumn, winter, spring and summer seasons. Highest pH value (9.0) was found at site 3 (S3), during rainy season and lowest pH value (7.2) at site 1, during autumn season. The highest pH value (9.0) recorded at site 3, in the present research was found very close to those reported by other researchers ^{19, 20} and higher than those recorded by other workers ^{17, 18, 21}. In the present work conducted during rainy, autumn, winter, spring and summer seasons the detected mean values of alkalinity (mg/l) were 60.06±1.00, 58.1±1.9, 61.33±1.15, 64.1±0.75 and 70.2±1.21, respectively. In the present course of work, maximum value of alkalinity (71.3 mg/l) at Site 2 and minimum value (56.2 mg/l) at site 1 were detected during summer and autumn seasons, respectively which were found to be very higher than those reported by other limnologist ^{20, 22}. In the present study period, the average values of dissolved oxygen (mg/l) were 7.83±0.05, 7.9±0.1, 8.23±0.05, 8.13±0.11 and 7.9±0.1, respectively during rainy, autumn, winter, spring and summer seasons. Maximum value (8.3 mg/l) of dissolved oxygen was detected at site 2 during winter and minimum value (7.8mg/l) was reported at site 1, during rainy and autumn seasons. These recorded dissolved oxygen values in the present research were found to higher than research conducted by other researchers ^{20, 23}. The mean values of total dissolved solids (mg/l) in the present results observed at diverse sampling sites were 218.3±2.08, 220±4.0, 224.6±2.51, 227.9±1.67 and 232.2±1.5, respectively in rainy, autumn, winter, spring and summer seasons. Highest total dissolved solids value (233.4 mg/l) at site 2 in summer and lowest value (216 mg/l) at site 1 in rainy and autumn season was observed. These recorded values were found to be lower than earlier studies ^{24, 25}. In the present research, average values of nitrates (mg/l) recorded at different sampling sites were 7.69±1.99, 2.57±1.29, 4.36±0.26, 21.07±13.56 and 14.74±4.07, respectively in rainy, autumn, winter, spring and summer seasons. Maximum nitrate value (28.92 mg/l) was observed at site 3 during rainy, while minimum value (1.688mg/l) at site 1 during autumn season which were found to higher than those reported in another researches ^{24, 25}. Average values of phosphates (mg/l) calculated from presently three studied sites were 10.05±0.24, 6.65±1.07, 3.83±3.00, 10.27±0.01 and 10.64±0.52, respectively in rainy, autumn, winter, spring and summer seasons. Maximum nitrate value (11.242 mg/l) at site 3 during summer and minimum value (0.058mg/l) at site 1 was recorded during winter season (Table 1). In another researches, these values were found to be highest than those reported by other scientists ^{24, 25, 26}.

It has been concluded from the observed values of all the parameters during the present course of study that they were lie under tolerable limits of drinking water satandards except pH, nitrates and phosphates (Table 2). Therefore, water quality value calculated from these parameters is 53.56 which fall under poor water category (Table 3). Correlation matrix among the various physico-chemical parameters of Harike Wetland from June 2018 to August 2019 is represented in Table 5. Graphical representation of the average values of various physico-chemical parameters recorded during different seasons at Harike Wetland are depicted in Figure 2, Figure 3 and Figure 4.

Water Temperature: Water resources play a crucial role for sustaining life on earth and human development. The physico-chemical properties represent the state of an aquatic environment and their abundance corresponds to the good water quality ²⁷. Water temperature (°C), ranged between 22.0-28.0 (24.78±2.10) and recorded maximum value 27.5±0.5 in summer and minimum (22.23±0.25) in winter season. Similar results have been recorded at Ropar wetland ²⁸. Water temperature in the present course of study showed significant positive relationship with pH (0.10861), alkalinity (0.52854), TDS (0.20072), nitrates (0.079723), phosphates (0.77917) and significant negative relationship with dissolved oxygen (-0.81584) which were commensurate to the earlier findings ²⁹.

pH: Mostly the aquatic organisms are very sensitive to pH variation and any alteration in pH can change the metabolic activities of aquatic organisms ³⁰. During the present study period, pH varied from 7.2-9.0 (7.89±0.55) which was observed highest (8.76±0.32) in rainy and lowest (7.3±0.1) in autumn. Our results are contradictory to a study conducted on Ranjit Sagar Wetland as Harike wetland receives high load of pollution from various quarters ³⁰. pH during the present study period shows positive relationship with phosphates (0.039041) and significant negative relationship with alkalinity (-0.26302), DO (-0.04678), TDS (-0.46167), nitrates (-0.05077). Similar observations were also recorded in earlier studies ³¹.

Alkalinity: Water alkalinity is due to the presence of various bicarbonates, hydroxides and carbonates in water, it is the ability of an aqueous solution to neutralize a strong acid ³². Alkalinity (mg/l) ranged between 56.2- 71.3 (62.76±4.47) recorded maximum (70.2±1.21) in summer and minimum (58.1±1.9) in autumn. Average values during all the seasons as compare to the present study were reported higher by other scientists ³². During the study period, alkalinity of water showed significant positive relationship with TDS (0.93019), nitrates (0.48125) and phosphates (0.52833) which were dissimilar than those reported by other authors ³³.

Dissolved Oxygen: Amount of life sustaining oxygen available in the water is referred as DO. Natural waters contain dissolved oxygen concentrations varied approximately from 5 to 14.5 (mg/l) depending on the physical and chemical characteristics of water body. The amount of DO present in water reflects atmospheric dissolution, as well as autotrophic and heterotrophic processes that produce and consume oxygen. ³⁴. Dissolved oxygen ranged between 7.8-8.3 (8.0±0.17) recorded maximum (8.23±0.05) in winter and minimum (7.83±0.05) in rainy. Other workers reported DO value which was ranged between 6.5-15 mg/l and 7.29 to 8.30 at Narmada river and Ganga river, respectively ^{32, 35}. In the present study, DO showed significant positive relationship with TDS (0.3061), nitrate (0.24788) and significant negative relationship with phosphates (-0.5577).

TDS: Solid materials dissolved in the water such as salts and other material (Nutrients to toxic materials) is termed as TDS. The nature and amount of dissolved matter occurring in liquid materials fluctuate significantly ³⁶. Total dissolved solids have been ranged between 216-233.4 (224.64±5.69), the value was recorded maximum in summer (232.2±1.5) and minimum (218.3±2.08) in rainy. In our results, higher values were observed as compared researchers ³⁷. In our results, TDS shows significant positive relationship with nitrates (0.52733) and phosphates (0.30916).

Nitrate: Natural water bodies pose the most highly oxidized form of nitrogen compound referred to as nitrates formation due to the decomposition of organic nitrogenous matter in the presence of oxygen. In the present study, nitrates have been ranged between 1.68- 28.92 (10.09±8.96) and recorded maximum (21.07±13.56) in spring and minimum value (2.57±1.29) in autumn which were found to be higher than those reported by other workers ^{27, 30}. In the present findings, nitrates showed significant positive relationship with phosphates (0.64734).

Phosphates: In natural water bodies phosphorus is present either as undifferentiated organic phosphate or orthophosphate. Phosphorus plays a crucial role in biological metabolism. It gets into the water via plenty of sources for instance leached or weathered soils from igneous rocks, run-off from fertilized land-farms, industrial effluents and domestic sewage. In the present study, phosphates have been ranged between 0.05-11.24 (8.29±3.07) and recorded maximum value (10.64±0.52) in summer and minimum value (3.83±3.00) in winter.

Six physico-chemical parameters such as Alkalinity, TDS, pH, Dissolved oxygen, nitrates and phosphates were recorded at the three selected sites of the wetland under study and their average values and standard deviations were calculated during each season to find out the WQI. The WQI value was recorded to be 53.56 which represents water quality at Harike Wetland falls under “Poor” according to the values gives in Table 4 ³⁸. The water quality index value recorded in the present course of research was found to be higher than those reported by other limnologists at S₁ site (Ropar Head Works), close to S₂ site (Budha Nallah in Phillaour) and lower than S₃ site (Budha Nallah in Ludhiana) of Sutlej River around Ludhiana city, Punjab ³⁹.

4. Conclusion

The seasonal variation of physico-chemical parameters of Harike wetland was conducted during five seasons: rainy (June to August), autumn (September to November), winter (December to February), spring (March to Mid April) and summer (Mid April to end of June). In our findings, the fluctuation in water quality parameters have been reported which may be due to inflow variation, seasonal variation, variation in the temperature, sewage addition, and direct release of untreated industrial effluents into this water body from nearby industries. Harike wetland received high concentration of pollutants (heavy metals, nitrates and phosphates), industrial effluents from textile, leather and chemical industries reached via Buddha Nullah at this wetland. Buddha Nullah carries industrial waste of almost 1060 industries of Ludhiana city. Hence, WQI of wetland under study was observed to be “Poor” water quality and unsafe for human consumption which can have detrimental effects on its entire ecosystem, if not dealt on time. Thus overall present study revealed that anthropogenic activities must be reduced and regular monitoring of water bodies should be done in order to supply receive safe water in the upcoming years as well as to stop its further deterioration.

Acknowledgements

The author would like to acknowledge the University Grants Comission, New Delhi for their financial support (NFSC fellowship) and also to the Head, Department of Zoology & Environmental Sciences, Punjabi University, Patiala for providing necessary facilities to carry out the research work.

References