Urban Pond Water Contamination in India

The stagnant water reservoirs in urban area of India are severely contaminated with surfactant and microbe due to anthropogenic activities. In this work, water quality of pond water of the most industrialized city: Raipur, CG, India is described. The concentration of surfactant in the term of sodium lauryl sulfate (SLS) in water (n = 16) is ranged from 7.0 27 mg/L with mean value of 17 ± 3 mg/L. All ponds are found to be contaminated with microbes i.e. bacteria, algae and fungi at elevated levels. The physico-chemical characteristics of the pond water are discussed.


Introduction
Pond is stagnant water reservoir used for various purposes i.e. bathing, drinking and washing for humans and other animals.The contaminants i.e. surfactants, microbes, nutrients, heavy metals, organic toxicants, etc. are brought to the pond by the streams, runoff water, municipal waste, etc. [1]- [3].The water contaminants (i.e.facial coliforms, facial streptococci, Salmonella, algae and fungi) and surfactants cause health hazards [4]- [6].Many animals that live in the surrounding area, such as migrating birds, and nearby plants depend on these ponds for a rich source of nutrients and water.However, the stagnant water bodies such as ponds, lakes and rivers are contaminated with the microbes and surfactants at hazardous levels [7]- [25].In this work, the water quality of ponds of Raipur city with emphasis on microbial and surfactant contamination is assessed.

Area of Study
Raipur (22˚33'N to 21˚14'N and 82˚6'E to 81˚38'E) is a capital of Chhattisgarh state, India with population of 2 million.Several ponds >20 occurs over ≈1000 km 2 area in the city for drinking, bathing, washing and fishing purposes.All pond waters are eutrophied with the decreased aquatic biodiversity.They recharge the groundwater resources by transporting the contaminants.

Sample Collection
The water from 16 ponds during April 2014 was sampled, Figure 1.The composite water sample (100 mL) from five points of each pond was collected into sterile glass bottles (500 mL) as prescribed in the literature [26].The physical parameters i.e. pH, temperature (T), electrical conductivity (EC), dissolved oxygen (DO) and reduction potential (RP) were measured at the spot.

Analysis
The water samples were filtered with glass micro filter of pore size, 2 µm.The total dissolved solid (TDS) value of the sample was determined by evaporation method [26].The total hardness (TH) and total alkalinity (TA) values were analyzed by the titration methods [27].The anionic surfactant concentration in the term of sodium lauryl sulfate (SLS) was determined by the flow injection spectrophotometric method [28].The fluoride content of the water was analyzed by the ion selective method using Metrohm-781 ion meter using the total ionic strength adjustment buffer (TISAB) in the 1:1 ratio.The concentration of ions was analyzed by the Dionex-1100 ion chromatography.The iron content of the water was monitored by the GBC flame AAS-932AA.The sodium adsorption ratio (SAR) and sodium hazard (SH) indices were calculated by using following equations.where, all ions are expressed in meq/L.The indicative microbes i.e. total coliforms (TC), fecal coliforms (FC), Pseudomonas aeruginosa, yeast and fungi were determined by the plate method prescribed by Rakiro Biotech System Pvt.Ltd [29].The bactaslyde is a presterilized slide coated with specially developed media of lactose and indicator.The slide no.BS-101, BS-102 and BS-103 were used for detection of E. coli + TC, Pseudomonas + TC and yeast-fungi + TC, respectively.The slide was plunged into the test liquid vertically for 20 -25 sec.The excess water of slide was removed by shaking, and incubated for 24 hrs at 37˚C.The grown colonies of the slide was compared with the standard chart.The Salmonella bacteria in the water was detected by the pouch pack method [29].The content (10 g) of two pouches (i.e. containing organics and sulfite material)were added into a 150-mL sterilized bottle filled with 100 mL of contaminated water, and incubatted for 24 hrs at 37˚C.The presence of Salmonella species was confirmed by changing of light blue color of the solution into dark black due to reduction of sulfite into sulfide.

Physical Characteristics
The physical characteristic of 16 ponds is summarized in Table 1.Among them, three ponds are in larger size, ranging in order of 1 -3 × 10 5 m 2 .All ponds are eutrophied and coloured due to algal blooms.The pH and T values of pond water (n = 16) was varied from 6.5 -8.2 and 29.6˚C -31.3˚C with mean value of 7.0 ± 0.2 and 30.4 ± 0.2˚C, respectively.The water of all ponds was found to be neutral with high value of TH, TA and TDS, ranging (n = 16) from 140 -450, 232 -546 and 1288 -2475 mg/L with mean value of 280 ± 45, 391 ± 34 and 1659 ± 164 mg/L, respectively.The DO, RP, EC values (n = 16) were ranged from 6.1 -8.3 mg/L, 90 -mV, 453 -1225 µS/cm with mean value of 7.2 ± 0.3, 145 ± 15 mV and 800 ± 124 µS/cm, respectively.The DO value of all pond water was found above the recommended value of 4.0 mg/L.The DO value in the summer (May-June) was reduced to the recommended value due to higher water temperature (40˚C).However, RP value was found to be several folds lower than recommended value of 650 mV, may be due to excessive organics load in the water.

Chemical and Microbe Characteristics
The chemical characteristics of the pond water are shown in SO − < Ca 2+ < K + < Cl − < 3 NO − < SLS < Mg 2+ < 4 NH + < F − < Fe.The chromatograms of indicative bacteria (i.e. total coliform, E. coli and Pseudomonas, yeast and fungi) are shown in Figure 3, Figure 4. Their extreme concentrations were observed in all pond water reservoirs, ranging from 10 2 -10 7 count/mL in Table 3.The positive test for Salmonella bacteria was marked for all water reservoirs in Figure 5.

Water Quality Assessment
The SH and SAR values of pond water were ranged from 31% -77% and 1.7 -11.3 with mean value of 62% ± 5% and 6.5 ± 1.1, respectively, indicating sodic nature of the water.The value of Fe, SLS, TA and TDS content of all pond waters were found above than recommended value of 0.3, 1.0, 120 and 500 mg/L, respectively [30] [31].All pond waters were found to be contaminated with TB beyond 100 count/100 mL.The pond water is found to be unsuitable for drinking purpose due to microbe and surfactant contamination at hazardous levels.
The contaminated pond water affect the water quality of the shallow tube well water lie in the nearby area.The SLS and microbe contents in the shallow tube well (n = 16) were ranged from 3.2 -5.1 mg/L and 1 × 10 3 count/mL, respectively.The surfactant and microbial contamination levels in the water of the studied area was found to be comparable to the contents reported in the water of other region of the country and world [10]- [25].

Sources
The correlation matrix of the water parameters is summarized in Table 4.Among them, Na + and K + contents were found to be correlated well with the SLS, indicating origin from the ( )  SO − and Mg 2+ was observed, showing similarity in their origins.The value of [Na + ]/[Cl − ] was found to be ranged from 2 -13 with mean value of 7 ± 2. It means that Na + was found to be originated mainly from the anthropogenic sources i.e. use of sodium lauryl sulphate as soap and detergent.The main inventories of the SLS and microbes contamination of the pond water are bathing, cloth washing and mixing of sewage waste and runoff water.

Conclusion
The pond water is polluted tremendously with the surfactant and microbe mainly due to anthropogenic activities i.e. bathing, washing and mixing of the runoff and municipal waste.The surfactant contamination of the pond imparts the water to be sodic in nature.In some ponds (≈25%), the F − content is found to be above the recommended value of 1.5 mg/L.All ponds are eutrophied with green algal blooms due to the nutrient over loadings.

Figure 1 .
Figure 1.Representation of pond location in Raipur city, Chhattisgarh, India.

Figure 2 .Figure 3 .
Figure 2. Spatial variation of sum of total concentration of 11 species i.e. ions, Fe and SLS.
correlation among three species i.e.

Table 1 .
Physical characteristics of pond and pond water.

Table 2 .
Chemical characteristics of pond water, mg/L.

Table 3 .
Microbe contamination of pond water.

Table 4 .
Correlation matrix of ions and SLS.