hydrochemistry and pollution load in the mayur...

Hydrochemistry and Pollution Load in the Mayur River 1st Phase Monitoring Report

Safiqul Islam, Farjana Akter, Kousik Ahmed, Rezaul Karim

Environmental Science Discipline Khulna University

June 22, 2011

Context

The River Mayur is situated at the back swamp of the Bhairab River. This has raised the potential of this river as a reservoir of fresh water.It is originated from the vast water body called Beel Dakatia, northbound to the Khulna City Corporation (KCC). It is locally known as the KhuderKhal at the point of origin. From Rayer Mahal it is known as Mayur. It has run through Chalk Mathurabad and Choto Boyra and has met the Bhairab River at Alutola. A branch of is also called Kazibacha or Hatia. The Hatia joint is now dead. The river is about 11.69km long and varies by width widely at different chains. About 30 years ago Mayur was a very forceful and mighty river. The water was fresh and people use to swim. Even Trawlers and gigantic country boats use to pass through this river. A City protection dam was constructed in 1982-1983 by BWDB to protect encroachment of saline water in the region. This blocked the natural flow of upstream water of the river and since then the Mayur started to die. The Mayur River is the main drainage channel for the eastern part of Polder 28/2, via a single 10 vent-sluice at Alutola (BWDB, 1992). Now-a-days the river is frequently cited as dead river (Kamal et al, 2007) and it is very

Mayur River(red line)

Bhairab

Figure 1: Location map of River Mayur

Urbanized area

important for the city of Khulna. It is now dominated by downstream flow (tidal water) and rainfall-runoff and is subjected to continuous exposure of industrial effluents and waste disposals from riverside establishments and city wastewater lines. Consequently, the water quality is assumed to be deteriorated, even though this water is still used in irrigation for its cost effectiveness and lack of alternatives. This river is important from numerous points of view: freshwater reservoir, transport, irrigation water, fishing ground and the city’s main wastewater route. The Mayur also plays an important role in contributing to local ground water table. Due to human interruption the natural flow of the river is now totally retarded and the river is completely converted into a dead channel which only revives cyclically during high tide. The 10 valve sluice gate on the City Protection Dam controls the current and flow of water courses of Mayur and from 1990s encroachment of Mayur River was started by some illegal fishermen and soil traders. This has been also the Mayur’s one most critical problem. The sluice gate is not maintained properly and only regulated by muscle-power, whichare mainly illegal fish culture practitioners within the river through forceful encroachment (Karim, 2011).

LiteratureReview

Although published literatures are scarce, river Mayur has been subjected to a few studies. The studies deal with physico-chemical characters with fisheries potential (Kamal et al., 2002) and agricultural potential (Das, 2010). Beside, information is found from Khulna City Corporation (KCC) and publications in various Newspapers of local and national base. Kamal et al. (2002) first reported the river as a dead river where

Figure 2: Satellite image of River Mayur. Notice that the region between Mayur and Bhairab River is heavily urbanized at the head while the Tail side is more or less covered by agricultural land.

Urbanized region Agricultural region

sedimentation of pollutants is taking place at a high rate due to its ephemeral character. TDS was reported ranging from 266 mg/L to 330mg/L with DO varying from 1mg/L to 8 mg/L. However, results of Das (2010) show a dramatic degradation of water quality of Mayur River as he found TDS 9528±5221 mg/L. Islam et al. (2011) in this present study found TDS a little less than that of Das (2010) but reported a drastic fall of DO in the river which is about 3.0±1.0 mg/L. This indicate two possible mechanism: one, pollution is getting higher with time due to possible increase of wastewater discharge to the river; and two, due to higher rate of sedimentation and faulty gate operation both at upstream and downstream, natural flushing of stream water is decreasing with time. Estimation of waste water discharge to Mayur River is in progress in Environmental Science Discipline at Khulna University. This estimation would further clarify the idea of waste water contribution to pollution load of the river. A comparative study of pollution load in Mayur River over various time scale and water quality standards is shown in Table 1. Das (2010) also reported the agricultural potential of Mayur River water to be unsuitable. Salinity hazard along with Electrical Conductance (EC) was found to be very high (Figure 1 and 2). These results are supported by Islam et al. (2011, current study).

Table 1:Comparative study of Mayur River water quality over various time scale and water quality standards. All parameters are reported in mg/L unless otherwise stated.

aBerner and Berner, 1987 bStallard et al., 1986 as quoted in Berner and Berner, 1987. c Department of Environment, Ministry of Environment and Forests, Government of Bangladesh. dRifat et al., 2011 e Kamal et al., 2007 fDas, 2010 g Islam et al., 2011

Parameters Average River water

in Asiaa

World

Average river water

pollutionb

BD Standardc

Bhairb River

(2010)d

Mayur River (2002)e Mayur River (2010)f

Mayur River 2011g

High Tide Low Tide

Actual Natural

DO - - 6 4 1.10-8.18 - 2.967±1.359 3.042±1.31 Na 8.7 6.6 2.0 200 12 16.8-33.9 3096.061±1748.092 5047.117±3099.198 6454.133±3747.743 K 1.7 1.6 0.1 12 3.7 1.5-6.9 95.02± 65.027 148.245±62.161 180.281±66.533 Ca 17.8 16.6 1.3 75 28.3 49-94 65.72± 17.911 40.5±17.244 41.917±10.37 Mg 4.6 4.3 0.3 35 6.89 31-59 121.23± 54.218 67.4±35.384 81.3±36.319 HCO 67.1 66.2 1.0 - 76.49 195.25±137.202 383.32±193.918 317.312±162.849 NO

3 - - - 10 2.77 - 76.669± 58.357 7.135±4.239 7.539±5.358

SO4 13.3 9.7 3.2 400 11.98 57.35 4178.69 ± 1447.872 217.755±132.744 396.486±246.47 PO

4 - - - 6 0.08 4.89-11.46 5.371±3.412 8.124±8.812 4.725±4.098

Cl 10.0 7.6 2.5 150-600 15.83 - 3918.03± 2823.051 276.215±71.084 385.519±117.118

EC (μS/cm) - - - - 241.70 159-275 11741.6 ± 6627.009 13.977±6.024 16.113±6.309

TDS 134.6 123.5 10.5 1000 168.61 255-305 9528.233±5221.425 6195.810±3138.496 7869.212±3722.669

Figure 3: USSL plot of agricultural water suitability of the River Mayur (Das, 2010).

Figure 4: Wilcox plot of agricultural water suitability of Mayur River (Das, 2010).

Objective

The objectives of this study are to explore and describe the present state of the river Mayur’s water quality and morphological characters. Water quality and morphological studies provide important understanding of the rivers present capacities of fresh, quality water supply as well as its impacts such as flood risks, groundwater (drinking water) quality, farming and fishing potential etc. on bank side communities. This report is a description of the results of 1st Phase monitoring of water quality in Mayur River. Its geomorphological studies are still in progress. 12 Monitoring stations have been established at Mayur River at different chains to monitor water quality. Locations of monitoring stations are shown in Table 2. Table 2: Location of monitoring stations (from country side to river side) Station No

Station's Name Latitude (N) Longitude (E) Elevation (m)

1 Hamid Nagar Sluice gate 22°50´00.0´´ 89°31´05.6´´ 3 2 Choto Boyra Sosanghat 22°49´35.1´´ 89°31´46.5´´ 3 3 Opposite KMC 22°49´21.1´´ 89°31´53.9´´ 1 4 Bamboo bridge, Sonadanga 22°48´55.2´´ 89°32´10.07´´ 1.9 5 Khader khal 22°48´32.0´´ 89°32´13.9´´ 4.7 6 Gollamari 22°47´59.6´´ 89°32´26.4´´ 6.4 7 Buromoulovidorga bridge 22°47´47.6´´ 89°32´34.7´´ 1.8 8 Mohammadnogor Biswaroad bridge 22°47´8.6´´ 89°32´19.5´´ 9 9 Sachibunia wapda kheya ghat 22°46´38.5´´ 89°32´28.9´´ 9

10 Putimari Kheya ghat 22°46´17.3´´ 89°32´34.05´´ 9 11 Putimari Talghat 22°45´54.2´´ 89°33´06.0´´ 4 12 Alutola Bridge 22°45´26.6´´ 89°33´04.03´´ 5

Materials and methods

The river Mayur was sampled systematically during April 2011 at depths 40 to 50 cm from the water surface approximately at the middle parts of the river with 1 liter polyethylene bottles. The sampling stations were lactated at 12 points representing the courses of the rivers and their adjoining channels. It was done both in High Tide and Low Tide. After collection of water samples the bottles were securely sealed with proper labeling (sample number, location name and date). Aeration during sampling was avoided as far as possible. The water samples were carefully transported to the laboratory and preserved for chemical analysis. Total analysis was carried out within one month of collection. The detail sampling and analytical methods for the water samples have been described elsewhere (Greenberg et al., 1992; APHA, 1995; Ramesh and Anbu, 1996).

Physical measures like pH was measured by microprocessor pH meter (HANNA instruments, pH 211), while Electrical Conductivity (EC) and Total Dissolve Solids (TDS) were determined by TDS meter (H1-9635, portable water proof Multi range Conductivity/TDS meter, HANNA). The cations Na+ and K+ were measured by Flame photometric method (Flame photometer- models PEP 7), and Ca2+ and Mg2+ were determined by titrimetric method (Ramesh and Anbu, 1996). HCO3- was analyzed by potentiometric method (Greenberg et al., 1992) while Cl-was quantified by ion electrode method (Cole-parmer R 27502-12, -13). PO43- and SO42- were determined by ascorbic acid method and turbidimetric method, respectively (Thermo spectronic UV-visible Spectrophotometers, Helios 9499230 45811) and dissolve silica (H4SiO42-) was analyzed by molybdo-silicate method (Thermo spectronic, UV-visible Spectrophotometers, Helios 9499230 45811) (Ramesh and Anbu, 1996).

Results and discussions 1. Dissolved Oxygen (DO) ranged

between 0.9 to 4.8 in Mayur and

did not vary widely between

high tide and low tide

conditions. 5 mg/L of DO is

essential to maintain healthy

aquatic life (Kamal et al.,

2007)while DO less than 3 mg/L

is indicative of absence of

fisheries species

(http://www.water-

research.net/Waters

hed/dissolvedoxyge

n.htm). However, in

bothhigh tide and

low tide DO shows

comparatively high

concentrations at

Station 7,8,9 and 10.

Figure 5: Aquatic life Index based on DO

Figure 6: Distribution of DO in Mayur River

http://www.water-research.net/Watershed/dissolvedoxygen.htm




In general DO increases from the countryside towards riverside, which may be

explained by the river’s water source, which is river Bhairab located at the river end,

as it has been mentioned that the Alutola Dam is the joint between Bahirab and

Mayur at south. It can be assumed that, due to mixing of Bhairab water, stations

close to the river side show higher values of DO.

2. pH varies from 6.0 to 7.5 over the Mayur with no significant variation between high

tide and low tide. Salinity

rather shows high

variation between low

and high tide period. At

high tide, salinity varies

between 5 to 14 ppt with

an average of 9 ppt while

at low tide it varies

between 4 to 16 ppt with

an average of 10 ppt.

Interestingly, from the

country side stations up to the stations located at the mid length of the river, high

salinity (around 10 ppt) starts decreasing and then again increase till the river end.

This can be explained as effect of tidal water in the Mayur and indicative of its reach

towards upstream. It is a possible case that, tidal water actually reach up to Station 5

(22°48´32.0´´N and

89°32´13.9´´E). The theory

is supported by high

variation of salinity during

high and low tide and in-

field observations. There is

also and increasing trend

of salinity from station 5 to

station 1 (Figure 7). This

might be characterized by

the discharge of salt

Figure 7: Distribution of salinity in Mayur River

Figure 7: Distribution of Mg in Mayur River

contributing ions like Ca, Mg, and Na etc. In fact, in these 5 stations salinity has been

found highly correlated with Mg2+ and Na+ (0.94 and 0.86, p<0.05). It can be

interpreted that, in stations 1 to 5, these Mg2+ and Na+ are not contributed by the

tidal water as these two species show low variation during low and high tide along

with salinity (standard deviation = 2.26) while Mg2+ does not vary much with

stations towards the river end but salinity starts to increase from station 6 to station

12(standard deviation = 3.3). The main source of Mg2+ in natural water is withering

of dolomite and Mg-silicates (90% of world average river water) while 8% is

contributed by pollution and the rest 2% is contributed by cyclic sea-salt (Berner

and Berner, 1987). As Mg2+ does not vary that much with tidal water but varies

highly with reaches of the Mayur at upper part (station 1 to station 5) it can be

concluded that main source of Mg2+ in Mayur is contributed by pollution at the upper

reaches while additional Mg2+ comes from tidal water at the downstream.

3. Bicarbonate was

found in Mayur

ranging from 158

to 670 ppm with a

high tide average of

383±193 ppm and

low tide average of

317±162 ppm. The

source of HCO3- in

natural water is

carbonate weathering and bacterial decomposition of soil that produce CO2. Only 2%

of world average river water HCO3-is contributed from pollution. However in this

case, high concentration of HCO3- in upper stream stations of the Mayur with low

variation due to tidal effects indicate either the source is pollution of bacterial

decomposition. However, the increasing trend from station 1 to station 5 and

smaller values and stable trend towards downstream stations might conclude that

the upper stations, water characters are contributed by bicarbonate pollution rather

than bacterial composition that are accumulated until station 5 is reached. It is

noticeable from Table 2 that, until station 4, elevation of Mayur decreases, then

certainly increases in station 5 and 6, then again starts decreasing until the river

Figure 8: Distribution of HCO3 in Mayur River

end. This means, there is stagnant water at station 5 which only is reached and

flushed by peak high tide. This might explain the higher values of bicarbonate at

station 6 and 7 at high tide and then decreasing values towards the river end.The

very same reason (elevation) also explains the salinity and Mg2+deviation of Mayur

at station 5.

4. Na+ ranges from 1474 ppm to 14938 ppm in Mayur and is the main source of ions

and major contributor

to TDS in the river.

According to the USSL

irrigation water

classification water

containing more than

TDS 3000 ppm is

unsuitable for

irrigation. Average

TDS of Mayur River

exceeds 7000 ppm. As

seen in Figure 9 Na+ is

mainly contributed by tidal water. From station 1 to station 5 the decrease of

Na+reflects the contribution of pollution as the figures do not vary much with tide.

Discussion

The results presented in this reports are primary results derived from first monitoring

work. Discussions on hydrochemistry, water quality and geo-morphology of river Mayur

and related topics need more information.

Conclusion From the results of first monitoring efforts of water quality analysis of the MayurRiver it

is clear the river is overwhelmed with pollution and due to lack of flow and drainage

congestion, localized pollution in increasing day by day. The major contributor of

natural water to this river is River Bhairab, although the tidal water cannot entirely

flush pollutants out of the river due to its drainage congestion. Detailed study and

Figure 9: Distribution of Na in Mayur River

information from the monitoring activities are needed for better understanding of the

river pollution mechanism. The source of the river’s ephemeral characteristics, rate of

sedimentation, source of water and waste water, amount of water and waste water,

river morphological statistics, runoff and urbanization contribution to river and

characteristics of climate change and its effects on Mayur’s water flow are important

information to acquire right now for management of this river. Therefore further

studies should be directed towards these subjects.

Table 1: Measured Physiciochemical parameters in Mayur River in April, 2011

Sample ID Physical parameters Anions Cations TDS

(ppm) DO (mg/l)

Temp (oC) pH Salinity

(ppt) EC

(mSi) Na

(ppm) K

(ppm) Ca

(ppm) Mg

(ppm) HCO3

(ppm) Cl

(ppm) NO3

(ppm) SO4

(ppm) PO4

(ppm)

2010 C1 HT12 3.2 32.6 6.93 14 22.30 11866 176.39 48 120.00 158.518 354.50 4.194 395.124 0.413 13123

2010 C1 HT11 3.8 31.5 7.08 11 20.0 9892 228.34 40 109.20 176.862 301.33 13.735 183.066 0.407 10945

2010 C1 HT10 4.5 31.6 6.80 12 18.80 6381 155.61 44 96.00 181.448 354.50 3.865 387.270 0.329 7604

2010 C1 HT09 4.8 28.9 7.40 11 17.40 4626 186.78 46 91.20 190.62 319.05 3.865 185.684 0.580 5650

2010 C1 HT08 4.4 29.1 6.79 13 21.0 6162 254.31 88 81.60 262.719 354.50 5.510 366.326 4.754 7580

2010 C1 HT07 3.8 29.5 6.59 5 6.52 2871 108.85 40 18.00 670.587 248.15 17.683 67.874 5.302 4047

2010 C1 HT06 2.9 29.0 6.72 7 9.87 2432 140.02 28 50.40 610.899 230.43 6.374 135.942 12.842 3647

2010 C1 HT05 1.0 28.7 6.43 5 5.31 1993 56.90 24 10.80 630.795 230.43 5.716 65.256 19.536 3037

2010 C1 HT04 0.9 28.2 6.10 5 7.34 2213 56.90 29 30.60 561.159 177.25 7.197 91.436 27.624 3194

2010 C1 HT03 2.1 33.0 6.34 7 9.90 3749 155.61 29 51.00 392.043 177.25 6.539 159.504 15.074 4735

2010 C1 HT02 2.7 31.5 6.44 10 14.98 4626 88.07 44 74.40 362.199 212.70 4.565 169.976 6.149 5588

2010 C1 HT01 1.5 31.8 6.57 10 14.30 3749 171.19 26 75.60 401.991 354.50 6.374 405.596 4.475 5194

2010 C1 LT12 3.1 34.8 7.17 14 21.90 8795 176.39 47 117.00 167.69 319.05 1.233 948.540 0.274 10572

2010 C1 LT11 4.2 34.8 7.03 16 25.80 14938 228.34 52 118.80 183.135 354.50 7.813 431.776 0.865 16315

2010 C1 LT10 4.2 35.2 7.47 14 23.40 8356 160.80 46 124.80 212.979 460.85 2.220 405.596 0.915 9770

2010 C1 LT09 3.9 32.2 7.25 14 22.20 8795 332.24 48 117.60 212.979 354.50 4.852 300.876 1.289 10167

2010 C1 LT08 4.4 33.5 7.50 11 17.10 5723 238.73 56 76.80 195.206 283.60 8.471 737.888 0.915 7321

2010 C1 LT07 3.5 36.6 7.01 10 15.60 7698 108.85 20 93.60 213.55 283.60 4.194 224.954 8.938 8655

2010 C1 LT06 4.6 34.3 7.13 10 16.40 7917 114.05 38 97.20 204.378 248.15 10.322 282.550 1.397 8913

* C1 denotes Cycle 1 * HT denotes High Tide, and LT denotes Low Tide

2010 C1 LT05 2.2 31.0 6.66 4 6.67 1774 140.02 52 15.60 620.847 319.05 19.328 130.706 9.217 3081

2010 C1 LT04 1.3 35.0 6.09 6 7.20 1774 155.61 31 36.60 591.003 336.78 15.709 83.582 10.890 3035

2010 C1 LT03 2.8 32.6 6.34 8 10.63 3958 145.22 37 46.80 411.939 496.30 5.881 517.976 8.380 5628

2010 C1 LT02 1.2 32.4 6.18 9 11.87 3529 238.73 42 55.80 431.835 567.20 4.400 293.022 6.985 5169

2010 C1 LT01 1.1 30.7 6.62 11 14.59 4187 124.44 34 75.00 362.199 602.65 6.045 400.360 6.640 5799

References Berner, E.K. and Berner, R. A. 1987.Global Water Cycle.Geochemistry and environment.Prentice-Hall Inc, New Jersey, p-396. Das, R. 2011. Irrigation Water suitability of Mayur River, Khulna, Bangladesh.Unpublished MSc thesis, Environmental Science Discipline, Khulna University. Islam, S., Akter, F., Ahmed, K and Karim, R. 2011.This Study. Kamal, D., Khan, A. N., Rahman, M. A. and Ahmed, F. 2007. Study on the Physico Chemical properties of water of Mouri River, Khulna, Bangladesh. Pakistan Journal of Biological Sciences, 1-8, 2007. Karim, F. 2011. Impact of Sluice Gate Operation on the Peri-urban Water Uses (A case study on Mayur River).Unpublished Undergraduate Thesis.Environmental Science Discipline, Khulna University. Rifat, K., Akter, S. and Haque, S. 2011. Nature of solute load and pollution in River Bhairab.Unpublished Undergraduate Thesis (data set used by three theses), Environmental Science Discipline, Khulna University. Wilcox, L.V., 1955. Classification and use of irrigation water. US Geological Department Agri. Circ., 969: 19.

Annex 1 Locations of sampling stations

Station 1:

Location: Hamid nagar Sluice gate

Sample station-1

Sample Station 2:

Location: ChotoBoyraSosanghat

Sample station-2

Sample Station 3:

Location: Opposite KMC

Sample station-3

Sample Station 4:

Location: Bamboo bridge, Sonadanga

Sample station-4

Sample Station 5:

Location: Khaderkhal

Sample station-5

Sample Station 6:

Location: Gollamaribridge (beside Raisa Clinic)

Sample station-6

Sample Station 7:

Location: Buromoulovidorga bridge

Sample Station-7

Sample Station 8:

Location: MohammadnogorBiswaroadbridge

Sample station-8

Sample Station 9:

Location: Sachibuniawapdakheyaghat

Sample station-9

Sample Station 10:

Location: PutimariKheyaghat

Sample Station-10

Sample Station 11:

Location: PutimariTaltola

Sample Station-11

Sample Station 12:

Location: Alutola Sluice gate.

Sample Station-12

hydrochemistry and pollution load in the mayur...

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