沙漠研究 22-1, 195 -198 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－

Water Quality Monitoring of the Chirchik River Basin, Uzbekistan
Murodjon NASEDJANOV*1), Hirozumi WATANABE2), Izumi WATANABE2),
Yoshiko KAWABATA3) and Dang Quoc THUYET4)
Abstract: The study investigates occurrence of ionic contaminants and pollutants in the tributaries of the Chirchik River in thenortheast part of Uzbekistan. Water samples collected in the Chirchik River Basin were analyzed by ion liquid chromatography todetermine ions such as Ca2+, Mg2+, K+, NH4+, Na+, Li+, SO42-, NO3-, Br-, NO2-, Cl-, F-, PO43-. Plant available forms of heavy metals insoils were extracted according to the methods established by Japanese Ministry of Environment. Elements such as Cr, Ni, Cu, Zn, V,Mn, Fe, Ga, Ba, As, Mo, Rb, Sr, Sb, Se, Cd, In, Cs, Co, Ag, Hg, Tl, Pb were detected with the help of ICP-MS. Toxic heavy metals
such as Hg, Cd and Pb were not detected in all water samples, while Fe and Ba exceeded the Maximum Admissible Concentrations(MAC) in several sites in the watershed. Contaminants such as NO3-, NO2-, SO42-, NH4+ and PO43- exceeded the MAC values forsome water samples probably due to discharges from agriculture and other industries. It was noticed that the level of most ionsincreased near to stationary sources, automobile road and residential area while the concentrations of As and Sb were initially high in
the Charvak water reservoir.
Key Words: Chirchik River, Heavy metals, Ionic contaminants, Monitoring, Water quality

2. Materials and Methods
1. Introduction
Presently, water quality associated with agriculture andindustrial activities in Uzbekistan is a great concern particularlyin economic region of Tashkent province.
Previous
monitoring results carried out in 2001-02 in the northeast partof Tashkent province revealed heavy metals pollution in theChirchik Watershed. The level of chromium (III) and nickel(II) were high in irrigation water and plough soils. The total
concentration of chromium in irrigation water fluctuated from
0.5 to 20 mg/L, and nickel ranged from 0.35 to 2.29 mg/L,
whereas allowable concentration of chromium and nickel was0.5 mg/L and 0.1 mg/L, respectively. The concentration ofchromium and nickel in plough soil layer ranged from 20 to83.1 mg/kg and from 17 to 30.3 mg/kg, whereas admissible
concentrations for serozem belt soils are 30 and 35 mg/kg forchromium and nickel, respectively (Riskieva et al., 2002).
However, the source of pollutants was not discovered yet, andmonitoring has not been carried out in the Chirchik Watershedsince 2002. More data are required for investigating possible
sources and effects on water quality and contamination level ofplough soils.
The objective of this study was to monitor theconcentrations of ionic contaminants and heavy metals in thetributaries of the Chirchik River.

2.1. Sampling and chemical analysis
Water samples were collected from the Charvak water
reservoir along the Chirchik River to downward. Arable soils
were sampled at low relief hills and near to urban areas (Fig. 1).
Sampling sites were appointed with the help of GPS device(Garmin). Sampling was conducted in the 14th, 17th, 21st ofAugust and the 4th of September, 2008.
Water samples were filtered through 0.45 µm Milliporefilter (Millipore Co., USA) and introduced to ion liquid
chromatography (Shimadzu, Japan) to analyze ions such as
Ca2+, Mg2+, K+, NH4+, Na+, Li+, SO42-, NO3-, Br-, NO2-, Cl-, F-,
PO43-.
Plant available forms of heavy metals in soils wereextracted according to the methods established by Japanese
Ministry of Environment (Yamanaka, 2007).
Elements such as Cr, Ni, Cu, Zn, V, Mn, Fe, Ga, Ba, As,Mo, Rb, Sr, Sb, Se, Cd, In, Cs, Co, Ag, Hg, Tl, Pb weredetermined with the help of ICP-MS (Agilent, USA).
Soil pH and soil humus were measured with Horiba pH
meter and Tyurin titration method, respectively. Bulk density
was determined by gravimetrical method.
Statistical analysis was performed by using SPSS – 11
Version for MacOSX based on Pearson_Spearman’s rankcorrelation. The values of p <0.05, <0.01, <0.001 wereconsidered to indicate statistical significance; all tests weretwo-tailed.

* Corresponding author: nmurodjon@gmail.com
Str. Kamarniso-3, Almazar district, P.O.Box 100179, Tashkent, Uzbekistan
1) Research Institute of Soil Science and Agrochemistry, Tashkent, Uzbekistan

3) International Center, Tokyo University of Agriculture and Technology, Japan

2) Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan

4) United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, JapanElevation

Site Description and Sampling

D2

R5A R
Charvak
R1
R6R2B Gazalkent town

A 862 m
B 656 mD3C S1

R7C1

C2 S3

D

R4 R3

FC5S7
S5 C4
S6 C3

LEGEND
Reservoir and river waters
Canal irrigation waters

Chirchik city
S8C 640 m

D1S2P1 S4Pump waterESoil samples

Kibray town

D 609 mDischarge waters
E 550 mFactories
Industrialized cities
Automobile roads

Tashkent city

F 463 mOrchardAgricultural fields

Scale:30 km

Residential area

Fig. 1. Sampling Sites in the Chirchik Watershed. Legend: R iswater sample in Charvak reservoir; R1, R2, R3, R4, R5, R6 andR7 are water samples in the Chirchik River and its tributaries; C1,C2, C3, C4, and C5 are water samples in irrigation canals; D1 andD2 are water samples in discharge water from agricultural fields;
D3 is water sample in discharge outlet from “C” factory; P1 ispump water sample (3 m in depth); S1, S2, S3, S4, S5, S6, S7 andS8 are plough soil samples collected in agricultural fields.

3. Results and Discussion
3.1. Physical and chemical parameters of water body
Water pH was about 7.5 which is similar to the pH in theChirchik River observed in August and September varying
from 7 to 7.8 (Toderich, 2000). Only in D3 point the pH
resulted in 6.6 possibly because of discharge of acidic chemicalfrom factory (Kuiyi et al., 2008). Hydrocarbonate (HCO3-)
concentration in Gazalkent town was 119 mg/L, while it
increased in Chirchik city resulting in 232 mg/L. Oxygen
regime of the river was in normal condition fluctuating from
10.7 to 11.47 mg/L (Toderich, 2000). According to thesanitary norms, in summer and winter seasons dissolved
oxygen must not reduce below 6 mg/L and 4 mg/L,respectively (Guseva et al., 2000). COD (chemical oxygendemand) in canal waters fluctuated from 8 to 50 mg/L.
3.2. General characteristics of irrigated soil
Soil humus varied from 1.33 to 1.85%, nitrogen 0.064 0.210%, phosphorus 0.165 - 0.210%, potassium 2.0 - 2.43%,
affirming average statistical database on humus and nutrient
contents in serozem belt soils in Central Asia (SoyuzNIXI,1963). In the serozem belt soils humus fluctuates from 1.06
to 1.96%, nitrogen from 0.04 to 0.15%, phosphorus 0.12 0.18%, and potassium 1.32 - 1.58% (Riskieva et al., 2002).
Soil pH varied from 8.1 to 8.4. Average soil moisture was
17.86%, with average bulk density of 1.49 g/cm3 in plough soil
(15-20 cm). Similar result of bulk density was observed inclay loam soil (agricultural field in northern Jordan) varying
from 1.4 to 1.5 g/cm3 in the 10-20 cm plough soil layer.

3.3. Average concentration of soluble ions and elements
The average concentrations of several ions and elements inwater sample were presented (Table 1). Contaminants suchas NH4+, NO3-, NO2-, SO42- and PO43- exceeded the MAC
values. However, the level of Cr, Ni, Cu, Zn, V, Mn, Ga, As,Mo, Rb, Sr, Sb, Se, Cd, In, Cs, Co, Ag, Hg, Tl, and Pb
elements and Ca2+, Mg2+, Li+ ions did not exceed
corresponding the MAC values in both water and soil samples.
Only, Fe and Ba exceeded the MAC values in R1, R2, R7, C5,
D1, and P1 sites.
3.3.1 Reservoir Water
The level of NO2- (nitrite) was two folds of the MAC
values and three folds of previous result (Glavgidromet, 1998).
According to Marcel (2006) nitrite is originated due to increaseof “nitrosomonas” bacteria which oxidizes ammoniumtransforming to nitrite form. It is usually found on surface
water under pH condition 6.0 - 9.0, and 20 - 30ºC watertemperature.
3.3.2 River Waters
The concentration of soluble ions and elements sharply
increased in water samples collected in R1 and R2 sites afterGazalkent town (Table 1). The concentration of nitrate(NO3-) in the river water was high than the MAC values in 1.7
times and nitrite (NO2-) exceeded 2 times in R1 and 3 times in
R2, where the MAC values for nitrite and nitrate were 0.02 and9.1 mg/L, respectively for surface waters in Uzbekistan
republic (Razakov et al., 2003).
For phosphate ion (PO43-) 0.3 and 3.5 mg/L were adopted
as the MAC values for fishery pond and drinking waters,respectively (Razakov et al., 2003). However, the phosphate
ion concentration in R1 and R2 sites showed 9.18 and 6.27
mg/L, respectively. Some forms of phosphorus are applied tocontrol corrosion in water supply or in cooling water system inindustrial sector, including a production of synthetic detergents(Tchobanoglous and Schroeder, 1985) and its usage inhouseholds in Gazalkent town which probably increased thelevel of phosphate ion in the river waters.
In R2 point, the concentration of most ions decreased, it isvery likely due to tributary stream the Aksakata which inflows
between R1 and R2. The concentration of ions in R3 and R4
sites collected before entering Chirchik city was lower than thesamples collected in residential area in R5, R6, R7 sites,
however the concentration of all ions did not exceed the MAC
values except Fe and SO42- in R7 site which is the down part ofChirchik city.
3.3.3. Canal and Pump Irrigation Waters
It must be pointed out that there is no MAC values forirrigation waters in Uzbekistan however, based on thestandards offered by the EU directives, and in consideration ofpresent sanitary norms used in Uzbekistan, France, the USA,

Table 1. Average concentrations of ions and elements in the Chirchik Watershed. Note: nd for not detected, -- for not available.

Samplingsites
R
R1
R2
R3
R7
C1
C2
C3C4C5P1
D1
D2
D3
MAC (river)
MAC (canal)

NH4+0.02
0.01
nd0.01
nd0.051.18
0.020.53
0.03
3.71
nd
0.04
nd
0.50
1.50

NO30.63
16.24
9.87
1.85
8.36
0.56
8.46
0.79
0.60
26.3
96.14
18.32
0.56
28.43
9.10
25.00

Water samples, mg/L
NO2SO42PO430.04
11.29
3.61
0.04
17.55
9.18
0.06
22.07
6.27
nd
16.97
3.43
nd
124.4
5.40
nd
10.26
3.00
0.50
39.51
3.00
nd
10.59
3.16
nd
11.95
3.56
nd
246.30
8.56
nd
58.19
7.89
nd
56.50
9.33
nd
26.69
3.06
nd
84.99
2.88
0.02
100
0.3
0.50
-1.00

Razakov et al. (2003) suggested standard values for 20
parameters for the irrigation waters in Uzbekistan. Theparameters are indicated as follows: water pH 6.5-7,
mineralization 1000 mg/L, PO43- 1 mg/L, NH4+ 1.5 mg/L,NO2- 0.5 mg/L, NO3- 25 mg/L, F- 1 mg/L, As 0.1 mg/L, Fe 5mg/L, Cr6+ 0.1 mg/L, Cu 1 mg/L, Zn 5 mg/L, and Pb 0.2 mg/L.
Considering these parameters for irrigation waters, PO43- ionexceeded the MAC values in all cases. For example, in C1,C2, C3 sites it exceeded 3 times, in C4 - 3.5 times, while in C5
and P1 - 8.5 and 7.9 times, respectively. The mean
concentration of PO43- in canal waters resulted in 4.2 mg/L, NO2in C2 and NO3- in C5 were above the MAC values (Table 1).
In the pump water (P1) NO3- exceeded the MAC values
3.8 times resulting in 96.14 mg/L, due to nitrification process
in soil layers, probably derived initially from ammonium andconverted to nitrate by “nitrobacter” in soil (Jalali et al., 2005), as
ammonium (NH4+) level was also higher than the MAC values.
Sulfate (SO42-) ion, collected near to “Tashkent Ring
Automobile Road” where intensive transport activities havebeen observed, was high resulting in 246.3 mg/L in C5 point.
According to Nurrohim et al. (2005) sulfur-dioxide (SO2) ismainly derived from road vehicles and cause air pollution.
Meanwhile, the concentrations of heavy metals did not exceed
the MAC values in C5 point.
3.3.4. Discharge Waters
All discharge waters were free from NO2-, NH4+ and Br-,
only at D2 point NH4+ concentration was 0.04 mg/L.
Concentration of NO3- at D1 and PO43- at D1, D2, D3 arehigher than the MAC values (Table 1). PO43- is mainly
derived from P-fertilizers, manures or sewage sludge applied tofields to support plants to uptake phosphorus, and soil is one ofbulk sources for both organic and inorganic phosphorus

Ca2+
27.75
66.98
45.06
19.43
55.07
25.16
34.45
18.93
26.83
74.34
62.15
75.92
24.09
45.78
180
--

Fe
143.40321.60289.80180.60312.20138.90189.90139.90143.00559.30463.70392.30149.60219.40300--

Water samples, µg/L
BaCr
60.60
nd145.80 3.28
124.8
1.29
60.57nd89.57
1.60
46.95
nd54.15
0.87
50.00
nd48.74
nd38.17
1.00
69.93
nd140.1
1.90
49.69
nd49.45
nd100
500
---Ni
0.01
0.17
0.12
nd0.190.01
0.12
nd0.15
0.83
0.52
0.34
0.06
0.40
100
--

(Guseva et al., 2000; Marcel, 2006, Tchobanoglous andSchroeder, 1985). The level of Fe, Cu and Ni was high at D1
point probably due to their strong interaction with organic
matter (Charlesworth et al., 1999).
3.4. Average concentration of elements in soils and waters
Water extractable forms of heavy metals were lower thanthat of acid extractable (1M HCl) forms except formolybdenum (Mo), probably due to abundance of molybdateion (MoO42-) in soils which is soluble in water, whereas othercompounds of Mo are less soluble (Fig. 2). Toxic heavy
metals such as Cd, Pb, and Se had the highest concentrations insoil samples obtained at S1 and S2 agricultural plots, ranging
4.27 - 3.64 µg/kg, 336.3 - 278.6 µg/kg and 23.15 - 18.82 µg/kg,respectively. Moreover, the level of other metals such as Cs,Fe, Co, Ni, Zn, Ga, Ba, Rb and Cr was higher in S1 and S2
plots as compared to the other plots downward. Thoseelements may be derived from a stationary source locateduppermost between R1 and R2, where the ions and elements
trend showed sharp increase. Some elements such as Co, Seand Cs are known to be used in glass or mirror factories, where
Co is mostly used to impart blue color to glass stuff, while
cesium is used to etch the surface of glass, due to CsOH form
is a very strong base and can etch the surface of glass. The
concentration of Cr and Ni in all water samples did not exceed
admissible norms and did not support previous results.
Statistical analysis showed that in water samples (treated byconcentrated HNO3) Cr significantly correlated with Se(P<0.001), with Li, Ca, Fe (P<0.01) and with V (P<0.05),
while Ni with Li (P<0.001), with Ca, V (P<0.01) and with Se,Rb (P<0.05).

Concentration (µg/kg)

1000000

Soil treated with water

100000
10000

Soil extracted with 1M HCl

1000
100
1010.1LiMg
CaVCrMn
FeCo
NiCuZnGaAsSeRbSrMoAgCdInSbCsBa
Hg
TlPb

0.01

Fig. 2. Concentration of elements in soil samples (ICP-MS).

4. Conclusion
Toxic metals such as mercury, cadmium and lead were notdetected in all water samples, while Fe and Ba exceeded theMAC values in several sites of the watershed. Contaminants
such as nitrate, nitrite, sulfate, ammonium and phosphates
exceeded the MAC values for some water samples probably
due to discharges from agricultural sector and other industries.
It was noticed that the level of most ions increased near tostationary sources, automobile road and residential area while
the concentration of As and Sb was initially high in thereservoir water. Consequently, further investigation on thewatershed is needed to reveal the exact sources ofcontaminants and pollutants under holistic way andsystematical approach.
Acknowledgements
This work was supported in part by Japanese Grant-in-Aidfor Human Resource Development Scholarship (JDS).
Special thanks for scientific advice to Dr. Riskieva
Khurshida at the Research Institute of Soil Science andAgrochemistry.
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