Education of the republic of uzbekistan tashkent state technical university named after islam karimov

EXPERIMENTAL PART. 
Seven rainwater samples were collected during rainy season 
between February and March 2020 in Tashkent (41°16′N, 69°13′E) (Fig. 1). The samples were 
collected cleaned bucket with capture 10L from 7 regions of the city. Samples numbered from 1 
to 7. Samples 1,3,4,7 from Mirzo Ulugbek region, collected nearby main roads several part of 
urban areas, Sample 2 from Almazar region traffic jam road, Samples 5 and 6 from Yunusabad 
region roads with high speed movement of automobiles respectively. 
Fig.1. Investigated area 
Before collection, a bucket washed with de-ionized water (DIW) after samples put into 
the bucket and analyzed. Each rain collection lasted for 24 h and a composited sample was 
collected for the 24 h period, regardless of the number of showers, which occurred during each 
collection period. 

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Civil and environmental engineering
75 
The pH was measured by pH meter – 150 MI equipped with glass electrode, the 
resolution of which is ± 0.01 units. All other analyses were conducted at the monitoring of 
groundwater and regional research laboratory, Institute of Hydrogeology and Engineering 
Geology (IHEG). Precense of Ca
2+
and Mg
2+
in samples were analyzed complexometric titration 
method. More than 60 elements determined by inductively coupled plasma mass spectrometry 
(ICP-MS). 
RESULTS AND DISCUSSION. 
Tashkent lies in the northeastern part of the country. It 
is situated at an elevation of 1,475 to 1,575 feet (450 to 480 metres) in the Chirchiq River valley 
west of the Chatkal Mountains and is intersected by a series of canals from the Chirchiq River 
[11]. Wind is blowing from South-West (SW) to North-East (NE), where most industries are 
located. These winds transport great amounts of air pollutants emitted by industries such as 
ferrous and non-ferrous smelter facilities, glass plants, bricks and ceramic factories, and 
thermoelectric power plants [12]. Resulting in the high concentrations of ionic species and trace 
metals observed in rainwater collected at this place (Fig.2). In accordance with the World Health 
Organization's (WHO) guidelines, the air quality in Uzbekistan is considered moderately unsafe. 
The most recent data indicates the country's annual mean concentration of PM2.5 is 28 µg/m
3
which exceeds the recommended maximum of 10 µg/m
3
. [13]. Contributors to poor air quality in 
Uzbekistan include dust storms, waste burning, the mining and oil and gas industries, and vehicle 
emissions. Available data indicates that Tashkent city with consistently high levels of air 
pollution [14].
0
50
100
150
200
250
Conce
ntr
atio
n, 
pp
m
Sample1
Cu
Zn
Ga
As 
Se
Br
Rb
Sr
Y
Zr
Nb
Mo
Ag 
Cd 
In
0
50
100
150
200
250
Conce
ntr
atio
n, 
pp
m
Sample2
Cu
Zn
Ga
As 
Se
Br
Rb
Sr
Y
Zr
Nb
Mo
Ag 
Cd 
In
0
50
100
150
200
250
Conce
ntr
atio
n, 
pp
m
Sample3
Cu
Zn
Ga
As 
Se
Br
Rb
Sr
Y
Zr
Nb
Mo
Ag 
Cd 
In
0
50
100
150
200
250
Conce
ntr
atio
n, 
pp
m
Sample4
Cu
Zn
Ga
As 
Se
Br
Rb
Sr
Y
Zr
Nb
Mo
Ag 
Cd 
In

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