2. "Analysis of the chemical
composition of wastewater at
gas stations"
3. Relevance of the topic
At present, the problem of environmental pollution by gas stations is relevant and is
associated with the prevalence and high density of this source of technogenic pollution
in the city or settlement.
In 2021, there were almost 6.4
thousand filling stations (gas stations),
gas filling stations (GAS) and autogas
filling compressor stations (CNG filling
stations) in Kazakhstan, which is 1.5%
more than in 2020. Of these, 2.1
thousand gas stations, gas stations
and CNG filling stations were located
in rural areas - an increase of 1.2%
over the year, energyprom.kz writes.
4. Targets and goals
Purpose:
•study the chemical
composition of gas station
wastewater
Research objectives:
Gather general information about the quality of
sewage from gas stations.
Assess the quality of water and determine the
degree of pollution by conducting studies of the
chemical composition of water.
Based on the data obtained during the study of
water, to conclude that it is necessary to take a
number of measures aimed at improving the
ecological state of wastewater from gas stations.
5. General information about gas stations
Gas stations usually have open areas and a
fairly developed road network, from
which rainwater is discharged,
contaminated with suspended solids,
mainly sand and clay particles and oil
products waste: gasoline, diesel fuel, oils,
etc.This wastewater is hazardous to the
environment and must be treated to
environmental standards before being
discharged.
6. General information
Two types of surface runoff pollution sources can be distinguished on the territory of gas
stations:
Ground sources of pollution - seepage of water-soluble fractions of oil products from the
territory of the gas station through non-asphalted surfaces, lawns, cracks in the coatings.
Underground sources of pollution - possible leakage of contaminated effluents from on-site
drainage networks or storm water wells
7. Composition of sewage from filling stations
Gas station wastewater has been
tested for pH, suspended solids,
salinity, chlorides and sulfates, BOD
and COD, and for heavy metals
(iron, copper, zinc, total chromium
and lead)
9. Measurement of petroleum products
To measure petroleum products in
water, the Fluorometric method is
used on the FLUORAT-02 apparatus.
10. Measurement of suspended solids,
sulfates and water salinity
Measurement of suspended particles, sulfates and water
mineralization is carried out by the gravimetric method.
11. Measurement of chlorides, pH and
BOD(biochemical oxygen demand) in water
The measurement of chlorides in water
is carried out by the mercumetric
method. To measure BOD(biochemical
oxygen demand) and pH, the
patentiometric method is used and
measured with an EXPERT-001 liquid
analyzer.
12. Water COD (chemical oxygen demand)
measurement
The photometric method is
used to measure the COD of
water.
Spectrophotometer UNIKO 2800.
13. Determination of iron and zinc in water
The concentration of iron and zinc in
water is carried out by the photometric
method.
Spectrophotometer UNIKO 2800.
14. Measurement of chromium, lead
and copper in water
The measurement of chromium,
lead and copper was carried out
using the method of atomic
absorption spectrometry with
electrothermal atomization
15. Analysis of results
The results of wastewater analysis showed that
there is an excess of MPC(Maximum allowable
concentration) by several times, as well as iron and,
in some cases, suspended solids.
16. Exceeding the MPC filling station №1
(Предельно допустимая концентрация)
20. Effect of oil products on water
Oil and oil products have a harmful effect on water.
Typically, oil components form an emulsion with
water, which is difficult to break. Most often, oil
floats on the surface of the water in the form of a
film, enveloping suspended particles, settling with
them to the bottom. Simultaneously with the
pollution of surface waters, the composition of soil
and ground waters also changes.
The content of individual substances can increase by
1-2 orders of magnitude. Organic pollutants,
including PAH(Polyaromatic hydrocarbons), are also
detected.
21. The effect of iron on water
Exceeding the MPC of iron in water is dangerous because when iron enters a water
body, it settles on bottom sediments. Further, acidification and oxidation of water
bodies occurs and this affects the physicochemical properties of water (change in
color, taste, smell). Also, the excess of the MPC of iron affects aquatic biocenoses,
hydrobionts, the destruction of the self-cleaning abilities of the reservoir occurs, and
leads to an increase in detritus..
22. Impact Reduction
Reducing the impact of filling stations is achieved by a combination of
complex measures that involve organizational and legal, construction and
planning, technical and sanitary and hygienic methods:
Selection of the site for the construction of gas stations, taking into
account urban planning conditions, the state of the natural environment
and possible emergencies at gas stations.
Development and observance of environmental measures.
Use of special coatings resistant to oil products.
Use of equipment that reduces the possibility of oil leakage and fuel
evaporation: breathing valves, tanks and pipelines with double walls, etc.
Measures to prevent and eliminate fuel spills.
Establishment of a sanitary protection zone.
Control over the discharge of household, industrial and rainwater
wastewater; control of air and soil pollution levels.
23. Question for you
By what method the concentration of iron and zinc in
water is carried out?
