Test-set for school studies of water bodies RKTP 01.2 for determination of oxygen contentof water, water clarity, and its temperature

A short description of the method, technology, process, etc., of the main features: water sampling is modified with the help of pseudobatometer of Vereshchagin from the depth of not more than 5 m. To determine the oxygen content of the water titration method of Winkler is used. For its realization, the equipment and reagents that allow research in the field are used. Water clarity is determined by the method of Secchi using white disc of 200 mm in diameter. Water temperature and its stratification is determined using aqueous thermometer.
The equipment we use includes: modified pseudobatometer of Vereshchagin, a conic flask with the ground-in stopper, a flask for titration, a pipette of Paster, a syringe batcher, a silicone hose, a spirit thermometer, a disc of Secchi.
The reagents we use are: MnCl2 , KJ, KOH, Na2S2O3, крахмал, H2SO4, K2Cr2O7.

The novelty: the test set is created by means of modifying and simplifying the standard methods of hydrochemical indicators analysis. Modification and simplification allows to get the possibility to work in the field with non-essential reduction of metrological characteristics, as well as to reduce the requirements for the qualification of the operator, which allows the use of a test set in school research works.

Accuteness: dissolved oxygen is needed for animals’ breathing, oxidation of decomposition products of plant and animal residues deposited on the bottom. Its deficiency leads to the fact that in the bottom layers of water there are created the conditions for anoxic processes of decomposition of organic substances that occur with the release of toxic hydrogen sulfide. As a result, in the deep water layers there appears a lifeless zone. In this regard, the oxygen content in the water at different depths is one of the most important indicators necessary to assess an ecological status of water bodies.
Water clarity – is a measure of the ability of water to transmit light. This index depends on the ability of substances dissolved in water and suspended particles to let the sun's rays pass into the depth and is conditioned by its color and turbidity, i.e., its content of different colored (dissolved) and suspended (insoluble) organic and mineral substances. Water clarity – is an important indicator of ecological health of the aquatic ecosystem. At low transparency in the pond there might get an unfavorable ecological situation associated with the lack of light for the life of green plants growing in the depth, slowing or complete cessation of photosynthesis in their cells, and, consequently, the deselection of their oxygen.
Water temperature – is the factor that influences almost all the processes occurring in the reservoir. It is linked to the solubility of oxygen in water and the spread of oxygen deep into the water. Consequently, the water temperature and its distribution in the depth largely determines ecological prosperity of the water body.
For the quantitative measurement of these water bodies parameters we use rather simple approach, which is however, seldom used in school studies. This is due to the complexity and high cost of equipment.
Recently, for school research work they began to frequently use test sets that allow to get the results of the measurement of these and other parameters of water bodies in the field conditions with required accuracy. However, in Belarus they do not produce such sets and foreign sets are costly and hardly available for school research groups.

The advantages over similar products: in Belarus, similar test sets are not made. To determine the amount of dissolved oxygen in the sample a drip method of nonburette titration is used. This method simplifies the operation of the test set in the field. In a similar test sets burette titration methods are used, which is hardly realizable in the field, or they use the method by titration tablets which significantly increases the accuracy and reduces the time required for analysis.
As aqueous thermometer a spirit thermometer is used, provided with a protective sheath made of PET preforms. This device does not contain toxic components such as mercury. It is protected from shock and other adverse external effects. In a similar test kits mercury thermometers without their defense are used.
To determine the clarity of the water they use Secchi disk that allows you to estimate the value of the photic layer in the pond. In a similar test kits for the determination of water clarity they use Snellen method that allows to determine the clarity of the water in the selected sample, but does not allow to estimate the size of the photic layer.

Purpose: test set RKTP1.02 is intended to identify some of hydrochemical characteristics in the field conditions: the content of dissolved oxygen, water temperature, oxygen stratification and temperature stratification of the reservoir, the water transparency.

Application: study of water bodies.

The security document: the paper "Development of a test set for school studies of water bodies" was assigned state registration number 20130086 from 07.02.2013.

The view of the exhibit (the presentation of the product at the exhibition): a full-scale model.

Where the product was implemented (organization): Institution "Center for Environmental Solutions", Minsk.

The main potential consumers of the product (organization): schools, students who conduct research on water objects.

The forms of cooperation:
a. The production of test sets for school studies of water bodies RKTP 01.2 to determine the oxygen content of water, its clarity and its temperature;
b. the introduction of a test set for school studies of water bodies RKTP 01.2 to determine the oxygen content of water, its clarity and temperature in its research activities of students.


Mogilev State A. Kuleshov University

212030, Republic of Belarus, Mogilev, Pervomayskaya St, 44, room 44

Telephone, fax: 80291312076, 80297402189
e-mail: perri@tut.by

Scientific leader, title, academic degree, academic rank: Pakhomenko Andrei, a senior lecturer of the department of chemistry

Students: Solovieva Nina, the 4th year, group "X" of the faculty of natural sciences;
Kostaltsova Anna, the 4th year, group "X" of the faculty of natural sciences.