Halogenated organic pesticides, being in large quantities and extremely dangerous for our
population in the Republic of Moldova, become increasingly widespread in the environment due to
the damage of old deposits from the Soviet period. Our study of the migration of chlorinated organic
pesticides has shown their movement in the soil depth. For instance, hexachlorocyclohexane migrates
during 10 months at a depth of 50 cm. The major amount of this substance is contained in the
upper soil layer of 10 cm. The chlorinated organic pesticides washing could be also accompanied
with the particles in suspension and humic substances. In order to establish the residues washing
in time from agricultural lands, a number of pesticides have been determined in: (a) soils from the
catchment area of the Bic River, which is the right tributary of the Nistru River, (b) fields treated by
pesticides around the Gratiesti village as well in (c) unprocessed lands for a long time (8-10 years).
Other chemical tests in the soils near pesticide deposits in the Draguseni village of the Hincesti
district (the Prut River Basin) show the presence of POP traces, indicating that the actual impact
of pesticide storage has been occurred through less than 8-10 years, or the effluent migrations
have taken place until the present. Testing soil samples for a long time in the uncontaminated area
shows that the full washing and decomposition of pesticides in soil under natural conditions take
place in a period of about ten years. Lakes and ponds are able to cumulate as well certain amounts
of pesticides. Negative effects of the secondary pollution by pesticides are found to be obvious in:
(I) strongly silted lakes near to the Copaceanca River at its shedding in the Raut River (upstream
the Balti city), (II) Cubolta River from the Plop until Putinesti villages, (III) Dubasari Lake dam,
(IV) cascade of lakes of the Ialpug River, (V) upstream the Comrat and up to Congaz cities etc.
Our laboratory simulations through the oxidation of reduced nitrogen forms highlight a clear braking
effect of the self-purification and nitrification processes in siltation tanks. This phenomenon
stimulates an additional eutrophication and pollution of surface waters. Homo- and heterogeneous
catalysis using precipitated tetraphenylporphyrin ((TPP)Co) cobalt(II) at a graphite foil electrode
is studying at present, which will allow the sensitive detection of a wide range of different organohalides,
including a number of industrial pollutants such as 1,2,3,4,5,6-hexachlorocyclohexane
(lindane) and carbon tetrachloride, a representative of haloalkane compounds, haloalkenes such
as tetrachloroethylene, and aromatics such as 2,4-dichlorophenoxyacetic acid, pentachlorophenol,
and the DDT insecticide. We intend also to investigate the electrochemical reduction of organohalides
catalyzed by the dicobalt [Co(II)L2] catalysts, where by “L” a number of ligands are denoted.
The combination of electrochemical and catalytic methods will be used in order to (a) amplify
the neutralizing and mineralization effects of halogenated organic chemicals, (b) increase the rate
of disposal of chemical waste and (c) minimize the cost of the disposal of halogenated chemical
wastes in the Republic of Moldova.