There are a number of cases of serious groundwater mercury pollution in Kazakhstan, many of them close to or in large cities. These problems pose a considerable risk to the people of this region.
The northern suburb of Pavlodar City is one such case. It is known that groudwater under the old Chlor-alkali plant is contaminated with HgCl2. The contamitated groundwater is moving towards the River Irtysh and, according to reports, it has already entered the surface waters of the Irtysh. Also, mercury is entering Lake Balkyldak where wastewater was disposed by the plant before. The territory of the plant will remain the source of chloride mercury (II) entering groundwater for a long time to come.
It is known that the processes of transformation of mercury compounds in the environment, both to the more dangerous form - methyl mercury and to the less toxic form, are mainly bacterially mediated.
The objective of the Project is to establish if the bacteria can be used to provide a cost-effective method to bind or immobilise the dissolved mercury in the groundwater.
The project will specifically aim to:
• Isolate a pure culture of aerobic and anaerobic bacteria from soils of Pavlodar (or another mercury-contaminated location if necessary) that have a high potential, given the right conditions, to bind or immobilise mercury.
• Identify the optimum conditions that will enable the potentially effective strains of bacteria to grow and be effective in binding and/or immobilising mercury (e.g. organic levels, sulphate level, pH).
• Select the most effective support materials to absorb bacteria with a high potential to bind or immobilise the mercury from the water phase.
• Create an artificial laboratory-scale bacterially impregnated filter system with absorbed bacteria, and evaluate its effectiveness on a lab scale.
Expected results and their application:
• A method of treatment of mercury-contaminated underground water using microorganisms will be developed and tested in laboratory conditions. The method can be used for clearing underground waters of mercury, which gets there from factories producing the chlorine and alkali and from other plants, where the mercury is used as the catalyst. It is necessary to prevent mercury contamination of natural reservoirs.
• The team participating in the project has considerable experience of work with mercury pollution. The chief of the project S. A. Abdrashitova and her IM&V team has been dealing with the study of microbiological processes of mercury transformation in environment for more than ten years. The team of the NCB RK monitoring laboratory has qualified chemists and microbiologists and much experience of work with soil contamination by heavy metals. The team of the AIPET laboratory has been conducting monitoring research of soils, underground and surface waters contaminated by mercury in Kazakhstan for more than seven years.
