Model of well clogging during in situ groundwater deironing

Summary

The study focused on the evolution of aquifer porosity during operation of in situ groundwater treatment systems at a water intake facility in the Russian Far East. The objective was to evaluate precipitate distribution and changes in aquifer hydraulic conductivity within the near-wellbore zone. Predictive simulations of precipitate accumulation were performed. The resulting additional drawdown, as well as reductions in permeability and porosity of the near-filter formation, were assessed. The precipitation zone develops directly adjacent to the well at the injected oxygen concentration of 12.5 mg/l. Simulations show that precipitate accumulation near the well caused an additional drawdown of approximately 5 m and reduced the specific capacity of the well. Coupled groundwater flow and geochemical models of well clogging were developed. The models account for variable permeability and porosity controlled by the volume of deposited iron oxides.

Key words

filter , iron , permeability , well , porosity , filtration of coefficient , injection , pumping , precipitate accumulation , oxidation kinetics , oxygen

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UDC 628.162:620.3

Kofman V. Ya.

Nanoparticles of metallic iron for ground water treatment (review of foreign publications)

Summary

The international experience in using the technology of ground water treatment with the help of nanoparticles of metallic iron is presented. The technology of injecting nanoparticles provides for their transfer through intake wells practically to any point at any depth of the ground water basin. Limitations are imposed exclusively by economic factors. The well number and placing are determined by geologic and geochemical characteristics of the polluted area subject to investigation. Prior to the implementation of a project studies shall be carried out to specify the required composition and concentration of iron particle suspension, injection equipment, well placing and depth, working pressure and consumption of the suspended matter, duration of treatment.

Key words

ground water , pollutants , injection , well , nanoparticles of metallic iron

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UDC 628.112.24:622.279.5.001.42

Ivashechkin V. V., Medvedeva Iu. A.

Improving the methods of inspecting and repairing sanding water abstraction wells

Summary

The issues of improving the methods of fault detection, repair of filters and casing of sanding water abstraction wells are considered. The designed instrument is described that has been developed for detecting places of water abstraction well sanding and consists of the control block and water turbidity indicator. In the process of inspection the instrument is moving along the filter during water pumping out of the well. The instrument has successfully passed laboratory and field tests. To simplify the inspection of sanding wells a special device is described that includes a submerged pumping unit and the instrument for detecting sanding places. The design of the device for plugging a damaged section of casing or filter of the water abstraction well is proposed that includes a container for cement mortar with a force opened valve and permanent shuttering. The advantage of this method is in low cost and relatively simple repair work. Some reduction of the filter capacity and well yield can be attributed to disadvantages.

Key words

filtration , water supply , filter , water intake , sanding up , well , turbidity indicator

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UDC 628.112.24:69.003.13

Fisenko V. N.

Energy saving in operating deep wells for underground water abstraction

Summary

The share of energy costs in the operating expenditures structure reaches 85%. Taking into consideration the requirements to the reduction of СО2 emissions into the atmosphere as well as the necessity of reducing the costs and water tariffs, energy saving is the priority task for the housing and utility enterprises, industrial, agricultural companies and water and wastewater services providers that are operating deep wells. Different options of installing water lifting equipment in deep wells are considered. The energy efficiency comparison was made on the basis of the software designed by Wilo Company (Germany), pump manufacturer. The specific features of hydraulic calculations of the combined operation of the pump and the well are considered. The data on the structural concepts for deep wells that provide for saving energy spent directly on underground water lifting is set. The economic and financial mechanism of inducing the measures to reduce the energy consumption by water and wastewater services providers on the basis of the conditions of their foreign investment self-sufficiency development is illustrated.

Key words

water intake , ground water , power saving , hydraulic design , submersible pump , well , lift pipes

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