Study of the eco-economic efficiency of electrochemical pH correction for reducing hardness salts

Summary

In industry, water recycling systems or units have been widely used to cool equipment and other industrial processes. One of the main problems associated with operating these systems is scale formation owing to the presence of hardness salts, such as calcium and magnesium compounds. Traditional addressing water hardness problems involves the use of chemicals such as phosphates and polyphosphates to bind calcium and magnesium ions, preventing their precipitation. Electrochemical pH correction provides for a more environmentally friendly solution. Changing water pH by electrolysis enhances the precipitation of hardness salts as insoluble compounds, that can be further removed from the system. The theoretical foundations and mechanism of water softening by electrochemical treatment are examined. It is noted, however, that direct reduction of hardness salts using electrochemical pH correction alone is not possible. It is expected that electrochemical methods can significantly enhance water softening processes and improve the efficiency. The eco-economic efficiency of the electrochemical pH correction method for the side stream filtration system of an industrial water recycling unit is estimated.

Key words

softening , electrolyzer , electrochemical treatment , water hardness , water recycling facilities , eco-economic efficiency

Improving the efficiency of water recycling systems at oil refineries and petrochemical enterprises (part 1)

Summary

Petrochemical enterprises produce a significant impact on the environment; therefore, they are obliged to develop and implement programs to improve the environmental sustainability; the programs have to reflect the compliance of the technological processes, equipment, technical methods, methods used at the enterprise with the best available technologies. Accordingly, the growing demand for practices of improving the effectiveness of environmental protection measures in the operation of specific economic entities stimulates the search and development of new methods as well as particular and integral indicators of the effectiveness of environmental investment projects at various levels. This study presents the results of applying proactive measures related to the implementation of an investment, environmentally oriented project for the reconstruction of water supply and wastewater disposal systems of the enterprise, development of technical measures aimed at improving the efficiency of water recycling systems, reducing the volume of effluents discharged by the plant and reducing the abstraction of raw water from the surface water source.

Key words

sewerage treatment facilities , water recycling facilities , industrial wastewater treatment , zero discharge system , pilot tests , feasibility study

Improving the efficiency of water recycling systems at oil refineries and petrochemical enterprises (part 2)

Summary

Comprehensive studies were carried out to improve the efficiency of water and wastewater treatment facilities at one of the oil refineries in the Southern Federal District by adding one or more stages of tertiary treatment; by improving the design of the existing facilities; and replacing the technological process of one of the treatment stages for a more efficient one. Research objectives: 1) analysis of the operation of the water recycling systems (units), existing wastewater disposal and treatment facilities; 2) development of the optimal solutions and schemes for upgrading the recycling water supply of the enterprise; 3) development of technical measures aimed at increasing the efficiency of the water recycling system, reducing the volume of wastewater discharged by the plant and reducing the amount of raw water abstraction by arranging the makeup of the existing water recycling units with effluent. The previous article on this topic presented the research materials on the first two tasks.

Key words

sewerage treatment facilities , water recycling facilities , industrial wastewater treatment , zero discharge system , pilot tests , feasibility study