V. Skorokhodov

Development of new highly efficient and economical technical and technological solutions for the treatment of waste water, containing oil products is one of ecological tasks of current importance.

The line of investigation that has been developing during the recent years, namely that of intensification of the separation processes by changing the properties of the surface of interacting phases was used as a basis for designing a new technological complex of waste water treatment from oil products, which comprises the application of froth fractionation and modified natural sorbents.

The method is implemented at the concentration of impurities in a multi-phase system with pre-designed surface properties of phases and includes coagulation, sorption and flotation in activated water-based air dispersion (AWBAD). The enhancement of sorption surface at the boundary of phase separation is achieved through the change of dispersed composition of the gas phase within a wide range and the use of the modified vermiculite sorbent Versoil of fine fractions with specific surface of 378 m2/g as both sorbent and a stabilizer of the gas phase, which allows to obtain the optimum indices of waste water treatment. All the above processes of treatment are implemented within one volume.

This method provides the needed degree of water cleaning from oil products, regardless of the initial contamination, without preliminary treatment of waste water from suspended solids. At the same time, the degree of treatment from oil products and suspended solids makes 99.9%. The application of the above method for waste water treatment of a large company motor vehicle division showed that with input contamination amounting to 900 mg/g the content of oil products in the output water did not exceed 0,04 mg/g.

Compared to its Russian and foreign counterparts the cost price of treatment is 2-3 times lower due to low specific materials consumption (all treatment processes are taking place within the same volume unlike in its multi chamber counterparts) and low energy power intensity (low-pressure air is used in AWBAD preparation). The use of Versoil sorbent as a gas phase stabilizer reduces considerably the sorbent consumption, thus, excluding the need in its regeneration.

The method allows, upon reaching the needed degree of treatment, to increase the performance of process of water treatment from oil products, suspended solids and other impurities, to reduce the amount and volumes of process tanks and water supply lines, to exclude the use of surfactants in the preparation of AWBAD, which increases the method’s environmental safety.

For implementation of the suggested new method of waste water treatment there has been developed a technological complex, which provides processes of coagulation, sorption, froth separation, flotation in water-based air dispersion taking place within the same volume. The technological complex is service-strong, easy to control thanks to a small number of adjustable parameters. The absence of moving parts determines a large overhaul period. The complex can be manufactured in different size standards (varying from 5 to 250 m3/hour).

The suggested technological solution provides the needed degree of waste water treatment, discharged in natural environment, whereas minimizing the cost of the treatment. In conditions of operating motor vehicle company the high efficiency of the complex in the treatment of discharged water was demonstrated, which is achieved through execution of several processes within one.

Operation at the level of the legally required degree of waste water treatment improves the environment condition, thus, providing a higher life standard of the population.

Summary:

Based on the operating motor vehicle company there has been demonstrated the high efficiency of operation of the technological complex for waste water treatment from oil products and other admixtures, which is achieved through implementation of several processes in one volume. The application of Versoil vermiculite sorbent both as sorbent and stabilizer of activated water-based air dispersions provides the needed indices of waste water treatment.