Enhancement of biological treatment of petrochemical industry wastewater

Summary

Possible utilization of water conditioning wastes of thermal power plants – carbonaceous sludge – for the enhancement of biological treatment of petrochemical industry wastewater is considered. The sorption capacity of carbonaceous sludge in relation to organic and inorganic admixtures in wastewater – phenols and ammonia nitrogen in standardized test solutions was determined. The results of experimental studies of wastewater of «Nizhnekamskneftekhim» PJSC showed that dosing of 600 mg/dm³ of carbonaceous sludge into aeration tanks provided for improving the efficiency of wastewater treatment in relation to COD by 36%; BOD5 by 15% ammonia nitrogen by 28% owing to the sorption component. Under contact conditions the kinetic dependencies of COD, BOD and ammonia nitrogen reduction were obtained. With biotesting method it was stated that aqueous extract of carbonaceous sludge did not produce any adverse toxic effect on fish (guppies) and crustaceans (daphnia). The potential of using carbonaceous sludge of water conditioning at the thermal power plants for the enhancement of wastewater biological treatment processes is shown.

Key words

wastewater , ammonia nitrogen , phenol , carbonate sludge , adsorption-biological treatment , sorption capacity

Improving barrier functions of the Metelevskii water treatment facilities of Tumen city

Summary

The results of the preliminary tests showed that during the periods of elevated pollution of the water source (the Tura River) with different toxicants, natural and anthropogenic odorants the process flow scheme with the use of specially prepared powdered activated carbon for the conditions of the Metelevskii water intake would be worth considering. The process flow diagram of the pilot test facility was designed that provided for modeling the existing water treatment technology at the Metelevskii water treatment plant. The pilot facilities included chemical treatment units, clarification units, filtration and disinfection units. During water treatment process modeling the chemical dosages used (ammonium sulfate, chlorine, aluminium oxychloride and polyacrylamide) were similar to those at the Metelevskii water treatment plant for the moment the tests were carried out. According to the results of the tests the trademarks of powdered activated carbon used were defined as most efficient for odor and toxicant removal (by example of phenol). Before dosing into the water the sorbents were specially prepared (following the technique of NII VODGEO) to provide for maximum exhibiting sorption properties in relation to the mentioned target components. Special pilot equipment designed at NII VODGEO allowed reproducing all the water treatment modes applied at certain facilities. This modeling provides for adjusting water treatment technology, developing new process solutions, selecting new chemicals and dosages without interrupting the operation of the basic facilities. The results of the tests and pilot investigations with the use of powdered activated carbon at the Metelevskii water treatment facilities to remove anthropogenic toxicants and odors are presented. Powdered carbon trademarks were selected; recommendations for designing powdered activated carbon unit were given.

Key words

clarification , reagent , filtration , powdery activated carbon , organics , water treatment facilities , phenol , odor control