Gabion filtration facilities for surface runoff treatment

Summary

The design and characteristics of gabion filtration treatment facilities developed and designed by the specialists of «ECOLANDSHAFT-XXI century» NPO LLC are presented. The analysis of wastewater and effluent samples collected at different seasons of the year from the inlet and outlet of the different gabion facilities showed that the efficiency of treatment both in terms of suspended solids and oil products and COD, BOD5 met the maximum permissible pollutant concentrations set for fishery waters. Gabion facilities are open gravity facilities, which do not require any chemicals, pumps, electricity or premises for their operation. They include two sections, each of them having four treatment stages: accumulating settling tank; filtration chamber with granular bed; bioplato; filtration chamber with sorbent. Gabion facilities include bioplato as a mandatory and very important element for treatment which is a shallow impoundment seeded with macrophytes and which ensures removing a number of pollutants. Due to the use of gabions, bioplato and chemical free treatment the gabion facilities can be qualified as nature like facilities which can be retrofitted into the landscape and have an attractive look becoming a part of the landscape. By now more than 120 gabion filtration treatment facilities with up to 15 years service time have been designed and built. The facilities provide for the treatment of surface runoff from highways, industrial sites of technology and industrial parks.

Key words

sedimentation tank , suspended substances , surface runoff , gabion filtration treatment facilities , petrol products , BOD5 , COD , filter with granular bed , bioplato , sorbent

Improving the efficiency of chemical treatment
of wastewater of fat-and-oil production

Summary

Wastewater of food industry enterprises is a complex physical and chemical system. Under production line conditions the high treatment efficiency of the main wastewater stream is provided with the help of chemical treatment with further solid phase separation by dissolved-air flotation method. The treatment process flow scheme used at the plant includes collection of wastewater of different composition and chemical treatment with subsequent sedimentation carried out in a batch reactor-settling tank, is characterized by the long process time and low efficiency. For the optimization of the treatment process it was suggested to replace the equipment with a comprehensive system including chemical dosing units (coagulants, flocculants), a pH-correction unit, a flocculator with static mixers and a dissolved-air flotation unit at retaining the collection and accumulation system of wastewater of different composition. The results of implementing different process flow schemes of chemical treatment of fat-and-oil production wastewater (mayonnaise section, refining section, mustard production) are presented. Chemical treatment of wastewater coming from the mayonnaise section provides for more than 97% COD and BOD5 elimination, more than 99% of fat removal and more than 98% of suspended solids removal. Chemical treatment of wastewater coming from the refining section provides for more than 65% COD and 45% BOD5 treatment efficiency, and more than 45% suspended solids removal. The treatment efficiency of wastewater coming from mustard production is more than 60% of COD and BOD5 elimination; more than 90% of suspended solids removal and more than 99% of fat removal.

Key words

reagent treatment , suspended substances , BOD5 , COD , wastewater of fat-and-oil production , fats , dissolved-air flotator