Upgrade of clarifiers at energy facilities with the use laminar modules

Summary

The need for upgrading clarifiers of obsolete and outmoded design is substantiated. The clarified water quality and capacity of these facilities do not meet the modern water treatment requirements which can be explained by the design and technological characteristics of these facilities. The suggested technical solutions aim at the elimination of such deficiencies as unstable turbulent mode of the suspension settling in a sufficiently high layer (1.5–2 m), low volume utilization factor of clarifiers, the lack of an efficiently operating flocculation chamber. The experience of introducing laminar modules in the water treatment sections of energy facilities is quoted. The upgrade of pretreatment facilities, production of clarified water with low suspended solids, iron and organics concentrations will provide for improving the technical and economic performance of the water treatment units and introducing advanced technologies at the subsequent water treatment stages.

Key words

natural water , membrane technology , clarifier , honeycomb module , pretreatment , laminar module

The experience of operating lamella settlers and clarifiers with built-in flocculation chambers

Summary

The results of upgrading primary water treatment facilities – flocculation chambers, sedimentation tanks and clarifiers based on the use of low-flow and low-pressure recirculators and lamella honeycomb modules made of polyethylene film 250–300 µm thick designed by ECOHOLDING Group experts are presented. The developed method of jointing film into a honeycomb construction with an inner rigid frame provides for the ruggedness and spacial stability of the honeycomb module and allows stretching it on the frames on perimeter only. Firm jointing of the film allows manufacturing a honeycomb construction of any size and angle of slope providing minimum loss of clarifying surface of the facilities of any configuration, both radial and rectangular. For long-term operated facilities honeycomb modules are tailormade after each of them has been measured. The possibility of ensuring the required recirculation rate at low head loss and minimum liquid flow rate to prevent the recycled suspension from destruction and facilitate efficient floc formation is an essential advantage of the developed methods of recirculator designing and constructing. The presented high-efficient methods of coagulation and sedimentation improvement form the basis of prefabricated «Struiia» and «Vlaga» modular water treatment units with 100–12000 m3/day capacities. The units are designed for natural water treatment: turbidity and color removal, softening, defluorination, de-ironing (composite forms, high concentrations of iron) and disinfection. They are used in water supply systems of settlements, towns, hospital care and health resorts, sport centers, fish farms, industrial enterprises or separate production facilities.

Key words

turbidity , water treatment , modernization , residual aluminium , flocculation chamber , lamella settler , clarifier , honeycomb module