Date of Publication :25th January 2018

Abstract: Flocculation is the second stage wherein the formation of readily settleable-flocs from destabilized colloidal particle is achieved by bringing particles into close proximity by gentle and prolonged mixing. In the present study, the jet flocculation aspect is considered since small towns in developing countries need water treatment plants which should be simple to operate, have the least number of moving parts, need no skilled labor for maintenance and are economical. It is very likely that the raw water pumping station may be located at a far away distance and the floculator may not have the electricity available simultaneously at all time periods. Hence floculators requiring regular maintenance and continuous power supply for the mechanical stirrers provided usually fail to give good results. These facts may compel the public health personnel engaged in water treatment to compromise on the quality of water being supplied to the community. Under these adverse conditions, it is therefore, necessary to improve and modify the design of floculator to obviate these problems. The jet floculator is a viable alternative for small water treatment plants (1000cum. /day) which needs to be thoroughly investigated. The jet action in a jet floculator produces the required velocity gradient essential for the formation of flocs without assistance from any moving mechanical parts. In this study, various experiments are performed on 3 jet model set i.e horizontal spiral set up, vertical setup and central helical path setup with varying pipe diameters to check the efficiency of the jet flocculation using jet flow. Slow mixing which is usually done with the help of rotating paddles in any conventional floculator, was done using a water jet which creates turbulence in water as required for slow mixing.Result obtained inferred that the jet can be effectively used for the purpose of flocculation with an increase in the duration of sedimentation.

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