Flocculation Behavior in Hexagonal-hole Grid System Dealing with Different Turbidity Water
|Keywords||Hexagonal-hole Flocculation Turbidity Flocs|
Water resource in our country faces severe situation:per-person holding rate is very low; water resource can not balance from time and space; the rate of water-using is low. Even though, water pollution seriously happens in our country. In the development of the water processing technology, new environment problem appeared. In the new carried out standard drinking water hygienic standard (GB 5749-2006), the water quality monitoring standard added from 35 items to 107 and turbidity limit from 3NTU to 1NTU, water processing has much higher requirement.To be directed against the worsen of the water pollution and water quantity change constantly, a new flocculating equipment named Six Kok Perforation Grid Flocculation was developing in this experiment in order to improve those situations. The number and siae of mesh can be changed according to the quality of raw water. In this thesis, the design and make of hexagonal-hole grid system was introduced. The hexagonal-hole grid system is very efficient to deal with 10NTU,20NTU,100NTU,500NTU raw water. The hexagonal-hole grid system is very efficient to deal with different turbidity water. The results show that when turbidity is 10NTU and color is 60PCU, turbidity decreased to 1.96NTU and color to 6.0PCU. When turbidity is 20NTU and color is 90PCU, turbidity decreased to 2.27NTU and color to 10PCU. When turbidity is 100NTU and color is 500PCU, turbidity decreased to 5.56NTU and color to 10PCU. When turbidity is 500NTU and color is 1800PCU, turbidity decreased to 9.96NTU and color to 60.0PCU. Fractal dimension is 2.033,2.335,2.113,2.515. The flocs strength is 0.02136 (N·m-2),0.02671 (N·m-2),0.02320 (N·m-2) 0.02980 (N·m-2)。Experiments show that raw water and flocculation chemical can form stronger vortex in hexagonal-hole grid system. Turbulence is caused by continuous vortex motion. That can increase the probability of particle collision. So quality of flocculation is very well. Flow area is increased and head loss is decreased. Flocculation time is shorten and quality of effluent water is improved. Hexagonal-hole grid system have a lot of merit, such as good flocculation quality, short flocculation time, little flocculation chemical, little area, low cost, excellent adaptability.