When chlorine disinfection process is used, free chlorine disinfection method is used when the ammonia nitrogen concentration of raw water is high; when the ammonia nitrogen concentration of raw water is low, combined chlorine disinfection method is used.
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Filtration without coagulation will influence the flotation efficiency.
The demand of bubble dispersity in flotation is that the diameter of bubbles should be less than 100 um. But in clean water, the bubble dispersity usually cannot reach this demand.
When treating oily wastewater by floatation, dosing clay particles will increase the flotation efficiency.
Suppose a certain kind of natural river is treated by coagulation and flocculation process in a reciprocating baffled flocculation tank. The water flow rate is 600 m3/h. Volume of the flocculation tank is 200 m3. There are 3 baffles in the flocculation tank. Assume that: the local headloss caused by all corners in the tank is 90% of the total headloss, and the local resistance coefficient of each corner is ζ=2.8. The average flow velocity in the corners is 0.2 m/s. Water temperature is 20 C. Water kinematic viscosity is ν=1.005×10-6 m2/s.Then, the average G is _________ __ s-1 (fill in an integer); The number of G is ___________ ______ (choose in/out of) the reasonable range.