The present invention provides a Z-shaped gas stripping 
reflux two-stage 
precipitation integrated 
sewage treatment tank, wherein the rectangular tank body contains a grid-containing sand 
settling pretreatment zone, an anoxic zone, an 
aeration zone, a clarifying 
reflux zone, an inclined 
pipe / plate 
precipitation zone, a contact disinfection 
ditch, and the like, and conventional 
water treatment equipment, a horizontal slit-type gas-water separator, a Z-shaped separation wall, a 
surface type gas stripping micro power 
reflux device arranged in a horizontal and completely-paving manner, and an L-shaped 
hydropower hybrid spiral flow generator are arranged inside the tank body. The Z-shaped gas stripping reflux two-stage 
precipitation integrated 
sewage treatment tank has a simple and compact structure, and has the following advantages that: denitrogenation, 
phosphorus removing, two stage precipitation and disinfection treatment are completed in the same tank; and compared with the conventional process adopting a plurality of independent small tanks, the Z-shaped gas stripping reflux two-stage precipitation integrated 
sewage treatment tank of the present invention has advantages of low investment, small occupation area, less agent consumption, less 
sludge discharge, low 
energy consumption, low cost, stable and controllable 
water quality, easy operation and management, and the like, and is especially suitable for sewage denitrogenation and 
phosphorus removing integrated treatments with a scale of 10000 tons / day and below.