The invention belongs to the field of distributed treatment of sanitary
sewage, and relates to a
sewage treatment system with separate
nitrification and
denitrification phases. The
sewage treatment system comprises a front-section vertical flow biological trickling
system and a rear-section horizontal flow multi-medium
soil infiltration system arranged below the front section, wherein the front section comprises a water distribution gravel layer, a natural
zeolite packing layer, a drainage gravel layer and a drainage false floor. The rear section comprises a rear-section intake pond, an intake
grating, a water distribution gravel layer, a natural
zeolite infiltration layer, a soil template layer, a sealing soil layer, a drainage gravel layer, a drainage
grating, a rear-section delivery tank and a delivery tank water outlet; the vertical interval of the front section and the rear-section intake pond is 30-50cm. Compared with the traditional two-stage multi-medium
soil infiltration system, the rear section of the system adopts a horizontal flow method, the
hydraulic retention time is effectively improved, the
effluent is submerged by the horizontal flow, the anaerobic environment is improved, and
total nitrogen removal is facilitated. Therefore, the system is ideal in overall
treatment effect, not easy to block, and low in construction and operation costs.