Mainstream deammonification at ambient temperature treating real sewage by a plug-flow fixed-bed reactor based on zeolite/tourmaline-modified polyurethane carriers

•Efficient mainstream deammonification at 16.8–19.7 °C was achieved in PFBRZTP.•Anammox dominated nitrogen removal in PFBRZTP with a higher contribution of 64.0 %.•PFBRZTP was affected less by pretreatment performance and operational parameters.•lower PN/PS indicated a better biofilm structure in PFBRZTP treating real sewage.•Partial denitrification was an important nitrite supply for Anammox in PFBRZTP.