The enhanced biomass attachment of novel functional carriers and its effect on facilitating the start-up of mainstream deammonification at ambient temperature

Abstract

Two novel functional carriers, including zeolite-modified polyurethane (ZP) carriers and zeolite/tourmaline-modified polyurethane (ZTP) carriers, were proposed to enhance biomass attachment and the rapid establishment of mainstream deammonification. Results showed that the surface roughness, specific surface area and Zeta potential of the ZTP carrier increased by 13.6 times, 2.24 times and 17.54 mV compared to the polyurethane (PU) carriers, and its surface metal element content also increased. The biomass increase rate and content on a ZTP carrier reached 0.431 mg VSS·d−1 and 42.3 ± 3.1 mg VSS, respectively, which were 1.74 and 2.50 times higher, compared with that on a PU carrier. Furthermore, the plug-flow fixed-bed reactor with ZTP carriers (PFBRZTP) was constructed for the mainstream deammonification in 21 d, with a final NRR of 0.18 kg N·(m3·d)−1. The AnAOB abundance (Candidatus Brocadia and Candidatus Kuenenia-dominated) reached an abundance of 9.4 %, and ammonium-oxidizing bacteria (AOB) (Nitrosomonas) reached an abundance of 4.0 %. Overall, the ZTP carriers have great engineering applications and promising perspective for enriching AnAOB and rapid establishing the mainstream deammonification.