Effect of recycling rate and low temperature on remedying northern landscaping water by ecological filter

Natural zeolite and coal cinder were chosen as main compound of the substrate layered ecological bed instead of traditional filling to bio-remedy the static lake water in Northern China, and its running mode was upward combining with downwards flow. Dynamic experiments were carried to study the effect of main factors on contamination removal rate by zeolite ecological filter. It showed that Removal ratios of NH₄⁺-N and TN were promoted with recycling rate increase. The increase of recycling rate made the nitrification more rapidly and completely, and the transition approach of nitrogen was shortened. And the aerobic denitrification was added in the nitrogen removal process. when the temperature declined, the instant removal rate of NH₄⁺-N fell, but the removal rate of remained when it operated for 24 hours and 48 hours respectively. It means that rest time played an important role in NH₄⁺-N removal; removal rates of TP after 24 h and 48 h decreased when temperature declined evidently, and it was from 72% and 77.4% in 15-25°C to 42.4% and 60.2% in 0-5°C respectively. Environment temperature was the important factor for TP removal.