Study On Purification Efficiency Of Cross-flow Compound Biofilter For High Nitrogen Landscape Water

With the landscape water is increasingly favored by the public life,but China's water resources has been in a state of shortage,especially in the northern cities due to precipitation resources and rivers and lakes less,so the landscape water supply resources have been plagued by the city water.The tailwater of urban sewage plant is one of the important water sources of landscape water,but there is excessive concentration of nitrogen and phosphorus in the tail water of sewage plant,which is easy to cause eutrophication of water body.The turbidity is too large and affect the aesthetic value of landscape water.The presence of pathogenic bacteria and viruses in water,for a certain amount of exposure to the landscape of water,endangering the health of the human body;therefore need to find in line with China's current development and coordination with the landscape environment of the new treatment process,making the sewage tail water to reach the landscape Replenishment requirements.In this study,the cross-flow compound biofilter was used to supplement the wetland park under the high nitrogen tail water in the study area.The removal efficiencies of TN,TP,SS and COD were 33.14%,19.07%,58.58% and 28.82%,respectively.At the same time,the effects of treatment under different temperature and different organic loading conditions were studied.The law of pollutant removal along the route was analyzed.Since the influent water was high nitrogen water,And the effect of C/N ratio on nitrogen removal in the biofilter was studied.The results showed that the water reuse was used to evaluate the effects of water reuse on human health risk,sensory index and eutrophication.?1?Under different temperature conditions,the average removal rates of TN were29.9%,43.3%,20.1% and 9.37% in the whole year,respectively.The average removal rates of NO₃-N were 28.1%,45.1% The average removal rates of SS in the four seasons were 26.5%,33.4%,23.9% and 15.2% respectively.The average removal rates of SS in the four seasons were 54.3%,63.9%,30.9%,26.7%,respectively;indicating that the temperature is an important factor affecting the removal of pollutants.?2?The removal rate of NO₃-N in the two volcanic fillers was 22.95% and22.74%,respectively.The removal rate of NO₃-N was 25.57%,and the removal rate of NO₃-N was 57.80%.The removal rate of COD was 32.12% in the middle of the gravel area of the middle of the filter,and the removal rate of COD in the volcanic fill zone was 16.33%.SS removal of volcanic rocks at both ends of the filter,the removal rate of SS was 41.56% and 24.17% for the volcanic fillers in the front of the filter.?3?When the organic load was increased,the TN removal rate increased first and then decreased,and the organic loading was 27.43kg/d,the removal rate of TN was75.53%,the removal rate of NO₃-N was generally increasing;the organic loading was30.42kg/d,the removal rate of NO₃-N was 97.49%,and COD removal rate decreased from 52.4% to 12%.When the organic load is 33kg/d,the suspended matter content in the effluent increases and the effluent becomes cloudy.?4?The nitrogen removal rate of different forms was 58.33%,the other forms of nitrogen?mainly organic nitrogen?were 30.17% and ammonia nitrogen was 11.51%,respectively.The concentration of nitrogen and nitrogen in the former volcanic fill was the largest And the concentration of ammonia nitrogen was increasing,the concentration of organic nitrogen was high and the high concentration of nitric acid accelerated the denitrification reaction,leading to the relative inhibition of nitrification.During the various stages of the filter,the nitrogen distribution in the water was dominated by nitr The concentration of nitrogen is only a little degraded in the volcanic fill zone before and after the two sections.The nitrite nitrogen concentration is very small and the change is small.When the influent TN is about 15mg/L,the TN removal rate increases with C/N.When the concentration of TN was about 15 mg / L,the removal rate of TN was 74.5% when the C/N ratio was about 5,and the C/N ratio was increased when the influent concentration was about 10 mg / L To about 5.5,TNremoval rate of 72.7% and 65.4%,TN best removal effect occurs in the C/N ratio of 5or so.?5?Biological filter effluent,the annual risk value is less than the acceptable annual risk of 10-4 probability of more than 90%;water color color is 17.7 degrees.The average removal rate of apparent color is 5.81%;the average apparent color of effluent is 29.2 degrees;the average removal rate of apparent color is 47.3%;the turbidity of effluent is stable,the mean is 1.7 NTU;the average removal rate of turbidity is 87.6?6.39 mg/L?,ammonia nitrogen?1.24 mg/L?and total phosphorus?0.81 mg/L?all meet the water quality standard of reclaimed water reuse landscape.During the whole summer monitoring process,The nutrient status of the effluent from the biofilter is in a slightly nutritious state.