Research On Removing Nitrate In A Low C/N Under The Conditions Of Electrode Biofilmof Test

With the change of people’s lifestyles and habits,nitrate has become a hot issue of water treatment.In recent years, the composition of the urban sewage also affected,the low C/N situation has happend in many cities discharge sewage.Biofilm-electrode process is often used for groundwater treatment,but the reports of this method used for the domestic sewage and industrial waste water are rarely.The research in this paper is to use biofilm-electrode process to remove the nitrate nitrogen of the analog low C/N water,and applied this method to domestic sewage and industrial wastewater.This research is divided into three parts.Today, nitrogen removed was been one of hot point of wastewater treatment. Biofilm-electrode process was been focused because of good effect which were no added carbon,no extend treatment, a high denitrification effect, stably running and controlled easily. Biofilm-electrode process is often used for groundwater treatment, while the reports of this method used for the domestic sewage and industrial waste water are rarely. The research in this paper is to use biofilm-electrode process to remove the nitrate nitrogen of the analog low C/N water,and applied this method to domestic sewage and industrial wastewater.By four factors of the C/N, temperature, HRT and current intensity constructed four levels of L16(44) orthogonal experiment.The reactions in high concentrations nitrate load test were effected mostly by HRT, followed by temperature, C/N and current intensity; the order of four factors in low concentrations nitrate load test was current intensity, temperature, C/N and HRT.Thought studying current, temperature, C/N, HRT, pH and ORP impact on the removal of COD, nitrate nitrogen and nitrite nitrogen, the results were as follows:1. It had a best effect under the condition of30℃. The removal of COD and nitrate nitrogen removal in the high concentrations of nitrates simulation were91.3%,76.3%and92.5%,92.9%, respectively.2.C/N had a certain impact on denitrification, when C/N ratio was3:00,it had a best nitrogen removed. Under this condition, The removal of COD and nitrate nitrogen removal in the high concentrations of nitrates simulation were56.9%,95.1%and 3. Current stimulation can increase the removal efficiency of denitrifying bacteria.15mA was a best running condition in tests. The removal of COD and nitrate nitrogen removal in the high concentrations of nitrates simulation were89.64%,83.47%and89%,86%respectively.4. A longer HRT, a higher removal of nitrate, but decreased with time.Though study different water samples,it found that, biofilm-electrode process can be used in sewage,landfill leachate and river to remove COD and nitrate nitrogen with a good effect. The removals of COD and nitrate nitrogen were94%,93.2%,98.1%and95%,95%,98%,respectively, without nitrite nitrogen increasing. But it came to a industrial park,the removals of COD and nitrate nitrogen79%and50%. The total of nitrate nitrogen was increased to53.40mg/L after8h.