Influence Of C/N Ratio On Nitrogen Removal By UASB Reactor

In recent years, nitrogen pollution had a negative impact on humans and theenvironment, having become an important indicator of the national monitoring of pollutionsources. In this paper, UASB reactor treated the high nitrogen-containing organicwastewater strive to find the best carbon and nitrogen ratio to achieve the highest removalefficiency, with a view to the selection of carbon and nitrogen sources in engineeringapplications and anaerobic reaction in the test the rational design of the device to provide ameaningful exploration.In the intermediate temperature （37±2°C） and pH-neutral conditions, UASB reactortreated nitrate methanol wastewater, nitrite methanol wastewater as well as nitrate, nitriteand methanol mixed wastewater, the main research results were as follows:UASB reactor treated nitrate methanol wastewater: In the phase of startup training,COD influent concentration increased from1190mg/L to5135mg/L, COD removal rateincreased from40.6%to98.7%. In the phase of stable operation and sludge inactivation,fixing COD influent concentration of5135mg/L, when the process of C/NO₃^--N ratiodecreased from70:1to3:1, COD, NO₃^--N and TN removal rates were respectively morethan90%,97%and80%; when C/NO₃^--N ratio dropped to2:1and1:1, NO₃^--N removalefficiency was not affected basicly, but COD and TN removal effect decreased rapidly, theremoval rate reduced to about50%and20%, NO₂^--N was the main composition ofeffluent TN. Learned from the trial, when C/NO₃^--N ratio was3:1, COD, NO₃^--N,TNremoval efficiency and TN removal rates were respectively97.1%,99.8%,84.3%and1443.5mg/L, and the system got the best affection of denitrification and the removal ofcarbon.UASB reactor treated nitrite methanol wastewater: In the phase of startup training,COD influent concentration increased from1190mg/L to5135mg/L, COD removal rateincreased from25.9%to98.3%. In the phase of stable operation and sludge inactivation,fixing COD influent concentration of5135mg/L, when the process of C/NO₂^--N ratiodecreased from70:1to9:1, COD, NO₂^--N and TN removal rates were all over97%; whenC/NO₂^--N ratio dropped to8:1and7:1, COD, NO₂^--N and TN removal rates reduced toabout50%, NO₂^--N was the main composition of effluent TN. Learned from the trial,when C/NO₂^--N ratio was9:1, COD, NO₂^--N, TN removal efficiency and TN removalwere respectively97.2％、99.9％、98.4%�'�561.1mg/L, and the system got the best affection of denitrification and the removal of carbon.UASB reactor treated nitrate, nitrite and methanol mixed wastewater, and fixed CODinfluent concentration of5135mg/L. When C/N ratio was10:1, NO₃^--N with NO₂^--Nmixed ratio of the change had no effect on removal affection of nitrogen and carbon; WhenC/N ratio was5:1, NO₃^--N/NO₂^--N ratio was0.2, the activity of denitrifying bacteriadeclined significantly, the less removal of nitrogen and carbon to the system, most of thecarbon source was removed through the production of methanation role.