Nitrogen Removal In An Anaerobic Sequencing Batch Reactor With Hydrogen Producing

In recent years, our country paying close attention to control the water pollution bynitrogen compounds.the key is technology research of efficient biological denitrification,and anammox has been one of hot spot of attention.Generally,anammox need the environmental conditions of pH greater than7, lowconcentration of organic matter or inorganic.Hardly a report on whether anammoxcould happen in high concentrations of organic matter and meta-acid condition.Thestudy discovered and identified that anammox could happen under high concentrationsof organic matter and meta-acid condition,using an anaerobic sequencing batchreactor(ASBR) with hydrogen producing fed with synthetic wastewater. The keyinfluence factors such as organic load, pH value, concentration of ammonium nitrogenand sulfate sulfur have been discussed in the system. Providing the technical foundationfor removing ammonia nitrogen and resource utilization of high organic wastewater.The results show that:1. Using synthetic wastewater with glucose as carbon source, keeoing CODconcentration of1800mg/L (glucose concentration is2g/L) and ammonia nitrogenconcentration of15.7mg/L in the synthetic wastewater, start the ASBR system withhydrogen producing in the condition that pH value of4.0~4.5, temperature of35±1℃,Oxidation-Reduction Potential (ORP) below-100mv, hydraulic retention time (HRT)of8h. The average gas production rate is6.0L/d, and hydrogen percentage is43%~55%, the fermentation type is ethanol type fermentation. The sludge appearyellowish-brown clour and exist in flocculation without filamentous fungus in thesystem, sedimentation performance is good. 2. When pH value between4.0~4.5stably, the hydrogen producing bacteria hasthe highest activity, The acidiced microbes can restore its production activity within acertain range (pH value is not less than3.6), but the changing of pH value is bad fordenitrifica tion;3. Along with the system running, the ammonia nitrogen lost in the reactor,considered as a denitrification result: the microbes use a small amount of sulfate in thewater to happen sulfate-typed anammox, generating nitrogen gas, sulfide or sulphur, themaximum denitrification efficiency is about64%. The mass ratio of nitrogen convertedinto nitrogen gas and sulfur converted to sulphur is1:(0.66~1.25) in the system;4. anammox microorganisms increased, the color of sludge gradually changedfrom yellowish-brown to pink. The sludge microbial mainly exist in flocculent structure,and the dominant microbe is bacillus, the size is2~3μm;5. Keeping the meta-acid condition, the high organic matter volume load and pHvalue effect hydrogen production and denitrification by influencing the microbialactivity. When the inflow concentration of NH4+-N is15.7mg/L, and directly affect thenitrogen removal efficiency; gradually increase the inflow concentration of SO42--S by9mg/L to50mg/L, the denitrification efficiency of the hydrogen production systemgradually improve, the maximum denitrification efficiency is about64%.The efficiencyof hydrogen production and the nitrogen removal rate appear negative correlation.