| Ammonia(NH3)and hydrogen sulfide(H2S)are two of the eight malodorous pollutants regulated by the Ministry of Environmental Protection.They are the two typical odor gases,which have serious harm to human health and ecological environment.Biological deodorization technology has many advantages,such as high efficiency,no secondary pollution and so on,which shows a wide range of application prospects.Most of the Biofilter operates under the condition of high humidity,which has some defects,such as easy corrosion of filler,low treatment efficiency,high cost of filler replacement and so on,restrict its development.In order to remove NH3 and H2S effectively under low humidity conditions,inoculated BFEM-2 which is a compound microbial agent suitable for low humidity developed by laboratory into a Biofilter reactor.The start-up characteristics,high efficiency and stable operation conditions of the reactor and the removal effect of NH3 and H2S mixed gases were studied.The experimental results showed that:1.Start the Biofilter for the first time.The results showed that under the condition of the temperature was 25? and the filler humidity was 51%,the NH3 removal rate of 50mg/m3,the volumetric load was 0.09 kg/(m3·d)can reach 100%and remained stable on the 8th day.Rapid start-up of Biofilter had achieved.2.Restarted the Biofilter directly after one month of unused under the conditions of the intake was 50 mg/m3 and the volumetric load was 0.69 kg/(m3·d)of NH3.The results showed that the removal rate of NH3 could reach 100%and remained stable after 10 hours.The Biofilter restarted quickly and had strong shock resistance.In addition,the humidity of filler decreased by only 9.3%during one month unused,and the moisture retention of filler was strong.3.The dynamic change of filler humidity in biofilter and the effect of humidity on NH3 removal were studied.The results showed that the filler had a good moisture retention property in the Biofilter.The humidity had been reduced from 51.2%to 25.6%after 17 days.the removal rate of NH3 with intake of 50 mg/n3 and volume load of 0.09 kg/(m3·d)had remained 100%.When the humidity decreased to 24%,the removal rate was still above 99%.The reactor could still operate normally at low humidity(25%?30%).4.Under the condition of low humidity(25%?30%),studied the effects of various process conditions on the removal efficency of NH3.The results showed that:a)The Biofilter had the ability to remove NH3 efficiently and stably.When the shortest empty bed residence time was 12.6s,the removal rate of NH3 below 96.2 mg/m3 could be kept above 99.4%;b)The reactor had a high processing capacity and could remove 100%with a load of 1.2 kg/(m3 d)of NH3;c)The optimum tenperature of the reactor was 11?33?.when the load was 0.69kg/(m3·d),the removal rate of NH3 was 100%.The removal rate was stable about 92%at 5?10?.The removal effect decreased rapidly below 5?.5.Under the condition of low humidity(25%?30%),studied the removal efficiency of H2S and the mixture of NH3 and H2S.The results showed that:a)The reactor had a good effect on the treatment of low concentration H2S gas.The removal rate was 98.1%with 15.7 mg/m3 and 0.11 kg/(m3·d)of H2S;b)The removal rate of NH3 at 100 mg/m3 was above 99.9%,and that of H2S at 50 mg/m3 was above 75%;c)When the intake of NH3 was stable(100 mg/m3),the removal rate of NH3 becomes unstable when the H2S in the mixed intake was more than 55 mg/m3.While the concentration of H2S is stable,the increase of NH3 concentration was beneficial to the removal of H2S.In conclusion,BFEM-2 microbial agent could start Deodorizing Biofilter quickly,and the Biofilter reactor could remove NH3 and H2S efficiently and steadily at low humidity,which has good application value. |
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