高氮垃圾渗滤液SBBR生物脱氮工艺特性研究

STUDY ON THE CHARACTERISTIC OF BIOLOGICAL NITROGEN REMOVAL IN SBBR TREATING LANDFILL LEACHATE WITH HIGH CONCENTRATED NITROGEN

应用序批式生物膜反应器(SBBR)处理实际垃圾渗滤液,在DO质量浓度分别为0.45mg·L-1和1.19mg·L-1的条件下,研究了系统的有机物、氨氮和总氮的去除特性以及游离氨(FA)、DO对系统同步硝化反硝化(SND)类型的影响。经过250d试验研究表明,SBBR系统能够稳定高效地同步去除渗滤液内高浓度有机物和高浓度氨氮。在初始COD为122～2385mg·L-1的情况下,出水COD为23～390mg·L-1,具有平均86.8%的去除率,有机物最大去除速率为20.44kgCOD·m-2载体·d-1。在初始NH4+-N质量浓度为40～396.5mg·L-1的情况下,出水NH4+-N质量浓度为0～41.2mg·L-1,最大硝化速率为2.87kgN·m-2载体·d-1,SBBR系统内发生了明显的SND现象,TN平均去除率分别为73.8%(ρ(DO)=0.45mg·L-1)和30%(ρ(DO)=1.19mg·L-1)左右。当FA质量浓度在1.5～11.6mg·L-1范围内时,系统中共存有硝酸型SND和亚硝酸性SND;当FA从18.6mg·L-1增加到56mg·L-1,系统中形成稳定的亚硝酸SND。FA是影响系统SND类型的主要因素,DO可促进亚硝酸性SND向硝酸型SND的转化。

The COD, NH4^＋-N and TN removal characteristics were investigated at DO was 0.45 mg·L^-1 and 1.19 mg·L^-1, respectively in a sequencing batch biofilm reactor （SBBR） treating landfill leachate; and the effect of free ammonia （FA） and DO on type of simultaneous nitrification and denitrification （SND） was studied. The experimental results clearly showed that the COD and ammonia was removed simultaneously stably and efficiently, and when feed COD was range from 122 mg·L^-1 to 2 385 mg·L^-1, effluent COD concentration was between 23 mg·L^-1 and 390 mg·L^-1, the average removal efficiency was 86.8%, the maximum COD removal rate was 20.44 kgCOD·m^-2 carrier·d^-1 and when the influent ammonia nitrogen （NH4^＋-N） was changed from 40 mg·L^-1 to 396.5 mg·L^-1, the effluent NH4^＋-N was varied from 0 mg·L^-1 to 41.2 mg·L^-1, the maximum NH4^＋-N removal rate was 2.87 kgN-m^-2carrier·d^-1 The obvious simultaneous nitrification and denitrification （SND） was observed in the SBBR, the average removal efficiency of TN was 73.8% at DO=0.45 mg. L-1 and 30% at DO= 1.19 mg. Ll, respectively. When free ammonia was changed from 1.5 to 11.6 mg·L^-1,the SND via nitrate the SND via nitrite were coexisted in the system, and FA increased from 18.6 mg·L^-1 to 56 mg·L^-1, the steady SND via nitrite was achieved, so it was concluded that FA was the main controlling factor which influenced the type of SND, and DO should promoted effect for the conversion of SND via nitrite to SND via nitrate.