好氧生物反应器填埋场的渗滤液回灌量研究

Study on Leachate Recirculation Volume of Aerobic Bioreactor Landfills

为了研究渗滤液回灌量对好氧填埋场稳定化进程的影响,通过模拟实验,探讨了不同回灌量时,好氧填埋场固相垃圾与渗滤液特性的变化趋势,填埋周期为122 d.结果表明,不同的渗滤液回灌下各反应器中填埋垃圾的含水率始终保持在70%左右;填埋过程中,回灌量为20%的反应器填埋垃圾中总有机质含量、(半纤维素+纤维素)/木质素比(Q)值与沉降量变化速度最快,至填埋结束时,总有机质含量与Q值较其他反应器低8.9%～14.6%和9.9%～16.9%,沉降量较其他反应器提高了6.6%～13.3%;在20%回灌量下,整个填埋周期填埋场所产渗滤液中的还原性有机物的量较10%、15%、30%和全回灌分别低9.8%、12.5%、17.8%和14.9%,氨氮在52 d,即降至25 mg/L,达到GB 16889—2008所规定的垃圾填埋场渗滤液氨氮排放浓度值,较其他反应器提前7～21 d.

To study the influence of leachate recirculation on the stabilization process of aerobic landfills, an experiment was conducted to assess the variation trend of solid waste and leachate characteristics in an aerobic landfill with different recirculation rates. The landfill period was 122 days. Results showed that the water content of landfill refuse in each reactor remained at about 70% under different leachate recirculation rates. The total organic carbon content,(hemicellulose + cellulose)/lignin ratio(Q),and sedimentation of landfill refuse with 20% recirculation changed fastest in the landfill process. At the end of the landfill period,the mass content and Q of landfill leachate were 8.9%–14.6% and 9.9%–16.9% lower,respectively,than that of other reactors,and the sedimentation was 6.6%–13.3% higher than that of other reactors. The amount of reductive organic matter in the leachate during the whole process with the recirculation volume as 20% was 9.8%, 12.5%, 17.8%, and 14.9% lower than that of 10%,15%,30%, and full recirculation,respectively,and the ammonia nitrogen was reduced to 25 mg/L,which met the concentration of ammonia nitrogen discharge in landfill leachate of GB 16889-2008,in 52 d,which was 7–21 d earlier than the other reactors.