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对南方某地区氨氮含量2.5~3.0 mg/L、浊度5~20 NTU微污染原水,以自制纳米Fe_2O_3改性砂(NMS)为固定填料的筛网,研究NMS筛网的生物预处理及其对混凝+沉淀+过滤的强化处理效果。结果表明:生物-纳米改性砂(BNMS)筛网对氨氮的平均预处理率为42.5%,NMS表面生物量为40 nmo L/g。BNMS预处理对浊度的去除率为30%。预处理出水中,微生物群落总数比进水时的数量增加82%。NMS表面污泥中主要含有以下几种门类微生物:变形菌门,厚壁菌门,拟杆菌门,硝化螺旋菌门等。与未设置BNMS预处理工艺的效果比较,微生物个数浓度增加,混凝、沉淀工艺的氨氮去除率提高了10%,后续NMS滤柱自然生物挂膜时间由12 d缩短到8 d,氨氮去除率由28%上升到35%,水头损失增长速率减缓,过滤周期由48 h提至60 h。BNMS预处理联合混凝+沉淀+过滤处理后的出水中,颗粒粒径由原水时的200 nm降至50 nm,COD_(Mn)总去除率由65%上升至75%,亚硝态氮含量为0,总氨氮去除率由无预处理时的50%上升至92%。
The biological pretreatment of NMS sieve and its pretreatment with nano-Fe 2 O 3 modified sand (NMS) as the fixed filler were studied for the slightly polluted raw water with ammonia nitrogen content of 2.5-3.0 mg / L and turbidity of 5-20 NTU in a southern area of China The effect of coagulation + sedimentation + filtration strengthening treatment. The results showed that the average pretreatment rate of ammonia nitrogen was 42.5% on BNMS sieve and 40 nmo L / g on NMS surface. BNMS pretreatment turbidity removal rate of 30%. In the pretreated effluent, the total number of microbial communities increased by 82% over the influent. NMS surface sludge contains the following types of micro-organisms: Proteus, Firmicutes, Bacteroidetes, Nitrosospirillum and other doors. Compared with the effect of BNMS pretreatment, the concentration of microorganism increased, the removal rate of ammonia nitrogen in coagulation and sedimentation increased by 10%, the duration of natural biological membrane attachment in subsequent NMS was shortened from 12 days to 8 days, and ammonia nitrogen removal The rate of increase of head loss slowed down from 28% to 35%, and the filtration period increased from 48 hours to 60 hours. BNMS pretreatment + coagulation + sedimentation + filtration treatment effluent, the particle size from the original water 200 nm down to 50 nm, COD Mn removal rate increased from 65% to 75%, nitrite nitrogen content Of 0, total ammonia removal rate increased from 50% without pretreatment to 92%.