鼠李糖脂对生物滴滤塔净化CH_(4)和NH_(3)废气的影响

Effect of Applying Rhamnolipid on Purification Efficiency of CH_(4)and NH_(3)Mixed Gases in a Bio-trickling Filter

生物表面活性剂鼠李糖脂被广泛应用于强化生物法净化疏水性物质的气液传质,但其对生物净化含疏水性甲烷(CH_(4))与亲水性氨(NH_(3))混合废气的影响尚不清楚。该研究通过开展生物滴滤塔模拟试验,解析了鼠李糖脂添加对生物滴滤塔净化粪尿存储产生的CH_(4)和NH_(3)混合废气性能的影响。结果表明,与对照生物滴滤塔A相比,添加2 cmc(临界胶束浓度)鼠李糖脂的生物滴滤塔B的挂膜启动快,CH_(4)去除效率高,当停留时间(EBRT)为65 min时,其挂膜启动期的CH_(4)去除效率可达到85%以上。而且,鼠李糖脂添加能够缩短生物滴滤塔的停留时间,当EBRT缩短至13 min时,生物滴滤塔B的CH_(4)去除效率为77%,而生物滴滤塔A只有42%。NH_(3)去除方面,鼠李糖脂添加对生物滴滤塔除NH_(3)效率无显著影响,2个生物滴滤塔的除NH_(3)效率均可达99%。而且,生物滴滤塔B营养液的NH_(4)+-N、NO_(3)^(-)-N和NO_(2)^(-)-N浓度均低于生物滴滤塔A,表明鼠李糖脂添加能够促进生物滴滤塔的氮转化。研究结果可为生物表面活性剂鼠李糖脂应用于生物法净化畜禽养殖场混合废气提供技术支持。

Rhamnolipid has been widely used to enhance gas-liquid mass transfer in the biodegradation of hydrophobic pollutants,but its effects on bio-purification efficiency of hydrophobic methane(CHa)and hydrophilic ammonia(NHs)mixed gases is unclear.This paper described a simulation experiment using a bio-trickling filter for treating CH_(4)and NHs mixed gases generated from feces and urine storage investigating the effect of addition of rhamnolipid to the bio-trickling filter on its performance.Results of the experiment showed that compared with bio-trickling filter A(control unit),the bio-trickling filter B,into which 2 cmc(critical mecille concentration)of rhamnolipid was added,had a shorter bio-film culturing time during start-up period and higher CH_(4)removal efficiency,besides CH_(4)removal efficiency could reach up to 85%when the empty bed retention time(EBRT)was 65 min.Moreover,addition of rhamnolipid could make it possible to curtail EBRT,CH4 removal efficiency of bio-trickling filter B was 77%with EBRT of 13 min,while that of bio-trickling filter A was only 42%;as to NH_(3)removal,however,no significant impact was noted after rhamnolipid was acded,and NHs removal efficiency of both the biotrickling filters(A,B)could be up to 99%.In addition,concentrations of NH_(3)-N,N、NO_(3)^(-)-N and NO,-N in nutrient solutions of bio-trickling filter B were lower than those of bio-trickling filter A,which indicated that addition of rhamnolipid could promote nitrogen conversion process.It is expected that the results can provide technical assistance to applying bio-surfactants in the bio-purification of waste gases emitted from livestock and poultry farms.