固定沼泽红假单胞菌构建悬浮式生物反应器对室内甲醛的去除

Performance of suspension bioreactor with fixed Rhodopseudomonas palustris for removal of formaldehyde in indoor

利用海藻酸钠及羧甲基纤维素包埋沼泽红假单胞菌海绵作为吸附剂,对甲醛进行吸收处理,其动力学行为与多孔材料相似。用这种海绵组装悬浮式生物反应器,考察其去除室内甲醛污染的性能,结果表明,海绵体积和进风量是影响反应器甲醛净化效率的关键因素。装入6L海绵和6L水的反应器在进风量最大(7.8m^3·min^(-1))时,对室内空气污染浓度为2.0mg·m^(-3)甲醛的净化效率约为80%。分析水箱水溶液甲醛浓度的变化,结果表明,含有甲醛的空气吹入反应器后溶解于水,然后被包埋的光合菌吸收。反应器在污染甲醛浓度为3.5 mg·m^(-3)的试剂室内运行过程中,其甲醛去除率逐渐上升,室内污染甲醛浓度逐渐降低,运行31d后室内甲醛浓度降为0.04mg·m^(-3)(低于国标值),其净化甲醛污染的CADR(clean air delivery rate)值达到481.4m^3·h^(-1),沼泽红假单胞菌细胞的存活率为98%,说明固定沼泽红假单胞菌具有应用于室内甲醛污染去除的应用潜力。

This study showed that the formaldehyde uptake kinetics of the sponge with embedded Rhodopseudomonas palustris（R. palustris） by alginate and carboxymethylcellulose is similar to that of porous materials. A suspension bioreactor was constructed using this sponge. The performance of this bioreactor for removal of formaldehyde pollution in indoor air was investigated. Results indicate that the sponge volume and the inlet airflow is the key factor affecting the formaldehyde removal efficiency of the reactor. The reactor filled with 6 L sponge and6 L water had a removal efficiency of 80% for 2.0 mg·m^（-3） of formaldehyde in indoor air under conditions with the maximum inlet airflow（7.8 m^3·min^（-1））. The analysis for changes in the formaldehyde concentration in the water of the reactor suggests that formaldehyde was first dissolved in the water and then absorbed and transformed by the embedded R. palustris after the formaldehyde-containing air was blown into the reactor. The reactor was placed in a laboratory reagent room with 3.5 mg·m^（-3） formaldehyde in indoor air. During the operation of this reactor,the formaldehyde concentration in the room decreased gradually, accompanied by an increase in the formaldehyde removal efficiency of the reactor. The formaldehyde concentration in the room decreased up to 0.04 mg·m^（-3）（lower than the national standard） after a 31 d running. The C ADR（clean air delivery rate） value of the reactor for purification of formaldehyde reached 481.4 m^3·h^（-1）. R. palustris cells maintained a survival rate with 98%. The results suggest that the fixed R. palustris has an application potential to the removal of formaldehyde pollution in indoor air.