醋酸纤维素包埋非水溶性介体催化强化生物反硝化特性

利用醋酸纤维素包埋法固定非水溶性醌类介体,研究其催化强化Paracoccus versutus菌株GW1的反硝化作用。结果表明,醌浓度在26.7 mmol/L时,固定化蒽醌(AQ)、1-氯蒽醌(1-AQ)、2-氯蒽醌(2-AQ)、1,5-二氯蒽醌(1,5-AQ)、1,8-二氯蒽醌(1,8-AQ)和1,4,5,8-四氯蒽醌(1,4,5,8-AQ)催化反硝化效率依次为:1,5-AQ1,8-AQ1,4,5,8-AQAQ1-AQ空白对照2-AQ。反应10 h时,1,5-AQ可使硝酸盐去除率比空白对照提高1.84倍;硝酸盐氮反硝化动力学拟合为零级反应,其速率常数Kx随1,5-AQ浓度的增加均呈线性增加(Kx=0.1885C1,5-AQ+8.378);水中溶解氧会降低GW1菌反硝化的效果;投加1,5-AQ的反硝化体系中亚硝酸盐积累的最大值比不投加介体的低48.3%;醋酸纤维素介体小球经过4次的重复利用,催化效果始终是空白对照的1.5倍以上。醋酸纤维素固定化非水溶性醌可以有效加速生物反硝化,表明其是一种较优的醌固定化方法,具有良好的应用价值。

Accelerating characteristic of non-dissolved redox mediators immobilized by cellulose acetate(CA) on denitrification

The accelerating effect of non-dissolved redox mediators immobilized by cellulose acetate (CA) on the denitrification with Paracoccus versutus strain GW1 was investigated. The results showed that the accelerating order of immobilized anthraquinone(AQ), 1-chloroanthraquinone(1-AQ), 2-chloroanthraquinone(2-AQ), 1,5-dichloroanthraquinone(1,5-AQ), 1,8-dichloroanthraquinone(1,8-AQ), 1,4,5,8-tetrachloroanthtaquinone(1,4,5,8-AQ) was 1,5-AQ>1,8-AQ>1,4,5,8-AQ>AQ>1-AQ>the control>2-AQ. The nitrate removal rate with 1,5-AQ increased 1.84 times in 10 h. Denitrification kinetic fitted with zero order kinetic, which the denitrification rate constants (K_x) increased linearly with the 1,5-AQ concentration(C_1,5-AQ) (K_x=0.1885C_1,5-AQ+8.378). Dissolved oxygen in water will reduce denitrification rate of strain GW1. The maximum accumulated nitrite concentration with 1,5-AQ was 48.3% lower than the control during the denitrification process. After 4 repeated experiments, the accelerating denitrification rate with the immobilized 1,5-AQ maintained 1.5 times. This indicated that non-dissolved redox mediators immobilized by CA accelerated the denitrification rate, which also avoided secondary pollution and reduced operating cost. The immobilized redox mediator by CA is favorable application for denitrification.