芦苇生物炭复合载体固定化微生物去除水中氨氮

为了去除水体中的氮素并实现水生植物的有效利用，以芦苇生物炭为无机载体，结合海藻酸钠(SA)、聚乙烯醇(PVA)作为复合载体，固定驯化后的硝化污泥制成固定化颗粒，去除水中氨氮。通过考察固定化颗粒机械强度、酸碱稳定性及传质性能，探究了生物炭添加量及生物炭粒径对固定化颗粒降解氨氮性能的影响。结果表明，芦苇生物炭有丰富的孔结构，表面含有较多的含氧官能团和胺基、磺酸基、羧基和酰胺基等基团，从而具有良好的吸附性能以及较强的酸碱缓冲能力，有利于微生物的黏附和增殖。以添加芦苇生物炭作为复合载体，固定化颗粒的破损率降低了2.4%，酸碱稳定性和传质性分别提升12.5%和55.8%；在72 h内，可以使氨氮降解率达到96.3%。此外，不同粒径生物炭的固定化颗粒对氨氮的吸附量有显著影响，随着生物炭粒径从0.60 mm减小至0.15 mm，氨氮的最大吸附量可以从0.30 mg·g-1增加到0.46 mg·g-1。因此，在固定化微生物的载体中添加生物炭，可以提升固定化颗粒性能，打通微孔孔道从而有利于基质的运输和扩散；同时减小生物炭粒径，为微生物提供更多的吸附位点，从而显著提高固定化微生物对氨氮的降解能力。

Removing ammonia nitrogen from wastewater by immobilized microorganism with reed biochar composite carrier

In order to remove nitrogen from wastewater and realize the resource utilization of aquatic plants, the reed biochar, being taken as an inorganic carrier, combined sodium alginate (SA) and polyvinyl alcohol (PVA) to form a composite carrier. The acclimation nitrifying sludge was fixed on these composite carriers, and composite sludge pellets were produced to remove the ammonia nitrogen from wastewater. Through investigating the mechanical strength, acid-base stability and mass transfer performance of these pellets, the effects of biochar addition and particle size on the ammonia degradation ability of immobilized pellets were studied. The results showed that the reed biochar has an abundant pore structure, and lots of oxygen-containing functional groups, as well as amino, sulfonic, carboxyl and amide ones. This led to its good adsorption ability and strong acid-base buffer capacity, which was conducive to the adhesion and proliferation of microorganisms. Due to the reed biochar addition, the breakage rate of immobilized pellets was reduced by 2.4%. Acid-base stability and mass transfer increased by 12.5% and 55.8%, respectively. The degradation rate of ammonia nitrogen reached 96.3% after 72 h. Besides, the size of reed biochar has a significant effect on the adsorption capacity of ammonia nitrogen. When the diameter of biochar decreased from 0.60 mm to 0.15 mm，the maximum adsorption amount of ammonia nitrogen increased from 0.30 mg·g-1 to 0.4 mg·g-1. Therefore, biochar addition could improve the performance of immobilized pellets, open microporous channels for transport and diffusion of matrix. At the same time, the reduction of biochar size could provide more adsorption sites for microorganisms, thus significantly improve the degradation ability for ammonia nitrogen.