【摘要】 本研究将固定化微生物与氮源缓释相结合，以提高一般固定化微生物在氮源缺乏环境中的生物降解效率。利用尿素作为缓释氮源，通过将聚乙烯醇-海藻酸钠混合凝胶（包含尿素）在3%CaCl₂饱和硼酸溶液中一次交联，在0.5 mol·L^-1硫酸钠溶液中二次交联，最终制得的缓释尿素固定化微生物颗粒包封率高达98%以上，溶胀率在15%～25%，同时有较高的机械强度。在无氮条件下，颗粒可在4、8、12 h内分别完成对100 mg·L^-1苯酚、吡啶或喹啉的降解；在高碳氮比的模拟焦化废水环境下，可在6 h内完成对100 mg·L^-1苯酚、10 mg·L^-1吡啶及10 mg·L^-1喹啉混合底物的降解。另外，固定化微生物颗粒所包含的尿素提供的氮源能满足固定化微生物每天降解100 mg·L^-1苯酚并持续20 d。以上研究结果表明所制备的缓释尿素固定化微生物颗粒可应用于氮源匮乏的污水治理中并有较好的应用效果。更多还原

【Abstract】 In this study, the immobilized microorganisms coupling with controlled release of nitrogen source was used to improve the biodegradation efficiency of common immobilized microorganisms in nitrogen source deficient environment. Urea was used as the controlled release of nitrogen source. The mixed gel（containing urea） of polyvinyl alcohol and sodium alginate was first crosslinked in 3% CaCl₂ saturated boric acid solution and then crosslinked in 0.5 mol·L^-1 sodium sulfate solution. The prepared immobilized microbial particles with controlled release of urea had an encapsulation efficiency of higher than 98%, swelling rate of 15%～25% and high mechanical strength. In nitrogen free environments, 100 mg·L^-1 phenol, pyridine or quinoline could be biodegraded by these particles within 4, 8 and 12 hours, respectively. In the simulated coking wastewater with high C/N ratio, the mixture of 100 mg·L^-1 phenol, 10 mg·L^-1 pyridine and 10 mg·L^-1 quinoline could be degraded within 6 hours. Meanwhile, the nitrogen source provided by the urea in the immobilized microbial particles could meet the needs of the immobilized microorganisms to degrade 100 mg·L^-1 phenol every day for20 days. The above results show that the prepared immobilized microbial particles with controlled release of urea can be used to treat wastewater lack of nitrogen source and have a good application effect.更多还原