生物吸附及微生物降解对4-溴联苯醚污染水体的修复

Bioremediation of 4-bromine biphenyl ether polluted water using biosorption and microbial degradation

多溴联苯醚(PBDEs)作为阻燃剂被广泛使用。因为它对人类的器官、神经系统和免疫系统的危害以及向周边环境的不断迁移,已经逐渐成为人们迫切需要处理的污染物之一。以同系物4-溴联苯醚(BDE-3)作为降解对象,将海藻酸钠和生物碳混合制成微球制剂,对该制剂吸附BDE-3的潜力、机制及添加降解菌Sphingomonas sp.DZ3后微球菌剂的吸附增益效应进行研究。结果表明:2%的海藻酸钠为微球制备的最佳质量浓度,该微球制剂在液相中的吸附过程符合Lagergren准一级动力学方程和Elovich方程,微球的最大吸附量为28.6 mg·g^(-1)。用添加微生物的微球菌剂对BDE-3污染水体进行修复时发现,微球菌剂在溶液中能加速BDE-3的降解,与游离的微生物相比,差异达极显著水平(P<0.01)。利用Monod降解动力学方程对该降解过程进行拟合,得到降解动力学方程为υ=υ_(max)·S/(K_S+S)=14.29·S/(31.71+S)。

Polybrominated diphenyl ethers （PBDEs）, widely used as fire retardants, can migrate to the surrounding environment. To prevent damage to human organs, nervous system, and immune system a method was devised to remove this dangerous pollutant from the environment. In this research, microspheres were success- fully made by mixing different concentrations of sodium alginate and biochar to degrade PBDEs. Then using 4- bromine biphenyl ether （BDE-3） as a homologous compound of PBDEs, the microspheres＇ potential for adsorption of BDE-3 was studied. The degradation effect was also explored with a newly produced microspheremicrobe complex, which was made by adding a degrading strain of Sphiugomouas sp. DZ3. Results showed that 2% sodium alginate was the optimum prepared concentration. The microsphere adsorption process for BDE-3 in liquid was in accord with the Lagergren pseudo-first-order kinetic model and Elovich equation. The maximum biosorption capacity was 28.6 mg· g-1. Also, compared to free microbes, in BDE-3-polluted water the micro- sphere-microbe complex significantly increased the BDE-3 removal rate （P〈0.01 by SPSS analysis）. Degradation data from the microsphere-microbe complex were fitted with the Monod Model yielding the degradation dynamics equation of v = vmax· S/（K, ＋ S） = 14.29＂ S/（31.71 ＋ S）. The results provide a theoretical basis for the actual development and utilization of microsphere agent in treatment of PBDEs-polluted water [ Ch, 5 fig. 4 tab. 20 ref].