微生物对水-沉积物中苯并[a]芘-镉复合污染修复的研究

从广东汕头贵屿镇的沉积物中分离得到1株对PAHs有较好降解能力且有较强重金属耐受性的菌株（简称B4）,菌种鉴定表明该菌为氧化节杆菌属。以土著微生物、处理方式、沉积物、修复时间等为不同的影响因子对该菌修复水体/沉积物中苯并a]芘（BaP）-镉（Cd）复合污染进行了初步研究。结果表明：该菌同时具有降解BaP和吸附Cd的性能;土著微生物对BaP有一定的降解能力,并能显著促进B4降解BaP,当体系中BaP质量浓度为1.00 mg.L-1时,降解率达到了68.3%;Cd的吸附却因土著微生物的存在发生一定程度的解吸。振荡培养对BaP的降解效果略优于静止培养修复,而静止修复却更有利于Cd的去除。沉积物促进体系Cd的吸附,却减弱了菌种对BaP的降解。在静止培养修复中,BaP的降解主要发生在7 d以前,降解率保持在35%左右,此时Cd的去除效果亦较好。

Remediation of benzo[a]pyrene-cadmium combined pollution in water and sediment by microorganism

A strain assigned the code name B4 was isolated from the sediment of Guiyu in Guangdong Province,and was identified as Arthrobacter oxydans by 16S rDNA analysis,and showed the ability to effectively degrade PAHs and tolerate heavy metal.The research on the remediation of benzoa]pyrene（BaP）-cadmium（Cd） combined pollution in water and sediment using B4 was investigated.The results showed that B4 possessed excellent ability both to degrade BaP and bio-adsorb Cd.The removal of BaP and Cd in water-sediment system was significantly affected by such factors as indigenous microorganisms,treatment approach,sediment,as well as remediation time.The biodegradation of BaP was accelerated in the coexistence of indigenous microflora and B4 because of the mutualism relationship between them.The degradation rate was 68.3% in the nonsterilized system containing 1 mg·L-1 BaP.However,part of desorption for Cd was observed when the indigenous microorganisms existed.The degradation of BaP under shaking cultivation was slighly better than that in static remediation,but the static remediation was preferred to the removel of Cd.The presence of sediment was more beneficial for B4 to adsorb Cd than to degrade BaP.Under the static remediation,the degradation of BaP with the best removal of about 35% mainly occurred after degradation for 7 days,and most of the Cd was also removed during this period.