添加不同营养助剂对石油污染土壤生物修复的影响

BIOREMEDIATION OF PETROLEUM CONTAMINATED SOIL BY VARIOUS NUTRIENT AMENDMENTS

实验室条件下研究NPK复合肥、诺沃肥和腐殖酸三种物质不同配比添加对石油污染土壤的生物修复效果.在60d的修复实验中,定期取样测定土壤含油量、总异养菌数、石油烃降解菌数和脱氢酶活性,并采用PCR-DGGE技术研究修复过程中微生物多样性变化.结果表明,NPK肥的添加和NPK肥-诺沃肥-腐殖酸复合添加能够提高土壤中微生物的数量、微生物多样性和脱氢酶活性.在含油量为84600mg.kg-1的土壤中,添加营养助剂的处理60d后石油烃降解率为31.3%—39.5%,不添加营养助剂的石油烃降解率仅为3.5%.NPK肥-诺沃肥-腐殖酸复合添加对石油烃的降解率要高于NPK肥的单独添加(高8%),其原因可能是诺沃肥-腐殖酸能够有效提高土著微生物的活性,增加微生物的多样性,增强石油烃的降解.

Under laboratory conditions,NPK fertilizer,NovoGro and humic acid were added to petroleum contaminated soil in different proportions and their effects on bioremediation were evaluated.During the 60-day experiments,soil samples were collected and analyzed periodically to determine the oil content,heterotrophic bacteria number,hydrocarbon degrader number and dehydrogenase activity.In addition,PCR-DGGE was utilized to analyze the change of biodiversity during bioremediation.The results show that microorganism population,dehydrogenase activity and bacterial biodiversity were significantly enhanced in the treatments with NPK fertilizer alone and the combined amendments （including NPK fertilizer,NovoGro and humic acid）.After 60 days,the initial oil content （84600 mg·kg^-1） was reduced by 31.3%—39.5% in nutrients amended soils,whereas it was only reduced by 3.5% in nonamended soil.Soil with combined amendment showed more efficient degradation than soil with NPK fertilizer alone （about 8% higher）.The degradation may be the results of the significantly enhanced microbial activity and biodiversity which were stimulated by NovoGro and humic acid addition.