粗砂-砾石海滩溢油污染的现场生物修复

在天津港六号码头的粗砂-砾石海滩进行了人工模拟溢油条件下的生物修复现场实验,考察了添加水溶性肥料、添加缓释肥料以及同时添加缓释肥料和石油烃降解菌等修复措施的有效性.结果表明,在120,d的修复时间内,同时添加缓释肥料和石油烃降解菌的体系石油烃生物降解常数（ks）最高,达0.007,2,d-1,为对照体系的2.4倍,该体系中氮、磷浓度和石油烃降解菌数量在较长时间内都维持较高水平,表明接种的石油烃降解菌能够直接利用缓释肥料所释放出来的营养元素而快速生长繁殖;添加水溶性肥料的体系短期内氮、磷含量显著提高,石油烃降解菌密度明显增大,石油烃降解速率加快,ks为对照试验池的1.8倍;而添加缓释肥料的体系氮、磷含量尽管明显高于对照体系,ks却略低于对照体系,这可能是由于土著微生物无法直接利用缓释肥料所释放的营养元素,甚至其释放的尿素在局部形成高氨氮环境而抑制微生物的生长.

Field-Scale Bioremediation of Coarse Sand-Gravel Beach Contaminated by Oil Spill

A series of field bioremediation experiments were undertaken on the coarse sand-gravel beach in Tianjin Port NO.6 jetty,in which crude oil had been intentionally added into plots to simulate oil spill.The objectives were to evaluate the effectiveness of various bioremediation strategies,including addition of slow-release fertilize（SRF）,addition of water-soluble fertilizer（WSF）and addition of SRF supplemented with oil-degrading bacteria（ODB）.The results showed that the plots treated with addition of SRF and ODB had the highest biodegradation rate constant（ks） of hydrocarbons,which was as high as 0.007,2,d-1 and was 2.4 times that of the control plot,and accordingly the contents of dissolved nitrogen and phosphorus,as well as the density of ODB could keep a high level in a longer pe-riod of time.This indicated that ODB could directly utilize the nutrients realsed from SRF to multiply rapidly.The contents of nitrogen and phosphorus in the plot treated with addition of WSF rose obviously in a short period of time.Meanwhile,the ODB cell densities increased,and the biodegradation constant of hydrocarbons was 1.8 times that of the control plot.However,the oil-degrading rate in the plot treated with addition of SRF were slower than that in the control plot,in spite of the fact that the contents of nitrogen and phosphorus were higher.This may be because that the indigenous bacteria growth was not supported by the urea released from SRF,but inhibited by the high local con-centrations of ammonium.