含油泥砂生物法处理室内研究

A Laboratory Study on Biological Treatment of Oily Sandy Sludge

从孤东油田被原油污染的土壤中分离、驯化、培养出3株烃氧化菌,代号为GD-1、GD-2和GD-3,在20℃下测定的BOD5值分别为165、145和175(对照样为100),在油泥砂培养基中于35℃培养48 h后,发酵液变褐色,含菌>6.0×107个/mL,发酵液滤液的表面张力比对照样(65.0 mN/m)分别降低47.2%,45.4%,51.1%。GD-1和GD-2产出的表面活性剂经鉴定属于脂肽类,GD-3产出的属于脂多糖类。3种菌混合液与油泥砂按5∶1混合,按85mg/L和15 mg/L加入氮源和磷源,在35℃通气培养过程中,油泥砂含油量(12.3%)下降,10天后下降趋缓,30天后降至2.9%;菌数迅速上升,4天达最高,10天后趋于下降,显示氮源和磷源不足;加入0.01%某表面活性剂后,在相同条件下菌数达最高的时间缩短为3天,其余变化相同。讨论了该降解烃、产表面活性剂混合菌的除油机理及菌产和外加表面活性剂在除油中的增效作用。该混合菌可用于油田含油污泥砂的除油处理。图2表1参6。

Three bacterial strains, namely GD-1, GD-2, and GD-3, are separated from the crude oil polluted soil in Gudong, Shengli, habituated, cultivated and identified as hydrocarbon degrading bacteria. Their BOD5 value delermined at 20℃ is of 165, 145, and 175, respectively, in comparison with 100 for the control. The bacterial population of the broth cultivated in a sludge nutrient medium at 35℃ in 48 hrs is of 〉 6.0 × 10^7 cell/mL and the broth becomes brown colored. The surface tension of the broth filtrate is decreased by 47.2%, 45.4%, and 51.1%, being of 65.0 mN/m for the control. The biosurfactants produced by GD-1 and GD-2 are identified as lipopeptides and that by GD-3-as lipolypolysaccharides. The mixed broth of the three bacteria and an oily sandy sewage sludge are mixed at ratio 5：1 and aerated and cultivated at 35℃ with N（85 mg/L） and P （15 mg/L） sources introduced and in the course of cultivation the oil content （OC） in the sludge decreases rapidly at the first stage and slower after 10 days; the bacterial population （BP） increases very fast at the beginning, reaches a maximum in 4 days and decreases somewhat in 10 days; when 0.01 % chemical surfactant introduced additionally, similar changes in OC and BP are observed besides that the BP reaches its maximum in 3 days. The deoiling mechanisms and the synergistic functions of the biosurfactants and the chemical surfactant added are discussed for the biotreatment. These mixed hydrocarbon degrading and sufactant producing bacteria can be used for deoiling of the sandy sewage sludge created in oil fields.