Study On Bioremediation Technology Of Petroleum Contaminated Soil By Immobilized Microbial Agent

Petroleum pollution is becoming increasingly serious with the sharp increase in petroleum consumption.It's harmful to the human and the environment.At present,bioremediation technology has made great progress both at home and abroad.However,because the large number and complexity of petroleum components and long period of bioremediation technology,the screening and utilization of high efficient degradation bacteria have been paid much attention.In this paper,long-term oil-contaminated soils in oil-producing areas are studied.To isolate and filter the efficient oil degradation bacteria and to use the embedding method and adsorption method made solid bacteria that can be used for repairing the soil.The degradation properties of two solid bacteria were studied by simulation experiments.The main conclusions are as follows:1.By streak plate method,we got four bacteria which degradation rate had more than60% in petroleum contaminated water.Through the identification of 16 SrDNA ?physiological and biochemical of each bacteria,four degradation bacteria are Advenella kashmirensis?Brevundimonas diminuta?Pseudomonas geniculata and Bacillus thuringiensis.2.Using four bacteria,six combination bacteria were constructed.The degradation rate of the combined bacteria Z2 and Z6 were 78.92% and 74.01% one week in petroleum I pollution water,which were higher than single bacteria.The results showed these kinds of degradation bacteria were synergistic.3.Using sodium alginates as an embedding agent,six groups of solid bacteria were obtained by embedding.The degradation rate of solid bacteria Z1(Advenella kashmirensis?Brevundimonas diminuta and Bacillus thuringiensis)? Z4(Advenella kashmirensis and Bacillus thuringiensis)?TX1(Advenella kashmirensis)and TX2(Brevundimonas diminuta)were separately improved 3.65%? 4.86%? 6.30%?9.72% than the corresponding liquid bacteria.4.Using biomass charcoal as a carrier,six groups of solid bacteria were founded by adsorption.The degradation rate of solid bacteria Z1?Z4?TX1 and TX2 were separatelyimproved 6.90%?3.63%?6.54%?4.80% than the corresponding liquid bacteria.5.Under the condition of the shaking bed culture,the degradation rate of adsorption solid bacteria was higher than embedding solid bacteria.The degradation rate of adsorption solid bacteria Z2?TX1 were separately improved 11.07%?9.86% than the embedding solid bacteria.6.Under solid culture conditions,the petroleum II pollution soil concentration was1%(w/w).Water content of soil was 12% ~ 15%.Embedding and adsorption method immobilized bacteria Z2 could reach respectively 34.86% and 30.18% 21 d.7.Under solid culture conditions,the mixed immobilized bacteria Z2 has a first-order kinetics of degrading petroleum contaminants.8.The analysis of GC-MS shows that immobilized bacteria Z2 has good ability of degradation to n-alkenes,isoparaffins and naphthenes,and it has good selectivity to the linear alkanes C14.