Systematic adsorption process of petroleum hydrocarbon by immobilised petroleum-degradation bacteria system in degradation pathways

In order to effectively control petroleum hydrocarbon pollution by immobilisation technology,it is necessary to understanding the degradation pathways of petroleum hydrocarbon in immobilised petroleum-degradation bacteria system.However,the adsorption in degradation process is rarely studied.In this study,adsorption process of petroleum hydrocarbon was synergistically studied by means of the surface properties,adsorption thermodynamics and molecular simulation.The results indicate that the immobilised petroleum-degradation bacteria have many holes for the bacteria to adsorb.The diesel adsorption by immobilised petroleum-degradation bacteria is a spontaneous,entropy-increasing and endothermic process.Diesel is first adsorbed to the surface of immobilised petroleum-degradation bacteria through hydrogen bonding,and then is biodegraded.This study provided substantial knowledge of immobilised technology in controlling petroleum hydrocarbon pollution.

A Study of the Characteristics of Microorganisms for Effective Degradation of Marine Oil Spills

Four microorganism strains were isolated from coastal petroleum-polluted soil and sand samples of Bohai Sea oilfield; they were found to degrade marine oil spills effectively. The experimental results show that the degradation efficiency of crude oil with these four strains （XT-4, SZ-1-25, B-4-9, BS-3-12） is 95.97%, 96.01%, 97.99% and 98.99%, respectively, in their optimum conditions. The characteristics of bacterial biodegradation are investigated. The simulation biotreatment of oil-contaminated beach sand, with an initial oil content of 5,664mg/kg-dry-sand, shows that the residual oil content is 2,700 mg/kg-dry-sand and 2,679 mg/kg-dry-sand after 170 days＇ treatment with two bacteria （B-4-9, BS-3- 12）, respectively.

Plasma remediation for petroleum pollution of the sea

This paper is concerned about the application of glow discharge plasma for the remediation of petroleum pollution of the sea.We used diesel fuel as the processing target and conducted a series of lab-scale studies.Several factors including the discharge voltage,gas flow rate,the concentration of NaCl,initial temperature,and initial concentration of diesel fuel can influence the performance of glow discharge plasma systems on removal efficiency of diesel fuel.To determine the optimal reaction conditions,the diesel degradation rate and energy efficiency were calculated.The experiment result for 2178 mg/L diesel fuel solution treatment was that removal efficiency of 93.3%was achieved after 12 min treatment with the energy yield of 17 g(kWh)^(−1).Higher voltage leads to larger removal efficiency,while the energy yield may be reduced.The removal efficiency of diesel fuel reached the maximum at the gas flow rate factor 700 mL/min,decreased with an increase in gas flow rate,and became a minimum value when the gas flow rate is 1000 mL/min as a result of the unstable discharge.Decreasing the concentration of sodium chloride can cause an increase in the removal efficiency of diesel fuel,because the conductivity tended to significantly increase the degradation efficiency.Moreover,temperature and initial concentration are demonstrated to have little influence on the rate constant,but higher initial concentration favors higher energy efficiency.During the remediation of diesel fuel,pH decreases to 2.76,while the conductivity of the solution and temperature are increased,especially for the temperature,which has an increase from 25℃ to 63℃.