不同原油浓度对两种农作物的生长特性影响评价

通过测定农作物的生长状况及产品品质,研究了不同原油含量对农作物生长状况的影响.试验结果表明,随着土壤中原油含量的增加,玉米、大豆中总烃、芳烃、总酚含量也相应增多,呈明显的正相关性.当加入0.5 g/kg的石油时,玉米果实中的总烃、芳烃、总酚含量分别为37.25 m g/kg、9.80 m g/kg、1.394 m g/kg,大豆中分别为52.14 m g/kg、12.77 m g/kg、1.693 m g/kg.当石油含量为0.5～1.0 g/kg时,对农作物的生长发育有促进作用,同时促进淀粉、蛋白质的合成,增加果实质量;当含量为3.0 g/kg时,促进效果下降.

不同石油浓度对两种作物生理生化的影响

初步探索小麦和玉米对石油污染土壤的耐受性,同时摸索这两种农作物在石油污染的胁迫下对石油污染土壤的潜在修复效果,以期为现场进行相关的植物修复提供理论依据。实验设置了0%、0.5%、1.5%、3%四组石油污染土壤处理,对小麦和玉米两种供试植物进行了温室盆栽观测试验。结果表明,受试植物的发芽率在石油的胁迫下均呈下降的趋势,并且当浓度达到3%时影响显著;石油对小麦和玉米的生长表现出抑制作用,其株高、叶片数、干物质量与对照相比有较明显的降低;小麦和玉米的叶绿素含量随着石油浓度的升高而降低;小麦叶片中丙二醛(MDA)含量及可溶性蛋白含量随着石油浓度的升高呈先增加后下降的趋势,而玉米种的MDA含量则是随着石油浓度的升高而升高,可溶性蛋白含量则是随着石油浓度的升高呈下降趋势。

Batch washing of saturated hydrocarbons and polycyclic aromatic hydrocarbons from crude oil contaminated soils using bio-surfactant

Desorption of total saturated fractions(i.e. SAT, defined for this study as the summation of the concentrations of the saturated hydrocarbon from n-C10 to n-C26) and polycyclic aromatic fractions(i.e. PAH, defined as the summation of the concentrations of all polycyclic aromatic fractions including the 16 EPA priority PAH) in two types of soils subjected to the changes of p H and salinity and different bio-surfactant concentrations were investigated. In general, compared with the experiments without bio-surfactant addition, adding rhamnolipid to crude oil-water systems at concentrations above its critical micelle concentration(CMC) values benefits SAT and PAH desorption. The results indicate that the change of p H could have distinct effects on rhamnolipid performance concerning its own micelle structure and soil properties. For loam soil, the adsorption of non-aqueous phase liquid(NAPL) and rhamnolipid would be the principle limiting factors during the NAPL removal procedure. For sand soil, less amount of rhamnolipid is adsorbed onto soil. Thus, with the increase of salinity, the solubilization and desorption of rhamnolipid solution are more significant. In summary, the p H and salt sensitivity of the bio-surfactant will vary according to the specific structure of the surfactant characteristics and soil properties.

Spatial Distribution Patterns and Potential Sources of Heavy Metals in Soils of a Crude Oil-Polluted Region in China

Twenty-two soil samples were collected at the subregional scale （50 km2） around Gudao Town, a typical oil-producing region of the Shengli Oilfield in the Yellow River Delta, China to determine the spatial distribution patterns and potential sources of heavy metals in soils of crude oil-polluted regions. The concentrations of total petroleum hydrocaxbons （TPHs） and heavy metals as well as other soil properties were determined and the enrichment factor values were calculated for the heavy metals measured. Principal component analysis （PCA） and cluster analysis （CA） were used to estimate potential sources contributing to the concentrations of heavy metals in the soils. The results revealed that the soils were slightly alkaline （pH = 7.33-8.05） and high in salinity （1.43-41.30 g kg-1）, TPHs （0.51 28.40 g kg-1） and organic matter （1.74-31.50 g kg-1）. The mean concentrations of the measured heavy metals Cu, Zn, Pb, Cd, Cr, Ni and V were 18.4, 78.2, 20.8, 0.19, 56.6, 26.3 and 62.1 mg kg-1, respectively. Although the concentrations of all the metals measured in this study were not high enough to exceed the national control standards, there was a significant enrichment of Cd in the study area and Zn and Ni were in the category of deficiency to minimal enrichment. The spatial distribution patterns of Cu, Cr, Ni and V were similar and partially affected by oil exploitation and petroleum hydrocarbon spills. Potential sources of Cr, Ni, V and Cu in the soils were both natural sources and petroleum hydrocarbon spills, while Zn, Pb and Cd were probably from anthropogenic sources such as farming activities and traffic.