石油烃污染底泥的理化性质及酶活性研究

Study on Physicochemical Properties and Enzyme Activity of Petroleum Hydrocarbon Contaminated Sediment

石油烃是环境中典型的持久性有机污染物,为研究石化废水中石油烃对底泥理化性质及酶活性的影响,以及选择典型监测参数。以黄河三角洲地区石化厂区为典型研究区,通过野外现场采集代表性石化废水排放处底泥样品,室内测定底泥理化性质和酶活性指标。结果表明,总石油烃质量分数变化范围为1.98—13.13 g·kg^−1,其组分构成以饱和烃为主。不同石油烃质量分数分组之间总石油烃和饱和烃差异显著,芳香烃、沥青和胶质则差异不显著,并且底泥中饱和烃相对容易发生降解作用。底泥的pH、比表面积、总氮、铵氮、硝态氮、总磷、有效磷和有机质质量分数,以及淀粉酶、脱氢酶、脂肪酶和硝酸还原酶均未受在1.98—7.21 g·kg^−1的质量分数范围内石油烃的显著影响,而过氧化氢酶和脲酶则被显著影响。石油烃高质量分数(13.13 g·kg^−1)的底泥中总氮、总磷、有效磷、有机质质量分数最高,且脲酶、过氧化氢酶和脱氢酶活性最高,而淀粉酶、脂肪酶和硝酸还原酶活性为最低值。脲酶活性特征表明石油烃降解过程中微生物以铵态氮作为主要氮源。高质量分数石油烃污染提高了过氧化氢酶活性,高酶活也表明微生物降解性能较高。脲酶和过氧化氢酶的测定有利于判断石油烃污染及其降解特征。总石油烃及不同组分之间的显著相关表明选择的石油烃参数具有代表性。总氮、总磷与总石油烃及各组分之间均显著相关,而电导率、铵氮、硝态氮和有效磷则均与石油烃及组分无显著相关;有机质与除饱和烃之外的石油组分、以及总氮、总磷均为显著正相关。过氧化氢酶与饱和烃和芳香烃为显著正相关,脂肪酶与芳香烃为显著正相关,表明微生物降解代谢活动为以饱和烃和芳香烃为主。

Petroleum hydrocarbons are typical persistent organic pollutants in the environment.In order to study the effects of petroleum wastewater on physical and chemical properties and enzyme activities of sediment,and to select the typical parameters,field investigation and research work were carried out in petroleum industry area of Yellow River Delta.Total petroleum hydrocarbon content ranged from 1.98 to 13.13 g·kg^−1 in the sediment samples,which was dominated by saturated hydrocarbons.Significant differences of total petroleum hydrocarbons and saturated hydrocarbons were found between groups with different petroleum hydrocarbon,but no significant differences of aromatic hydrocarbons,asphalt,and colloids were identified.Meanwhile,saturated hydrocarbons in the sediment were relatively prone to degradation.Sediment pH,specific surface area,total nitrogen,ammonium nitrogen,nitrate nitrogen,total phosphorus,available phosphorus,organic matter and four enzymes(amylase,dehydrogenase,lipase and nitrate reductase)were not affected by the petroleum hydrocarbon with content of 1.98-7.21 g·kg^−1;while catalase and urease were significantly affected.Total nitrogen,total phosphorus,available phosphorus,and organic matter were the highest in the sediment of petroleum hydrocarbon with high content(13.13 g kg^−1),at the same time the urease,catalase,and dehydrogenase activities were the highest,while amylase,fat enzyme and nitrate reductase activities were the lowest.Urease activity characteristics indicated that the microorganisms use ammonium nitrogen as the main nitrogen source during the degradation of petroleum hydrocarbons.The high content petroleum hydrocarbon increased catalase activity,which showed higher microbial degradation performance.The determination of urease and catalase was useful for identifying petroleum hydrocarbon pollution and its degradation characteristics.The significant correlation between total petroleum hydrocarbons and different components indicated that the selected petroleum hydrocarbon parameters were representative.Total nitrogen and total phosphorus were significantly related with total petroleum hydrocarbons and its components,while conductivity,ammonium nitrogen,nitrate nitrogen and available phosphorus were not significantly related to petroleum hydrocarbons and components;organic matter was significantly positively correlated with total nitrogen,total phosphorus and petroleum hydrocarbon components except saturated hydrocarbon.Catalase was significantly and positively correlated with saturated hydrocarbons and aromatic hydrocarbons,and lipase was significantly and positively correlated with aromatic hydrocarbons.It indicated that microbial degradation and metabolism activities were mainly related to saturated and aromatic hydrocarbons.