矿化垃圾生物反应器修复石油污染土壤的优化试验研究

发布时间：2018-01-03 05:36

本文关键词：矿化垃圾生物反应器修复石油污染土壤的优化试验研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：由于社会经济的快速发展,人们对石油的需求量越来越大,但在勘探、开采、炼制和储运石油过程中,均可能由于操作及工艺的缺陷使石油进入土壤中,从而导致土壤污染。目前,石油污染土壤修复多采用生物修复方法,然而传统的生物修复方法通常存在高效菌种难以获得、菌种筛选难度高,且易受环境影响的缺点,由于矿化垃圾中含有种类繁多、代谢能力强及耐受环境能力的微生物群落,因此本文提出利用矿化垃圾来修复石油污染土壤。以宜宾市卫生填埋场(填埋龄为8年)的矿化垃圾及自配的石油污染土壤为研究对象,通过室内模拟,采用单因素研究了(盐分含量、石油含量、表面活性剂含量、翻动次数、含水量)等因素对矿化垃圾修复石油污染土壤的影响,并利用前期实验成果及单因素实验结果,筛选出影响石油污染土壤的主要因素(石油含量、含水量、矿化垃圾与石油污染土壤的比例),通过响应面法对筛选因素进行了优化,最终采用准好氧生物反应器对优化结果进行验证。通过对影响石油污染土壤中石油降解的单因素研究结果表明,盐分、表面活性剂的含量及翻动次数均对石油去除率具有一定的抑制作用。通过石油降解动力学的研究,各因素的石油降解均符合二级降解动力学。随着含水量的增加,石油去除率先增加后减少,在含水量40%时去除效果最好,其半衰期为87d,降解速率常数为0.00458d-1。随着石油含量的增加,石油去除率先增加后减少,在含油量为4%时去除效果最好,其半衰期为51d,降解速率常数为0.00655d-1。各因素条件下石油污染土壤中的总氮均随时间变化先增加后维持稳定不变,有机质均随时间变化逐渐减少,经过94d修复后,土壤有机质中的碳氮比为37:1～60:1。通过GC-MS对石油降解前后成分分析,矿化垃圾降解石油污染土壤其降解成分主要以十八烷烃以下的烷烃为主,更长链及环烷烃主要经微生物降解为酸、酯、酮等有机物后再继续降解。通过对石油含量、含水量、矿化垃圾与石油污染土壤的比例三因素进行响应面优化研究,得出了其二阶多项式回归模型,通过回归模型得出最优条件为矿化垃圾与石油污染土壤的比例为1.6,含水率为41%,石油含量为3.8%,最优预测石油去除效果为 59.89%。通过验证实验结果表明,经过4个月的处理其石油去除率为51.38%(紫外分光光度法)、55.51%(GC-MS法),均与模型预测值(59.89%)的结果相近,表明模型具有较好的相关性。
[Abstract]:Because of the rapid development of social economy, the demand for oil is increasing, but in the process of exploration, exploitation, refining and oil storage and transportation, oil may enter the soil due to the defects of operation and technology. At present, bioremediation methods are mostly used in oil contaminated soil remediation. However, traditional bioremediation methods are usually difficult to obtain high efficient bacteria species, and it is difficult to screen them. And vulnerable to the shortcomings of the environment, because of the mineralized waste contains a variety of strong metabolic ability and tolerance to the environment of the microbial community. Therefore, this paper proposes to use mineralized garbage to remediate oil-contaminated soil. Taking mineralized refuse and self-made petroleum-contaminated soil from the sanitary landfill site of Yibin City (the age of landfill is 8 years) as the research object, the indoor simulation is carried out. The effects of single factor (salt content, oil content, surfactant content, turning times, water content) on the remediation of petroleum contaminated soil by mineralized garbage were studied. The main factors (oil content, water content, the ratio of mineralized garbage to petroleum-contaminated soil) were selected by using the results of previous experiments and single-factor experiments. The screening factors were optimized by response surface method, and the results were verified by quasi-aerobic bioreactor. The content of surfactant and the number of turning times have certain inhibition on the removal rate of petroleum. Through the study of the kinetics of oil degradation. With the increase of water content, the oil removal increased first and then decreased, and the removal effect was the best when the water content was 40, and its half-life was 87 days. The degradation rate constant was 0.00458 d ~ (-1). With the increase of oil content, the oil removal increased first and then decreased, and the removal effect was the best when the oil content was 4, its half-life was 51 days. The degradation rate constant was 0.00655d-1.The total nitrogen in the oil-contaminated soil increased first with time and then remained stable, while the organic matter gradually decreased with time. After 94 days of remediation, the ratio of carbon to nitrogen in soil organic matter was 37: 160: 1.The composition of oil was analyzed by GC-MS before and after degradation. The degradation of petroleum contaminated soil by mineralized waste was mainly composed of alkanes below 18 alkanes, longer chains and cycloalkanes were mainly degraded into acids and esters by microorganism. By optimizing the response surface of three factors, the oil content, water content and the ratio of mineralized garbage to petroleum contaminated soil, the second order polynomial regression model was obtained. Through the regression model, the optimum conditions are as follows: the ratio of mineralized garbage to petroleum contaminated soil is 1.6, the water content is 41 and the oil content is 3.8%. The best predicted oil removal efficiency is 59.89. The experimental results show that the oil removal rate is 51.38 after 4 months treatment (UV spectrophotometry). The results of the GC-MS method were similar to those of the model prediction value (59.89), which indicated that the model had a good correlation.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

【相似文献】