| 某焦化场地非均质包气带中多环芳烃(PAHs)来源及垂向分布特征 |
| 摘要点击 1982 全文点击 596 投稿时间：2019-03-16 修订日期：2019-05-24 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 包气带 非均质 多环芳烃(PAHs) 垂向分布 源解析 |
| 英文关键词 unsaturated zone heterogeneous soil polycyclic aromatic hydrocarbons(PAHs) vertical distribution sources apportionment |
|
| 中文摘要 |
| 利用某废弃焦化场地内6眼深层采样孔，样品最大采集深度9.5~42 m不等，分析包气带剖面上16种PAHs分布特征、污染来源以及影响迁移的因素.结果表明，各钻孔∑PAHs最大含量介于134.79~11266.81 mg·kg-1之间，主要分布层位为地表以下1~5 m，含量以低环（2+3环）为主，单体以萘含量最高.场地污染主要来自于煤的燃烧源.焦油、沥青及其深加工产物的污染对场地∑PAHs含量起控制作用.包气带砂卵砾石层作为污染物良好的下渗通道，砂层透镜体通过吸附及截留作用成为PAHs的主要富集层.化产区排放或泄漏的各类油液通过混溶、竞争性吸附等作用增强了PAHs垂向迁移能力，并致使深部包气带受到污染.地表0~1 m土壤受人为扰动、降雨淋滤、降解作用，30 m以下岩层受到地下水溶滤作用，导致低环/高环比例随深度增加呈现先升高后降低的趋势.污染来源、包气带理化指标及水文地质条件等共同作用控制PAHs垂向分布及迁移. |
| 英文摘要 |
| Six deep sampling boreholes are used for studying the sources and vertical distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in an abandoned coking plant. The maximum depth of soil sampling ranged from 9.5-42 m. The present study analyzes the distribution characteristics and sources of PAHs in addition to the important factors affecting migration of PAHs in the unsaturated zone. Results showed that the maximum values of total PAHs range of 134.79-11266.81 mg·kg-1 at vertical depths ranging from 1-5 m. We found that 2+3 rings dominated total PAHs and that the highest content was Nap. Results also showed that the main source of PAH pollution was coal combustion. Coal tar pitch and different oils from deep processing of tar played an important role in PAH pollution. The gravel layer served as a good infiltration channel for pollutants, and the sand lens below 20 m depth became the main enrichment layer for PAHs through adsorption and interception. Oils and wastewater from discharge and leaching of chemicals contributed to the migration of PAHs through inter-miscibility and competitive adsorption, which led to deep soil pollution. Soil layers above 1 m depth were affected by artificial disturbance, rainfall leaching, and degradation, and the unsaturated zone below 30 m depth was affected by leaching from groundwater. Consequently, the ratio of low to high rings first increased before decreasing with increased depth of the unsaturated zone. The types of pollution sources, rock particle sizes, organic matter content, and hydrogeological conditions all affected the vertical distribution and migration of PAHs. |
