Construction and analysis of knowledge graphs for multi-source heterogeneous data of soil pollution

The decommissioning and overall relocation of urban industrial enterprises have generated a large number of decommissioned contaminated sites, and the leftover soil pollution is gradually becoming a major problem that restricts urban green development and damages human health. Deep mining and efficient management of site soil pollution information through digitization and informatization are needed to solve these problems more accurately and efficiently. Knowledge mapping for visual analysis of relevant pathways is a forward-looking approach in soil contamination management that does not require complex testing instruments, thus saving research manpower, time and cost. Data associated with contaminated sites come from a wide range of sources and have different structures. Through the natural language processing technology of computer, suitable methods such as entity recognition, relationship recognition and knowledge fusion are selected to extract various types of information from contaminated sites and establish semantic networks for fast targeting of soil contamination sources, thus providing a more convenient solution. In this paper, we propose a knowledge graph construction method for multi-source heterogeneous data of contaminated sites, find sulphide contamination sources through visual analysis of knowledge graph and explore the application prospects of natural language processing techniques such as knowledge graph in contaminated site management.     

Effect of soil pH on the sorption capacity of soil organic matter for polycyclic aromatic hydrocarbons in unsaturated soils

Sorption by soil organic matter (SOM) is considered the most important process affecting the bioavailability of hydrophobic organic chemicals (HOCs)in soil.The sorption capacity of SOM for HOCs is affected by many environmental factors.In this study,we investigated the effects of soil pH and water saturation level on HOC sorption capacity of SOM using batch sorption experiments.Values of soil organic carbon-water partition coefficient (K_OC) of six selected polycyclic aromatic hydrocar...     

Model experimental study on the migration behavior of heavy metals in electrokinetic remediation process for contaminated soil

Recently in Japan, like in other industrialized countries, treatment of contaminated soil or ground has become an important issue in redeveloping such areas as old factories, mining sites, and other polluted sites. In these cases, measures such as a construction of cut-off walls and disposal to controlled waste disposal sites have been so far taken. But, the treatment of contaminated soils has become more difficult nowadays. Therefore, remediation of contaminated soil by removal or extraction of contaminants is necessary and various methods have been developed and applied in many countries. Authors have tried to develop an electrokinetic remediation method for soil contaminated with heavy metals and some basic and pilot scale experiments have been carried out. In this paper, the results of a model experiment using an artificial soil contaminated with Cu or Ph or Cr are presented as follows. i) In the electrokinetic process, migration of water to the cathode by electroosmosis, migration of ions to the cathode or anode by electrophoresis and electrolysis of water occur spontaneously. ii) Upon DC loading, Cu and Pb migrate to the cathode and accumulate as oxides or hydroxides near the cathode but are not removed from contaminated soil. However, in the case of Cr contaminated soil, Cr in the form of Cr(VI) migrates to the anode and is removed from soil through the drainage water. iii) After DC loading for 2 weeks, the concentration of exchangeable cations and composition of soil changed drastically while the CEC and clay mineralogy did not change appreciably.     

不同施磷水平对土壤中重金属镉的钝化效果评价

通过室内培养试验,以P/Cd摩尔配比分别为0,2∶3,3∶2,2∶1,4∶1进行了不同磷肥钝化修复Cd污染土壤试验。采用毒性淋溶提取法(TCLP)和形态分析法评价了磷酸氢二铵(DAP)、磷酸二氢钾(MPP)、过磷酸钙(SSP)和磷酸钙(TCP)对污染土壤中Cd的钝化效果。结果表明,4种磷肥的钝化效果依次为:MPPDAPSSPTCP,4种磷肥的钝化处理可显著降低土壤中TCLP提取态Cd含量,在磷肥剂量水平P/Cd为4∶1时对土壤中Cd的钝化效果最佳,最大降低幅度为49%;添加磷肥能够大幅度提高土壤中速效磷的含量,相同磷水平下,土壤中速效磷含量高低次序为:MPPDAPSSPTCP,TCLP提取态Cd含量随土壤速效磷含量升高而显著降低(R=-0.903**);DAP,MPP,SSP和TCP处理后交换态Cd的浓度降幅分别为23.75%,39.06%,16.60%和18.36%,而碳酸盐结合态(WSA)、铁锰氧化物结合态(Fe-Mn-OX)、有机结合态(OM)和残渣态(RES)Cd的含量均有所升高,表明磷素是通过改变Cd的存在形态而降低其有效态含量的。     

多金属污染农田土壤固化／稳定化修复研究进展

固化／稳定化剂修复农田土壤重金属污染简单易行、成本低廉且不破坏土壤结构,但不同的固化／稳定化剂对土壤、作物及重金属离子的修复效果各不相同。文章概述了几种固化／稳定化剂的修复效果及优缺点,探讨了固化,稳定化修复重金属污染的作用机制以及影响重金属固化／稳定化修复效果的主要因素,分析了固化／稳定化修复农田土壤重金属污染的局限性,并从不同角度提出了今后的发展方向。     

自然霉变玉米及添加甘露寡糖对断奶仔猪肝脏结构与功能的影响

本试验旨在研究自然霉变玉米对断奶仔猪生长性能、肝脏结构与功能的影响,并初步探讨甘露寡糖可能的缓解作用。试验采用2×2因子设计,20头体重(8.10±0.32)kg的35日龄PIC断奶仔猪随机分为4组,分别饲喂添加不同水平霉变玉米(0、100%)和甘露寡糖(0、0.2%)的饲粮。结果表明:霉变玉米组仔猪全期平均日增重(P<0.01)和平均日采食量显著降低(P<0.05);肝细胞发生严重颗粒和空泡变性,肝脏丙二醛含量显著升高(P<0.05)和Bax mRNA表达量极显著升高(P<0.01)。添加甘露寡糖极显著提高仔猪肝脏总抗氧化力(T-AOC)(P<0.01),缓解霉变玉米导致的肝脏病理损伤,且霉变玉米与甘露寡糖对T-AOC的影响具有显著的交互效应(P<0.01)。由此可见,自然霉变玉米降低仔猪生长性能,诱导肝脏氧化应激并损伤肝脏结构;添加甘露寡糖对自然霉变玉米导致的肝损伤有一定程度的缓解作用。     

污染场地采样调查技术与设备研究进展

近年来,随着重点行业企业用地土壤污染状况调查工作的开展,以及建设用地地块环境调查制度的规范,我国污染场地调查的市场需求急剧增长.污染场地采样是保障场地调查结果可靠性的重要环节,但是我国污染场地调查采样技术与设备的研究和实践还处于初级阶段.因此,本文系统梳理了国内外先进的土壤和地下水采样技术与设备,包括其发展情况、适用范...     

氯丹和灭蚁灵在污染场地中的空间分布研究

氯丹和灭蚁灵是两种杀虫剂类POPs,在我国仍然生产和使用。在多年生产氯丹、灭蚁灵的企业厂区内及周围布设采样点,采取不同深度的土壤进行分析,研究了POPs生产企业土壤中污染物的空间分布规律。结果表明,生产厂区内污染严重,在土壤表层,靠近生产车间的土壤中氯丹的浓度高达2927.95mg·kg-1,灭蚁灵浓度高达61.90mg·kg-1,并且已经扩散到周边土壤。在土壤深层,氯丹和灭蚁灵有明显的垂直扩散,10m深处土壤均能检出两种污染物。由于灭蚁灵产量小于氯丹产量,灭蚁灵的污染不及氯丹的污染严重。     

猪粪源沼液振荡淋洗修复铬污染土壤效果及机制

针对铬污染土壤不易处置的难题,文章通过室内模拟实验,采用振荡淋洗的方法研究了猪粪源沼液对铬污染土壤中铬的淋洗效果,优化了固液比、淋洗时间和淋洗次数等影响土壤中总铬和六价铬洗脱效果的因子,并研究了猪粪源沼液淋洗前后土壤中铬形态分布及DOM的变化。结果表明,当环境温度为20℃,振荡速度200 r·min^-1时,沼液洗脱土壤铬的最优条件为:固液比1∶10,振荡6 h,淋洗1次。该条件下,当土壤总铬浓度为121.54 mg·kg^-1(六价铬浓度为119.9 mg·kg^-1)时,其总铬和六价铬洗脱率分别为43.27%,48.99%;当土壤总铬浓度为941.9 mg·kg^-1(六价铬浓度为856.9 mg·kg^-1)时,洗脱率达84.89%,96.32%。猪粪源沼液对水溶态、弱酸提取态和残渣态铬有较好的洗脱效果,有效削减了土壤环境风险。紫外-可见光谱和三维荧光光谱显示:淋洗后土壤DOM芳香性物质及疏水性物质减少,类腐殖酸类还原性物质增多,使得沼液对铬污染土壤有解毒效果。该研究可为铬污染土壤淋洗修复提供一定的参考价值。     

原油顺序输送工艺在东黄复线上的应用

东黄复线是我国第一条自动化输油管道,其中黄岛-广饶段于1999年12月正式开始进口原油的顺序输送.介绍了顺序输送工艺的特点,分析了顺序输送混油产生的机理,给出了混油量的计算公式.对影响混油量的因素进行了分析,给出了混油的切割方法,并对顺序输送管道的水力特性进行了分析.