Ambient Air Quality at the Site of a Former Manufactured Gas Plant

Prior to the 1950's, manufactured gas was commerciallyproduced from the pyrolysis of coal, coke, and oil atfacilities that are termed manufactured gas plants (MGPs). The constituents of residual coal tar present on many MGPsites are an environmental health concern because of theirtoxicity and the possibility for their off-site migration viawater and air. Atmospheric concentrations of five volatileorganic compounds (VOCs, e.g., benzene), sixteen polycyclicaromatic hydrocarbons (PAHs, e.g., naphthalene), and particulate matter less than 10 microns in aerodynamicdiameter (PM₁₀) were measured at the site of a former MGP. Air samples were obtained before, during, and after excavationof subterranean coal tar at the site. The results of thisinvestigation indicate that subterranean coal tar was not aprimary source of VOCs and PAHs in the local atmosphere beforeor after remediation of the site. However, excavation,treatment, blending, and transfer of the coal tar duringremediation generated concentrations of selected aromatic andsemi-volatile organic compounds that were substantiallygreater than typical ambient levels. In addition, these datasuggest that blending and mixing of coal tars could lead toexceedance of the U.S. National Ambient Air Quality Standardfor PM₁₀, although additional research is required to fullyevaluate this possibility. Nuisance odors associated with thesite remediation were likely the result of naphthalene andpossibly isomers of xylene. Air pollutant concentrationsmeasured adjacent to the excavation area and at the siteperimeter during remediation activities were less than therelevant occupational and environmental exposure limits.     

油罐常用环氧煤沥青涂层的防护寿命研究

利用电化学阻抗谱（EIS）测试技术,研究储油罐起防护作用的环氧煤沥青涂层逐渐被破坏后的阻抗变化规律。结果表明,涂层上孔洞面积增大到一定程度时,10mHz频率处10^3Ω数量级的总阻抗值是判定环氧煤沥青涂层防护性能失效的量值。     

煤焦油加工废气治理方法简述

煤焦油加工项目属于重污染行业,产生的废气大部分有致癌作用,必须做好配套的环保设施和安全设施,本文介绍了煤焦油加工过程中废气产生及防治对策,减少环境污染。     

萃取浓缩-薄涂柱气相色谱法测定煤焦油废水中的联苯和菲

用苯萃取浓缩煤焦油废水中的联苯和菲，然后用薄涂柱气相色谱法进行测定。试验表明：该法具有色谱柱温低、快速、准确等特点。     

适宜燃气生产的逆流清洁装置设计与试验

为了减少生物质热解燃气中焦油含量,设计了一种适宜燃气生产过程净化脱焦的逆流清洁装置。该清洁装置与气化机组进行选型匹配和参数优化,确定喷嘴口径和水压后再进行性能测试试验。试验表明:该清洁装置能较好的去除生物质热解燃气中的焦油和灰尘,除焦效率大于70%;在入口焦油和灰尘平均含量为539.92 mg/m3时,采用清洁管52的平均除焦效率为80%;在其他条件相同的情况下,燃气清洁管采用管径较小的52管比62管的除焦效率高。该研究为生物质热解燃气的净化提供了一种新的手段和技术参考。     

Ni/钙铝石催化剂对焦油模拟物甲苯的催化研究

以高温烧结法制备的钙铝石为载体,利用溶液浸渍法制备出Ni/钙铝石催化剂。以甲苯为生物质焦油模拟物,在N2气氛下研究Ni/钙铝石催化剂对甲苯催化裂解的性能。采用XRD、SEM、BET等分析手段对催化剂进行表征,然后在实验室自制固定床反应装置中考察了反应温度、镍负载量对催化产气成分、产氢量及甲苯转化率的影响。结果表明:随着反应温度的增加,甲苯转化率升高,产气量增加;较高温度下,增加镍负载量有利于提高产氢量。     

Tar Balls: The End State

Tar balls are frequently reported as an indicator of the extent of the impact of a spill incident. The determination of the density of tar balls is basic to the shoreline cleanup assessment team (SCAT) process, and is frequently used by the media as an indication of oil pollution. The processes involved in the evolution of tar balls are not well understood and there is a paucity of literature on the science of tar ball formation.     

Sorption of heterocyclic compounds from a complex mixture of coal-tar compounds on natural clayey till

The sorption and desorption of heterocyclic organic compounds in a complex multisolute system to a natural clayey till was investigated. The composition of the solutes reflect a simplified composition of an aqueous phase in contact with coal tar. Sorption was studied for two ratios (s:l) of clayey till (solid) to aqueous phase (liquid). The effect of the complex mixture of solutes on sorption of the four heterocyclic compounds: benzofuran, dibenzofuran, benzothiophene, and dibenzothiophene is evaluated by comparison with their sorption measured in single-solute systems. Sorption of the four compounds is affected by the complex mixture, with sorption decreases for all four compounds at high s:l ratio indicating competitive sorption. The effect on sorption of the individual compounds is not related to solubility or hydrophobicity of the compounds. Freundlich-type isotherms are observed for all compounds in the high s:l-ratio experiments, but for the most hydrophobic compounds isotherms are close to linear. The sorption of N-compounds and benzofuran is apparently influenced by cation exchange and dipole–dipole attraction to clay minerals. At high concentrations a dramatic increase in the sorption of the most strongly sorbing compounds is observed in the low s:l-ratio experiment. The dramatic increase in sorption appears to be a result of multimolecular layer sorption or condensation on surfaces in the clayey till at high surface density of organic compounds, and the data are fitted by BET (Brunauer, Emmet, and Teller) type 2 isotherms. The increase may or may not be induced by the presence of N-heterocyclic compounds sorbed by cation exchange and dipole–dipole attraction. The desorption of the compounds was studied for the low s:l ratio where multimolecular layer formation apparently had occurred. Partially irreversible sorption, hysteric Langmuir type desorption with isotherms of very high K_l coefficient, or behaviour reflecting dissolution of a condensed phase is observed.     

固体废物在固定床内热解焦油的实验研究

在小型固定床热解炉内对部分固体废物进行的热解实验 ,目的是研究所得的热解产物中焦油 (含水 )的产量及其物理化学特性。结果表明 ,物料挥发分和水分含量越高 ,焦油 (含水 )的产量就越多 ;焦油 (含水 )的产率随热解终温的升高呈先升后降的趋势 ;焦油 (含水 )密度很大 ,但其随热解终温的升高而下降 ;同时 ,部分废弃物的焦油 (含水 )热值较高 ,饱和烃的含量很高 ,有很高的利用价值。     

鲁奇低温煤焦油的致突变性及致突变性组分的鉴定

煤焦油样品经提取分离为酸性、碱性和中性组分,后两组分再经硅胶柱制备色谱分作B_1—B_33个级分和N_1—N_66个级分.Ames试验表明,B_2级分致突变活性最高.该级分经HPLC进一步分级表明,其中d、f级分具较高的致突变性经HRGC、HRGC-MS分析,分别从d级分鉴定出苯并喹啉等60多种氮杂多环芳烃,f级分鉴定出氮杂苯并芴等40多种氮杂多环芳烃.