东莞市农业土壤多环芳烃污染及其空间分布特征研究

选取位于珠江三角洲的东莞市为研究区域,采集59个代表性表层农业土壤样品,分析了16种优控PAHs的含量.结果显示,13种PAHs检出率均在90%以上,其中Fle,Phe,Chr和Bbf的检出率为100%,Ant的检出率最低(13.56%).∑PAHs介于29～2184μg/kg之间,远超出土壤内源性PAHs含量,分别有44.07%,8.47%和3.39%的土壤样品达到了PAHs的轻、中、重度污染水平.主成分分析及源解析结果表明,该市农业土壤PAHs主要有燃烧源、石油源和煤燃烧源3个主要来源.与国内其他地区相比,东莞市农业土壤PAHs含量处于相对较高的水平.还对可能影响PAHs环境行为的因素进行了分析,认为环境因素(温度、湿度、光照)、土壤性质(pH值、有机质含量)以及其他污染物(重金属)均会对PAHs环境行为产生影响.采用克里格插值法对东莞市农业土壤PAHs的空间分布特征进行了分析,发现不同PAHs组分的空间分布差别很大,总体上该市西北部土壤PAHs含量较高,PAHs异常的富集中心在东莞市望牛墩镇附近,该区域可能存在一些有毒废物焚烧污染源.     

索氏抽提-柱层析分离-高效液相色谱法测定煤沥青中多环芳烃

以甲苯为溶剂对煤沥青进行索氏抽提,抽提液经过有机滤膜过滤,过滤后的抽提液用二氯甲烷溶解,将样品溶液用硅胶柱分离,然后用体积比为1∶1的石油醚与甲苯混合液以5.0mL/min的流量进行淋洗,将淋洗液旋干后用乙腈定容至10mL,利用ZORBAX Eclipse PAH柱以不同体积比的乙腈-水体系为流动相对样品溶液进行梯度洗脱,建立了煤沥青中16种多环芳烃(PAHs)的高效液相色谱分离检测方法。结果表明,16种PAHs的线性范围为0.50~20mg/L,相关系数(r)不小于0.999,检出限为0.04~0.33μg/L,按照实验方法对湘钢煤沥青实际样品中16种PAHs进行测定,测得结果的相对标准偏差(RSD,n=6)为0.20%~3.5%,回收率为97%~109%。采用实验方法分别测定湘钢、涟钢两种不同煤沥青中16种PAHs的含量,测得结果与湘钢、涟钢两公司提供的推荐值基本一致。结果表明,每1kg湘钢煤沥青中16种致癌性PAHs质量为107.9g,即质量分数为10.79%;每1kg涟钢煤沥青中16种致癌性PAHs质量为104.1g,即质量分数为10.41%;其中苯并[a]芘分别为11.86g/kg和13.82g/kg,即质量分数为1.186%和1.382%。     

轧钢油泥与生物质共热解特性

为探究轧钢油泥与生物质混合共热解处理工艺，本文利用热重分析仪在N₂气氛下对轧钢油泥、生物质(玉米秸秆、稻草秸秆)单独热解并对3种不同混合配比的轧钢油泥与生物质混合进行试验研究，讨论上述混合物的协同热解特性；同时，在不同升温速率(β)条件下，采用Friedman-Reich-Levi法对混合热解过程进行动力学分析，得到动力学参数。结果表明：轧钢油泥的热解过程主要为水分析出、油分分解、铁氧化物还原3个主要阶段，生物质的热解主要失重阶段为挥发分析出；玉米秸秆、稻草秸秆与轧钢油泥共热解协同作用与生物质种类和混合比有关，当生物质混合比为70%时促进作用更明显，稻草秸秆对轧钢油泥的促进作用优于玉米秸秆；两种生物质与轧钢油泥共热解的活化能出现随转化率的增加先升高后降低的趋势，在转化率为0.6或0.7时达到最大活化能，为52.45～80.02 kJ/mol。     

气相色谱法分析洗油组分的应用

焦化厂粗苯工序在生产过程中存在洗苯塔阻力高、贫油冷却器堵塞等问题,分析出其主要原因是洗油中高沸点有害组分苊、氧芴、芴等含量较高.通过增加气相色谱分析项月,能够快速、准确地检测出洗油中甲基萘、联苯、苊、氧芴、芴等各有利有害组分的含量,为提高进厂洗油质量提供了可靠依据,为降低洗苯塔阻力、洗油单耗、优化技术操作指标创造了条件.     

酸—碱联合溶样法测定Si—Al合金中的硅,铝

该样品在用稀盐酸溶样时，出现黑色油泥状不溶物，是一般处理法操作时，以油泥状物不与氢氟酸发生反应，滤液测定铝含量、硅铝结果均相差很大且不稳定，本文要用新的溶样方法，先酸溶、再将不溶物用碱熔融处理，将黑色油泥状不溶物（估计为Ｓｉ－Ａｌ化合物）全部转入溶液中，然后进行测定，最后向得到准确稳定的结果。     

炼焦过程中多环芳烃排放特性及影响因素

以炼焦过程中排放的多环芳烃(PAHs)为研究对象,分析了PAHs的排放规律以及温度、热解产物和PAHs的特性、挥发分对多环芳烃产生排放的影响。通过对3种单煤和配合煤进行实验室炼焦、超声波萃取和高效液相色谱的检测,测定了炼焦过程中各阶段产生排放的16种PAHs浓度。结果发现:在结焦初期1～5 h内PAHs产生排放量最多,并且在整个炼焦过程中产生排放量逐渐减少。PAHs化学性质不稳定使得炼焦初期PAHs的产生排放量较大,且低环PAHs产生排放较多。在挥发分小于26%时,PAHs产生排放量随着挥发分的增大而减小。     

高炉喷吹煤粉混加冶金油泥的燃烧性能

 将冶金油泥与煤粉混合用于高炉喷吹可实现油泥资源化利用,提高煤粉燃烧效率。通过TG-MS研究了高炉喷吹煤粉添加污泥后的燃烧特性与气体释放特征,探究油泥有机组分和无机组分对高炉喷吹煤粉燃烧过程的影响。多种检测手段系统考察了油泥的理化性质,并通过TG-MS研究了高炉喷吹煤粉添加污泥后的燃烧特性与气体释放特征。结果表明,油泥组成主要为润滑油等有机物和以Fe₂O₃为主要成分的无机物,其粒度主要集中在0.7~3 μm,孔隙发达且多为介孔。添加油泥可以降低煤粉的着火温度和最大燃烧速率对应的温度,从而改善反应性,同时提高燃烧过程的放热量,使燃料燃烧更加充分,但当油泥添加量过大时,对煤粉燃烧热量影响较低。动力学研究发现,油泥的添加会降低煤粉燃烧反应的活化能,从而使煤粉燃烧更易进行。     

苏南地区中、古生界沉积岩地球化学特征——以圣科1井为例

通过对苏南地区圣科1井333块沉积岩样品的微量元素和稀土元素进行测试和分析,揭示了苏南地区中、古生界的沉积环境、物质来源及其大地构造背景.研究表明:苏南地区二叠系栖霞组上郝沉积时呈现明显的富氧特征;研究区中、古生界海陆环境交替出现.另外,通过对所有碎屑岩样品中的∑REE、∑LREE/∑HREE、w(La)、w(Ce)、La/Yb、δEu等以及La-Th-Sc和Th-Sc-Zr/10图解判定:研究区龙潭组上部、坟头组、高家边组沉积时其物质来源应为活动大陆边缘的构造环境;龙潭组下部为大陆岛弧的构造环境;并推测五通组也可能为被动大陆边缘的构造环境.依据碎屑岩样品中δEu的大小、REE配分模式和La/Yb-∑REE投影图上所体现的规律,表明苏南地区中、古生界物质主要来源于上地壳并且存在多个物源区;志留系高家边组和坟头组其母岩以沉积岩和花岗岩为主;五通组的源岩应为沉积岩,其物源区为华夏板块及江南隆起.     

冷轧油泥在烧结系统中的工业试验研究

主要介绍了在烧结系统开展的配用冷轧总厂油泥工业试验。通过对试验过程及生产数据分析,评估冷轧油泥配用对烧结过程及烧结矿产质量的影响,为冷轧油泥的处置寻找新的途径。     

钢厂典型含油污泥热解特性试验研究

钢铁冶炼过程中产生的含油污泥属于危险废物,其产量高、危害大已成为企业环保难题之一。针对钢厂的三种典型油泥,先通过实验室小型热解反应装置获取其程序升温过程中油、水、固及不凝热解气产率情况,再通过气相色谱仪测定不凝热解气中可燃组分比例;后续通过热重分析仪对油泥热解过程进行研究,解析其热解过程中发生的热化学转化和动力学特性。结果表明,由室温程序升温至873K可实现三种油泥中油的完全释放,不凝热解气组分以H_(2)、CO、CH_(4)为主,热值可达4000kCal/Nm^(3)左右,可对钢厂余能提供有效补充。轧钢油泥中油在相对较高温度下发生裂解,反应活化能较大,两种水站油泥在低温下更多以脱附、挥发为主,反应活化能较小。结果同时说明,可采用热解方式实现钢厂油泥的资源化利用。     

Isolation of priority polycyclic aromatic hydrocarbons from natural sediments and sludge reference materials by an anti-fluorene immunosorbent followed by liquid chromatography and diode array detection

The selective isolation of PAHs from complex environmental mixtures was accomplished by means of a new methodology based on antigen--antibody interactions. This method consists on the extraction of PAHs from water samples onto an anti-fluorene immunosorbent (IS) followed by liquid chromatography with diode array detection. Environmental sediments and a sludge reference material containing PAHs were analyzed using this methodology in order to validate the performance of the IS for the cleanup procedure of such materials. Sediments were extracted by sonication with dichloromethane/methanol (2:1), and the extracts were brought to a volume of 100 mL of water in order to perform the extraction with the anti-fluorene IS. The reliability of the cleanup achieved by the IS was well demonstrated in the analysis of sediment and sludge complex samples containing the priority PAHs established by the U.S. EPA at concentrations varying from 56 micrograms/kg to 26 mg/kg. Results were compared to those obtained with conventional cleanup procedures showing a better selectivity for PAHs. The chromatograms presented a clear baseline allowing the determination and quantification of PAHs at the ppb level. Using immunosorbents, extraction, trace enrichment, and cleanup were accomplished in only one step.     

含油污泥铁组元的高效分离及其制备复合纳米催化剂

钢铁含油污泥是轧钢工艺过程中产生的一种危险性废物(HW08),其资源化利用难度大。采用碱洗法对含油污泥进行分离处理,并将分离所得的铁组元制备成复合纳米催化剂。碱洗脱油研究表明,当温度为80 ℃、碱溶液/含油污泥的质量比为1∶2、碱浓度为15%、反应时间为1 h时,含油污泥的脱油率达到94.14%,并得到铁质量分数为62.49%的固相。将脱油后的含铁固相通过共沉淀方法,得到粒径约为8 nm的磁性纳米Fe₃O₄,并与硅藻土通过溶剂热法制备了复合纳米催化剂,应用于罗丹明B催化降解,其降解率达到99.53%。本方法实现了对含油污泥的无害化处理和资源化利用。     

含油污泥铁组元的高效分离及其制备复合纳米催化剂

钢铁含油污泥是轧钢工艺过程中产生的一种危险性废物(HW08),其资源化利用难度大。采用碱洗法对含油污泥进行分离处理,并将分离所得的铁组元制备成复合纳米催化剂。碱洗脱油研究表明,当温度为80 ℃、碱溶液/含油污泥的质量比为1∶2、碱浓度为15%、反应时间为1 h时,含油污泥的脱油率达到94.14%,并得到铁质量分数为62.49%的固相。将脱油后的含铁固相通过共沉淀方法,得到粒径约为8 nm的磁性纳米Fe₃O₄,并与硅藻土通过溶剂热法制备了复合纳米催化剂,应用于罗丹明B催化降解,其降解率达到99.53%。本方法实现了对含油污泥的无害化处理和资源化利用。     

超临界水氧化轧钢含油污泥减量无害化处理

轧钢含油污泥含有大量油类、复杂有机物、氧化铁及重金属等有害固体废弃物,常规方法如焚烧法、填埋法不仅占地面积大,而且造成生态环境的二次污染。依据超临界水氧化(supercritical water oxidation,简称SCWO)技术对有机废物处理效果明显的优势,对宝钢轧钢含油污泥进行降解试验。采用单因素分析确定工艺参数,在反应温度为440℃、反应压力为25MPa、停留时间为330s和过氧倍数为300%时,反应结束后出水COD去除率接近98%,剩余固体容积减少了98.5%左右。此外,固体中氧化铁质量分数达30%以上,可深度提纯实现资源化利用。采用SCWO技术处理轧钢含油污泥,减量化、无害化效果显著,达到了预期目标,对国内同类型的轧钢含油污泥处理提供了一定的参考和借鉴意义。     

Electrolytic Oxidation of Polynuclear Aromatic Hydrocarbons from Creosote Solution Using TI/IRO2 and TI/SNO2 Circular Mesh Electrodes

The electrooxidation of polynuclear aromatic hydrocarbons (PAHs) in solution was investigated. Most of the PAHs compounds are toxic and hardly biodegradable, so that a chemical or physicochemical treatment is required. In this paper, we reported treatment of synthetic creosote oily effluent (COE) containing several PAHs by using Ti/IrO2 and Ti/SnO2 circular or cylindrical mesh anode electrodes. COE was prepared with distilled water and a commercial creosote solution in the presence of an amphoteric surfactant (CAS). In addition to anode material, different operating parameters were investigated such as current density, reaction time, recycling flow rate, and oxygen injection flow rate. The first series of experiments carried out in the recirculating batch reactor showed that circular Ti/SnO2 electrode was found to be more effective in removing PAHs than circular or cylindrical Ti/IrO2 electrodes. Current density and retention time played important roles for PAHs degradation efficiency, whereas circulation flow rate and oxygen injection slightly influenced the removal efficiency. Finally, the best and simplest operating conditions (82–84% of PAHs removal) determined for PAHs degradation in COE were obtained at a current density of 15?mA/cm2 through 90 min of treatment with a recycling rate of 3.6 L/min but without O2 injection in the close loop. Likewise, in the recirculating batch tests, PAHs decomposition exhibited behaviors of the fist-order reaction with a rate coefficient (k) of 0.015?min?1. The energy consumption was 7.5?kWh/m3. The second series of experiment using successively batch and continuous treatment of COE shows that the percentage of PAHs degradation could be maintained above 80% up to 18 h of treatment, thereafter, removal efficiency decreased owing to the formation of organic substances on the electrodes surface.     

Polycyclic aromatic hydrocarbons in placenta, maternal blood, umbilical cord blood and milk of Indian women

Human placenta, umbilical cord blood, maternal blood and breast milk samples from mothers were analysed for the presence of selected polycyclic aromatic hydrocarbons (PAHs). Benzo(a) pyrene (B(a)P), dibenzo(a,c)anthracene (DBA) and chrysene (Chy) were detected in all the four types of sample. Levels of dibenzo(a,c)anthracene were higher in the above samples compared with the other two PAHs. Umbilical cord blood and breast milk samples showed relatively high concentrations of all the three PAHs and thus demonstrated that the developing foetus/new born were exposed to these carcinogenic environmental contaminants. The possible implications of PAHs in relation to human health are discussed.     

Solid-liquid phase separation and resource recycling study for waste rolling oily sludge

Abstract:On the basis of the characteristics of a highly emulsified solid-liquid phase(fine particles,sticky consistency,black color,and low reuse ratio),waste rolling oily sludge has been a focal problem in the steel industry.In this article,a solid-liquid phase separation and resource recycling process was described,with pilot test results showing that flocculation-sedimentation is an effective pretreatment,and that the filtration-coagulation-vacuum distillation process is simple and feasible with a 53.5%recovery rate for regenerated oil that is qualified for return to the rolling production line.Then,solid phase oil-sludge was extracted by solvents with a 77%metal resource recovery rate and a wide utilization range.Finally,according to the experimental results,a set of feasibility plans for a 50 t/a waste rolling oily sludge solid-liquid separation and resource recycle project was designed,with the expectation of50%regenerated oil yield,70%solid metal resource recovery,and a 2.5-year investment payback period.     

EAF Smelting Trials of Waste‐Carbon Briquettes at Avesta Works of Outokumpu Stainless AB for Recycling Oily Mill Scale Sludge from Stainless Steel Production

The EAF steel plant of Avesta Works, Outokumpu Stainless AB, has been used to perform smelting reduction trials of briquettes consisting of oily mill scale sludge, carbon and other wastes. A total of 7 briquette smelting trials were performed. The heats were processed smoothly smelting 3 t of briquettes or 3.4 mass‐% of metal charges. The quantities of FeSi powder and O₂ gas injected and electric energy supplied were increased to smelt briquettes of 6 t. No impacts were found on the analyses of the crude stainless steel tapped from the EAF during the trials. The results of the briquette smelting have been evaluated by referring to the data from the reference heats and results from earlier laboratory tests. The recovery of Cr, Ni and Fe elements from the briquettes was nearly complete and was found to occur mainly through carbon reduction. The slag masses were not increased in three trials as compared with the reference heats. There were moderate increases in the slag masses in four trial heats. The increases were, nevertheless, lower by 52‐69% than the slag masses generated by Sireduction of the briquette oxides. Afterwards, by referring results from the present trials, waste‐carbon briquettes amounting to 1‐3 t were smelted very smoothly in many of the EAF heats at Avesta Works to recycle the oily mill scale sludge and other wastes from stainless steel production.     

Leaching Behavior of Metals Released from Cement-Stabilized/Solidified Refinery Oily Sludge by Means of Sequential Toxicity Characteristic Leaching Procedure

In this study, stabilization/solidification (S/S) of refinery oily sludge was applied using two types of cement (I and II), in cement-to-waste ratio from 0.1 to 0.7. The leaching behavior of heavy metals was investigated, by means of a five-point sequential toxicity characteristic leaching procedure (TCLP) test. Sequential TCLP was used to provide an improved assessment of long-term contaminant potential leachability, because the acidic leachant is renewed, whereas in the single TCLP, contaminant leachability is limited by the pH neutralization of the alkaline binder. Cement-based S/S of real refinery oily sludge resulted in very low leachability of heavy metals. Pb and Cd were not detected in any TCLP leachate. The maximum leachability of Fe, Zn, and Ni occurred in the pH range between 5.5 and 6.5. The leachability of Cu and Cr increased with increasing pH. Maximum cumulative percentage of Fe, Ni, and Zn leaching after five consecutive TCLP extractions (for worst case conditions, i.e., 10% II42.5) were 0.01, 22, and 1.2%, respectively, on the basis of metal content of each solidified sample. Further, the leaching behavior of Zn and Ni was modeled using the chemical equilibrium program Visual MINTEQ. Using several combinations of suspected solid phases of Zn and Ni hydroxides, carbonates and sulfides, and surface complexation onto ferrihydrite the diffuse double layer model did not accurately describe the leaching behavior of Zn and Ni.     

Comparison of Bacterial Bioluminescence with Activated Sludge Oxygen Uptake Rates during Zinc Toxic Shock Loads in a Wastewater Treatment System

The use of a bioengineered bioluminescent bacterium (Shk1) for monitoring zinc toxicity was evaluated with samples from a municipal activated sludge wastewater treatment plant and in a bench-scale activated sludge system. Bioluminescent measurements were compared with oxygen uptake rates of activated sludge samples. In batch experiments with activated sludge, the Zn EC50 for Shk1 bioluminescence was 16 mg/L, while the Zn EC50 for activated sludge OURs was approximately 58 mg/L. In the bench-scale system, the influent Zn concentrations tested were 50 and 200 mg/L in toxic shock loads of about 4 h duration. Soluble Zn transport through the influent, aeration basin, and clarifier was able to be monitored by the decrease in Shk1 bioluminescence. However, bioluminescence in samples from the aeration basin decreased faster than activated sludge specific oxygen uptake rates. Differences in responses of Shk1 and the activated sludge community may be due to differences in the assay conditions, the growth forms, physiology of the organisms, or previous cultivation conditions.