一种新的废塑料油化生产工艺的研究

针对废塑料油化工艺中的问题 ,应用新型的流化床反应釜催化裂解废塑料 ,并利用混合废塑料为原料进行了中试试验 ;研究了催化剂种类和催化改质温度对所得液体油品产率、催化剂积碳率等的影响以及热裂解中裂解温度对液体油品产率的影响。油品经催化改质后 ,其质量得到明显提高 ,该法所生产的汽油和柴油产品符合国家标准     

废塑料的裂解利用评述

本文对废塑料热裂解生产燃料油或单体原料的技术条件和在我国的应用进行综述分析。     

一种废塑料回收再生新方法

现有的废塑料回收再生方法是用螺杆式塑料挤出机,在200～230℃温度下挤出造粒回收.这种方法存在以下不足:①不能有效地分离出废塑料中的杂质.②不同颜色的废塑料不能混合加工.③不能分离废塑料中的降解产物.因此,这种方法回收的产品质量低,颜色黑,使用价值也比较低.目前,国外开发了一种热裂解废塑料的回收方法,但投资高,回收率低,回收的产品为液体燃料,较塑料的使用价值低.辽宁省锦西炼油总厂的刘宏仁发明了一种能够深度脱除废塑料中的杂质,并能脱除废塑料中的颜色和降解产物,使回收的废塑料质量接近于新塑料的回收再生方法.本法适用于溶剂可溶性废塑料.     

废弃塑料裂解油化技术

废弃塑料裂解油化技术对废弃塑料进行热裂解和催化裂解可以获得聚合单体、柴油、汽油和燃料气。将废弃聚苯乙烯塑料（产业废塑料、快餐饭盒和聚苯乙烯泡沫）制成直径５－８ｍｍ的颗粒，用金属氧化物作催化剂，当反应釜内升至一定温度时连续投入，温度升至３５０℃时通入气...     

杂质对废塑料裂解产物及污染物排放的影响

从垃圾中分选出的废塑料混有大量杂质,杂质对现有废塑料裂解工艺有直接的影响.针对这一问题,对混有厨余、纸、织物和渣土等杂质的废塑料裂解产物和污染物排放进行了研究.同时检测和分析了厨余、纸、织物和沙土等常见杂质所含N、Cl、S元素向裂解油、裂解气中的迁移规律.研究表明,厨余的混入将对裂解油的产物产生严重不利影响,如热值降低至27 MJ/kg,油品的含水率高达25%以及多环芳烃含量大大提高,因而应在分选过程中除去.厨余、织物和纸张等杂质的混入导致裂解气体中污染物浓度的显著上升.渣土的混入对气体产物有有利影响,对油品无明显不利影响.     

蒸气裂解制乙烯评价(SCEE)装置的功能与特点

介绍了广东石油化工学院蒸气裂解制乙烯评价(SCEE)装置的特点、组成和功能。利用本装置可以开展裂解原料特性、研究裂解产物分布规律、研究加热炉结垢结焦腐蚀机理、优化工业裂解炉生产条件方面的模拟实验。通过在小试条件下求取反应动力学参数,可为工业炉更换、优化原料,优化裂解炉的工艺参数提供基础数据,以及为乙烯原料裂解评价提供参考。     

利用废塑料裂解生产油漆

正当世界各国都在积极寻求科学有效处理废塑料技术和办法的时候,广州天河高新技术开发区的广州环境资源开发研究所的科研人员,对“利用废塑料裂解生产系列油漆”的科研项目进行了攻关。该项目被列为国家科委、建设部八五攻关项目。     

烃类热裂解生产防火探讨

烃类热裂解生产过程中设备、管线、阀门的泄漏是引起火灾的重要原因，此外，还存在着管式裂解炉易产生结焦，高压操作具有爆炸危险，深冷分离易发生冻堵，高温裂解气、加氢反应火险性较大，工艺中存在引火源等特点。因此，防火防爆措施应从合理布置工艺装置，严格控制操作温度、压力、物料流量、流速及液位，避免裂解炉结焦，防止冻堵，设置安全装置，加强防火管理，采取紧急处理措施，配置灭火设施诸方面加以考虑。     

废塑料生产汽油,柴油的工艺及设备

考察了废旧塑料生产汽油、柴油的实际情况。结合多年的试验开发，采用溶剂预热熔化、管式炉加热、自动循环排渣裂解炉、采用自制同效催化剂，可年处理１５０－３００ｔ废塑料，生产１００－２００ｔ汽油、柴油。     

用废塑料生产汽油、柴油

考察了废旧塑料生产汽油、柴油的工厂及生产情况，结合几年的试验开发，设计了一套以中小城市废弃塑料为原料，采用溶剂预热溶化，管式炉加热，自动循环排渣裂解炉，采用自制高效催化剂，生产汽油、柴油新工艺生产线，该生产线造价16.5万元/套，年处理150吨废塑料，年产100吨汽油、柴油，年利税15万元，适合城郊乡镇小企业。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.