浅析露天煤矿扬尘综合治理措施

露天煤矿因为其工作环境与作业过程,会产生自然粉尘和生产作业粉尘,这不但严重影响当地生态环境,而且对露天煤矿采矿效率和安全生产带来影响,同时会对煤矿员工的身心健康带来极大危害。本文通过分析粉尘产生原因,针对各种粉尘特点,提出了合理有效的防尘措施。     

微颗粒在表面粘附的力学模型

微颗粒粉尘对于工农业生产及人的身体健康都会造成危害,而微颗粒粘附数学模型是对其进行研究和控制的基础,有着十分重要的意义。微颗粒与表面粘附力学模型研究取得了很大的进展,作者通过在一些重要中外文数据库对微颗粒在表面粘附的力学模型研究成果进行了分析,这些粘附力主要是物理吸附力的范德华力、静电力、磁力、毛细作用力。在此基础上对各个力进行归纳、评述,并指出了各个模型的实际应用。对各种力学模型进行总结,然后以一个例子说明微颗粒粉尘在多种力同时作用时的力的简单合成情况,最后提出了本领域的研究展望。     

碱厂石灰生产中除尘系统的改进

简述了石灰生产系统中粉尘产生的原因,着重介绍了布袋除尘器在运行过程中存在的问题及处理办法,从而在源头上控制了粉尘给职工身心健康带来的危害.     

粮食粉尘爆炸及防治技术的研究进展

粮食加工、运输过程中产生的粉尘不但对健康和环境造成巨大危害,也会损坏机械设备,更为重要的是粉尘爆炸成为粮食加工储运企业的安全隐患,危及着人类的生命和生产的安全.本文对粮食粉尘的爆炸过程、特点及爆炸条件进行了分析,并以此阐明了粮食粉尘爆炸控制的指导思想,在实际中应采用综合措施,做到防治结合,以防为主,具体可分为惰化、控制粉尘浓度、防止产生点火源的预防措施和泄爆、爆炸遏制、隔爆防护措施两大类;同时对粮食粉尘爆炸的防治技术及粮食中转筒仓防尘防爆技术的进展进行了讨论.     

安徽省庐江县钟山铁矿床地质特征及找矿方向

安徽庐江钟山铁矿床位于庐枞火山岩盆地北部,矿体主要赋存于安山岩、安山角砾岩、粗安斑岩(隐爆角砾岩筒)中,矿石类型为赤铁矿石和磁铁矿石,矿床成因类型属于中低—中高温热液交代充填矿床。依据前人研究成果,结合采矿过程中收集的地质资料,总结并论述该矿床的地质特征、成矿控制因素、成矿过程、找矿标志及找矿方向等,这对在庐枞火山岩盆地寻找同类型铁矿,扩大钟山铁矿床的铁矿石资源量具有一定意义,为该矿区深部及外围找矿提供参考。     

机械加工中粉尘污染的研究进展及防治措施

在机械加工生产过程中,粉尘随处可见,是机械加工生产过程中产生的主要副产品[1],粉尘虽然微小,但影响巨大,主要体现有:一方面,粉尘会使加工车间的工作环境受到污染,从而对车间的工作人员身体健康产生一定的危害;另一方面,粉尘还会影响车间的机械加工设备的运行以及加工产品的质量。为了减少粉尘污染,本文针对机械加工过程中粉尘污染的研究进展进行了阐述,并提出了一些相关的防治措施。     

金鸡岩洗选厂粉尘综合治理的实践

通过对金鸡岩洗选厂粉尘产生的原因进行了综合分析,找到了产生粉尘的主要原因,然后结合不同工艺环节点分别采用密封、喷水以及加装布袋式除尘器对粉尘进行了改造治理,尤其是对布袋式除尘器产生的二次扬尘通过修建吸尘池收到较好的效果。     

大力推广呼吸性粉尘监测技术

粉尘是指悬浮于空气中的固体微粒。大多数情况下，它是由固体材料通过机械作用产生的，也有一部分粉尘是由于物质的不完全燃烧、爆炸和物质被加热时产生蒸气在空气中凝结或被氧化形成溶胶等。一句话，在大自然中，各种运动（物理运动、化学运动、生物运动等）最终均能在不同程度上产生粉尘。当空气中的粉尘量达到一定程度，就会产生多方面的危害。如对人体健康，生产及其产品质量，大气环境等均会产生不同程度的影响。因此，目前世界各国把它列为主要的职业危害之一。为了控制职业粉尘的危害，党和国家投入了大量的人力、物力和财力，颁布了…     

散粮储运系统除尘设计研究

如何控制散粮在装卸储运作业中产生的大量粉尘是清洁生产需要解决的重大问题。通过对散粮储运系统各环节逸尘特点研究,有针对性地提出关键节点的除尘设计要点及设计方案,可以达到很好的抑尘效果,改善作业环境。     

催化剂生产过程粉尘治理对策

粉尘已成为催化剂生产企业的主要职业病危害因素。通过点对点除尘,采用气力输送及新的密闭自动化工艺,现场无组织粉尘可控制在较好水平,8 h加权平均浓度均在1. 0 mg/m^3以下;通过采用旋风分离、袋式过滤、超重力湿法洗涤及云式除尘等技术,对催化剂生产过程尾气进行治理,可将粉尘浓度稳定降低至20 mg/m^3以下,实现达标排放。并提出应尽量设计连续流程,注重采用新设备、新工艺,从源头解决粉尘问题。     

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.     

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.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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