腐植酸对纳米TiO2催化降解土壤中萘和菲的影响

化石燃料的采输和使用致使土壤中多环芳烃类污染物持续增加，影响了农作物的生长并威胁人类健康。腐植酸(HA)作为土壤中的有机质，含有多种官能团，在光催化降解有机污染物中具有敏化或抑制作用。将HA与TiO₂以不同质量比进行复配制备了复合催化材料，考察了材料组成、pH、光源等因素对多环芳烃降解率的影响。采用气相色谱-质谱联用仪(GC-MS)对降解情况进行定量分析，结合傅里叶变换红外光谱仪和X射线光电子能谱仪分析了HA影响TiO₂降解作用的机理。结果表明：复合催化材料有利于提高萘和菲的降解率，萘和菲的降解率分别为72.1%和83.3%;HA与纳米TiO₂之间产生了静电作用以及配合作用，提高了TiO₂表面的催化反应位点。     

气相色谱仪校准用烷烃杂质分析

建立了一套基于气相色谱的正构烷烃杂质定量分析方法，对常见气相色谱仪校准用物质正十四烷、正十五烷、正十六烷中互为杂质的情况进行研究和准确定量，解决在烷烃混合溶液制备过程中制备量值不准确的问题，方法可应用于混合烷烃溶液制备量值的确定，定值结果能够满足气相色谱仪校准的溯源需求。     

超声降解有机污染物的研究概况

本文介绍了超声降解有机污染物的原理、效果以及对降解有影响的主要声学因素，并对存在的问题和发展方向提出见解。     

超声降解有机污染物的研究概况

本文介绍了超声降解有机污染物的原理、效果以及对降解有影响的主要声学因素,并对存在的问题和发展方向提出见解.     

单体正构烷烃及其混合物的热性能比较

使用差示扫描量热法从吸热温度范围及吸热量大小两个方面研究了单体正构烷烃及其混合物的热性能 ,实验结果表明 ,单体正构烷烃与正构烷烃混合物的热性能明显不同 ,正构烷烃中碳原子数的数目及其分布 ,对相变材料用石蜡的吸热温度范围及吸热量大小影响很大 ,石蜡中正构烷烃种类越少 ,正构烷烃含量越高 ,其热性能越好     

我国研制出氧化生物双降解生态地膜

正我国从1978年开始推广地膜覆盖技术至今,每年地膜用量达125万t,覆盖3亿亩40多种农作物。但目前废旧地膜的回收率不足30%,残留在土壤耕层里的地膜越积越多,形成了严重的"白色污染"。为此,山东一家企业成功研究出了氧化生物双降解生态地膜,不仅解决了多年困扰我国农业生产中难题,也使我国成为世界上第三个掌握此技术的国家。氧化生物双降解生态地膜综合利用了氧化降解和生物降解技术,可以根据不同作物的生育期需求,通过添加不同剂量     

聚乳酸降解的影响因素和降解机理的分析

综述了可降解塑料聚乳酸(PLA)的降解机理及影响其降解能力的各种因素,为进一步研究PLA可生物降解性,达到速度可控提供了良好的实验数据分析.同时根据其良好的相容性,阐述了PLA在医学领域中的应用及研究进展.     

氮掺杂生物炭吸附降解有机污染物的研究进展

生物炭是生物质热解和碳化后产生的高含碳物质。氮掺杂生物炭改善了生物炭的性能，使其在吸附降解有机污染物等方面的应用前景更为可观，引起了学者的广泛关注。而氮掺杂生物炭对有机污染物的吸附降解性能受多种因素影响，如生物炭的制备条件及其性质等。详细讨论了生物质原料和掺杂方式等因素对氮掺杂生物炭性质的影响，总结了氮掺杂生物炭吸附和降解有机污染物的影响因素及机理，并提出了氮掺杂生物炭的未来研究方向。     

石油污泥中高效甲苯降解菌的筛选及降解特性研究

以长期被石油污染的污泥为驯化培养对象,采用曝气法在密闭环境中对甲苯降解菌进行驯化筛选,并进行最佳降解条件的确定、降解率的测定和菌种的鉴定。结果显示筛选出的3种株均对甲苯有良好的降解效果,其中菌种C为短杆状,革兰氏染色为阳性,在甲苯环境中生长情况最好,对甲苯降解率最高,可达99．2％。菌株的最佳生长条件为pH为7、温度为35℃、甲苯加入量为60L、接种量为5.0％,其中影响菌株生长的最重要因素为甲苯浓度,菌株对质量浓度在0-250mg／L的甲苯可以直接进行好氧降解,甲苯的降解速率也屉大。     

难降解有机废水可生化性预处理探讨

难降解有机废水主要是染料、农药、医药、化工、焦化等生产过程中产生的废水,废水污染物浓度高、毒性大、盐份较高难于生物降解,因此必须采用预处理技术和方法,方能有效处理。本文从物理法、化学法和生物法三个方面介绍降解有机废水可生化性预处理探讨。     

Bioremediation of contaminated mixtures of desert mining soil and sawdust with fuel oil by aerated in-vessel composting in the Atacama Region (Chile)

Since early 1900s, with the beginning of mining operations and especially in the last decade, small, although repetitive spills of fuel oil had occurred frequently in the Chilean mining desert industry during reparation and maintenance of machinery, as well as casual accidents. Normally, soils and sawdust had been used as cheap readily available sorbent materials of spills of fuel oil, consisting of complex mixtures of aliphatic and aromatic hydrocarbons. Chilean legislation considers these fuel oil contaminated mixtures of soil and sawdust as hazardous wastes, and thus they must be contained. It remains unknown whether it would be feasible to clean-up Chilean desert soils with high salinity and metal content, historically polluted with different commercial fuel oil, and contained during years. Thus, this study evaluated the feasibility of aerated in-vessel composting at a laboratory scale as a bioremediation technology to clean-up contaminated desert mining soils (fuel concentration>50,000 mg kg(-1)) and sawdust (fuel concentration>225,000 mg kg(-1)) in the Atacama Region. The composting reactors were operated using five soil to sawdust ratios (S:SD, 1:0, 3:1, 1:1, 1:3, 0:1, on a dry weight basis) under mesophilic temperatures (30-40 degrees C), constant moisture content (MC, 50%) and continuous aeration (16 l min(-1)) during 56 days. Fuel oil concentration and physico-chemical changes in the composting reactors were monitored following standard procedures. The highest (59%) and the lowest (35%) contaminant removals were observed in the contaminated sawdust and contaminated soil reactors after 56 days of treatment, respectively. The S:SD ratio, time of treatment and interaction between both factors had a significant effect (p<0.050) on the contaminant removal. The results of this research indicate that bioremediation of an aged contaminated mixture of desert mining soil and sawdust with fuel oil is feasible. This study recommends a S:SD ratio 1:3 and a correct nutrient balance in order to achieve a maximum overall hydrocarbon removal of fuel oil in the weathered and aged contaminated wastes.     

Life in oil: Hydrocarbon-degrading bacterial mineralization in oil spill-polluted marine environment

The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which an oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. This paper describes the three main processes of the Nakhodka oil spill, including: (1) the weathering of hydrocarbon-degrading bacteria (genus Pseudomonas) and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years; (2) the laboratory-scale biodegradation of the Nakhodka oil spill over a 429-day period; and (3) the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill.Upon the slow evaporation of the Nakhodka oil spill during the 9-year weathering, the dendritic crystal growth of paraffin (a mixture of alkanes) occurred in the oil crust under natural conditions. Heavy metals were obtained in the original heavy oil samples of three seashores in the Sea of Japan. Si, S, Ti, Cr, Ni, Cu, and Zn were found in the original Nakhodka oil spill samples whereas these heavy metals and S were no longer present after 9 years. The anaerobic reverse side of the oil crust contained numerous coccus-type bacteria associated with halite. The hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9-year bioremediation.A biodegradation process of heavy oil from the Nakhodka oil spill by indigenous microbial consortia was monitored over 429 days in the laboratory. The indigenous microbial consortia consisted of bacteria and fungi as well as the bacterium Pseudomonas aeruginosa isolated from Atake seashore, Ishikawa Prefecture, Japan. Both bacteria and fungi had a significant role in the observed biodegradation of heavy oil during the 429-day bioremediation with respect to the pH of the solution. Hydrocarbon-degrading bacteria had a tendency to play the greatest role under neutral to alkaline condition (pH; 7–7.8). On the contrary, when pH shifted to acidic (pH; 2–4) levels, the fungi took over to degrade heavy oil. During the period, the aliphatic hydrocarbons were reduced significantly but the aromatic hydrocarbons remained relatively constant even after 429 days of bioremediation.Experimental study was undertaken to investigate the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. TEM/EDS imaging suggested that the clays present in oil-polluted seawater were capable of stimulating oil-degrading bacteria probably because Si from clays facilitates bacterial usage of oil and C-O-Na-Si complexes on the surfaces of bacterial cell walls are a stimulator for oil-degrading bacterial growth in seawater contaminated with the Nakhodka oil spill.     

Trials of bioremediation on a beach affected by the heavy oil spill of the Prestige

The objective of this study was to assess the efficiency of several bioremediation products in accelerating the in situ biodegradation of the heavy fuel oil spill of the Prestige. Trials of bioremediation were conducted in sand, rocks and granite tiles on the beach of Sorrizo (A Coruña, NW Spain) that was polluted by the spill. Neither the added microorganisms nor the nutrients significantly enhanced the degradation rate of the fuel oil in rocks, granite tiles or sand. PAH degradation up to 80% was determined in sand and tiles. In tiles the oxygen content of the residual oil increased from 1.6% up to 8% in 90 days, which could be explained by the accumulation of products coming from the partial oxidation of the hydrocarbons. Eighteen months after the spill, the rocks of the beach were still coated by a black layer of weathered fuel oil. For this reason an oleophilic product, sunflower biodiesel was tested on a rock. The application of biodiesel accelerated the gradually clean-up of the polluted surface and could also accelerate the degradation of the residual oil.     

Kinetic modeling and half life study on bioremediation of crude oil dispersed by Corexit 9500

Hydrocarbon pollution in marine ecosystems occurs mainly by accidental oil spills, deliberate discharge of ballast waters from oil tankers and bilge waste discharges; causing site pollution and serious adverse effects on aquatic environments as well as human health. A large number of petroleum hydrocarbons are biodegradable, thus bioremediation has become an important method for the restoration of oil polluted areas. In this research, a series of natural attenuation, crude oil (CO) and dispersed crude oil (DCO) bioremediation experiments of artificially crude oil contaminated seawater was carried out. Bacterial consortiums were identified as Acinetobacter, Alcaligenes, Bacillus, Pseudomonas and Vibrio. First order kinetics described the biodegradation of crude oil. Under abiotic conditions, oil removal was 19.9% while a maximum of 31.8% total petroleum hydrocarbons (TPH) removal was obtained in natural attenuation experiment. All DCO bioreactors demonstrated higher and faster removal than CO bioreactors. Half life times were 28, 32, 38 and 58 days for DCO and 31, 40, 50 and 75 days for CO with oil concentrations of 100, 500, 1000 and 2000 mg/L, respectively. The effectiveness of Corexit 9500 dispersant was monitored in the 45 day study; the results indicated that it improved the crude oil biodegradation rate.     

Life in oil: Hydrocarbon-degrading bacterial mineralization in oil spill-polluted marine environment

The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which an oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. This paper describes the three main processes of the Nakhodka oil spill, including: (1) the weathering of hydrocarbon-degrading bacteria (genus Pseudomonas) and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years; (2) the laboratory-scale biodegradation of the Nakhodka oil spill over a 429-day period; and (3) the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. Upon the slow evaporation of the Nakhodka oil spill during the 9-year weathering, the dendritic crystal growth of paraffin (a mixture of alkanes) occurred in the oil crust under natural conditions. Heavy metals were obtained in the original heavy oil samples of three seashores in the Sea of Japan. Si, S, Ti, Cr, Ni, Cu, and Zn were found in the original Nakhodka oil spill samples whereas these heavy metals and S were no longer present after 9 years. The anaerobic reverse side of the oil crust contained numerous coccus-type bacteria associated with halite. The hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9-year bioremediation. A biodegradation process of heavy oil from the Nakhodka oil spill by indigenous microbial consortia was monitored over 429 days in the laboratory. The indigenous microbial consortia consisted of bacteria and fungi as well as the bacterium Pseudomonas aeruginosa isolated from Atake seashore, Ishikawa Prefecture, Japan. Both bacteria and fungi had a significant role in the observed biodegradation of heavy oil during the 429-day bioremediation with respect to the pH of the solution. Hydrocarbon-degrading bacteria had a tendency to play the greatest role under neutral to alkaline condition (pH; 7–7.8). On the contrary, when pH shifted to acidic (pH; 2–4) levels, the fungi took over to degrade heavy oil. During the period, the aliphatic hydrocarbons were reduced significantly but the aromatic hydrocarbons remained relatively constant even after 429 days of bioremediation. Experimental study was undertaken to investigate the bioavailability of kaolinite clay minerals and the role they play in seawater polluted with the Nakhodka oil spill. TEM/EDS imaging suggested that the clays present in oil-polluted seawater were capable of stimulating oil-degrading bacteria probably because Si from clays facilitates bacterial usage of oil and C-O-Na-Si complexes on the surfaces of bacterial cell walls are a stimulator for oil-degrading bacterial growth in seawater contaminated with the Nakhodka oil spill.     

Statistical factor-screening and optimization in slurry phase bioremediation of 2,4,6-trinitrotoluene contaminated soil

Since slurry phase bioremediation is a promising treatment for recalcitrant compounds such as 2,4,6-trinitrotoluene (TNT), a statistical study was conducted for the first time to optimize TNT removal (TR) in slurry phase. Fractional factorial design method, 2(IV)(7-3), was firstly adopted and four out of the seven examined factors were screened as effective. Subsequently, central composite design and response surface methodology were employed to model and optimize TR within 15 days. A quadratic model (R(2) = 0.9415) was obtained, by which the optimal values of 6.25 g/L glucose, 4.92 g/L Tween 80, 20.23% (w/v) slurry concentration and 5.75% (v/v) inoculum size were estimated. Validation experiments at optimal factor levels resulted in 95.2% TR, showing a good agreement with model prediction of 96.1%. Additionally, the effect of aeration rate (0-4 vvm) on TR was investigated in a 1-liter bioreactor. Maximum TR of 95% was achieved at 3 vvm within 9 days, while reaching the same removal level in flasks needed 15 days. This reveals that improved oxygen supply in bioreactor significantly reduces bioremediation time in comparison with shake flasks.     

基于AHP-TOPSIS法的自闭症儿童攻击行为干预产品研究

目的 为减少自闭症儿童攻击行为的发生,对其攻击行为的影响因素和能够改善该行为的产品进行研究。方法 采用层次分析法（AHP）,建立攻击行为影响因素的评价矩阵,对影响因素进行权重分析。采用逼近理想解排序法（TOPSIS）,通过评分的方式建立评价矩阵,根据得出的权重值,计算出正负理想解和各方案的相对贴度,从而选出最有效的解决方案。结果 个人认知、亲子关系、同伴关系和移情能力是自闭症儿童攻击行为产生的主要影响因素,在根据主要影响因素设计的3款产品中,智能交互音乐鼓的设计为最优解决方案。结论 通过层次分析法与逼近理想解排序法,排除了主观因素的影响,对自闭症儿童玩具产品的设计要素进行优化,填补了自闭症儿童攻击行为干预产品的市场空白,能够有效减少自闭症儿童攻击行为的发生。     

Monitoring of the pesticide levels in some water supplies and agricultural land, in El-Haram, Giza (A.R.E.)

Monitoring of pesticide residues were conducted at different locations in the El-Haram region Giza, Egypt. The water samples were collected from El-Haram Giza, canal water supplies (El-Zomor, Abd-el-aal land and seaside and El-Mansorya), in addition to El-Moheet drainage water. The soil samples were collected from the arable land that surrounds water canals. Water samples were obtained by solid phase extraction (SPE) and soil samples by gel permeation chromatography (GPC). The combination of gas chromatography and mass spectroscopy with different ionization techniques was used for determination and identification of the pesticides, which were quantitatively determined as 1 microgram 1(-1) levels in environmental samples. The residues of pesticides were varied between different locations. Also, organochlorine pesticide residues in El-Moheet drainage water were relatively higher than in the canal water. The concentrations of organophosphorous compounds (chlorpyrifos, dimethoate and parathion) seem to be low in water as compared to soil samples. Most findings were less than 1 microgram g(-1), which is considered a low-level finding. Sixteen organochlorine pesticides were detected in most of the water samples and the percent of positive samples followed the order drins > total BHC > total DDT > endosulfan > heptachlor epoxid > heptachlor. Pentachlorophenol (PCP) was detected only in El-Zomor and Abd-el-aal canal water. Results obtained confirm the presence of different pesticide residues representing different chemical classes in the canal waters. This means that the discharging of wastes in to the water supplies must be controlled. Drainage water was highly polluted and contains much more pesticide residues than different canal waters.     

Low-temperature thermal desorption of diesel polluted soil: influence of temperature and soil texture on contaminant removal kinetics

Five soil size aggregate fractions, corresponding to coarse (500-840 μm), medium (200-350 μm), fine (75-200 μm) sand, silt (10-75 μm) and clay (<4 μm), were artificially contaminated with diesel, and thermally treated using a laboratory scale apparatus to investigate the effect of soil texture on contaminant adsorption and removal. Ex situ thermal process was simulated using helium as the carrier gas at a flow rate of 1.5 L min(-1), different temperatures (100-300 °C) and different treatment times (5-30 min). The amount of contaminant adsorbed on the soil and the residual amount after thermal treatment was determined by gas chromatography. Results showed that adsorption phenomena and desorption efficiency were affected by the soil texture and that temperature and time of treatment were key factors in remedial process. A temperature of 175 °C is sufficient to remedy diesel polluted sandy and silty soils, whereas a higher temperature (250 °C) is needed for clays. Thermal desorption of diesel polluted soil was shown to be governed by first-order kinetics. Results are of practical interest and may be used in scaling-up and designing desorption systems for preliminary cost and optimal condition assessment.     

A reliability allocation method for agricultural machinery based on AHP-IFM

In the product design phase, the available product failure data are limited, and the weight allocation method is often used to assign reliability targets to each unit. The integrated factors method (IFM) can calculate the reliability allocation weights considering multiple influencing factors simultaneously, but it cannot reflect the difference in the importance of each factor and each unit. The analytic hierarchy process (AHP) can calculate the relative importance weights of each factor and each unit. Combining the AHP with the IFM can make the IFM more adaptable to the system and more accurate for reliability allocation. However, the current combination method can cause two problems: the invalidation of the influencing factor weights and the imbalance of the unit weights. To address these two shortcomings, the AHP-IFM proposed in this paper introduces a weight weakening factor and exponentially corrects the unit weights for units, which can better apply the relative importance weights of each influencing factor and each unit to the reliability allocation. The effectiveness of the AHP-IFM is verified by comparison with existing methods and data. Finally, an AHP-IFM applicable to agricultural machinery is proposed, and the reliability allocation of a no-till seeder is used as a case to verify the feasibility of the AHP-IFM.